94-Pu-236
94-Pu-236 JAERI EVAL-FEB02 O.Iwamoto
DIST-MAR02 REV3-FEB02 20020226
----JENDL-3.3 MATERIAL 9428
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
79-04 New evaluation was made by T.Hojuyama (MAPI) /1/ in the
energy range from 1.0E-5 eV to 20 MeV.
89-07 Cross sections below 9.15 eV were modified by Y.Kikuchi and
T.Nakagawa (JAERI).
94-06 JENDL-3.2.
nu-p, nu-d and nu-total were modified.
Compiled by T.Nakagawa (NDC/JAERI)
01-12 JENDL-3.3
Resonance parameter, Cross section, angular distribution
and energy distribution were modified by O.Iwamoto
(NDC/JAERI)
***** Modified parts for JENDL-3.3 ********************
(2,*), (3,*), (4,*), (5,*)
***********************************************************
MF=1 General Information
MT=451 Comment and dictionary
MT=452, 455, 456
Data were not modified from JENDL-3.2.
MF=2 Resonance Parameters
MT=151 Resolved and unresolved resonance parameters
1) Resolved resonance : 1.0E-5 to 10 eV
Multilevel Breit-Wigner type resonance parameters
were taken from ENDF-B/VI
2) Unesolved resonance : 1 eV to 30 keV
Parameters were obtained to reproduce evaluated total,
fission and capture cross sections. The fission cross
section were evaluated based on measured data/2/.
Other cross sections were estimated from statistical model
calculation and multiplied by the ratio of calculated to
the experimental fission cross section.
3) Thermal Cross Sections and Resonance Integrals
Calculated 2200-m/s cross sections and resonance integrals.
2200 m/sec Res. Integ.
total 331.1 b -
elastic 16.34 b -
fission 169.4 b 58.8 b
capture 145.4 b 401 b
MF=3 Neutron Cross Sections
MT=1 Total cross section
Obtained by CC optical model calculation. Optical potential
parameters were taken from Sukhovitskii's evaluation/3/.
The deformation parameters were taken from Moller's
calculation/4/.
MT=2 Elastic scattering cross section
Obtained by subtracting the other cross sections from total
cross section.
MT=4,51-54,91 Inelastic scattering cross sections
Obtained by optical and statistical model calculations.
Level scheme was taken from Ref./5/
No. En(keV) Spin-Parity
g.s. 0.0 0 +
1 44.63 2 +
2 147.45 4 +
3 305.80 6 +
4 515.7 8 +
Continuum levels assumed above 640 keV.
MT=16,17 (n,2n) and (n,3n) cross sections
Obtained by statistical model calculations.
MT=18,19,20,21 Fission cross sections
Obtained by statistical model calculations.
Fission barrier parameters were adjusted to reproduce
experimental fission cross section/2/.
MT=102 Capture cross section
Obtained by statistical model calculations.
MF=4 Angular Distribution of Secondary Neutrons
MT=2,51-54
Based on optical and statistical model calculation.
MT=16,17,18-21
Isotropic in the laboratory system.
MT=91
Statistical plus excition model calculation with Kalbach's
systematics/6/.
MF=5 Energy Distribution of Secondary Neutrons
MT=16,17,91
Based on statistical model calculation.
MT=18,19,20,21
Fission spectrum of Maxwellian form adopted. Temperatures
were estimated by Howerton's systematics/7/.
References
1) T. Hojuyama: Proc. '79 Fall Meet. of A.E.S.J.,Tokai (1979)
C43.
2) E.A. Gromova et al.: Sov. J. At. Energ., 68, 223 (1990)
3) E.Sh. Sukhovistskii et al.: J. Nucl. Sci. Tech. 37, 120 (2000)
4) P. Moller et al.: Atomic Data and Nucl. Data Tables 59, 185
(2000)
5) M.R. Schmorak: Nucl. Data Sheets, 63, 139 (1991)
6) C. Kalbach: Phys. Rev. C37, 2350 (1988)
7) R.J. Howerton, R.J. Doyas: Nucl. Sci. Eng. 46, 414 (1971)
------------------------------------------------------------------
JENDL-3.2 comment
------------------------------------------------------------------
94-Pu-236 MAPI,JAERI Eval-Apr79 T.Hojuyama, Y.Kikuchi, T.Nakagawa
Dist-Sep89 Rev2-Jun94
History
79-04 New evaluation was made by T.Hojuyama (MAPI) /1/ in the
energy range from 1.0E-5 eV to 20 MeV.
89-07 Cross sections below 9.15 eV were modified by Y.Kikuchi and
T.Nakagawa (JAERI).
94-06 JENDL-3.2.
nu-p, nu-d and nu-total were modified.
Compiled by T.Nakagawa (NDC/JAERI)
***** Modified parts for JENDL-3.2 ********************
(1,452), (1,455), (1,456)
***********************************************************
MF=1 General Information
MT=451 Comment and dictionary
MT=452 Number of neutrons per fission
Sum of Nu-p nad Nu-d.
MT=455 Delayed neutrons per fission
Average values of systematics by Tuttle/2/, Benedetti et
al./3/ and Waldo et al./4/ Decay constants were assumed
to be the same as those of Pu-238 evaluated by Brady and
England/5/.
MT=456 Prompt neutrons per fission
Based on systematics by Manero and Konshin/6/, and by
Howerton/7/.
MF=2 Resonance Parameters
MT=151 Resolved resonance parameters : 1.0E-5 to 9.15 eV
Average capture width, S0, and R were estimated from
systematics/8,9/. The first positive resonance was located
at 6.3 eV, and its neutron width was estimated from S0.
The fission width was determined so that the fission cross
section calculated from unresolved resonance formula with
the fission width might smoothly connect at 10 keV to the
cross section in high energy region. A negative resonance
was added at -0.8 eV and the parameters were adjusted so as
to reproduce the fission cross section of 170 b at 0.0253
eV/10/ and reasonable capture cross section.
: 0.030 eV
R : 9.46 fm
: 6.3 eV
S0 : 1.25E-4 /8,9/
Calculated 2200-m/s cross sections and resonance integrals.
2200 m/sec Res. Integ.
total 331.1 b -
elastic 16.34 b -
fission 169.4 b 58.8 b
capture 145.4 b 401 b
MF=3 Neutron Cross Sections
MT= 1 Total cross section
Obtained by optical model calculation. Optical potential
parameters were taken from Murata's evaluation /11/ except
real potential.
---Optical Potential Parameters---
V = 39.5-0.05*En (MeV)
Ws = 6.5+0.15*En (MeV)
Vso= 7.0 (MeV)
r0 = rso= 1.32 ,rs = 1.38 (fm)
a = aso= 0.47 ,b = 0.47 (fm)
MT= 2 Elastic scattering cross section
Obtained by optical and statistical model calculations.
MT=4,51-54,91 Inelastic scattering cross sections
Obtained by optical and statistical model calculations.
Level scheme was taken from Ref./12/ except 4th level of
which energy was based on Lynn /13/.
No. En(keV) Spin-Parity
g.s. 0.0 0 +
1 44.6 2 +
2 145 4 +
3 305 6 +
4 523 8 +
Continuum levels assumed above 661 keV.
MT=16,17 (n,2n) and (n,3n) cross sections
Calculated with statistical model based on Pearlstein /14/.
MT=18,19,20,21 Fission cross sections
Below 10 keV:
Calculated from the unresolved resonance formula with the
following parameters.
S0 = 1.25E-4, S1 = 2.22E-4, = 6.3 eV,
= 0.0415 eV. = 0.00355 eV.
Above 10 keV:
Calculated from fission plateau cross sections /11,15/ and
Hill-Wheeler type barrier penetration factor /16/.
Fission barrier parameters were taken from Weigmann /17/.
MT=102 Capture cross section
Calculated by optical and statistical model with of
41.5 milli-eV and of 6.3 eV.
MT=251 Mu-bar
Calculated with optical model.
MF=4 Angular Distribution of Secondary Neutrons
MT= 2 Based on optical and statistical model calcula-
tion.
MT=51-54 Isotropic in the center-of-mass system.
MT=16-21,91 Isotropic in the laboratory system.
MF=5 Energy Distribution of Secondary Neutrons
MT=16,17,91 Evaporation spectrum assumed
MT=18,19,20,21 Fission spectrum of Maxwellian form adopted.
Theta taken from evaluation of Terrell/18/.
References
1) Hojuyama T.: Proc. '79 Fall Meet. of A.E.S.J.,Tokai (1979)
C43.
2) Tuttle R.J.: INDC(NDS)-107/G+special, p.29 (1979),
3) Benedetti G. et al.: Nucl. Sci. Eng., 80, 379 (1982).
4) Waldo R. et al.: Phys. Rev., C23, 1113 (1981).
5) Brady M.C. and England T.R.: Nucl. Sci. Eng., 103, 129 (1989).
6) Manero F. and Konshin V.A.: At. Energy Rev.,10, 637 (1972).
7) Howerton R.J.: Nucl. Sci. Eng.,62, 438 (1977).
8) Mughabghab S.F. and Garber D.I.: BNL 325,3rd Ed.,1,(1973).
Mughabghab S.F.: "Neutron Cross Sections, Vol. 1, Part B",
Academic Press (1984).
9) Musgrove A.R.de L.: AAEC/E 277 (1973).
10) Gindler J.E. et al.: Phys. Rev.,115, 1271 (1959).
11) Matsunobu H. et al.: Proc. Int. Conf. on Nuclear Cross
Sections for Technology, Knoxville (1979) 715.
12) Schmorak M.R.: Nucl. Data Sheets,20, 165 (1977).
13) Lynn J.E.: The Theory of Neutron Resonance Reactions(1968),
Oxford University Press.
14) Pearlstein S.: Nucl. Sci. Eng.,23, 238 (1965).
15) Behrens J.W.: Phys. Rev. Lett.,39,(1977) 68
16) Hill D.L. and Wheeler J.A.: Phys. Rev.,89, 1102 (1953).
17) Weigmann H. and Theobald J.P.: Nucl Phys.,A187,(1972) 305
18) Terrell J.: Proc. IAEA Symposium on Physics and Chemistry of
Fission , Salzburg (1965)