Proposal to the n_TOF Collaboration at CERN on IFIN-HH joining

Vlad Avrigeanu / Mihai Mirea n_TOF Collaboration Meeting 2006, Paris, 4-5 Dec. 1

Proposal to the n_TOF Collaboration at CERN on IFIN-HH joiningProposal to the n_TOF Collaboration at CERN on IFIN-HH joiningActivities at the neutron time of flight facility at CERN – Second Activities at the neutron time of flight facility at CERN – Second

Phase Phase (n_TOF-Ph(n_TOF-Ph22)) http://pceet075.cern.ch/Documents/LoI_2005/n_TOF-Ph2_LoI.pdfhttp://pceet075.cern.ch/Documents/LoI_2005/n_TOF-Ph2_LoI.pdf

n_TOF Collaboration Meeting 2006 n_TOF Collaboration Meeting 2006 Paris, Dec. 4-Paris, Dec. 4-55, 2006, 2006

Vlad Avrigeanu, Mihai Mirea

“Horia Hulubei” National Institute for Physics & Nuclear Engineering,

Bucharest, Romania

http://tandem.nipne.ro/~Dante/, http://fp6.cordis.lu/fp6/partners

Activation reactions: (n,p), (n,Activation reactions: (n,p), (n,), and (n,xc): ), and (n,xc): V. Avrigeanu, M. AvrigeanuV. Avrigeanu, M. Avrigeanu,, R.A. Forrest (UKAEA-Culham)R.A. Forrest (UKAEA-Culham)

αα-particle optical model / -particle optical model / nuclear matter density (T): nuclear matter density (T): M. Avrigeanu, V. AvrigeanuM. Avrigeanu, V. Avrigeanu, W. von Oertzen (HMI-Berlin), W. von Oertzen (HMI-Berlin)

Measurements of fission cross-sections and neutron interferometryMeasurements of fission cross-sections and neutron interferometry: : M. Petrascu, A. Isbasescu, H. PetrascuM. Petrascu, A. Isbasescu, H. Petrascu, , I. Tanihata (TRIUMF), W.Y. LynchI. Tanihata (TRIUMF), W.Y. Lynch

(MSU) New information on the basic mechanism of nuclear fission: New information on the basic mechanism of nuclear fission:

M. MireaM. Mirea,, L. Tassan-GotL. Tassan-Got (IN2P3-Orsay) (IN2P3-Orsay)

INTEREST IN FURTHER MEASUREMENTS INTEREST IN FURTHER MEASUREMENTS

http://pceet075.cern.ch/Documents/LoI_2005/n_TOF-Ph2_LoI.pdf

http://tandem.nipne.ro/~Dante/

http://fp6.cordis.lu/fp6/partners


Neutron capture cross section measurements

for nuclear astrophysics at n_TOF

Michael Heil

on behalf of the n_TOF collaboration

Michael Heil NIC IX, June 2006, Geneva

http://indico.cern.ch/getFile.py/access?contribId=270&sessionId=26&resId=1&materialId=slides&confId=059

Spark for this IFIN-HH proposal


Outlook - Plan for measurements in Phase-2

Michael Heil NIC IX, June 2006, Geneva

Capture measurements

Mo, Ru, Pd stable isotopes

Fe, Ni, Zn, and Se (stable isotopes)63Ni, 79Se

A≈150 (isotopes varii)

147Sm(n,), 67Zn(n,), 99Ru(n,),58Ni(n,p)

r-process residuals calculationisotopic patterns in SiC grains

s-process nucleosynthesis in massive starsaccurate nuclear data needs for structural

materials

s-process branching pointslong-lived fission products

p-process studies

n_TOF will continue:Letter of Intent signed by 24 research labs of the n_TOF Collaboration + 4 newcomers (January 2005)

Spark for this FIN-HH proposal


• all stable 50,51V isotopes (+ EC/JRC/IRMM-Geel)

[Phys. Rev. C 65, 014604 (2001) ]

• all stable 58,60,61,62,64Ni and 59Co isotopes (+ EC/JRC/IRMM-Geel)

[Nucl. Phys. A730, 255 (2004)]

• all stable 92,94,95,96,97,98,100Mo isotopes (+ IRMM, KRI-St.Petersburg) [Nucl. Phys. A705, 265 (2002)]

[Phys. Rev. C 71, 044617 (2005)]

• all stable 180,182,183,184,186W isotopes (+ KRI, UKAEA, TUD-Dresden, [Nucl. Phys. A765, 1 (2006)] NRC-Petten, BNL-

Brookhaven) • all stable 174,176,177,178,179,180Hf, 181Ta isotopes (+ UKAEA, NRC, BNL)

[PHYSOR-2006, …]

• all stable 55Mn, 63,65Cu isotopes (+ UKAEA, NRC, BNL)

Fast-neutron activation analysis (IFIN-HH, 2000-2006)


i. unitary use of common model parameters for different mechanisms

ii. use of consistent sets of input parameters - determined by analyses of various independent experimental data

iii. unitary account of whole body of related experimental data for isotope chains and neighboring elements

[ activation & particle-emission spectra ]

[ enlarged incident-energy range ]

YES

NO re-normalization or free parameters

Outline of activation consistent model calculations[ E.D. Arthur – P.G. Young, LANL, ’80 ]

[ IAEA/NDS RCs (12), Bucharest, 1982-2005 ]

n_TOF-Ph2


e.g.: Isotopic effects in the (n,p) reaction cross section on Hf and W isotopes

0.000

0.005

0.010

0.015

10 15 20

0.000

0.005

0.010

0.015

0.020

[3- 114.43 d]

Qaim+ (1975) Grallert+ (1993)LNZ (1997)Filatenkov+(2002)

EMPIRE-2.18, g=A/14 CC+GDH+HF TALYS-0.64, g

i=N

i/14

182W(n,p)182Ta

Qaim+ (1975) Grallert+ (1993)Filatenkov+(2002)


i=N

i/14

183W(n,p)183Ta

Qaim+ (1975)Ikeda+ (1988)Kasugai+ (1992)Grallert+ (1993)LNZ (1997)Filatenkov+(1999)Filatenkov+ (2002)


i=N

i/14

184W(n,p)184Ta

10 15 20

Coleman+ (1959)Poularikas+ (1960) Mukherjee+ (1963) Qaim+ (1975)Kasugai+ (1992)Sutoh+ (1994)Murahira+ (1995)Filatenkov+ (1999)Filatenkov+ (2002)


i=N

i/14

186W(n,p)186Ta

10 15 200.000

0.005

0.010

0.015

Meason+ (1966) Kirov+ (1993) Murahira+ (1995)


i=N

i/14

178Hf(n,p)178mLu[9- 23.1M]

EMPIRE-2.19, g=A/14 TALYS-0.64, g

i=N

i/14

CC+GDH+HF

Meason+ (1966)Kirov+ (1993)

178Hf(n,p)178gLu

[1+ 28.4M]

Konno+ (1990)Konno+ (1993)


i=N

i/14

CC+GDH+HF

179Hf(n,p)179Lu[7/2+ 4.59H]

10 15 20

En (MeV)

En (MeV)

(

b)


i=N

i/14

CC+GDH+HF

Kasugai+ (1994)Murahira+ (1995)

180Hf(n,p)180Lu[5+ 5.7MIN]


i=N

i/14

Woelfle+ (1988)Han-Lin+ (1989)Kasugai+ (1992)Xiangzhong+(1992)Begun+ (1999)Filatenkov+(1999)

181Ta(n,p)181Hf

[1/2- 42.39d]

Filatenkov+(2001)Begun+(2001)

0.16 0.18 0.20

-3

0

6

9

Sp

Sn

HfTaW

Q(n

,p) (

MeV

)

(N-Z) / A

[ Isotopic effect on W isotopes: R. Caplar et al., Z. Phys. A 313, 227 (1983) ]

Possible reason for actual model overestimation of 181Ta(n.p)181Hf data: • actual data: 181Ta(n.p)181gHf • unknown (long-life) isomer 181mHf

[Nucl. Phys. A765, 1 (2006)]

[PHYSOR-2006, D.10.2]


Comparison of measured and calculated 181Ta(p,xn) reaction cross sections

• PE threshold in CP-induced reactionse.g., H.C.Chiang+, Nucl.Phys. A340,466(1980):

PE ~ (1 - VC / E)

[ beff~ b(1 - VC / E)1/2 ]

10 20 30 40 50 600

1

2

n

(b

)

R

6n5n

3n

2n

4n

181Ta(n,xn)

En (MeV)

Interest of reaction cross-sections analysis within energy range En<100 MeV:

10 20 30 40 50 60 700.0

0.5

1.0

1.5

2n

1n

No PE Shubin+ (1994, MEDNL-2)

TALYS-0.64 [(p,3n)179m

W]

STAPRE-H.6 [(p,3n)179m

W]

4n

3n

Thomas+ (1967): (p,n)Thomas+ (1967): (p,2n)Birattari+ (1971): (p,3n) ?Birattari+ (1971): (p,4n)Zaytseva+ (1994)Michel+ (2002)

181Ta(p,xn)

(b

)

En (MeV)

Discrepant• Measured data ( if any! )• Calculated cross sections



BASIC QUESTIONS• NUCLEAR-SURFACE EFFECTS ?

– in particle-hole level densities [PLD, CPCLibrary , Belfast, 1998]:– Phys. Rev. C 58, 295 (1998)– Comp. Phys. Comm. 112, 191 (1998)

– in GDH model for pre-equilibrium emission [STAPRE-H95, NEA-DB,1995]:– J. Phys. G: Nucl. Phys. 20, 613 (1994)– Phys. Rev. C 65, 014604 (2001) – J. Nucl. Sci. Tech. Suppl. 2, 803 (2002)

• NUCLEAR MOMENT OF INERTIA (I/Ir) ?– in nuclear level densities:

[e.g., S.F. Mughabghab, C. Dunford: Phys. Rev. Lett. 82, 4083 (1998)]– J. Nucl. Sci. Tech. Suppl. 2, 746 (2002)– Nucl. Phys. A730, 255 (2004)

• -PARTICLE OPTICAL MODEL POTENTIAL– low-energy -particle emission:

– Nucl. Phys. A723, 104 (2003)– Nucl. Phys. A764, 246 (2006)– Phys. Rev. C 73, 038801 (2006)


[ Cf: H. Weigmann et al., Nucl. Phys. A368,117(1981) ]

0 3 6 9 1210

0

101

102

103

1 I/I

r =0.75

0.5

Vonach+ (1988)RIPL (1998)

E*=10.646 MeV

51V

(a)

Vonach+ (1988)RIPL (1998)

(E

*,J)

(Le

vels

/MeV

)

J (h)0 3 6 9 12 15

E*=10.646 MeV

51V

(b)

1 I/I

r =0.75

0.5

[Phys. Rev. C 65, 014604 (2001)]

The only data

The only D0 data useful within this method

I/Ir=0.75: describe both neutron (RIPL) and proton D0 data


OMPs describing -emission: not suitable for (,0) @ E~25 MeV

! ?


I

BRUSLIB [www-astro.ulb.ac.be]

I

III

OMPs from (,0) (at E<40 MeV): DO NOT DESCRIBE -emission


Almost identical at r >R7 (surface tail region): DF (2003) ROP (2003) McFadden-Satchler (1966)

VR(R7)=-7 MeV [Fernandez-Blair, Phys.Rev. C 1,523(1970)]

Surface tail: VR<10 MeV [Igo, Phys.Rev.Lett. 1,72(1958)]Larger aR-values: AHA (1994) [E<80 MeV]

0

40

80

12023.4 MeV

-V

R (

MeV

)

0

40

80

120

UDF

Regional OMP (ROP)

21 MeV

+ 90Zr

elastic scattering (cold nuclei)

0 2 4 6 8 100

40

80

120

25 MeV

r (fm)

1

10

100

-V

R [

MeV

]

R7

DF [DF+] WS

AHA (1994) McFadden-Satchler (1966)

15 MeV

+ 90Zr

1

10

100

-V

R [

MeV

]

R7

DF (=1) WS ~ DF (=1) WS2 ~ DF (=1)


1

10

100

-V

R [

MeV

]

R7

DF (=0.8) WS ~ DF (=0.8) WS2 ~ DF (=0.8)


0 2 4 6 8 10

-120

-60

0

l = 0-3 l = 4-7 l = 8-11

15 MeV

WS2 ~ DF(=0.8) V

C

+ 90Zr

U+V

l (

MeV

)

r (fm)


Additional usefulness for consistent description of -emission

5 10 15 200.00

0.02

0.04

Tmax

=1.87 MeV

Kanda (1972)Qaim (1974)

WS2 ~ DF (=0.8) WS2 ~ DF (=1) AHA (1994)

92Mo(n,)89ZrFujino+ (1977)Garuska+ (1980)Artemev+ (1980)Anemiya+ (1982)Pepelnik+ (1985)Marcinkowski+ (1985)Ikeda+ (1988)Liskien+ (1989)Kong+ (1991)Molla+ (1986,1997)Debrecen (1998)Filatenkov+ (1999)

(

b)

1E-3 0.01 0.1 1

1E-5

1E-4

Tmax

=1.04 MeV

WS2 ~ DF (=0.8) WS2 ~ DF (=1) AHA (1994)

Rapp+ (2003)

95Mo(n,)92Zr

10 15 200.000

0.005

0.010

Tmax

=1.59 MeV

Lu+ (1970)Fukuda+ (1978)

WS2 ~ DF (=0.8) WS2 ~ DF (=1) AHA (1994)

Artemev+ (1980)Amemiya+ (1982)Atsumi+ (1984)Rahman+ (1986)Greenwood+ (1987)Ikeda+(#1) (1988)Ikeda+(#2) (1988)Liskien+ (1990)Kong+ (1992) Molla+ (1997)Filatenkov+ (1999)

98Mo(n,)95Zr

(

b)

En (MeV)

10 15 200.000

0.002

0.004

0.006

Tmax

=1.57 MeVIRMM (2001)Filatenkov+(2001) WS2 ~ DF (=0.8)

WS2 ~ DF (=1) AHA (1994)

Qaim+ (1974)Artemev+ (1980)Atsumi+ (1984)Marcinkowski+ (1986)Ikeda+(#1) (1988)Ikeda+(#2) (1988)Ikeda+(#3) (1988)Liskien+ (1989) Grallert+ (1993)

100Mo(n,)97Zr

En (MeV)

DF: ρ(r,T)= ρ0 / [1+exp[(r-c)/a]]γ

γ=1, for T=0γ<1, for T>0


High precision:uncertainties <3-4%(data basis average: ~15%)

New opportunitiesalso for model understanding

New features ofexp. data

X 5


2006

19942003

2006

International Symposium on Nuclear Astrophysics – Nuclei in the Cosmos–IXCERN, Geneva, 25-30 June, 2006 [ PoS (NIC-IX) ]

Present work: ‘cold’ side


UDERSTANDING THE FISSION MECHANISM / INVESTIGATION OF THE INTERMEDIATESTRUCTURE IN THE RESONANCE REGION

(1/2)EXPLANATION OF Th ANOMALY / DYNAMICAL SINGLE-PARTICLE EFFECTS / ANGULAR DISTRIBUTION OF FISSION FRAGMENTS

ISOTOPIC DISTRIBUTION OF FISSION PRODUCTS / IMPROVEMENT OF EVALUATIONS

FISSION:

Th anomaly (fine structure)PERFECT AGREEMENT

Fission single-particle level schemeDYNAMICAL SINGLE-PARTICLE EFFECTS


UDERSTANDING THE FISSION MECHANISM / INVESTIGATION OF THE INTERMEDIATESTRUCTURE IN THE RESONANCE REGION

(2/2)EXPLANATION OF Th ANOMALY / DYNAMICAL SINGLE-PARTICLE EFFECTS / ANGULAR DISTRIBUTION OF FISSION FRAGMENTS

ISOTOPIC DISTRIBUTION OF FISSION PRODUCTS / IMPROVEMENT OF EVALUATIONS

FISSION:

234U neutron induced cross sectionINTERMEDIATE RESONANCE STRUCTURE

Minimal action trajectory in a multidimensional configuration space


Fig.1. Schematic representation of collision 11Li

+ Si target Fig.2. Schematic representationof collision 11Li + C target

One can see from Fig.1 and Fig. 2 that there is a marked difference In the screening between the Si and the C targets. In Table I it is shown that the two neutron pre-emission probability P{2} calculated by sharp-cutoff is 0.492 for C target and 0.144 for Si tar-get, that is by about 3.5 times larger for C target than for Si target.


Fig. 1. This fig. is taken from ref. [1]. In the insert is shown the Cnn correlation function for 11Li calculated by using a 3-body model [1]. The minimum in the insert is due to the coherence bet-ween the 2 halo neutrons. In Table 3 it is shown that the new theory can be tested (Case 2) for a statistics of nn predicted in previous attached paper. [1] M.T.Yamashita et al., Phys. Rev. C72, 011601(R) (2005)


Correlation Functions

0 10 20 30 40 50 60 700

2

4

6

8

10

12

14

16

18

20

22

24

26

28

Fission neck(r

0=1.88 fm)

C(q

)

COSMA1

(r0=3.3 fm)

COSMA2

(r0=2.7 fm)

q (MeV/c)



Activation reactions: (n,p), (n,Activation reactions: (n,p), (n,), and (n,xc): ), and (n,xc): V. Avrigeanu, M. AvrigeanuV. Avrigeanu, M. Avrigeanu,, R.A. Forrest (UKAEA-Culham)R.A. Forrest (UKAEA-Culham)

αα-particle optical model / -particle optical model / nuclear matter density (T): nuclear matter density (T): M. Avrigeanu, V. AvrigeanuM. Avrigeanu, V. Avrigeanu, W. von Oertzen (HMI-Berlin), W. von Oertzen (HMI-Berlin)

Measurements of fission cross-sections and neutron interferometryMeasurements of fission cross-sections and neutron interferometry: : M. Petrascu, A. Isbasescu, H. PetrascuM. Petrascu, A. Isbasescu, H. Petrascu, , I. Tanihata (TRIUMF), W.Y. LynchI. Tanihata (TRIUMF), W.Y. Lynch

(MSU)

New information on the basic mechanism of nuclear fission: New information on the basic mechanism of nuclear fission: M. MireaM. Mirea,, L. Tassan-GotL. Tassan-Got (IN2P3-Orsay) (IN2P3-Orsay)

SUMMARYSUMMARY

PROPOSAL BASIS / INTEREST IN FURTHER MEASUREMENTS PROPOSAL BASIS / INTEREST IN FURTHER MEASUREMENTS


Thank you

- for kindest consideration & readiness to discuss our proposal - for invitation to attend n_TOF Meeting 2006 - for your attention !