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!
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
10-5 10-3 10-1 101 103 105 107 109
Energy (eV)Photons ELSA
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
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)
8 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)
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
Imix(t) = mU YU(t) + mTh YTh(t)
10-5 10-3 10-1 101 103 105 107 109
Energy (eV)Photons ELSA
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Energy (eV)Photons ELSA
INPHO
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
From photofission to “satellite” projects on DN studies
DN Yields & Time Spectra from p(1 GeV) + natFe, natPb, 209Bi, 238U
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
short Hg transit time delayed neutron (DN) activity
Prompt neutrons
Delayed neutrons
J-PARK/JAEA - thanks to H. Nakashima
Examples (A)
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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!
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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)
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
• Reproduced with 4 major contributions : 9Li, 17N, 88Br, and 87Br
DN decay curves: p + natPb, 209Bi
A. Prévost et al.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
• The same 4 major contributions : 9Li, 17N, 88Br, and 87Br
DN decay curves: p + 209Bi
A. Prévost et al.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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(
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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)
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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…
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
~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.
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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?
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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?
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
“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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
“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
Contact: [email protected] Workshop, CEA Saclay, 6 Dec. 2007
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