96-Cm-248
96-CM-248 JAERI EVAL-OCT95 T.NAKAGAWA AND T.LIU
DIST-MAR02 REV2-OCT00 20001003
----JENDL-3.3 MATERIAL 9649
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
84-03 EVALUATION FOR JENDL-3 WAS MADE BY Y.KIKUCHI AND
T.NAKAGAWA (JAERI). DETAILS ARE GIVEN IN REF. /1/.
95-10 NEW EVALUATION FOR JENDL ACTINIDE FILE WAS MADE BY
T.NAKAGAWA AND T.LIU.
00-04 MODIFICATION WAS MADE BY T.NAKAGAWA.
***** Modified parts from JENDL-3.2 *******************
MF=2
MF=3 All data
MF=4 All data
MF=5 All data
*******************************************************
MF=1 GENERAL INFORMATION
MT=451 COMMENTS AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF MT'S =455 AND 456.
MT=455 DELAYED NEUTRON DATA
SEMI-EMPIRICAL FORMULA BY TUTTLE /2/.
MT=456 PROMPT NEUTRON DATA
SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.
MF=2,MT=151 RESONANCE PARAMETERS
(TAKEN FROM JENDL-3.2)
RESOLVED RESONANCE REGION (MLBW) : 1.0E-5 TO 1.5 KEV
RESONANCE ENERGIES, NEUTRON AND RADIATIVE WIDTHS WERE
TAKEN FROM THE EXPERIMENTAL DATA OF BENJAMIN ET AL./4/.
FOR RESONANCES WHOSE RADIATIVE WIDTH WAS UNKNOWN, THE
AVERAGE VALUE OF 0.026 EV /4/ WAS ADOPTED. THE FISSION
WIDTHS were adopted from Moore and Keyworth /5/ and
Maguire et al. /6/ THE AVERAGE FISSION WIDTH OF 0.0013
EV /5/ WAS USED FOR ALL RESONANCES OF WHICH FISSION
WIDTH HAD NOT BEEN MEASURED. Then the fission widths were
roughly adjusted to the fission cross section measured by
Maguire et al. R=9.1 FM WAS ASSUMED TO REPRODUCE THE
POTENTIAL SCATTERING CROSS SECTION OF 10.4 BARNS ASSUMED
BY BENJAMIN ET AL./4/. THE NEUTRON WIDTH OF THE FIRST
RESONANCE WAS SLIGHTLY ADJUSTED TO REPRODUCE THE CAPTURE
CROSS SECTION OF 2.57 BARNS AT 0.0253 EV. BACKGROUND
CROSS SECTIONS WERE GIVEN ONLY FOR THE FISSION AND TOTAL
CROSS SECTIONS BY ASSUMING THE FORM OF 1/V. THE THERMAL
CROSS SECTIONS TO BE REPRODUCED WERE ESTIMATED FROM
AVAILABLE EXPERIMENTAL DATA.
UNRESOLVED RESONANCE REGION : 1.5 KEV TO 30 KEV
PARAMETERS WERE DETERMINED WITH A FITTING CODE ASREP/7/
OBTAINED FROM OPTICAL MODEL CALCULATION:
S1=3.32E-4, S2=0.844E-4.
ESTIMATED FROM RESOLVED RESONANCES:
D-OBS=40.0 EV, GAM-G=26 MILLI-EV, S0=1.2E-4
GAM-F OBTAINED BY FITTING THE DATA OF STOPA ET AL./6/
Scattring radius R was adjusted so as to reproduce the
ealstic scattering cross section calculated with CASTHY
at 30 keV.
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200 M/S VALUE RES. INT.
TOTAL 9.456 B -
ELASTIC 6.514 B -
FISSION 0.372 B 10.0 B
CAPTURE 2.570 B 267. B
MF=3 NEUTRON CROSS SECTIONS
BELOW 30 KEV, CROSS SECTIONS WERE REPRESENTED WITH RESONANCE
PARAMETERS. BACKGROUND CROSS SECTION WAS GIVEN TO FISSION.
MT=1 TOTAL CROSS SECTION
CALCULATED WITH CASTHY CODE /8/ BASED ON THE SHERICAL
OPTICAL MODEL. THE OPTICAL POTENTIAL OF REF./9/ WERE
USED.
V = 45.036-0.3*EN (MEV)
WS= 4.115+0.4*EN (MEV)
WV= 0 , VSO = 7.5 (MEV)
R = RSO = 1.256 , RS = 1.260 (FM)
A = ASO = 0.626 , B = 0.555+0.0045*EN (FM)
COMPETING PROCESSES OF THE FISSION, (N,2N) AND (N,3N) WERE
TAKEN INTO ACCOUNT. THE FOLLOWING LEVEL DENSITY PARAMETERS
OF GILBERT-CAMERON'S FORMULA /10/ WERE USED.
ISOTOPE CM-248 CM-249
A(1/MEV) 27.8 34.2
SPIN-CUTOFF PARA. 30.39 33.79
PAIRING E(MEV) 0.0 0.903
TEMP. (MEV) 0.326 0.366
C(1/MEV) 10.8 12.2
EX(MEV) 1.85 4.30
THE LEVEL SCHEME TAKEN FROM REF. /11/.
NO. ENERGY(KEV) SPIN-PARITY
G.S. 0.0 0 +
1. 43.4 2 +
2. 143.8 4 +
3. 298.8 6 +
4. 506.0 8 +
5. 761.9 10 +
6. 1049.0 2 +
7. 1049.0 1 -
8. 1062.8 12 +
9. 1084.0 0 +
10. 1094.0 3 -
11. 1126.0 2 +
12. 1143.0 4 +
13. 1172.0 5 -
14. 1222.0 4 +
15. 1235.0 3 -
16. 1302.0 3 -
CONTINUUM LEVELS ASSUMED ABOVE 1314 KEV.
MT= 2 ELASTIC SCATTERING
CALCULATED AS TOTAL - PARTIAL CROSS SECTIONS.
MT= 4 TOTAL INELASTIC SCATTERING
SUM OF MT=51, 52, 53, 54 AND 91.
MT=16,17 (N,2N),(N,3N) CROSS SECTION
STAPRE RESULTS CALCULATED BY KONSHIN /12/ WERE ADOPTED.
MT=18 FISSION CROSS SECTION
BELOW 6 MEV TAKEN FROM JENDL-3.2 WHICH WAS EVALUATED ON
THE BASIS OF THE MEASURED DATA BY STOPA ET AL./6/ AND
FOMUSHKIN ET AL./13/. FROM 6 MEV TO 8 MEV, THE STAPRE
RESULT CALCULATED BY KONSHIN /12/ WERE USED. FROM 8 MEV
TO 20 MEV BY EYE GUIDE, BASED ON THE MEASURED DATA OF
FOMUSHKIN ET AL./14/
MT=51, 52, 53, 54 Inelastic scattering
CALCULATED BY ECIS /15/ AND CASTHY /8/ CODES.
LAGRANGE'S DEFORMED OPTICAL POTENTIAL PARAMETERS /16/ WERE
USED.
V = 49.82 - 17*((N-Z)/A) - 0.3*EN (MEV)
WS = 5.52 - 9*((N-Z)/A)+ 0.4*EN (MEV)