96-Cm-242
96-CM-242 JAERI EVAL-MAR89 T.NAKAGAWA
DIST-SEP89
----JENDL-3.2 MATERIAL 9631
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
79-03 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 DELAYED NEUTRON DATA
ESTIMATED FROM THE SYSTEMATICS BY TUTTLE /3/.
MT=452 NUMBER OF NEUTRONS PER FISSION
BASED ON THE EMPIRICAL FORMULA BY HOWERTON /4/.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCE REGION : 1.0E-5 EV TO 275 EV.
RESONANCE ENERGIES = ALTAMONOV ET AL. /5/,
NEUTRON WIDTHS = ALTAMONOV ET AL. /5/,
RADIATIVE WIDTHS = 0.040 EV,
FISSION WIDTHS = ALAM ET AL. /6/ FOR THE LOW-LYING 4
LEVELS, AND THE AVERAGE VALUE OF 0.004 EV
FOR OTHER LEVELS.
SCATTERING RADIUS = 9.38 FM.
A NEGATIVE RESONANCE WAS ADDED AT -3.45 EV, AND ITS
PARAMETERS WERE ADJUSTED SO AS TO REPRODUCE WELL THE
THERMAL CROSS SECTIONS/7/. BACKGROUND CROSS SECTION WAS
GIVEN TO THE FISSION CROSS SECTION.
UNRESOLVED RESONANCE PARAMETERS : 275 EV - 40 KEV
PARAMETERS WERE DETERMINED WITH A FITTING CODE ASREP /8/
SO AS TO REPRODUCE THE FISSION CROSS SECTION MEASURED BY
ALAM ET AL./6/, AND TOTAL CROSS SECTION AT 40 KEV.
ENERGY INDEPENDENT PARAMETERS:
R=9.093 FM, S0=0.92E-4, S2=0.97E-4, WG=0.04 EV.
ENERGY DEPENDENT PARAMETERS AT 1 KEV:
S1=3.04E-4, WF=0.093 EV, D=17.16 EV.
CALCULATED 2200M/S CROSS SECTIONS AND RESONANCE INTEGRALS.
2200 M/SEC RES. INTEG.
TOTAL 32.57 B ---
ELASTIC 11.61 B ---
FISSION 5.064 B 20.0 B
CAPTURE 15.90 B 109 B
MF=3 NEUTRON CROSS SECTIONS
BELOW 40 KEV, CROSS SECTIONS WERE REPRESENTED WITH RESONANCE
PARAMETERS.
MT=1,2,4,51-53,91,102,251 TOTAL, ELASTIC AND INELASTIC
SCATTERING, CAPTURE CROSS SECTIONS AND MU-L
CALCULATED WITH OPTICAL AND STATISTICAL MODEL CODE
CASTHY/9/.
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 /1/ TO
REPRODUCE WELL THE TOTAL CROSS SECTION OF AM-241 BY
PHILLIPS AND HOWE /10/.
IN THE STATISTICAL MODEL CALCULATION, COMPETING PROCESSES
OF FISSION, (N,2N) AND (N,3N), AND LEVEL FLUCTUATION WERE
CONSIDERED. THE LEVEL SCHEME OF CM-242 WAS TAKEN FROM
ENSDF /11/:
NO. ENERGY(MEV) SPIN-PARITY
G.S. 0.0 0 +
1 0.04213 2 +
2 0.138 4 +
3 0.284 6 +
OVERLAPPING LEVELS ARE ASSUMED ABOVE 0.35 MEV. THE LEVEL
DENSITY PARAMETERS WERE DETERMINED ON THE BASIS OF NUMBERS
OF EXCITED LEVELS/11/.
CM-243 CM-242
A(1/MEV) 28.0 28.0
T(MEV) 0.40 0.40
C(1/MEV) 7.5405 2.5771
E-X(MEV) 3.8863 4.3163
SPIN-CUTOFF(1/MEV**0.5) 30.08 30.00
PAIRING E(MEV) 0.72 0.15
AVERAGE RADIATIVE WIDTH = 0.040 EV AND D = 18 EV OBTAINED
FROM THE LEVEL DENSITY PARAMETERS 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 /12/.
NEUTRON EMISSION CROSS SECTION WAS ASSUMED TO BE (COMPOUND
NUCLEUS FORMATION CROSS SECTION CALCULATED WITH OPTICAL
MODEL - FISSION).
MT=18 FISSION CROSS SECTION
BELOW 1 MEV, CROSS SECTION WAS DETERMINED ON THE BASIS OF
DATA MEASURED BY ALAM ET AL./6/ AND VOROTNIKOV ET AL./13/.
ABOVE 1 MEV, JENDL-2 EVALUATION WAS ADOPTED, WHICH WAS
BASED ON THE SHAPE OF CM-244 /14/ AND THE EMPIRICAL
FORMULA ON THE FISSION-CROSS-SECTION SYSTEMATICS AROUND 4
MEV BY BEHRENS AND HOWERTON /15/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-53,91
LEGENDRE COEFFICIENTS CALCULATED WITH THE OPTICAL AND
STATISTICAL MODELS WERE GIVEN.
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 ESTIMATED FROM Z**2/A SYSTEMATICS BY SMITH ET AL. /16/,
ASSUMING E(CF-252) = 2.13 MEV.
REFERENCES
1) IGARASI S. AND NAKAGAWA T.: JAERI-M 8342 (1979).
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) ARTAMONOV V.S. ET AL. : PROC. OF 4TH ALL UNION CONF. ON
NEUTRON PHYSICS, KIEV (1977), VOL. 2, 257.
6) ALAM B. ET AL.: NUCL. SCI. ENG., 99, 267 (1988).
7) MUGHABGHAB S.F.: "NEUTRON CROSS SECTIONS, VOL. 1, PART B",
ACADEMIC PRESS (1984).
8) KIKUCHI Y.: PRIVATE COMMUNICATION.
9) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
10) PHILLIPS T.W. AND HOWE R.E.: NUCL. SCI. ENG. 69, 375 (1979).
11) ENSDF, EVALUATED NUCLEAR STRUCTURE DATA FILE, AS OF JAN. 1989.
12) PEARLSTEIN S.: J. NUCL. ENERGY 27, 81 (1973).
13) VOROTNIKOV P.E. ET AL.: SOV. J. NUCL. PHYS., 40, 726 (1984).
14) IGARASI S. AND NAKAGAWA T.: JAERI-M 7175 (1977).
15) BEHRENS J.W. AND HOWERTON R.J.: NUCL. SCI. ENG., 65, 464
(1978).
16) SMITH A.B. ET AL.: ANL/NDM-50 (1979).