98-Cf-249
98-CF-249 JAERI EVAL-MAR85 Y.KIKUCHI AND T.NAKAGAWA
JAERI-M 85-138 DIST-SEP89
----JENDL-3.2 MATERIAL 9852
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
85-03 NEW EVALUATION FOR JENDL-3 WAS MADE BY Y.KIKUCHI AND
T.NAKAGAWA (JAERI). DETAILS ARE GIVEN IN REF. /1/.
88-02 DATA WERE CHECKED AND ADOPTED FOR JENDL-3.
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
SEMI-EMPIRICAL FORMULA BY TUTTLE /1/.
MT=456 NUMBER OF PROMPT NEUTRONS PER FISSION
SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.
MF=2,MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCES FOR MLBW FORMULA : 1.0E-5 EV TO 70 EV
RESONANCE ENERGIES, NEUTRON AND FISSION WIDTHS WERE TAKEN
FROM THE EXPERIMENTAL DATA OF BENJAMIN+ /4/. THE RADIATIVE
WIDTH WAS ASSUMED TO BE 0.04 EV ACCORDING TO DABBS+ /5/.
A NEGATIVE RESONANCE WAS ADDED SO AS TO REPRODUCE THE THERMAL
CROSS SECTIONS. NO BACKGROUND CORRECTION WAS APPLIED.
UNRESOLVED RESONANCES : 70 EV - 30 KEV
OBTAINED FROM OPTICAL MODEL CALCULATION:
S1=3.15E-4, S2=0.83E-4, R=9.08 FM.
ESTIMATED FROM RESOLVED RESONANCES:
DOBS=1.16 EV, GAM-G=40 MILLI-EV ,S0=1.06E-4
FISSION WIDTHS WERE ESTIMATED FROM THE CHANNEL THEORY OF
FISSION /6/. S0, S1 AND S2 VALUES WERE ADJUSTED SO AS TO
REPRODUCE THE FISSION CROSS SECTION MEASURED BY DABBS+ /5/.
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 2176.7 B -
ELASTIC 6.22 B -
FISSION 1666 B 2220 B
CAPTURE 504.5 B 695 B
MF=3 NEUTRON CROSS SECTIONS
MT=1,2,4,51-63,91,102,251 SIG-T,SIG-EL,SIG-IN,SIG-C,MU-BAR
CALCULATED WITH OPTICAL AND STATISTICAL MODELS.
OPTICAL POTENTIAL PARAMETERS WERE OBTAINED BY FITTING THE
TOTAL CROSS SECTION OF PHILLIPS AND HOWE /7/ FOR AM-241:
V = 43.4 - 0.107*EN (MEV)
WS= 6.95 - 0.339*EN + 0.0531*EN**2 (MEV)
WV= 0 , VSO = 7.0 (MEV)
R = RSO = 1.282 , RS = 1.29 (FM)
A = ASO = 0.60 , B = 0.5 (FM)
STATISTICAL MODEL CALCULATION WITH CASTHY CODE /8/.
COMPETING PROCESSES : FISSION,(N,2N),(N,3N),(N,4N).
LEVEL FLUCTUATION CONSIDERED.
THE LEVEL SCHEME TAKEN FROM REF. /9/.
NO. ENERGY(KEV) SPIN-PARITY
G.S. 0 9/2 -
1 62.47 11/2 -
2 136.2 13/2 -
3 145.0 5/2 +
4 188.0 7/2 +
5 219.0 15/2 -
6 243.1 9/2 +
7 379.5 7/2 +
8 416.6 1/2 +
9 437.5 9/2 +
10 440.0 3/2 +
11 443.0 7/2 +
12 460.0 5/2 +
13 500.6 9/2 +
CONTINUUM LEVELS ASSUMED ABOVE 550 KEV.
THE LEVEL DENSITY PARAMETERS : GILBERT AND CAMERON /10/.
GAMMA-RAY STRENGTH FUNCTION OF 3.3E-2 DEDUCED FROM
RESONANCE PARAMETERS.
MT=16,17,37 (N,2N),(N,3N),(N,4N)
CALCULATED WITH EVAPORATION MODEL.
MT=18 FISSION
EVALUATED ON THE BASIS OF THE MEASURED DATA BY
SILBERT/11/, DABBS+ /5/ AND KUPRIYANOV+ /12/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-63 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+/13/.
REFERENCES
1) KIKUCHI Y. AND NAKAGAWA T.: JAERI-M 85-138 (1985).
2) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, P.29 (1979).
3) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).
4) BENJAMIN R.W. ET AL.: NUCL. SCI. ENG., 85, 261 (1983).
5) DABBS J.W.T. ET AL.: ORNL-4973, P.181 (1974).
6) KIKUCHI Y. AND AN S.: J. NUCL. SCI. TECHNOL., 7, 157 (1970).
7) PHILLIPS T.W. AND HOWE F.R.: NUCL. SCI. ENG., 69, 375 (1979).
8) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
9) LEDERER C.M. AND SHIRLEY V.S.: TABLE OF ISOTOPES , 7TH ED.
10) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446(1965).
11) SILBERT M.G.: NUCL. SCI. ENG., 51, 376 (1973).
12) KUPRIYANOV V.M. ET AL.: SOV. ATOM. ENERGY, 55, 472 (1984).
13) SMITH A.B. ET AL.: ANL/NDM-50 (1979).