94-Pu-246 JAERI EVAL-MAR95 T.Nakagawa
DIST-JAN09 20090105
----JEFF-311 MATERIAL 9458
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
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** Original data taken from: JEFF-3.1 **
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***************************** JEFF-3.1 *************************
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** Original data taken from: JENDL-3.3 **
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HISTORY
95-02 New evaluation was made by T.Nakagawa. STAPRE calculation
was performed by Konshin /Ko95/.
00-10 Compiled by T.Nakagawa.
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
Tuttle's systematics /Tu79/ was adopted.
MT=456 Prompt neutrons per fission
Obtained from Howerton's sytematics /Ho77/.
MF=2 Resonance parameters
MT=151
No resonance parameters were given.
Thermal cross sections and resonance integral (barns)
0.0253 eV resonance int.
Total 810.8 -
Elastic 10.8 -
Fission 0 3.94
Capture 800 696
MF=3 Neutron cross sections
Below 0.6 eV
No experimental data were available. The capture of 800 b was
estimated from the systematics/Ta90/. The elastic scattering
cross section of 10.8 b is the shape elastic scattering
calculated with optical model code CASTHY/Ig91/. The fission
cross section is assumed to be 0.0.
Above 0.6 eV
Three codes of CASTHY/Ig91/, ECIS/Ra00/ and STAPRE/Uh76/
were used.
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 =0.051
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-246 34.0 0.35 1.530 4.554 33.42
Pu-247 34.0 0.35 0.7635 3.787 33.51
STAPRE calculation is described in Ko95.
MT=1 Total
Calculated with CASTHY.
MT=2 Elastic scattering
Calculated as the (total) - (sum of partial) cross sections.
MT=4, 51-91 Inelastic scattering
Compound process was calculated with CASTHY, and direct one
with ECIS.
Level scheme/Sc89/:
Energy (keV) Spin-parity direct-component
0.0 0 +
46.0 2 + *
155.0 4 + *
Levels above 300 keV were assumed to be overlapping.
The direct process was calculated with ECIS for the levels
marked with *, and the compound process with CASTHY.
MT=16,17 (n,2n) and (n,3n) reactions
Calculated with STAPRE.
MT=18 Fission
In the MeV region, the cross section calculated with STAPRE
was adopted. The cross section was assumed to be 0.0 below 1
keV.
MT=102 capture
Calculated with CASTHY. 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 isotopic 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 Smith et al. /Sm79/ and Howerton-Doyas
/Ho71/. The ratios of multi-chance fission to total were
estimated from the STAPRE calculation/Ko95/.
References
Ho71) R.J. Howerton and R.J. Doyas: Nucl. Sci. Eng., 46, 414
(1971).
Ho77) R.J. Howerton: Nucl. Sci. Eng., 62, 438 (1977).
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).
Ra00) J. Raynal: available from OECD NEA Data Bank.
Sc89) M.R. Schmorak: Nucl. Data Sheets, 57, 515 (1989).
Sm79) A. Smith, et al.: ANL/NDM-50 (1979).
Ta90) N. Takagi, et al.: J. Nucl. Sci. Technol., 27, 853 (1990).
Tu79) R.J. Tuttle: INDC(NDS)-107/G+Special, p.29 (1979).
Uh76) M. Uhl and B. Stromaier: IRK-76/10 (1976).
Ya90) N. Yamamuro: JAERI-M 90-006 (1990).
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