96-Cm-248
96-CM-248 JAERI EVAL-MAR84 Y.KIKUCHI AND T.NAKAGAWA
JAERI-M 84-116 DIST-SEP89
----JENDL-3.2 MATERIAL 9649
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
84-03 NEW EVALUATION FOR JENDL-3 WAS MADE BY Y.KIKUCHI AND
T.NAKAGAWA (JAERI). DETAILS ARE GIVEN IN REF. /1/.
MF=1 GENERAL INFORMATION
MT=451 COMMENTS AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF MT=455 AND MT=456.
MT=455 NUMBER OF DELAYED NEUTRONS PER FISSION
SEMI-EMPIRICAL FORMULA BY TUTTLE /2/.
MT=456 NUMBER OF NEUTRONS PER FISSION
SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCE REGION (MLBW) : 1.0E-5 TO 1.5 KEV
RESONANCE ENERGIES, NEUTRON AND RADIATIVE WIDTHS WERE
TAKEN FROM THE EXPERIMENTAL DATA OF BENJAMIN ET AL./4/.
FOR RESONANCES WHOSE RADIATIVE WIDTH WAS UNKNOWN, THE
AVERAGE VALUE OF 0.026 EV /4/ WAS ADOPTED. FISSION WIDTHS
AND THE AVERAGE FISSION WIDTH OF 0.0013 EV WERE ADOPTED
FROM MOORE AND KEYWORTH /5/. THE AVERAGE FISSION WIDTH
WAS USED FOR ALL RESONANCES OF WHICH FISSION WIDTH HAD NOT
BEEN MEASURED. R=9.1 FM WAS ASSUMED TO REPRODUCE THE
POTENTIAL SCATTERING CROSS SECTION OF 10.4 BARNS ASSUMED
BY BENJAMIN ET AL./4/. THE NEUTRON WIDTH OF THE FIRST
RESONANCE WAS SLIGHTLY ADJUSTED TO REPRODUCE THE CAPTURE
CROSS SECTION OF 2.57 BARNS AT 0.0253 EV. BACKGROUND
CROSS SECTIONS WERE GIVEN ONLY FOR THE FISSION AND TOTAL
CROSS SECTIONS BY ASSUMING THE FORM OF 1/V. THE THERMAL
CROSS SECTIONS TO BE REPRODUCED WERE ESTIMATED FROM
AVAILABLE EXPERIMENTAL DATA.
UNRESOLVED RESONANCE REGION : 1.5 KEV TO 30 KEV
OBTAINED FROM OPTICAL MODEL CALCULATION:
S1=3.32E-4, S2=0.844E-4, R=8.88 FM.
ESTIMATED FROM RESOLVED RESONANCES:
D-OBS=40.0 EV, GAM-G=26 MILLI-EV, S0=1.2E-4
GAM-F OBTAINED BY FITTING THE DATA OF STOPA ET AL./6/.
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 9.455 B -
ELASTIC 6.514 B -
FISSION 0.370 B 17.5 B
CAPTURE 2.570 B 260. B
MF=3 NEUTRON CROSS SECTIONS
BELOW 30 KEV, CROSS SECTIONS WERE REPRESENTED WITH RESONANCE
PARAMETERS.
MT=1,2,4,51-58,91,102,251 TOTAL, ELASTIC AND INELASTIC
SCATTERING, CAPTURE CROSS SECTIONS AND MU-L
CALCULATED WITH OPTICAL AND STATISTICAL MODEL CODE
CASTHY/7/.
THE SPHERICAL OPTICAL POTENTIAL PARAMETERS (MEV,FM):
V =43.4-0.107*EN, R =1.282, A =0.60
WS =6.95-0.339*EN+0.0531*EN**2, RS =1.29, B =0.50
(DERIVATIVE WOODS-SAXON FORM)
VSO=7.0, RSO=1.282, ASO=0.60
THIS SET OF POTENTIAL PARAMETERS WAS DETERMINED /8/ TO
REPRODUCE WELL THE TOTAL CROSS SECTION OF AM-241 BY
PHILLIPS AND HOWE /9/.
IN THE STATISTICAL MODEL CALCULATION, COMPETING PROCESSES
OF FISSION, (N,2N), (N,3N) AND (N,4N), AND LEVEL
FLUCTUATION WERE CONSIDERED. THE LEVEL SCHEME OF CM-248
WAS TAKEN FROM REF./10/.
NO. ENERGY(KEV) SPIN-PARITY
G.S. 0 0 +
1 43.40 2 +
2 143.6 4 +
3 297 6 +
4 510 8 +
5 1048 2 +
6 1050 1 -
7 1084 0 +
8 1094 3 -
CONTINUUM LEVELS ASSUMED ABOVE 1126 KEV.
THE LEVEL DENSITY PARAMETERS : GILBERT AND CAMERON /11/.
GAMMA-RAY STRENGTH FUNCTION OF 6.5E-4 DEDUCED FROM
RESONANCE PARAMETERS.
MT=16,17,37 (N,2N), (N,3N) AND (N,4N) REACTION CROSS SECTIONS
CALCULATED WITH EVAPORATION MODEL/12/.
MT=18 FISSION
EVALUATED ON THE BASIS OF THE MEASURED DATA BY STOPA ET
AL./6/ AND FOMUSHKIN ET AL./13/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-58 CALCULATED WITH OPTICAL MODEL.
MT=16,17,18,37,91 ISOTROPIC IN THE LABORATORY SYSTEM.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,37,91 EVAPORATION SPECTRUM.
MT=18 MAXWELLIAN FISSION SPECTRUM.
TEMPERATURE ESTIMATED FROM SYSTEMATICS OF
SMITH ET AL./14/.
REFERENCES
1) KIKUCHI Y. AND NAKAGAWA T.: JAERI-M 84-116 (1984).
2) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, 29 (1979).
3) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438(1977).
4) BENJAMIN R.W. ET AL.: NUCL. SCI. ENG., 55, 440(1974).
5) MOORE M.S. AND KEYWORTH G.A.: PHYS. REV., C3, 1656(1971)
6) STOPA C.R.S. ET AL.: 1982 KIAMESHA, 1090 (1982), AND
MAGUIRE JR. H.T. ET AL.: NUCL. SCI. ENG., 89, 293 (1985).
7) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
8) IGARASI S. AND NAKAGAWA T.: JAERI-M 8342 (1979).
9) PHILLIPS T.W. AND HOWE F.R.: NUCL. SCI. ENG., 69, 375(1979).
10) LEDERER C.M. AND SHIRLEY V.S.: TABLE OF ISOTOPES , 7TH ED.
(1978).
11) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446(1965).
12) PEARLSTEIN S.: NUCL. SCI. ENG., 23, 238 (1965).
13) FOMUSHKIN E.F. ET AL.: SOV. J. NUCL. PHYS., 31, 19(1980).
14) SMITH A.B. ET AL.: ANL/NDM-50 (1979).