96-Cm-244
96-CM-244 JAERI EVAL-MAR89 T.NAKAGAWA
DIST-SEP89
----JENDL-3.2 MATERIAL 9637
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
77-03 EVALUATION FOR JENDL-2 WAS MADE BY S.IGARASI AND T.NAKAGAWA
(JAERI) /1/.
89-03 RE-EVALUATION FOR JENDL-3 WAS MADE BY T.NAKAGAWA(JAERI)/2/.
MF=1 GENERAL INFORMATION
MT=451 DESCRIPTIVE DATA
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF MT=455 AND MT=456.
MT=455 NUMBER OF DELAYED NEUTRONS PER FISSION
ESTIMATED FROM SEMI-EMPIRICAL FORMULA BY TUTTLE /3/.
MT=456 NUMBER OF PROMPT NEUTRONS PER FISSION
DETERMINED FROM SEMI-EMPIRICAL FORMULA BY HOWERTON /4/.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCE REGION (MLBW) : 1.0E-5 TO 1 KEV
ABOVE 20 EV, PARAMETERS BY MOORE AND KEYWORTH /5/ WERE
ADOPTED ASSUMING NEUTRON WIDTH OF 0.2 EV FOR 646.9, 759.7,
914.0 AND 971.5-EV LEVELS, AND BELOW 20 EV, EVALUATION BY
BENJAMIN ET AL. /6/. THE FISSION WIDTHS OF LOW-LYING 4
LEVELS WERE REPLACED WITH THOSE BY MAGUIRE ET AL. /7/.
RADIATIVE WIDTH = 0.037 EV (ASSUMED)
SCATTERING RADIUS = 11.2 FM (ADJUSTED TO 11.6 B
AT 0.0253 EV /8/.
A NEGATIVE RESONANCE AT -1.48 EV WAS ADOPTED AND ITS
PARAMETERS WERE ADJUSTED SO AS TO REPRODUCE WELL THE
THERMAL CROSS SECTIONS/8/.
UNRESOLVED RESONANCE PARAMETERS : 70 EV - 40 KEV
PARAMETERS WERE DETERMINED WITH A FITTING CODE ASREP/9/ SO
AS TO REPRODUCE THE FISSION CROSS SECTION OF MAGUIRE ET
AL. /7/, AND THE TOTAL AND CAPTURE CROSS SECTIONS CALCU-
LATED WITH OPTICAL AND STATISTICAL MODELS.
ENERGY INDEPENDENT PARAMETERS:
R=9.221 FM, S0=0.9E-4, S2=0.92E-4, WG=0.04 EV.
ENERGY DEPENDENT PARAMETERS AT 1 KEV:
S1=3.06E-4, WF=0.00244 EV, D=11.98 EV.
CALCULATED 2200M/S CROSS SECTIONS AND RESONANCE INTEGRALS.
2200 M/SEC RES. INTEG.
TOTAL 27.20 B -
ELASTIC 11.06 B -
FISSION 1.037 B 13.2 B
CAPTURE 15.10 B 661 B
MF=3 NEUTRON CROSS SECTIONS
BELOW 40 KEV, CROSS SECTIONS WERE REPRESENTED WITH RESONANCE
PARAMETERS.
MT=1,2,4,51-62,91,102,251 TOTAL, ELASTIC AND INELASTIC
SCATTERING, CAPTURE CROSS SECTIONS AND MU-L
CALCULATED WITH OPTICAL AND STATISTICAL MODEL CODE
CASTHY/10/.
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 /11/ TO
REPRODUCE WELL THE TOTAL CROSS SECTION OF AM-241 BY
PHILLIPS AND HOWE /12/. THE STRENGTH FUNCTION OF 0.91E-4
CALCULATED WITH THIS OMP IS IN VERY GOOD AGREEMENT WITH
EXPERIMENTS/8/.
IN THE STATISTICAL MODEL CALCULATION, COMPETING PROCESSES
OF FISSION, (N,2N) AND (N,3N), AND LEVEL
FLUCTUATION WERE CONSIDERED. THE LEVEL SCHEME OF CM-244
WAS TAKEN FROM THE COMPILATION BY SHURSHIKOV /13/:
NO. ENERGY(MEV) SPIN-PARITY
G.S. 0.0 0 +
1 0.04297 2 +
2 0.14235 4 +
3 0.29621 6 +
4 0.50179 8 +
5 0.970 2 +
6 0.98491 0 +
7 1.0208 2 +
8 1.038 2 +
9 1.0402 6 +
10 1.0842 1 +
11 1.1059 1 -
12 1.187 2 +
OVERLAPPING LEVELS ARE ASSUMED ABOVE 1.2 MEV. THE LEVEL
DENSITY PARAMETERS WERE DETERMINED ON THE BASIS OF NUMBERS
OF EXCITED LEVELS/14/ AND RESONANCE LEVEL SPACING/8/.
CM-245 CM-244
A(1/MEV) 30.0 28.0
T(MEV) 0.391 0.395
C(1/MEV) 11.288 1.8807
E-X(MEV) 4.0295 4.2893
SPIN-CUTOFF(1/MEV**0.5) 31.31 30.17
PAIRING E(MEV) 0.72 1.22
AVERAGE RADIATIVE WIDTH = 0.037 EV AND D = 12 EV
WERE USED FOR THE CAPTURE CROSS SECTION CALCULATION.
MT=16,17 (N,2N) AND (N,3N) CROSS SECTIONS
CALCULATED WITH THE EVAPORATION MODEL BY PEARLSTEIN /15/.
NEUTRON EMISSION CROSS SECTION WAS ASSUMED TO BE (COMPOUND
NUCLEUS FORMATION CROSS SECTION CALCULATED WITH OPTICAL
MODEL - FISSION).
MT=18 FISSION CROSS SECTION
BELOW 100 KEV: SMOOTH CURVE BASED ON MAGUIRE ET AL. /7/.
100 - 800 KEV: JENDL-2 WAS ADOPTED, WHICH WAS OBTAINED BY
FITTING A SEMI-EMPIRICAL FORMULA TO THE
EXPERIMENTAL DATA OF REF. /5/.
0.8 - 8 MEV : ESTIMATED FROM EXPERIMENTAL DATA/5,16,17/
ABOVE 8 MEV : THE SAME AS JENDL-2.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-62,91
LEGENDRE COEFFICIENTS WERE GIVEN BY THE OPTICAL AND
STATISTICAL MODEL CALCULATIONS.
MT=16,17,18
ISOTROPIC DISTRIBUTIONS IN THE LABORATORY SYSTEM.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,91 EVAPORATION SPECTRUM
MT=18 FISSION SPECTRUM ESTIMATED FROM Z**2/A SYSTEMATICS BY
SMITH ET AL. /18/ BY ASSUMING E(CF-252) = 2.13 MEV.
REFERENCES
1) IGARASI S. AND NAKAGAWA T.: JAERI-M 7175 (1977).
2) NAKAGAWA T.: TO BE PUBLISHED AS JAERI-M REPORT.
3) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, 29 (1979).
4) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).
5) MOORE M.S. AND KEYWORTH G.A.: PHYS. REV., C3, 1656 (1971).
6) BENJAMIN R.W. ET AL.: NUCL. SCI. ENG. 47, 203 (1972).
7) MAGUIRE JR.H.T. ET AL.: NUCL. SCI. ENG., 89, 293 (1985).
8) MUGHABGHAB S.F.: "NEUTRON CROSS SECTIONS, VOL.1, PART B",
ACADEMIC PRESS (1984).
9) KIKUCHI Y.: PRIVATE COMMUNICATION.
10) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
11) IGARASI S. AND NAKAGAWA T.: JAERI-M 8342 (1979).
12) PHILLIPS T.W. AND HOWE R.E.: NUCL. SCI. ENG. 69, 375 (1979).
13) SHURSHIKOV E.N.: NUCL. DATA SHEETS, 49, 785 (1986).
14) ENSDF, EVALUATED NUCLEAR STRUCTURE DATA FILE, AS OF JAN. 1989.
15) PEARLSTEIN S.: NUCL. SCI. ENG., 23, 238 (1965).
16) FOMUSHKIN E.F. ET AL.: SOV. J. NUCL. PHYS., 31, 19 (1980).
17) VOROTNIKOV P.E. ET AL.: SOV. AT. ENERGY, 57, 504 (1985).
18) SMITH A.B. ET AL.: ANL/NDM-50 (1979).