99-Es-255
99-ES-255 TIT EVAL-AUG87 N.TAKAGI
DIST-SEP89 REV2-JUN94
----JENDL-3.2 MATERIAL 9915
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
87-08 NEW EVALUATION WAS MADE BY N. TAKAGI (TOKYO INSTITUTE OF
TECHNOLOGY, TIT) /1/.
94-06 JENDL-3.2.
NU-P, NU-D AND NU-TOTAL WERE MODIFIED.
COMPILED BY T.NAKAGAWA (NDC/JAERI)
***** MODIFIED PARTS FOR JENDL-3.2 ********************
(1,452), (1,455), (1,456)
***********************************************************
MF=1 GENERAL INFORMATION
MT=451 COMMENT AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF NU-P NAD NU-D.
MT=455 DELAYED NEUTRONS PER FISSION
AVERAGE VALUES OF SYSTEMATICS BY TUTTLE/2/, BENEDETTI ET
AL./3/ AND WALDO ET AL./4/ DECAY CONSTANTS WERE ASSUMED
TO BE THE SAME AS THOSE FOR ES-254 EVALUATED BY BRADY AND
ENGLAND/5/.
MT=456 PROMPT NEUTRONS PER FISSION
CALCULATED FROM THE SEMI-EMPIRICAL FORMULA OF HOWERTON/6/.
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 79.03 B -
ELASTIC 10.60 B -
FISSION 13.43 B 93.3 B
CAPTURE 55.00 B 278 B
MF=3 NEUTRON CROSS SECTIONS
MT=1 TOTAL CROSS SECTION
BELOW 2.47 EV, CALCULATED AS SUM OF MT'S = 2, 18 AND 102.
ABOVE 2.47 EV, OPTICAL MODEL CALCULATION WAS MADE WITH
CASTHY/7/. THE POTENTIAL PARAMETERS/8/ USED ARE AS
FOLLOWS,
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)
MT=2 ELASTIC SCATTERING CROSS SECTION
BELOW 2.47 EV, THE CONSTANT CROSS SECTION OF 10.6 BARNS
WAS ASSUMED, WHICH WAS THE SHAPE ELASTIC SCATTERING CROSS
SECTION CALCULATED WITH OPTICAL MODEL. ABOVE THIS ENERGY,
OPTICAL MODEL CALCULATION WAS ADOPTED.
MT=4,51-53,91 INELASTIC SCATTERING CROSS SECTIONS.
OPTICAL AND STATISTICAL MODEL CALCULATION WAS MADE WITH
CASTHY/7/. THE LEVEL SCHEME WAS ASSUMED TO BE THE SAME AS
THAT OF ES-253 TAKEN FROM REF./9/.
NO ENERGY(KEV) SPIN-PARITY
G.S. 0.0 7/2 +
1 48.0 9/2 +
2 50.0 3/2 -
3 420.0 7/2 -
LEVELS ABOVE 500 KEV WERE ASSUMED TO BE OVERLAPPING.
THE LEVEL DENSITY PARAMETERS WERE TAKEN FROM REF./10/.
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 13.43 BARNS WAS TAKEN
FROM REF./11/, AND 1/V FORM WAS ASSUMED BELOW 2.47 EV.
ABOVE 2.47 EV, THE CROSS SECTION SHAPE WAS ASSUMED TO BE
THE SAME AS CF-252 FISSION CROSS SECTION AND IT WAS
NORMALIZED TO THE SYSTEMATICS BY BEHRENS AND HOWERTON/12/.
MT=102 CAPTURE CROSS SECTION
MEASURED THERMAL CROSS SECTION OF 55.0 BARNS WAS TAKEN
FROM REF./11/, AND 1/V FORM WAS ASSUMED BELOW 2.47 EV.
ABOVE 2.47 EV, CALCULATED WITH CASTHY. THE GAMMA-RAY
STRENGTH FUNCTION WAS ESTIMATED FROM GAMMA-GAMMA = 0.040
EV AND LEVEL SPACING = 4.94 EV.
MT=251 MU-L
CALCULATED WITH CASTHY.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-53,91 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/13/.
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) BRADY M.C. AND ENGLAND T.R.: NUCL. SCI. ENG., 103, 129 (1989).
6) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).
7) IGARASI S. AND FUKAHORI T.: JAERI 1321 (1991).
8) IGARASI S. AND NAKAGAWA T.: JAERI-M 8342 (1979).
9) SCHMORAK M.R.: NUCL. DATA SHEETS, 34, 1 (1981).
10) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446 (1965).
11) MUGHABGHAB S.F.: "NEUTRON CROSS SECTIONS, VOL.1, NEUTRON
RESONANCE PARAMETERS AND THERMAL CROSS SECTIONS , PART B,
Z=61-100", ACADEMIC PRESS (1984).
12) BEHRENS J.W., HOWERTON R.J: NUCL. SCI. ENG., 65, 464 (1978).
13) SMITH A.B. ET AL.: ANL/NDM-50 (1979).