Fission Workshop, CEA Saclay, 6 Dec. 2007 Contact: [email protected] DN Yields & Time Spectra from p(1 GeV) + 238 U Chaos in… my presentation but not in physics

Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007

DN Yields & Time Spectra from p(1 GeV) + 238U

Chaos in… my presentation but not in physics I will be talking about!


10-5 10-3 10-1 101 103 105 107 109

Energy (eV)Photons ELSA

PhotoNuc: experiment

Delayed neutron & delayed photon measurements

BGO

He-3

Targets: 232Th, 235,238U, 237Np, 239PuCollaborationExperiments: CEA/DAM+DRT+DEN, Geel

data for non-destructive interrogation with photons

CeeatY irradii Tt

ii

)1()(

6

1

6 groups of {ai, i}

waste characterization & material detection on borders

D. Doré et al.


10-5 10-3 10-1 101 103 105 107 109

Energy (eV)Photons

PhotoNuc: modeling Contribution of DAPNIA:• 6 major actinide evaluations ENDF-B/VII• future evaluations for JEFF will include

extension up to 130 MeV fission fragment distributions delayed neutron data

CollaborationModeling: LANL, GSI, NRG

238U

235U15 MeV 25 MeV

Yie

ld(%

)

DATAABLA

Mass (A) Mass (A)

Yie

ld(%

)

15 MeV 25 MeV

Calculation in progress for Calculation in progress for 239239Pu, Pu, 237237NpNp

238U

235U15 MeV 25 MeV

Yie

ld(%

)

DATAABLADATAABLA

Mass (A) Mass (A)

Yie

ld(%

)

15 MeV 25 MeV

Calculation in progress for Calculation in progress for 239239Pu, Pu, 237237NpNp

E. Dupont et al.

E. Van Lauwe et al.


10-5 10-3 10-1 101 103 105 107 109


PhotoNuc: experiment

0

5

10

15

20

25

30

35

408 MeV Kull et al. (1970)10 MeV Kull et al. (1970)15 MeV Nikotin et al. (1965)

~55 ~20 ~5 ~2 ~0.5 ~0.2Group half-lives (s)

Rel

ativ

e co

ntri

butio

n (%

)

0

5

10

15

20

25

30

35

408 MeV Kull et al. (1970)10 MeV Kull et al. (1970)15 MeV Nikotin et al. (1965)

~55 ~20 ~5 ~2 ~0.5 ~0.2Group half-lives (s)

Rel

ativ

e co

ntri

butio

n (%

)

0

5

10

15

20

25

30

35

408 MeV Kull et al. (1970)10 MeV Kull et al. (1970)15 MeV Nikotin et al. (1965)15 MeV This work (2004)

0

5

10

15

20

25

30

35

408 MeV Kull et al. (1970)10 MeV Kull et al. (1970)15 MeV Nikotin et al. (1965)15 MeV This work (2004)

0

5

10

15

20

25

30

35

408 MeV Kull et al. (1970)10 MeV Kull et al. (1970)15 MeV Nikotin et al. (1965)15 MeV This work (2004)18 MeV This work (2005)

0

5

10

15

20

25

30

35



238238UU

CeeatY irradii Tt

ii

)1()(

6

1

• Improvement of the old data: 238U, 232Th, 235U• Provision of new measurements: 237Np, 239Pu

1 2 3 4 5 6

DN energy dependence similar to n-fission 2nd chance fission ABLA contains the experimental trend

M.L. Giacri, A. Van Lauwe et al.

V. Macary et al.


Imix(t) = mU YU(t) + mTh YTh(t)

10-5 10-3 10-1 101 103 105 107 109


PhotoNucIsotopic identification:Use of delayed neutrons

238U

232Th

Old parameters

New parameters

Time (s)

DN

act

ivity

Use of the new parameterization for uranium enrichment determination from DN decay curves

impact of the new high precision parameterization!

New parametersExperiment

D. Doré et al.


Delayed Photons

No available data

DP/fission ~ 10* DN/fission

DP low sensibility to H content

DP/DN promising

Given mass M

238U 235U 239Pu

DN 1 x 0.03 2x0.01 2 x 0.04

DP 1 x 0.175 2x0.111 2 x 0.073

DP/DN 5.8 11.1 18.3Experiments Elsa 2 BGO detectors, 5 actinides Analysis based on ABLA model {Ai,Ti

1/2} groups for the 1st timeTi ½, sTheoretical

Ai(%) Theoretical

Ai(%) Experimental

212.51 23.6 27.3

46.62 30.8 28.5

11.07 12.3 15.1

3.81 24.8 19.1

0.55 8.4 9.9

P. Dighe, E. Berthoumieux et al.

10-5 10-3 10-1 101 103 105 107 109


INPHO

ridikas

some text is modifef6-group table changed into 5-group tabel


From photofission to “satellite” projects on DN studies

DN Yields & Time Spectra from p(1 GeV) + natFe, natPb, 209Bi, 238U


short Hg transit time delayed neutron (DN) activity

Prompt neutrons

Delayed neutrons

J-PARK/JAEA - thanks to H. Nakashima

Examples (A)


1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

Fis

sion

cha

mbe

rs

1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

1MW

prot

ons

Meg

aPie

targ

et

1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

Fis

sion

cha

mbe

rs

~5.3 m

DN/PN = ?

Examples (B)

MegaPie/PSI - thanks to F. Groeschel

Ep

Ip

W

570 MeV

1.2 mA (1.8)

0.7MW (1.0)

VPbBi ~ 82 liters

Main pump ~4.00 l/s

Ttransit ~20 s

Successful operation for 4 months in 2006!

D. Ridikas et al., Proc. of PHYSOR2006, Vancouver, Canada.

DN and PN estimates using MCNPX+CINDER’90 Φn (DN)~ 106 n/(s cm2) Φn (PN)~ 106 n/(s cm2)

Important: DN yields are very sensitive to the choice of physics models and no data were found!


DN measurements from p (1GeV)+Pb at PNPI Gatchina (Russia)

Location of the experiment

SC

1 GeV protons ~20 nA

3He counter

Pb target

PNPI synchrocyclotron


He-3 counter calibration: 252Cf neutron source + Monte Carlo

Proton beam monitoring: 27Al foils and gamma spectroscopy from 22Na, 24Na and 7Be

Measurement strategy:a) No target at all – long irradiationsb) Concrete block – long irradiationc) Iron thick target – long irradiations

d) Lead target of variable thickness; short (350 s), intermediate (20 s) and long (300 s) irradiations

Experimental strategy


Beam size/profile: by photo-films at exit and entrance positions Beam intensity: by 27Al foils and gamma spectroscopy from 22Na, 24Na and 7Be

Proton beam monitoring

1GeV protons

Al foils

• 27Al(p,x)7Be monitor reaction cross section 7.5 0.3 mb was taken as a reference • ratios of 24Na & 22Na with respect to 7Be were equal to 1.73 0.15 & 1.99 0.07

uncertainty in proton beam monitoring from 8 % to 12 %

Photo-films


DN decay curve: p + natPb (55 cm)

87Br

17N

88Br

9Li

background

Group Half-life, s Precursor Pn (-n), %

1 55.60 87Br 2.52

2 16.29 88Br 6.58

3 4.173 17N 95.10

4 0.178 9Li 50.80

CTtatDN irradiii

i ))exp(1)(exp()(

“Understandable” from x-sections

• p(1GeV)+Pb 9Li ~ 1000 b • p(1GeV)+Pb 17N ~ 600 b• p(1GeV)+Pb 87Br ~ 33 bD. Ridikas et al., EPJA 32 (2007)


Why only 4 exponentials are sufficient?

1,0E-07

1,0E-06

1,0E-05

1,0E-04

1,0E-03

1,0E-02

1,0E-01

74 76 78 80 82 84 86 88 90 92 94 96 98

Mass A

yiel

d/f

issi

on

p(1GeV)+Pb

n(14MeV)+U

n(fiss)+U

U fission Pb fission; low energy high energy

Production of Br isotopes

T1/

2 (s)

55.6

16.0

4.

4

1.8

0.18


• Reproduced with 4 major contributions : 9Li, 17N, 88Br, and 87Br

DN decay curves: p + natPb, 209Bi

A. Prévost et al.


• The same 4 major contributions : 9Li, 17N, 88Br, and 87Br

DN decay curves: p + 209Bi

A. Prévost et al.


Experimental precursor yields (atoms/proton)

• Saturation seems observed for targets thicker than 20 cm

• Similar shapes and absolute values both for Pb and Bi

17N

87Br

88Br

17N

87Br

88Br

)/( 3 cycleschpHeiii

n NtIaYP

CTtatDN irradiii

i ))exp(1)(exp()(

CatDNi

i )0(


Precursor yields: data versus PHITS simulations

• INC (JAM) + EVAP(GEM) JAM: Jet AA Microscopic Transport ModelGEM: Generalized Evaporation ModelH. Iwase, K. Niita, T. Nakamura, Journal of Nuclear Science & Technology 39 (2002) 1142.

17N

87Br

88Br

Predictions within a factor of 2!

Pb

V. Blideanu et al.


Physics: ratios of relative yields relative to 87Br

Target thickness, cm a2(88Br)/a1(

87Br) a3(17N)/a1(

87Br)

5 1.7 354

10 1.4 235

20 1.3 118

40 1.3 102

55 1.4 90

Target thickness, cm

a2(88Br)/

a1(87Br)

a3(17N)/

a1(87Br)

a4(9Li)/

a1(87Br)

5 0.96 104 235

10 0.95 89 200

20 0.89 86 159

40 0.86 64 125

55 0.97 62 121

Experiment

Confirmed by PHITS predictions

stable decreasing

Produced by different reaction mechanisms

V. Blideanu et al.


Extraction of x-sections : 17N & 87,88Br

p(1GeV)+A-->17N

0,01

0,10

1,00

10,00

100,00

0 50 100 150 200 250

A

sigm

a (m

b)

Dostrovsky'65

Batist'77

This work

Using thin targets

Br-35

1,0E-03

1,0E-02

1,0E-01

1,0E+00

1,0E+01

72 74 76 78 80 82 84 86 88 90A

sig

ma

(m

b)

MCNPX (INCL4+ABLA)PHITS(NMTC-JAM+GEM)GSI dataThis work

Good agreement with old data and/or systematics!

D. Ridikas et al., EPJA 32 (2007)


Absolute DN production yields: consequences

Assumption: p(1GeV) + Pb (55 cm thick; 10 cm ) at 1mA (1 MW)

~51010 n/s

~20 s after

Important data for:• SNS based on liquid metal targets• ToF facilities (DNs background neutrons)

Prompt neutrons

Delayed neutrons


Conclusions and outlook

importance of DN in liquid metal high-power targets for radioprotection issues importance of the measurements to test model calculations

DN yields and time spectra measured for the 1st time for p(1GeV) on thick natPb and Bi targets

Estimates of errors on DN decay curves : below 20 % Major contributors are: 87Br, 88Br and 17N extraction of x-sections PHITS code “recommended” for such studies

Consequences and “in-situ” experiment…


~2-3m 3He

U5 WD

Np Am

U5

Moniteurs

WD

WDU5

1 m

1,3 cm

U5 WD

Np Am

U5

Moniteurs

WD

WDU5

1 m

1,3 cm

Delayed neutrons

Prompt neutrons

1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

Fis

sion

cha

mbe

rs

1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

1MW

prot

ons

Meg

aPie

targ

et

1MW

prot

ons

Meg

aPie

targ

et

Pb

Bi

Fis

sion

cha

mbe

rs

CEA/DSM/DAPNIA’s contribution for MegaPie

S. Panebianco et al.

A. Letourneau et al.


… and if one comes back to physics


DN yield as a function of incident neutron energy

Séminaire Saclay 53

n + U8 (n,f)

n

U8 (n,nf)

U7 (n,2nf)

2n

U6 (n,3nf)

3n

Pa8

p

(n,pf)

U9

U5 (n,4nf)4n

Th5(n,f)

6MeV

12 24 32

p(1GeV) + 238U in Nov. 2007

Thanks to P. Romain et al. CEA/DIF/DPTA What is beyond 20 MeV?


1,0E-07

1,0E-06

1,0E-05

1,0E-04

1,0E-03

1,0E-02

1,0E-01

74 76 78 80 82 84 86 88 90 92 94 96 98

Mass A

yiel

d/f

issi

on

p(1GeV)+Pb

p(1GeV)+U

n(14MeV)+U

n(fiss)+U

U fission Pb fission; low energy high energy

Production of Br isotopes: dependence on energy

T1/

2 (s)

55.6

16.0

4.

4

1.8

0.18


p(1GeV)+U

Dostrovsky et al.: from DN curves

GSI data: inverse kinematicsProduction of 87Br ~3.8 mb * 0.025 0.095

Nearly a factor of 2!

No change with energy?


Modeling of DNs in 3 steps: p(1GeV)+238U

T1/2, s Yn*Pn, x 106

g1: 55.598 13.83926g2: 19.252 64.42184g3: 4.975 48.61182g4: 2.051 124.89912g5: 0.450 38.10098g6: 0.197 12.99792 <T1/2>=9.397 Total: 303.3795

1) INCL4+ABLA for Y(A,Z) 2) Summation of Y(A,Z)*Pn according to T1/2

----------Group 2------------------ Y*Pn, *10e6 T1/2,sBa144 g - 9.26051 - 11.500Br88 g - 25.1614 - 16.290Te136 g - 1.62791 - 17.630I137 g - 28.16053 - 24.500Cs141 g - 0.21140 - 24.940 Total: 64.42184 <T1/2>: 19.25251

3) Construction of DN tables


Photo of the experimental setup: p(1GeV)+238U

• 0.3mm, 1cm & 2cm thick 238U targets• 3cm x 3cm

238U + Al foilAl foil

Nov. 2007PNPI Gatchina


“Raw” experimental data: p(1GeV)+ 238U DNs

• 1 bunch – 2 s; channel=5ms• 20 s – 100 s; channel=0.2s• 300 s – 300 s; channel = 0.2s

signal

backgroundsignal

background

“background” empty Al envelope


“Raw” data versus modeling

T1/2, s ai, x 106

g1: 55.598 13.83926g2: 19.252 64.42184g3: 4.975 48.61182g4: 2.051 124.89912g5: 0.450 38.10098g6: 0.197 12.99792

+g8 (N17): 4.173s ~450g9 (Li9): 0.178s ~2500

CTtatDN irradiii

i ))exp(1)(exp()(

T1/2, s Yn*Pn, x 106

g1: 55.598 13.83926g2: 19.252 64.42184g3: 4.975 48.61182g4: 2.051 124.89912g5: 0.450 38.10098g6: 0.197 12.99792 <T1/2>=9.397 Total: 303.3795


From the DN decay curve: p (1GeV)+ U

Group Half-life, s Precursor Pn (-n), %

1 55.60 87Br 2.52

2 16.29 88Br 6.58

3 4.173 17N 95.10

4 0.178 9Li 50.80

“Understandable” from x-sections

p(1GeV)+U p(1GeV)+Pbin ( * Pn) due to production of

• 9Li ~1.7 mb * 0.510 0.87 0.51• 17N ~1.1 mb * 0.950 1.05 0.57• 87Br ~3.8 mb * 0.025 0.10 0.0008• 88Br ~2.9 mb * 0.066 0.19 0.0009

Short lived fragmentation products dominate over longed lived fission products (?!)

Detailed analysis in progress as a part of PhD thesis by G. Stankunas

Documents

Fission Workshop, CEA Saclay, 6 Dec. 2007 Contact: [email protected] DN Yields & Time Spectra from p(1 GeV) + 238 U Chaos in… my presentation but not in physics