94-Pu-244 JAERI EVAL-MAR95 T.Nakagawa, V.A.Konshin
JAERI-Research 95-067 DIST-MAR02 20001004
----JENDL-3.3 MATERIAL 9452
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
95-02 New evaluation was made by Nakagawa and Konshin /Na95/.
00-10 Compiled by T.Nakagawa.
The following quantities are re-evaluated after JAERI-
Research 95-067:
MF=3 MT=102
MF=5 MT=16, 17, 18, 19
MF=1 General information
MT=451 Descriptive data
MT=452 Number of neutrons per fission
Sum of MT=455 and 456.
MT=455 Delayed neutrons per fission
Determined from the systematics of Manero and Konshin /Ma72/.
MT=456 Prompt neutrons per fission
Determined from the data for Pu-240 and Pu242.
MF=2 Resonance parameters
MT=151
Resolved resonance paramters for MLBW formula: up to 290 eV.
Recommendation of Mughabghab /Mu84/ was adopted. Mughabghab
adopted experimental data of Auchampaugh et al. /Au71/ In the
present evaluation, the average capture width of 20 meV was
assumed. Fission widths were determined so as to reproduce
integrated measured fission cross sections around each
resonance peak. The scattering radius of 9.33 fm was obtained
from an optical model calculation.
No unresolved resonance parameters were given.
Thermal cross sections and resonance integral (barns)
0.0253 eV resonance int.
Total 12.04 -
Elastic 10.35 -
Fission 0.0017 5.07
Capture 1.68 50.0
MF=3 Neutron cross sections
Below 290 eV
No background cross sections were given.
Above 290 eV
Three codes of CASTHY/Ig91/, ECIS/Ra00/ and STAPRE/Uh76/ were
mainly used. EGNASH/Ya90/ was used to calculate neutron
spectra.
Parameters (MeV, fm) of deformed potential/Ko93/ for ECIS:
V = 46.03 - 0.3*E
W-d = 3.05 + 0.4*E 0 =< E =< 10 MeV
= 7.05 - 0.082*(E-10) 10 < E <=20 MeV
W-v = 8.0/(1+exp(-(E-50)/10))
V-so= 6.2
r-r = 1.26 a-r = 0.63
r-d = 1.26 a-d = 0.52
r-so= 1.12 a-so= 0.47
beta-2 = 0.204 beta-4 =0.07
The spherical potential parameters/Ig85/ used in CASTHY:
V = 45.036 - 0.3*E, r-r = 1.256, a-r = 0.626
W-d = 4.115 + 0.4*E, r-d = 1.260, a-d = 0.555+0.0045*E
V-so= 7.5, r-so= 1.256, a-so= 0.626
Level density parameters used in CASTHY:
a(1/MeV) T(MeV) delta(MeV) E-x(MeV) spin-cutoff
Pu-244 31.0 0.380 1.536 4.7720 31.74
Pu-245 34.87 0.315 0.7667 3.1895 33.76
STAPRE calculation is described in Ref./Ko95/. Fission barrier
parameters used are as follows:
Ef-A(MeV) Ef-B(MeV)
Pu245 5.75 5.40
Pu244 5.50 5.20
Pu243 6.00 5.70
Pu242 5.60 5.35
MT=1 Total
290 eV - 10keV: the sum of fission, capture and elastic.
Above 10 keV : calculated with ECIS.
MT=2 Elastic scattering
290 eV - 10 keV: a constant value of 13.36 b.
10 keV - 4.5MeV: calculated as the (total) - (sum of partial)
cross sections.
Above 4.5 MeV : calculated with ECIS.
MT=4, 51-91 Inelastic scattering
Compound process was calculated with CASTHY, and direct one
with ECIS.
Level scheme/Sh86/:
Energy (keV) Spin-parity direct-component
g.s. 0.0 0 +
1 46.0 2 + *
2 153.0 4 + *
3 315.4 6 + *
4 531.8 8 + *
5 708.0 2 + *
6 798.3 10 + *
7 957.0 3 -
8 1015.0 2 +
Levels above 1.068 MeV were assumed to be overlapping.
The direct process was calculated with ECIS for the levels
marked with *.
MT=16,17 (n,2n) and (n,3n) reactions
Calculated with STAPRE. The results were reported in Ref.
/Ko95/.
MT=18 Fission
Above 8 MeV, the cross section /Ko95/ calculated with STAPRE
was adopted, which was in good agreement with experimental
data. Below 8 MeV, a smooth curve was determined by
eye-guiding of experimental data /Au71, Mo83/. Below 10 keV,
the data of Auchampaugh et al. /Au71/ were smoothed out.
MT=102 capture
Calculated with CASTHY. The average capture width of 0.020 eV
and the level spacing of 17 eV were assumed. The direct and
semi-direct cross section was calculated with DSD /Ka99/.
MF=4 Angular distributions of secondary neutrons
MT=2 Elastic scattering
Calculated with ECIS.
MT=16,17, 18 (n,2n), (n,3n) and Fission
Assumed to be isotropic in the laboratory system.
MT=51-91 Inelastic scattering
Calculated with CASTHY and ECIS.
MF=5 Energy distributions of secondary neutrons
MT=16, 17, 91
Calculated with EGNASH/Ya90/.
MT=18
Evaporation spectrum with nuclear temperature obtained from
the systematics of Howerton-Doyas /Ho71/. The ratios of
multi-chance fission to total were estimated from the STAPRE
calculation/Ko95/. This is in very good agreement with the
systematics of Smith et al. /Sm79/ (1.347) at the thermal
energy.
References
Au71) G.F. Auchampaugh, et al.: Nucl. Phys., A171, 31 (1971).
Ho71) R.J. Howerton and R.J. Doyas: Nucl. Sci. Eng., 46, 414
(1971).
Ig85) A.V. Ignatyuk, et al.: Sov. J. Nucl. Phys. 42, 360 (1985).
Ig91) S. Igarasi and T. Fukahori: JAERI 1321 (1991).
Ka99) T. Kawano: private communication (1999).
Ko93) V.A. Konshin, et al.: Proc. Workshop on Computation and
Analysis of Nuclear Data Relevant to Nuclear Energy and
Safety, Trieste, Italy, 10 Feb. - 13 Mar 1992, World
Scientific, p.775 (1993).
Ko95) V.A. Konshin: JAERI-Research 95-010 (1995).
Ma72) F. Manero, V.A. Konshin: At. Energy Review, 10, 637 (1972).
Mo83) M.S. Moore, et al.: Proc. Int. Conf. on Nuclear Data for
Science and Technol., Antwerp, 6-10 Sep. 1982, p.74 (1983).
Mu84) S.F. Mughabghab: "Neutron Cross Sections, Vol.1, Part B,"
Acadenic Press (1984)
Na95) T. Nakagawa and V.A. Konshin: JAERI-Research 95-067 (1995).
Ra00) J. Raynal: unpublished.
Sh86) E.N. Shurshikov: Nucl. Data Sheets, 49, 785 (1986).
Sm79) A. Smith, et al.: ANL/NDM-50 (1979).
Uh76) M. Uhl and B. Stromaier: IRK-76/10 (1976).
Ya90) N. Yamamuro: JAERI-M 90-006 (1990).