96-Cm-250 JAERI EVAL-OCT95 T.NAKAGAWA AND T.LIU
DIST-JAN09 20090105
----JEFF-311 MATERIAL 9655
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
*************************** JEFF-3.1.1 *************************
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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
87-08 EVALUATION WAS MADE BY N. TAKAGI (TOKYO INSTITUTE OF
TECHNOLOGY, TIT) /1/.
89-08 CROSS SECTIONS WERE MODIFIED BELOW 90 EV.
94-06 JENDL-3.2.
NU-P, NU-D AND NU-TOTAL WERE MODIFIED.
COMPILED BY T.NAKAGAWA (NDC/JAERI)
95-10 NEW EVALUATION FOR JENDL ACTINIDE FILE WAS MADE BY
T.NAKAGAWA AND T.LIU.
00-04 MODIFICATION WAS MADE AND COMPILED BY T.NAKAGAWA
***** Modified parts from JENDL-3.2 *******************
ALL DATA of Mf's = 2, 3, 4 and 5.
*******************************************************
MF=1 GENERAL INFORMATION
MT=451 COMMENTS AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF MT'S =455 AND 456.
MT=455 DELAYED NEUTRON DATA
AVERAGE VALUES OF SYSTEMATICS BY TUTTLE/2/, BENEDETTI ET
AL./3/ AND WALDO ET AL./4/
MT=456 PROMPT NEUTRONS PER FISSION
BASED ON SYSTEMATICS BY MANERO AND KONSHIN/5/, AND BY
HOWERTON/6/.
MF=2,MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCES FOR MLBW FORMULA : 1.0E-5 EV TO 150 EV
HYPOTHETICAL RESONANCE LEVELS WERE GENERATED, AND THEIR
PARAMETERS WERE DETERMINED FROM THE ASSUMED AVERAGE PARAMETERS
D-0 = 180 EV, RADIATIVE CAPTURE WIDTH = 0.04 EV,
S-0 = 1.0E-4, Ratio of neutron to fission widths = 1.0E-4,
R = 9.21 FM.
PARAMETERS OF THE NEGATIVE AND FIRST POSITIVE LEVELS WERE
ADJUSTED SO AS TO REPRODUCE THE THERMAL CROSS SECTIONS:
Fission = 0.002 b estimated from systematics
Capture = about 80 b /7/
UNRESOLVED RESONANCES: 150 eV TO 30 keV
S-0 = 1.0E-4, S-1 = 3.0E-4, D-0=180 eV, R = 8.998 fm,
Radiative width = 0.04 EV, Energy dependent fission width to
reproduce the fission cross section estimated.
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 124.9 B
ELASTIC 39.5 B
FISSION 0.002 B 6.91 B
CAPTURE 85.3 B 304 B
MF=3 NEUTRON CROSS SECTIONS
MT=1 TOTAL CROSS SECTION
CALCULATED WITH CASTHY CODE /8/ BASED ON THE SHERICAL
OPTICAL MODEL. THE OPTICAL POTENTIAL OF REF./9/ WERE
USED.
V = 45.036-0.3*EN (MEV)
WS= 4.115+0.4*EN (MEV)
WV= 0 , VSO = 7.5 (MEV)
R = RSO = 1.256 , RS = 1.260 (FM)
A = ASO = 0.626 , B = 0.555+0.0045*EN (FM)
COMPETING PROCESSES OF THE FISSION, (N,2N) AND (N,3N) WERE
TAKEN INTO ACCOUNT. THE FOLLOWING LEVEL DENSITY PARAMETERS
OF GILBERT-CAMERON'S FORMULA /10/ WERE USED.
ISOTOPE CM-250 CM-251
A(1/MEV) 30.0 28.2185
SPIN-CUTOFF PARA. 31.74 30.86
PAIRING E(MEV) 1.585 0.72
TEMP. (MEV) 0.40 0.3748
C(1/MEV) 1.6351 4.3075
EX(MEV) 5.0821 3.6489
THE LEVEL SCHEME TAKEN FROM REF. /11/
NO. ENERGY(KEV) SPIN-PARITY
G.S. 0.0 0 +
1. 43.0 2 +
2. 142.0 4 +
CONTINUUM LEVELS ASSUMED ABOVE 160 KEV.
MT= 2 ELASTIC SCATTERING
CALCULATED AS TOTAL - PARTIAL CROSS SECTIONS.
MT= 4 TOTAL INELASTIC SCATTERING
SUM OF MT=51 to 52 AND 91.
MT=16,17 (N,2N), (N,3N) CROSS SECTIONS
STAPRE RESULTS CALCULATED BY KONSHIN /12/ were adopted.
MT=18 FISSION CROSS SECTION
Above 700 keV, Konshin's calculation /12/ with STAPRE
was adopted. Below 700 keV, estimated by eye-guiding.
MT=51, 52 Inelastic scattering
CALCULATED BY ECIS /13/ AND CASTHY /8/ CODES.
LAGRANGE'S DEFORMED OPTICAL POTENTIAL PARAMETERS /14/
WERE USED.
V = 49.82 - 17*((N-Z)/A) - 0.3*EN (MEV)
WS = 5.52 - 9*((N-Z)/A) + 0.4*EN (MEV) EN=<10 MEV
= 9.52 - 9*((N-Z)/A) (MEV) 10 =< EN <=20 MEV
VSO = 6.2
R = RS = 1.26, RSO = 1.12 (FM)
A = 0.63, AS = 0.52, ASO = 0.47 (FM)
BETA-2 = 0.204, BETA-4 = 0.051
Statistical model calculation with CASTHY code was made by
using the above-mentioned parameters.
MT=91 Inelastic scattering to continuum levels
CALCULATED WITH CASTHY CODE /8/ and modified to a
decreasing curve above 10 MeV.
MT=102 RADIATIVE CAPTURE
CALCULATED WITH CASTHY CODE/8/.
DIRECT AND SEMI-DIRECT CAPTURE CROSS SECTIONS WERE
ESTIMATED with DSD code /15/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2
BELOW 300 KEV: CALCULATED WITH CASTHY CODE /8/
ABOVE 500 KEV: CALCULATED WITH ECIS CODE /13/
MT=16,17,18
ASSUMED TO BE ISOTROPIC IN THE LABORATORY SYSTEM.
MT=51,52
SUM OF ECIS AND CASTHY CALCULATIONS.
MT=91
CALCULATED WITH CASTHY CODE.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,91
CALCULATED WITH EGNASH /16/.
MT=18
MAXWELLIAN FISSION SPECTRUM WITH TEMPERATURE ESTIMATED FROM
SYSTEMATICS OF HOWERTON AND DOYAS /17/. THE RATIOS OF
MULTI-CHANCE FISSION TO TOTAL WERE ESTIMATED FROM STAPRE
CALCULATION/12/.
REFERENCES
1) TAKAGI N. ET AL.: J. NUCL. SCI. TECHNOL., 27, 853 (1990).
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) MANERO F. AND KONSHIN V.A.: AT. ENERGY REV.,10, 637 (1972).
6) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).
7) Lougheed R.W. et al.: BNL-NCS-22500, 99 (1977).
8) IGARASI S. AND FUKAHORI T.: JAERI 1321 (1991),
9) IGNATYUK A.V. ET AL.: SOV. J. NUCL. PHYS., 42, 360 (1985).
10) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446(1965).
11) SCHMORAK M.R.: NUCL. DATA SHEETS, 57, 515 (1989).
12) KONSHIN V.A.: JAERI-RESEARCH 95-010 (1995).
13) RAYNAL J.: IAEA SMR-9/8 (1970).
14) LAGRANGE CH. and JARY J.: NEANDC(E) 198 "L" (1978).
15) Kawano T.: private communication (1999).
16) YAMAMURO. N.: JAERI-M 90-006 (1990).
Young P.G. and Arthur E.D.: LA-6947 (1977).
17) HOWERTON R.J. AND DOYAS R.J.: NUCL. SCI. ENG., 46, 414
(1971).
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