89-AC-227 TIT EVAL-AUG88 N.TAKAGI
DIST-SEP89
----JENDL-3.2 MATERIAL 8931
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
88-08 NEW EVALUATION WAS MADE BY N. TAKAGI (TOKYO INSTITUTE OF
TECHNOLOGY, TIT)
MF=1 GENERAL INFORMATION
MT=451 COMMENT AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
EVALUATED WITH SEMI EMPIRICAL FORMULA OF HOWERTON/1/.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS
NO RESONANCE PARAMETERS WERE GIVEN.
2200-M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 902.40 B -
ELASTIC 12.40 B -
FISSION 0.00029 B 0.138 B
CAPTURE 890.00 B 1650 B
MF=3 NEUTRON CROSS SECTIONS
MT=1 TOTAL CROSS SECTION
BELOW 36 EV, CALCULATED AS SUM OF MT'S = 2, 18 AND 102.
ABOVE 36 EV, OPTICAL MODEL CALCULATION WAS MADE WITH
CASTHY/2/. THE POTENTIAL PARAMETERS/3/ USED ARE AS
FOLLOWS,
V = 41.0 - 0.05*EN (MEV)
WS= 6.4 - 0.15*SQRT(EN) (MEV)
WV= 0 , VSO = 7.0 (MEV)
R = RSO = 1.31 , RS = 1.38 (FM)
A = ASO = 0.47 , B = 0.47 (FM)
MT=2 ELASTIC SCATTERING CROSS SECTION
BELOW 36 EV, THE CONSTANT CROSS SECTION OF 12.4 BARNS WAS
ASSUMED, WHICH WAS THE SHAPE ELASTIC SCATTERING CROSS
SECTION CALCULATED WITH OPTICAL MODEL. ABOVE THIS ENERGY,
OPTICAL MODEL CALCULATION WAS ADOPTED.
MT=4,51-59,91 INELASTIC SCATTERING CROSS SECTIONS.
OPTICAL AND STATISTICAL MODEL CALCULATION WAS MADE WITH
CASTHY/2/. THE LEVEL SCHEME WAS TAKEN FROM REF. 4.
NO ENERGY(KEV) SPIN-PARITY
G.S. 0.0 3/2 -
1 27.36 3/2 +
2 29.95 5/2 -
3 46.37 5/2 +
4 74.14 7/2 -
5 84.56 7/2 +
6 110.00 9/2 +
7 126.85 9/2 -
8 187.36 11/2 -
9 210.92 13/2 +
LEVELS ABOVE 273 KEV WERE ASSUMED TO BE OVERLAPPING.
THE LEVEL DENSITY PARAMETERS WERE TAKEN FROM REF. 5.
MT=16,17,37 (N,2N), (N,3N) AND (N,4N) REACTION CROSS SECTIONS
CALCULATED WITH EVAPORATION MODEL.
MT=18 FISSION CROSS SECTION
MEASURED THERMAL CROSS SECTION OF 0.29 MILLI-BARN WAS
TAKEN FROM REF. 6 , AND 1/V FORM WAS ASSUMED BELOW 36 EV.
ABOVE FISSION THRESHOLD ENERGY, EXPERIMENTAL DATA/7/ WERE
ADOPTED, AND IN THE ENERGY RANGE BETWEEN 36 EV AND FISSION
THRESHOLD, CROSS SECTION WAS ASSUMED TO BE CONSTANT WITH
THE VALUE AT 36 EV.
MT=102 CAPTURE CROSS SECTION
MEASURED THERMAL CROSS SECTION OF 890 BARNS WAS TAKEN FROM
REF. 6 , AND 1/V FORM WAS ASSUMED BELOW 36 EV. THE CROSS
SECTION NEAR 36 EV WAS ADJUSTED SO AS TO REPRODUCE THE
MEASURED RESONANCE INTEGRAL/6/. ABOVE 0.45 EV, CROSS
SECTION WAS CALCULATED WITH CASTHY. THE GAMMA-RAY
STRENGTH FUNCTION WAS ESTIMATED FROM GAMMA-GAMMA = 0.040
EV AND LEVEL SPACING = 72 EV.
MT=251 MU-L
CALCULATED WITH CASTHY.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-59,91 CALCULATED WITH OPTICAL MODEL.
MT=16,17,18,37 ISOTROPIC IN THE LAB SYSTEM.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,37,91 EVAPORATION SPECTRA
OBTAINED FROM LEVEL DENSITY PARAMETERS.
MT=18 MAXWELLIAN FISSION SPECTRUM.
TEMPERATURE WAS ESTIMATED FROM Z**2/A DEPENDENCE/8/.
REFERENCES
1) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).
2) IGARASI S.: J.NUCL.SCI.TECHNOL.,12,67 (1975).
3) OHSAWA T., OHTA M.: J. NUCL. SCI. TECHNOL., 18, 408 (1981).
4) MAPLES C.: NUCL. DATA SHEETS, 22, 275 (1977).
5) GILBERT A., CAMERON A.G.W.: CAN. J. PHYS., 43, 1446 (1965).
6) MUGHABGHAB S.F.: "NEUTRON CROSS SECTIONS, VOL.1, NEUTRON
RESONANCE PARAMETERS AND THERMAL CROSS SECTIONS , PART B,
Z=61-100", ACADEMIC PRESS (1984).
7) KUKS I.M. ET AL.: YAD. FIZ. ISS., 26, 46 (1978).
8) SMITH A.B. ET AL.: ANL/NDM-50 (1979).