98-Cf-252
98-CF-252 JAERI EVAL-MAR87 T.NAKAGAWA
JAERI-M 88-004 DIST-MAR02 REV2-FEB02 20020222
----JENDL-3.3 MATERIAL 9861
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
===========================================================
JENDL-3.2 data were automatically transformed to JENDL-3.3.
Interpolation of spectra: 22 (unit base interpolation)
(3,251) deleted, T-matrix of (4,2) deleted, and others.
===========================================================
HISTORY
87-03 NEW EVALUATION WAS MADE BY T.NAKAGAWA (JAERI).
DETAILS ARE DESCRIBED 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 DELAYED NEUTRON DATA
BASED ON SEMI-EMPIRICAL FORMULA BY TUTTLE /2/.
MT=456 NUMBER OF PROMPT NEUTRONS PER FISSION
BASED ON SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.
MF=2,MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCE PARAMETERS (MLBW) : 1.0E-5 EV TO 1 KEV
RESONANCE PARAMETERS WERE TAKEN FROM MOORE EL AL. /4/ BY
ASSUMING AN AVERAGE VALUE OF RADIATIVE CAPTURE WIDTH (0.035
EV) AND FISSION WIDTH (0.035 EV). TWO HYPOTHETICAL RESONANCES
AT 1.4 AND -3.5 EV WERE ADOPTED TO REPRODUCE THE 2200-M/S
CROSS SECTIONS AND RESONANCE INTEGRALS /5,6/. SCATTERING
RADIUS OF 9.23 FM WAS ESTIMATED FROM THE SHAPE ELASTIC
SCATTERING CROSS SECTION CALCULATED WITH CASTHY /7/ FROM
OPTICAL POTENTIAL PARAMETERS GIVEN BELOW.
UNRESOLVED RESONANCES : 1 TO 30 KEV
PARAMETERS WERE ESTIMATED FROM RESOLVED RESONANCES AND
ADJUSTED SO AS TO REPRODUCE THE EVALUATED FISSION AND CAPTURE
CROSS SECTIONS BY USING ASREP /8/. VALUES OF THE PARAMETERS
ARE D-OBS = 27 EV, R = 8.9 FM AND S0, S1, CAPTURE AND FISSION
WIDTHS ARE AS FOLLOWS.
ENERGY S0 S1 CAPT-WIDTH FISS-WIDTH
1.0 KEV 1.22-4 3.37-4 0.035 EV 0.056 EV
30.0 1.22-4 3.37-4 0.035 0.096
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 64.77 B -
ELASTIC 11.04 B -
FISSION 33.03 B 111. B
CAPTURE 20.71 B 47.4 B
MF=3 NEUTRON CROSS SECTIONS
BELOW 30 KEV, CROSS SECTIONS ARE REPRESENTED WITH RESONANCE
PARAMETERS. ABOVE 30 KEV, DATA WERE MAINLY CALCULATED WITH
OPTICAL AND STATISTICAL MODELS.
1) THE OPTICAL MODEL CALCULATION WAS PERFORMED WITH CODE CASTHY
/7/. OPTICAL POTENTIAL PARAMETERS USED WERE OBTAINED /9/ BY
FITTING THE TOTAL CROSS SECTION MEASURED BY PHILLIPS AND HOWE
/10/ FOR AM-241:
V = 43.4 - 0.107*EN (MEV)
WS= 6.95 - 0.339*EN + 0.0531*EN**2 (MEV)
(IN THE DERIVATIVE WOODS-SAXON FORM)
WV= 0 , VSO = 7.0 (MEV)
R = RSO = 1.282 , RS = 1.29 (FM)
A = ASO = 0.60 , B = 0.5 (FM)
2) IN THE STATISTICAL CALCULATION, THE FISSION, (N,2N), (N,3N)
AND (N,4N) CROSS SECTIONS WERE CONSIDERED AS THE COMPETING
PROCESS CROSS SECTIONS.
3) THE LEVEL DENSITY PARAMETERS WERE DERIVED FROM RESONANCE
LEVEL SPACINGS AND LOW LAYING EXCITED LEVELS ON THE BASIS OF
GILBERT-CAMERON'S FORMULA /11/.
-----------------------------------------------------------
ISOTOPE 249 250 251 252 253
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A(1/MEV) 29.4 31.2 32.2 31.6 32.2
SPIN-CUTOFF FACT 31.25 32.36 32.97 32.74 33.14
PAIRING E(MEV) 1.16 1.673 0.77 1.635 0.77
TEMP.(MEV) 0.3693 0.4025 0.3809 0.3927 0.3322
C(1/MEV) 1.625 2.093 14.84 1.895 3.59
EX(MEV) 3.954 5.418 4.204 5.233 3.226
-----------------------------------------------------------
MT=1,2 TOTAL AND ELASTIC SCATTERING
THE OPTICAL MODEL CALCULATION WAS ADOPTED.
MT=4, 51 TO 59 AND 91 INELASTIC SCATTERING
THE LEVEL SCHEME WAS TAKEN FROM REF. /12/.
NO. ENERGY(KEV) SPIN-PARITY
--------------------------------------------
GROUND 0.0 0 +
1 45.75 2 +
2 151.73 4 +
3 804.82 2 +
4 830.81 2 -
5 845.72 3 +
6 867.51 3 -
7 900.3 4 +
8 917.03 4 -
9 969.83 3 +
--------------------------------------------
LEVELS ABOVE 1.03 MEV WERE ASSUMED TO BE OVERLAPPING.
MT=16, 17 AND 37 (N,2N), (N,3N) AND (N,4N)
CALCULATED WITH EVAPORATION MODEL BY TAKING THE COMPOUND
NUCLEUS FORMATION CROSS SECTION CALCULATED WITH OPTICAL MODEL.
MT=18 FISSION
EVALUATED ON THE BASIS OF EXPERIMENTAL DATA BY MOORE EL AL.
/4/.
MT=102 RADIATIVE CAPTURE
CALCULATED WITH CASTHY. THE AVERAGE RADIATIVE WIDTH OF 0.035
EV AND S-WAVE LEVEL SPACING OF 27 EV WERE ASSUMED.
MT=251 MU-BAR
CALCULATED WITH CASTHY.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-59 CALCULATED WITH OPTICAL MODEL.
MT=16,17,18,37,91 ISOTROPIC DISTRIBUTIONS IN THE LABORATORY
SYSTEM WERE ASSUMED.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,37,91 EVAPORATION SPECTRUM ASSUMED.
MT=18 MAXWELLOAN FISSION SPECTRUM.
TEMPERATURE ESTIMATED FROM SYSTEMATICS OF
SMITH ET AL./13/.
REFERENCES
1) NAKAGAWA, T.: JAERI-M 88-004 (1987).
2) TUTTLE, R.J.: INDG(NDS)-107/G+SPECIAL, P.29 (1979).
3) HOWERTON, R.J.: NUCL. SCI. ENG., 62, 438 (1977).
4) MOORE, M.S., ET AL.: PHYS. REV., C4, 273 (1971).
5) HALPERIN, J., ET AL.: NUCL. SCI. ENG., 37, 228 (1969).
6) HALPERIN, J., ET AL.: ORNL 4706, 53 (1971).
7) IGARASI, S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
8) KIKUCHI, Y.: PRIVATE COMMUNICATION.
9) IGARASI, S. AND NAKAGAWA T.: JAERI-M 8342 (1979).
10) PHILLIPS, T.W. AND HOWE, F.R.: NUCL. SCI. ENG., 69, 375(1979).
11) GILBERT A. AND CAMERON A.G.W. : CAN. J. PHYS., 43, 1446(1965).
12) SCHMORAK, M.R.: NUCL. DATA SHEETS, 32, 87 (1981).
13) SMITH A.B. ET AL.: ANL/NDM-50 (1979).