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Fission rates and transactinide formation in the r-process. Igor Panov

Fission rates and transactinide formation in the r-process. Igor Panov

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Fission rates and transactinide formation in the r-process. Igor Panov. Subject of the talk. Fission in the R-process Astrophysical site for the main r-process Actinides and transactinides Data: T 1/2 , P n , (n,g), (n,f), b df, s.f. Renovation of data for the r-process: - PowerPoint PPT Presentation

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Page 1: Fission rates and transactinide formation in the r-process. Igor Panov

Fission rates and transactinide formation in

the r-process

Igor Panov

Subject of the talkSubject of the talk

bull Fission in the R-process bull Astrophysical site for the main r-processbull Actinides and transactinidesbull Data T12 Pn (ng) (nf) df sf bull Renovation of data for the r-process Purpose and motivation bull Pdf different approaches ndash S

bull samples of predictionsbull conclusions

bull Seeger Fowler Clayton 1965 Seeger Fowler Clayton 1965 fission -fission - long and short solutionslong and short solutionsbull TThielemahielemannn n Me Mettzzingeingerr K Klapdor lapdor ZZttPPhhyys A309s A309 (1983) 301(1983) 301 P Pdfdf

bull Lyutostansky Panov Ljashuk Izv RAN ser fiz 1990 PLyutostansky Panov Ljashuk Izv RAN ser fiz 1990 Pdfdf

bull PMoller JRNix K-LKratzPMoller JRNix K-LKratz ADNDT 66 (1997) 131 ADNDT 66 (1997) 131 TT1212 P Pinin

bull Goriely et al Goriely et al Astron Astrophys 346 798ndash804 (1999)Astron Astrophys 346 798ndash804 (1999) sfsfbull Panov et al Nucl Phys A 718 (2003) 647 Panov et al Nucl Phys A 718 (2003) 647 (nfission) vs P(nfission) vs Pdf df

bull IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 YYffff(ZA)(ZA)bull KKelic elic et al et al PPhhysys L Leetttt B B 616 616 (2005) (2005) 48 48 YYffff(ZA)(ZA)bull IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz

NP A 747 (2005) 633 NP A 747 (2005) 633 (nfission) (n(nfission) (n) P) Pdf df

bull GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) 199 199 (nfission) vs P(nfission) vs Pdf df

bull Y-Z Qian Y-Z Qian Astron JAstron J 569 (2002) p L103 569 (2002) p L103 Kolbe Langanke FullerKolbe Langanke Fuller Phys Phys

Rev Lett 2004Rev Lett 2004 induced fissioninduced fissionbull I Petermann et al NIC-2008 GMartinec-Pinedo et al GMartinec-Pinedo et al ProgrProgr in in Particle Particle

and Nucland Nucl Phys Phys 5959 ((20072007)) 199-205 199-205 (nfission) P(nfission) Pdf df sfsf induced finduced fbull K Langanke G Martinez-Pinedo IPetermann FK Thielemann PPNP 2011

(nfission) P(nfission) Pdf df sfsf induced finduced f

Importance of fission for the r-processImportance of fission for the r-process

fission

Main r-process R ge05 s cycling number ncycl (log2(YfinYinit)) gt 0 ~1

Model of Model of NSM-simulation Freiburghaus et al AJ 525 (1999)

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

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Page 2: Fission rates and transactinide formation in the r-process. Igor Panov

Subject of the talkSubject of the talk

bull Fission in the R-process bull Astrophysical site for the main r-processbull Actinides and transactinidesbull Data T12 Pn (ng) (nf) df sf bull Renovation of data for the r-process Purpose and motivation bull Pdf different approaches ndash S

bull samples of predictionsbull conclusions

bull Seeger Fowler Clayton 1965 Seeger Fowler Clayton 1965 fission -fission - long and short solutionslong and short solutionsbull TThielemahielemannn n Me Mettzzingeingerr K Klapdor lapdor ZZttPPhhyys A309s A309 (1983) 301(1983) 301 P Pdfdf

bull Lyutostansky Panov Ljashuk Izv RAN ser fiz 1990 PLyutostansky Panov Ljashuk Izv RAN ser fiz 1990 Pdfdf

bull PMoller JRNix K-LKratzPMoller JRNix K-LKratz ADNDT 66 (1997) 131 ADNDT 66 (1997) 131 TT1212 P Pinin

bull Goriely et al Goriely et al Astron Astrophys 346 798ndash804 (1999)Astron Astrophys 346 798ndash804 (1999) sfsfbull Panov et al Nucl Phys A 718 (2003) 647 Panov et al Nucl Phys A 718 (2003) 647 (nfission) vs P(nfission) vs Pdf df

bull IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 YYffff(ZA)(ZA)bull KKelic elic et al et al PPhhysys L Leetttt B B 616 616 (2005) (2005) 48 48 YYffff(ZA)(ZA)bull IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz

NP A 747 (2005) 633 NP A 747 (2005) 633 (nfission) (n(nfission) (n) P) Pdf df

bull GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) 199 199 (nfission) vs P(nfission) vs Pdf df

bull Y-Z Qian Y-Z Qian Astron JAstron J 569 (2002) p L103 569 (2002) p L103 Kolbe Langanke FullerKolbe Langanke Fuller Phys Phys

Rev Lett 2004Rev Lett 2004 induced fissioninduced fissionbull I Petermann et al NIC-2008 GMartinec-Pinedo et al GMartinec-Pinedo et al ProgrProgr in in Particle Particle

and Nucland Nucl Phys Phys 5959 ((20072007)) 199-205 199-205 (nfission) P(nfission) Pdf df sfsf induced finduced fbull K Langanke G Martinez-Pinedo IPetermann FK Thielemann PPNP 2011

(nfission) P(nfission) Pdf df sfsf induced finduced f

Importance of fission for the r-processImportance of fission for the r-process

fission

Main r-process R ge05 s cycling number ncycl (log2(YfinYinit)) gt 0 ~1

Model of Model of NSM-simulation Freiburghaus et al AJ 525 (1999)

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
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Page 3: Fission rates and transactinide formation in the r-process. Igor Panov

bull Seeger Fowler Clayton 1965 Seeger Fowler Clayton 1965 fission -fission - long and short solutionslong and short solutionsbull TThielemahielemannn n Me Mettzzingeingerr K Klapdor lapdor ZZttPPhhyys A309s A309 (1983) 301(1983) 301 P Pdfdf

bull Lyutostansky Panov Ljashuk Izv RAN ser fiz 1990 PLyutostansky Panov Ljashuk Izv RAN ser fiz 1990 Pdfdf

bull PMoller JRNix K-LKratzPMoller JRNix K-LKratz ADNDT 66 (1997) 131 ADNDT 66 (1997) 131 TT1212 P Pinin

bull Goriely et al Goriely et al Astron Astrophys 346 798ndash804 (1999)Astron Astrophys 346 798ndash804 (1999) sfsfbull Panov et al Nucl Phys A 718 (2003) 647 Panov et al Nucl Phys A 718 (2003) 647 (nfission) vs P(nfission) vs Pdf df

bull IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 IKorneev et al NIC-2006 Astronomy Letters 66 (2008) 131 YYffff(ZA)(ZA)bull KKelic elic et al et al PPhhysys L Leetttt B B 616 616 (2005) (2005) 48 48 YYffff(ZA)(ZA)bull IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz IV Panov E Kolbe F-K Thielemann T Rauscher B Pfeiffer K-L Kratz

NP A 747 (2005) 633 NP A 747 (2005) 633 (nfission) (n(nfission) (n) P) Pdf df

bull GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) GMartinec-Pinedo et al Progress in Particle and Nuclear Physics 59 (2007) 199 199 (nfission) vs P(nfission) vs Pdf df

bull Y-Z Qian Y-Z Qian Astron JAstron J 569 (2002) p L103 569 (2002) p L103 Kolbe Langanke FullerKolbe Langanke Fuller Phys Phys

Rev Lett 2004Rev Lett 2004 induced fissioninduced fissionbull I Petermann et al NIC-2008 GMartinec-Pinedo et al GMartinec-Pinedo et al ProgrProgr in in Particle Particle

and Nucland Nucl Phys Phys 5959 ((20072007)) 199-205 199-205 (nfission) P(nfission) Pdf df sfsf induced finduced fbull K Langanke G Martinez-Pinedo IPetermann FK Thielemann PPNP 2011

(nfission) P(nfission) Pdf df sfsf induced finduced f

Importance of fission for the r-processImportance of fission for the r-process

fission

Main r-process R ge05 s cycling number ncycl (log2(YfinYinit)) gt 0 ~1

Model of Model of NSM-simulation Freiburghaus et al AJ 525 (1999)

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
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  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
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  • Slide 30
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Page 4: Fission rates and transactinide formation in the r-process. Igor Panov

fission

Main r-process R ge05 s cycling number ncycl (log2(YfinYinit)) gt 0 ~1

Model of Model of NSM-simulation Freiburghaus et al AJ 525 (1999)

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
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Page 5: Fission rates and transactinide formation in the r-process. Igor Panov

Model of Model of NSM-simulation Freiburghaus et al AJ 525 (1999)

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
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  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 6: Fission rates and transactinide formation in the r-process. Igor Panov

Y(A) during r-process with fission cycling for NSM conditions Y(A) during r-process with fission cycling for NSM conditions (t-duration time of the r-process t=0 - initial composition)(t-duration time of the r-process t=0 - initial composition)

Panov I Thielemann F-K Astronomy Letters Vol 30 (2004) 711

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 7: Fission rates and transactinide formation in the r-process. Igor Panov

11 -delayed rates-delayed rates - - Pdf for Zlt100

22 (n(n)-rates )-rates Zlt115Zlt115

33 Neutron-induced fission rates Neutron-induced fission rates nifnif ~ lt ~ lt vgt vgt Zlt115

44 Spontaneous fission Spontaneous fission ndash phenomenologicalndash phenomenological models Zlt115 models Zlt115

55 -decay -decay Zlt115Zlt115

66 Mass predictions ETFSI HFB Thomas-Fermi Zlt115Mass predictions ETFSI HFB Thomas-Fermi Zlt115

77 ConclusionsConclusions

motivation further data reevaluation in the actinide and transactinide region

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
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  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 8: Fission rates and transactinide formation in the r-process. Igor Panov

Bf lt Sn nuclei with Bf ge Sn inclined crosses nuclei with neutron binding energy predicted by the ETFSI [5] Sn sim 2 MeV and dots nuclei in which 2 gt Sn gt 0

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 9: Fission rates and transactinide formation in the r-process. Igor Panov

U Cm

Fm Z=104

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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  • Slide 35
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  • Slide 37
  • Slide 38
  • Slide 39
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  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 10: Fission rates and transactinide formation in the r-process. Igor Panov

sf - Smolanchuk et al

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 11: Fission rates and transactinide formation in the r-process. Igor Panov

model-independent evaluations of model-independent evaluations of sf

bullBased on predicted Bf (GMartinec-Pinedo)

MS Lgsf = 23887 ndash 80824 x Bf

ETFSI Lgsf = 50127 - 10145 x Bf

bullBased on experimental values of Bf

Lgsf = 33 3 - 7 77 x Bfexp

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
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Page 12: Fission rates and transactinide formation in the r-process. Igor Panov

Lgsf = 33 3 - 7 77 x Bexp

f

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
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  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 13: Fission rates and transactinide formation in the r-process. Igor Panov

If ltPdf gt ~ 50 then Ksurviv(from Z=94 to Z=114)~0000001

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
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  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
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  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
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  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 14: Fission rates and transactinide formation in the r-process. Igor Panov

BETA - STRENGTH FUNCTION OF NEUTRON-RICH BETA - STRENGTH FUNCTION OF NEUTRON-RICH NUCLEINUCLEI

Fig 1 Schema of S (E) ndash for function for neutron-rich nuclei and -delayed processes

In calculation of weak process connected with -decay -absorption -delayed processes the Beta-Strength function S (E) plays the main role S (E) - function for neutron-rich nuclei

presented on Fig1

S (E)ndash function has a resonance

character with high lying Gamow-Teller (GTR) and Isobaric Analog (IAR) resonanses Lower by energy are situated the so-called ldquopigmy resonansesrdquo The GTR with low going ldquotailrdquo influence strongly on the average neutrino- absorption cross-section and on the charge-exchange reactions probabilities ldquoPigmy resonansesrdquo plays the main role in the T12 values -delayed neutron

emission -delayed fission and in neutron emission after neutrino- absorption process

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
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Page 15: Fission rates and transactinide formation in the r-process. Igor Panov

Calculation of Calculation of BetaBeta-Strength function in TFFS -Strength function in TFFS theorytheory

Beta-Strength function S (E) is formed by isobaric states in the Theory of Finite Fermy Systems

(TFFS) calculated solving the nuclear effective field equations of Gamov ndash Teller type

In this equations all types of particle-hole quasiparticle excitations are included except of l ndash forbidden type For the local single quasiparticle (στ) interaction g` constant used included pion-exchanging mode

222

2222

q0эф0 )q1(Rm

4

q1

q

d

dnfegg

In our low energy case (ΔEpnlt 20 MeV) the second pion-depending term is negligible For the

isovector constants f0 and g0 selfconsistent procedure was used Beta-Strength function S (E)

was calculated using matrix elements MGT

i iii

N

EГEE

EГEM

CES

4)()(

)()(

2)(

222

Normalization = Sum-rule S(E) dE = eq2 3 ( N - Z )

For Emax = 20 MeV and eq = 08 quenching value is q = 064 (for Emax = infin eq = 10 q = 10 )

Emax

0

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
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  • Slide 7
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Page 16: Fission rates and transactinide formation in the r-process. Igor Panov

Quasiclassical Beta - ModelQuasiclassical Beta - Model

We change sums to integrals as usual in quasiclassic and come to the equations

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

where = -

21ll2 )r(Ra

212121 ll)(Rb

a 13

b = b+ + b- 23

31)A2(13

1b

A

ZN

E

E

ls

(j1-j2=1)

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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Page 17: Fission rates and transactinide formation in the r-process. Igor Panov

Pa240 -gt U240

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
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Page 18: Fission rates and transactinide formation in the r-process. Igor Panov

Pa260 -gt U260

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
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Page 19: Fission rates and transactinide formation in the r-process. Igor Panov

Idn+df)

I = I

I = Idf

I + Idf + Idn ) =1

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
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Page 20: Fission rates and transactinide formation in the r-process. Igor Panov

U -gt Np Beta ndash Delayed Fission ProbabilitiesU -gt Np Beta ndash Delayed Fission Probabilities TFFS-calculations (beta-model) TFFS-calculations (beta-model)

For dashed regions BfltEltSnf ~ tot Otherwise f ltlttot

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
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  • Slide 7
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Page 21: Fission rates and transactinide formation in the r-process. Igor Panov

BETA - DELAYED FISSIONBETA - DELAYED FISSION

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

P

bE

EEb

E

EEa

E

g

1

ls

ls

ls

ls

0

For BfltEltSn f ~ tot

Otherwise f ltlttot

where = -

21ll2 )r(Ra

212121 ll)(Rb

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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  • Slide 57
Page 22: Fission rates and transactinide formation in the r-process. Igor Panov

ConclusionsConclusionspredicted bd (and probably sf ) Rates predicted bd (and probably sf ) Rates looks overestimatedlooks overestimated

bull exp Data on superheavyexp Data on superheavy

bull Experimentally knowen branchings of beta-Experimentally knowen branchings of beta-deay (as well as theor Predictions) showdeay (as well as theor Predictions) show

aveage Intensity of beta-decays into low lying aveage Intensity of beta-decays into low lying states ~ 30states ~ 30

bull QRPA ndash predictions Pin ~ 80 ~ PbdfQRPA ndash predictions Pin ~ 80 ~ Pbdf

bull TFFS predictions Pin~ 60 and Pbdf ~ 20TFFS predictions Pin~ 60 and Pbdf ~ 20

Pin + Pbdf lt100Pin + Pbdf lt100

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
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  • Slide 54
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  • Slide 57
Page 23: Fission rates and transactinide formation in the r-process. Igor Panov

Thank you for the Thank you for the attentionattention

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
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  • Slide 33
  • Slide 34
  • Slide 35
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  • Slide 42
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  • Slide 46
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  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 24: Fission rates and transactinide formation in the r-process. Igor Panov

Isobaric Collective StatesIsobaric Collective States

TFFS equations follows Lane Theory of NucleusK Ikeda S Fujii and J I Fujita 1963-1967Gaponov amp Lutostansky 1972-1981

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
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  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 25: Fission rates and transactinide formation in the r-process. Igor Panov

127127XeXe Beta-Strength functionBeta-Strength function

The comparison of measured and predicted S (E) ndash function for 127Xe

Breaking line ndash experimental data (1999) Solid line ndash TFFS calculations by Lutostansky and Shulgina (Phis Rev Lett 1991) GTR and low-lying ldquopigmyrdquo resonanses are well distinguishedThe experimental qwenching is q = 054 theoretical q = 064

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
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  • Slide 55
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  • Slide 57
Page 26: Fission rates and transactinide formation in the r-process. Igor Panov

ETFSI Lgsf = 50127 - 10145 Bf

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
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  • Slide 57
Page 27: Fission rates and transactinide formation in the r-process. Igor Panov

Pbdf Masses barriers ETFSI SPbdf Masses barriers ETFSI Sndash quasiclassical approach on ndash quasiclassical approach on

the basis of FFST(the basis of FFST(ТКФСТКФС) Gaponov Lutostansky Panov 1979) Gaponov Lutostansky Panov 1979

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
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  • Slide 7
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  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 28: Fission rates and transactinide formation in the r-process. Igor Panov

Pa

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 29: Fission rates and transactinide formation in the r-process. Igor Panov

bull

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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  • Slide 48
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  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 30: Fission rates and transactinide formation in the r-process. Igor Panov

bull neutron-induced ndashneutron-induced ndash and - and -fission rates were calculated on fission rates were calculated on the basis of the nextthe basis of the next mass predictions and fission mass predictions and fission barriers TFETFSIFRDMHFB-14barriers TFETFSIFRDMHFB-14

bull

For explanation of yields in tnexplosionFor explanation of yields in tnexplosionbull Odd-even effect is reduced for HFB Odd-even effect is reduced for HFB predictionspredictionsbull The initial composition should consist from U The initial composition should consist from U

with admixture of some other actinides with admixture of some other actinides bull Inversion of odd-even effect can appear due Inversion of odd-even effect can appear due

both both df and Np (odd Z) admixture as welldf and Np (odd Z) admixture as wellbull Beta-delayed fission rates should be revisedBeta-delayed fission rates should be revised

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
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Page 31: Fission rates and transactinide formation in the r-process. Igor Panov

4242

n n fissionfission competitioncompetitionPPdf df (SnBf1(1+exp(2 (Bf-E)h) )

Gs

n f

BfSn

Sn

n

γ

Bf

(ZA)(ZA)

(Z+1A)(Z+1A)

--

QQ

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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  • Slide 57
Page 32: Fission rates and transactinide formation in the r-process. Igor Panov

Can we test the fission rates on the basis of Can we test the fission rates on the basis of the yields measured in impulse r-process the yields measured in impulse r-process experiments (thermonuclear explosions) experiments (thermonuclear explosions)

bull and what we can learn from the comparison and what we can learn from the comparison of calculated and experimental dataof calculated and experimental data

11 Compare results based on different Compare results based on different predictions (Masses Bpredictions (Masses Bff ) )

22 Test odd-even dependence and inversion of Test odd-even dependence and inversion of odd-even effectodd-even effect

33 Whether the (nf)-rates based on predicted Whether the (nf)-rates based on predicted fission barriers can fit the observed yieldsfission barriers can fit the observed yields

44 How the How the -delayed fission affect on -delayed fission affect on calculated yieldscalculated yields

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
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Page 33: Fission rates and transactinide formation in the r-process. Igor Panov

R-processR-process Nuclear data I Nuclear data I bull Beta decay lifetimes and beta-delayed neutron emissionBeta decay lifetimes and beta-delayed neutron emission

bull PMoller JRNix K-LKratz ADNDT 66 (1997) 131PMoller JRNix K-LKratz ADNDT 66 (1997) 131 TT1212 P Pinin

bull (( n n)) and (n and (n ) rates ) rates RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83) RauscherampThielemann 2000 (Zlt84) Panov et al 2005 (Zgt83)

bull Neutron induced fission ratesNeutron induced fission rates Panov et al AampA (2010) Panov et al AampA (2010) bull Spontaneous fission Spontaneous fission rates rates (Smolanchuk et al (Smolanchuk et al

phenomenological models fphenomenological models f11(Z(Z22A) fA) f22(B(Bff) )) )bull Alpha-decay Alpha-decay ratesrates (Sobichevsky et al) (Sobichevsky et al)bull beta-delayed fission ratesbeta-delayed fission rates

Panov et al Nucl Phys A 747 (2005) 633 (Zlt101)Panov et al Nucl Phys A 747 (2005) 633 (Zlt101) data for Zgt100 neededdata for Zgt100 needed

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 34: Fission rates and transactinide formation in the r-process. Igor Panov

Nuclear data II mass and Nuclear data II mass and fission barrier predictionsfission barrier predictions

11 Masses - Extended Thomas-Fermi + Strutinsky Masses - Extended Thomas-Fermi + Strutinsky integral (ETFSI)integral (ETFSI)

ndash Y Aboussir JMPearson AK Dutta and FTondeur Y Aboussir JMPearson AK Dutta and FTondeur 19951995

bull Fission Barriers ndash ETFSi Fission Barriers ndash ETFSi ndash Mamdouh et al 2001Mamdouh et al 2001

22 Masses - Masses - Myers W D Swiatecki W JMyers W D Swiatecki W J 1996 1996bull Fission Barriers Fission Barriers Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

33 Masses ndash FRDM Masses ndash FRDM - - Moller PMoller P ADNDT v59 185 1995

bull Fission Barriers - Fission Barriers - Myers W D Swiatecki W JMyers W D Swiatecki W J 1999 1999

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 35: Fission rates and transactinide formation in the r-process. Igor Panov

6 Data for the r-process (+SHE-6 Data for the r-process (+SHE-region)region)bull ETFSi mass and barrier predictions for Z up to 118ETFSi mass and barrier predictions for Z up to 118bull beta-rates for Zlt118 (QRPA+FRDM)beta-rates for Zlt118 (QRPA+FRDM)bull neutron-induced fission rates up to Z=115-118 neutron-induced fission rates up to Z=115-118

(will be published in AampA) and Available at CDS (will be published in AampA) and Available at CDS via httpcdswebu-strasbgfrcgi-binqcatJA+Abull Pdf for 90ltZlt100 ndash Krumlinde Moller 1984 qrpa (T12 - Kratz Moller Nix NP A 1997)bull Pdf for 100ltZlt110 were considered on the basis of

S calculated in framework of TFFS( model bull sf - phenomenological models or existed sf - phenomenological models or existed

calculations of Smolanchuk et alcalculations of Smolanchuk et al

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 36: Fission rates and transactinide formation in the r-process. Igor Panov

Lg(Tsf) s

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 37: Fission rates and transactinide formation in the r-process. Igor Panov

IPetermann AArcones AKeliacutec KLanganke GMartiacutenez-Pinedo WSchmidt K-HHix I Panov T Rauscher F-K Thielemann NZinner NIC-2008

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 38: Fission rates and transactinide formation in the r-process. Igor Panov

5151

HFTHFT ndash ndash parametrizations parametrizations used used

bull Double-humped fission barrier - Strutinskybull complete damping approximation which

averages over transmission resonancesbull levels in the second minimum are equally

spacedbull Hill-Wheeler transmission coefficient through a

parabolic barrierAB define the level densities above the saddle

points ABbull The back-shifted Fermi-gas description of the

level density was improved by introducing an energy dependent level density parameter a

bull The basis of experimentally known fission barriers was increased

bull deformed optical potentialbull The details are described in Rauscher amp The details are described in Rauscher amp

Thielemann ADNDT 2000 Panov et al NP 2005Thielemann ADNDT 2000 Panov et al NP 2005

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
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  • Slide 22
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  • Slide 46
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  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 39: Fission rates and transactinide formation in the r-process. Igor Panov

R Smolanacuteczuk Acta Polonica 1999

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
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  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
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  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 40: Fission rates and transactinide formation in the r-process. Igor Panov

Smolanacuteczuk PHYSICAL REVIEW C VOLUME 56 812 (1997)

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
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  • Slide 22
  • Slide 23
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  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 41: Fission rates and transactinide formation in the r-process. Igor Panov

1 Mass and fission barriers predictions up to Z ~ 115 (ETFSI HFB TF)

2 (n)-rates for Z lt ~ 115

3 Neutron-induced fission rates nif ~ lt vgt for Zlt115

Panov et al AampA 2010 (extension to Rauscher and

Thielemann ADNDT 2000)

4 -delayed fission rates df for 90ltZlt101 Panov et al Nucl

Phys A 2005

5 spontaneous fission rates sf - from phenomenological rates to macro-micro

predictions (Sobichevski amp Pomorski 2007 Smolanchuk et al 1997)

6 and motivation

7 SHE modeling in the r-process

8 reevaluate -delayed fission rates df

9 Contribution of different fission types into nucleosynthesis

ReasonsReasons

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
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  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 42: Fission rates and transactinide formation in the r-process. Igor Panov

Beta ndash Delayed Multy-Neutron Beta ndash Delayed Multy-Neutron EmissionEmission

Q

B

Q

0nkn

kn

kn

dUdE)EU(W)U(IP

Probability for 2n - emission

U I(U) ndash energies and intensities in the daughter nucleus

Wn(U E) ndash probability of neutron emission

nBU

0infn

nfnn

)U(Г)U(q2dE)BEU(q)E(T

)BEU(q)E(T)EU(W

qi and qf ndash level densities of

compound and final nucleusТn(Е) mdash transitivity factor

Q

0 i

i

Q

B ijlmmn

ijl2

i

n2

dE)E(S)EQ1Z(f

dE)EE(W)E(S)EQ1Z(f

P n2

Probability for kn - emission

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
  • Slide 16
  • Slide 17
  • Slide 18
  • Slide 19
  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
  • Slide 24
  • Slide 25
  • Slide 26
  • Slide 27
  • Slide 28
  • Slide 29
  • Slide 30
  • Slide 31
  • Slide 32
  • Slide 33
  • Slide 34
  • Slide 35
  • Slide 36
  • Slide 37
  • Slide 38
  • Slide 39
  • Slide 40
  • Slide 41
  • Slide 42
  • Slide 43
  • Slide 44
  • Slide 45
  • Slide 46
  • Slide 47
  • Slide 48
  • Slide 49
  • Slide 50
  • Slide 51
  • Slide 52
  • Slide 53
  • Slide 54
  • Slide 55
  • Slide 56
  • Slide 57
Page 43: Fission rates and transactinide formation in the r-process. Igor Panov

Beta ndash Delayed Fission CalculationsBeta ndash Delayed Fission Calculations

Q

0 i

i

Q

0 i tot

fi

f

dE)E(S)EQZ(f

dEГ

Г)E(S)EQZ(f

PProbabilities - Pβf d

4

)E(Г)EE(

)E(Г)E(M

2

C)E(S

22

ii

i2i

N

Beta Strength function

Г(Е) widths approximation Г(Е) = αE2 + βE3 + hellip

where α asymp 1εF and β laquo α so we used only the first term

As Гf laquo Гn so neutron emission dominates when this energetically possible

Sub-barrier fission probabilities in the daughter nucleus are small to gamma decay of exited states (barrier was taken in standard parabolic form) Main dependence of Pβf is from barrier energy Bf but not from barrier

thickness or form

  • Slide 1
  • Slide 2
  • Slide 3
  • Slide 4
  • Slide 5
  • Slide 6
  • Slide 7
  • Slide 8
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Slide 13
  • Slide 14
  • Slide 15
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  • Slide 17
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  • Slide 20
  • Slide 21
  • Slide 22
  • Slide 23
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