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Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
2
Overview of the surrogate method
Principle of the surrogate nuclear reactions method and its limitations
(3He,x) as a surrogate : modeling and uncertainties
- Cm, Pa isotope measurements
- 175Lu measurement
Summary
OutlookOutlook
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
3
Consist
of a transfer
of one or few nucleonsfrom
the projectile to the target
(stripping) or vice versa (pick
up)
Under the condition
:
Surrogate
nuclear
reaction
method
The transfer
reaction
)b, a( yNyxAxZN
AZ YX
projectile aThe trasfer
reaction
barrier coulombVEproj
ejectile b
Indirect measurement
of cross sections
The Absolute
Surrogate
Technique (the transfer
reaction) was
first suggested
by Cramer and Brittin 1970 to overcome
the problem
associated
with
neutron induced
cross sections on short-lived
targets.
-
Many of these nuclei are too difficult to produce with currently
available experimental techniques
-
too
short lived
to serve as targets
in present-day
set-ups.Huge radio toxicities:(strong neutron and alpha emitters)e. g. 0.12·109 bq/g for 242Cm
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
4
RECENTLY, interest has been renewed …
Nucleosynthesis
process Neutron-capture reactions on neutron-rich nuclei : s and r-process
Nuclear Astrophysics
Reactor designs & waste management
Transmutation of Minor Actinides produced in U/Pu
cycle
In transmutation the intention is
to convert
the MAs
into
fission products.
Nuclear data needs for Thorium/Uranium fuel cycle innovative fuel cycle for GEN IV reactors
used
to obtain
cross sections for neutron-induced
fission for various
protactinium and thorium nuclei
CENBG (2000)
In the world …
USA (LLNL, LBNL, …)Japan (ASRC-JAEA)India (BARC)…
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
5
Overview of the surrogate method
Principle of the surrogate nuclear reactions method and its limitations
(3He,x) as a surrogate : modeling and uncertainties
- Cm,Pa isotope measurements
- 175Lu measurement
Summary
OutlookOutlook
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
6
An alternative solution exists… : transfer reactions
+ b ←
Y + a
Surrogate reaction
Measured
a
n + AX
H.C. Britt et al.
(Los Alamos 1970…!!)
Y
b
)()(1nn
ACN EPE
Microscopic optical model calculation (BIII), TALYS
A+1X* A+1X*
nAX
gs
A+1X*
Bn
E*,J
P
(E*,J)
Neutron-induced reaction
)( nA
nE
tnN
XA
bCNCN
CN NNwhereEEN
ENEP
*)(*)(*)(
*)(
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
7
Neutron-induced reaction Surrogate reaction
),(),()( ),(),()( 1111
JEPJEEJEPJEE nJ
nA
nA
CNnJ
nA
nA
CN
1) Ewing-Weisskopf
limit : (E* > Bn+2.5MeV)
)1),(( )()()( )(),( 11
Jn
Ann
ACNn
Ann JEEPEEEPJEP
2)
are quite similar in neutron-induced and surrogate reaction),( ),( 11 JEandJE nA
nA
A+1X*
E*,J
Y + a b +
A+1X*n + AX
A+1X*
J
population mismatchThe surrogate
acceptance
limits
P
(E*,J)
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
8
Overview of the surrogate method
Principle of the surrogate nuclear reactions method and its limitations
(3He,x) as a surrogate : modeling and uncertainties
- Cm,Pa isotope measurements
- 175Lu measurement
Summary
OutlookOutlook
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
9
242Cm 244Cm243Cm
245Cm
243Am
+n +n+n
3He
242Am( 3He,p)
( 3He,d)( 3He,t)
( 3He,α)
Curium isotopes and Americium produced by transfer reactions 243Am(3He,=[p,d,t,α])
Fission cross section of minor actinidesCm isotopes
T1/2
=7370 y
Performed @ Tandem-Orsay/ 24 MeV
/ 50nAe/2005
One experiment
provides
a simultaneousmeasurement
of (n,f) reactions.
G. Kessedjian PhD thesis, Univ Bordaux 1, 2008
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
10
Carbon
foil75µg/cm²
243Am152µg/cm²=6mm
*)(*)(*)(
*)(EEN
ENEP
eje
eje
eje
cos21* ejeprojprojejeejeejeejejprojprojrecoil
ejeproj EmEmEmEmm
EQEE
3He beam
*EejeE
eje
E - E
%7.0 4keV 150at low excitation energy
243Am(3He,d)244Cm
208Pb(3He,d)209Bi208Pb(3He,)207Pb
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
11
*)(*)(*)(
*)(EEN
ENEP
eje
eje
3He beam
E - E
=fission fragment
15 Solar
cells
)90()0(,,
4*)( int W
WfEfission
- Geometry
simulation - 252Cf measurements
(46±1)%
252Cf measurements-Coincidences
Cell-Silicon
detector(96±1)%
In beam
ejetile-frag-fragcoincidences
measurementsW(0°)/W(90°)=1.47±0.17for E*=7.5 MeV 243Am(3He,t)
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
12
Carbon
foil75µg/cm² 243Am
152µg/cm²=6mm
*)(*)(*)(
*)(EEN
ENEP
eje
eje
3He beam
E - E
pdt
3He
%1.0%1.0
)%01.0(85,99purity isotopichigh need
244
241
243
CmAmAm
atoms...light other target
impuritiesof presence16 oxydeO
backingtarget 1312 CandC
*Ehigh at reactionsn evaporatio-fusion
theofon contributi
),3(backing same
12 HeC
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
13
),( 312243 pHebackingCAm
),( 312 pHebackingC
),( 312243 dHebackingCAm
),( 312 dHebackingC
*)(*)(*)( ENfENEN CarboneejeNeje
Ameje
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
14
*)(*)(*)( ENfENEN CarboneejeNeje
Ameje
*)(*)(*)(*)( tcontaminensingles, ENENfENEN Carbone
ejeNejeAmeje
Introduces-
Systematic
uncertainties-
correlations
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
15
*)(*)(*)(
*)(EEN
ENEP
eje
eje
= fission fragment
=
cascade
( light nuclei
don’t
contribute)
( light nuclei
should
contribute)
)()()( 1nn
ACNn
A EPEE
10%
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
16
242Cm(n,f) T1/2 =163 d 243Cm(n,f) T1/2 =29.1 y241Am(n,f) T1/2 =432.6 y
5,4737 1,9098 10,9368 10 3,5599 2,6342
5,6887 1,9931 11,0162 10 3,5685 2,9383
5,9032 1,9241 11,2231 10 3,6832 3,521
6,1182 1,9072 11,3531 10 3,7615 3,8158
6,3332 1,8681 11,2154 10 3,8635 3,2258
Neutron f uncertainties
energy (barn) total (f) CN statistical systematic
(MeV) (%) (%) (%) (%)
0,1027 0,4459 16,8828 10 13,3595 2,5184
0,3172 0,703 14,3968 10 9,6983 3,4626
0,5322 1,2634 12,6495 10 7,0897 3,056
SEND TO EXFOR 23076
Backgroud
subtractionand
fission detector efficiency
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
17
231Pa 233Pa232Pa
234Pa
232Th
+n +n +n
3He
231Th
( 3He, pf and p)
( 3He,d)( 3He,t)
( 3He,α)
Protactinium and thorium isotopes produced
by transfer
reactions
232Th(3He,x=[p,d,t,α])
Capture cross section of the Th/U fuel cycle nucleiPa isotopes
Performed @ Tandem-Orsay/ 24 MeV
/ 50nAe / 2000&2002
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
18
M. Petit, et al.
Nucl. Phys. A 735, 345-371 (2004)
Derived
233Pa(n,n’) et 233Pa(n,) using
a local
statistical
Hauser-Feschbach
model
Modeling
Energie neutron (MeV)0,0 0,2 0,4 0,6 0,8 1,0
(n,) (barns)
0,0
0,5
1,0
1,5
2,0
2,5Petit et al.endf 6.8jendl 3.3nos résultats
Equivalent233Pa(n,)234Pa
S. Boyer et al. Nucl. Phys. A775 (2006) 175
Unfortunately there is no neutron-induced data for comparison.
equivalent 233Pa(n,f)234Pa
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
19
4 C6 D6 Scintillators
2 E-E
6 Ge
New set-up
Performed @ Tandem-Orsay/ 24 MeV
/ 15nAe/ Feb 2010
Validation of the Transfer réaction
with existing (n,) data
Validation of the surrogate method for capture reactions in the rare earth nuclei
174Yb (3He,p) 176Lu as a surrogate reaction 175Lu(n,)176Lu
Efficiency
determined with MCNP simulations and validated with a set
of -calibrations and nuclear reactions.
C6
D6
detectors
*)(*)(*)(
*)(EEN
ENEP
eje
eje
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
20
Next
Step
: Surrogate
method
applied
to the actinide regionA 238U target
is
now
available
(from
GSI)238U(d, p) 239U is
planned
for 2011 at
OCL OSLO
0
0,2
0,4
0,6
0,8
1
1,2
5,5 6 6,5 7 7,5 8
Excitation energie / MeV
norm
aliz
ed p
roba
bilit
y
this workprob_500175Lu(n,g)
p
pc N
NEP )(
Normalized
to 1
176Lu*
Sn
= 6,29 MeV
E*,J
175Lu*
n
C6
D6
in coincidence
with
E-E
TALYS
Preliminary
resultsThe decay
probability
P
calculated
with
Talys
is
compared
to themeasured
probability
deduced
from
the (3He,p) transfert reaction
:
- in Fig.1
the extracted
P
from
(3He,p) is
overestimated
by a factor 3.The red
curve
is
obtained
as the blue
one but with
a threshold
of 500 keV
on the C6D6
detectors (in order
to eliminate
the (n,n’) contamination below
500 keV
excitation energy).
- the compound elastic
probability
dominate
in the case of a neutron inducedreaction
(70% just
above
the neutron energy
separation
Sn (Talys
calculation))
- large differences
observed
here
for P
could
be
explained
by angularmomentum
J
mismatch
of the populated
states in the two
reactions.113 keV
Number
of compound nucleus decaying
by
Number
of compound nucleus formed
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
21
Motivations
How to overcome experimental difficulties for Actinides (n,f) ,(n,)
(3He,x) as a surrogate :
- Pa,Cm measurements
- 175Lu measurement
Summary
OutlookOutlook
Centre d’Etude Nucléaire Bordeaux-GradignanCENBG
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
22
� Surrogate
reaction
technique allows
us to use a more readily
obtainable
target.
� Allows
us to expand
our
measurement
abilities
into
previously
inaccessibleregions
of the periodic
chart.
� Designed
correctly
one experiment
provides
a simultaneous
measurementof (n,γ), (n,2n) and (n,f) covering
a surrogate
neutron energy
range from
about 0 to 20 MeV.
�uncertainties
are minimised
with
high
isotope purity
target
and less
impurities
� 238U(d, p)239U to bentchmark
the (n,) cross section in the actinides mass region.
� need
for DWBA calculations
(differentiel
cross section, J
distributions)
Summary and perspectives…
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
23
Surrogate
method
applied
to Minor
actinide collaboration
M. Aiche1), G. Boutoux1) , B. Jurado1), G. Barreau1), N. Capellan 1) , I. Companis 1) ,S. Czajkowski1) , D. Dassie1), B. Haas1) ,L. Mathieu 1) , E. Bauge 2) , J.M. Daugas 2) , T. Faul
2) , L. Gaudefroy 2) , V. Meot 2) , P. Morel 2)
, N. Pillet 2) , O. Roig 2), J. Taieb 2), O. Serot 3), F. Gunsing 4), L. Tassan-Got 5) , J.T. Burke 6) and X. Derkx 7) .
1) CENBG, Chemin du Solarium B.P. 120, 33175 Gradignan, France2) CEA DPTA/SPN, F-91297 Arpajon, France3) CEA-Cadarache, DEN/DER/SPRC/LEPh, 13108 Saint Paul lez Durance, France4) CEA Saclay, DSM/IRFU/SPhN, 91191 Gif-sur-Yvette cedex, France5) Institut
de Physique Nucléaire, 15 rue Georges Clemenceau, 91406 ORSAY, France6) LLNA, US Department of Energy, Livermore, California 94551, USA.7) GANIL, Bld
Henri Becquerel B.P. 55027, 14076 CAEN Cedex
05, France8) Horia
Hulubei
NIPNE, P. O. Box MG-6, 077125 Bucharest-Magurele, Romania
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
24
176Lu*
Sn
= 6,29 MeV
E*,J
175Lu*
174Yb (3He,p)
n’
Ig a m m a = f c t ( E * )
0
2 0 0
4 0 0
6 0 0
8 0 0
1 0 0 0
1 2 0 0
1 4 0 0
1 6 0 0
1 8 0 0
3 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0 9 0 0E * ( 1 0 k e V / c a n a l )
Ig
3 4 3 k e V ( 1 7 5 L u )7 0 k e V ( 1 7 6 L u )1 9 2 . 2 k e V ( 1 7 6 L u )
Sn=6,29 MeV
Ge in coincidence
with
E-E
Centre d’Etudes Nucléaires Bordeaux-GradignanCENBG
25
are quite similar in neutron-induced and surrogate reaction
),(),()( 1
JEPJEEP nJ
nA
n
),(1 JEnA
Spin distribution of the compound nucleus 176Lu for :En=100 keV
, 1 MeV
and
2 MeV
Calculations-solid line, extracted from TALYS code-dotted line, extracted from FRESCO DWBA code
174Yb (3He,p) 176Lu as a surrogate reaction 175Lu(n,)176Lu
Theoretical studies