12-Mg- 26
12-MG- 26 DEC,NEDAC EVAL-MAR87 M.HATCHYA(DEC),T.ASAMI(NEDAC)
DIST-SEP89
----JENDL-3.2 MATERIAL 1231
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
87-03 NEW EVALUATION WAS MADE FOR JENDL-3.
87-03 COMPILED BY T.ASAMI.
MF=1 GENERAL INFORMATION
MT=451 DESCRIPTIVE DATA AND DICTIONARY
MF=2 RESONANCE PARAMETERS
MT=151 RESOLVED RESONANCE PARAMETERS
RESOLVED PARAMETERS FOR MLBW FORMULA WERE GIVEN IN
THE ENERGY REGION FROM 1.0E-5 EV TO 450 KEV.
PARAMETERS WERE TAKEN FROM THE RECOMMENDED DATA OF BNL/1/ AND
THE DATA FOR A NEGATIVE RESONANCE WERE ADDED SO AS TO REPRODUCE
THE RECOMMENDED THERMAL CROSS SECTIONS FOR CAPTURE AND SCATTER-
ING/1/.
THE SCATTERING RADIUS WAS ASSUMED TO BE 4.3 FERMI.
CALCULATED 2200 M/SEC CROSS SECTIONS AND RESONANCE INTEGRALS
ARE AS FOLLOWS:
2200 M/S CROSS SECTION(B) RES. INTEGRAL(B)
ELASTIC 2.83
CAPTURE 0.038 0.0190
TOTAL 2.87
MF=3 NEUTRON CROSS SECTIONS
BELOW 450 KEV, ZERO BACKGROUND CROSS SECTION WAS GIVEN AND ALL
THE CROSS-SECTION DATA ARE REPRODUCED FROM THE EVALUATED RESOLV-
ED RESONANCE PARAMETERS WITH MLBW FORMULA.
ABOVE 450 KEV, THE TOTAL AND PARTIAL CROSS SECTIONS WERE GIVEN
POINTWISE.
MT=1 TOTAL
OPTICAL AND STATISTICAL MODEL CALCULATION WAS MADE WITH
THE CASTHY CODE/2/. THE OPTICAL POTENTIAL PARAMETERS USED ARE:
V = 49.68, VSO = 7.12 (MEV)
WS = 7.76 - 0.5*EN, WV = 0 (MEV)
R = 1.17, RS = 1.09, RSO = 1.17 (FM)
A = 0.6, ASO = 0.6, B = 0.69 (FM)
MT=2 ELASTIC SCATTERING
OBTAINED BY SUBTRACTING THE SUM OF THE PARTIAL CROSS SECTIONS
FROM THE TOTAL CROSS SECTION.
MT=4, 51-63, 91 INELASTIC SCATTERING
CALCULATED WITH CASTHY /2/, TAKING ACCOUNT OF THE CONTRIBUTION
FROM THE COMPETING PROCESSES. THE DIRECT COMPONENT WAS
CALCULATED WITH THE DWUCK CODE/3/.
THE LEVEL DATA USED IN THE ABOVE TWO CALCULATIONS WERE TAKEN
FROM REF./4/ AS FOLLOWS:
MT LEVEL ENERGY(MEV) SPIN-PARITY
0.0 0+
51 1.8087 2+
52 2.9384 2+
53 3.5880 0+
54 3.9405 3+
55 4.3180 4+
56 4.3320 2+
57 4.3500 3+
58 4.8340 2+
59 4.9000 4+
60 4.9720 0+
61 5.2910 2+
62 5.4740 4+
63 5.6900 1+
LEVELS ABOVE 8.0 MEV WERE ASSUMED TO BE OVERLAPPING.
MT=16, 22, 28, 103, 107 (N,2N), (N,NA), (N,NP), (N,P), (N,A)
CALCULATED WITH THE GNASH CODE/6/ USING THE ABOVE OPTICAL
MODEL PARAMETERS
THE (N,A) CROSS SECTIONS WERE NORMALIZED TO THE EXPERIMENTAL
DATA OF BORMANN/5/ AT 14 MEV.
MT=102 CAPTURE
CALCULATED WITH THE CASTHY CODE/2/ AND NORMALIZED TO 1.7 MB
AT 30 KEV.
MT=251 MU-BAR
CALCULATED WITH THE OPTICAL MODEL.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2
CALCULATED WITH THE CASTHY CODE/2/.
MT=51-63
CALCULATED WITH THE CASTHY CODE/2/ AND THE DWUCK CODE/3/.
MT=91
CALCULATED WITH THE CASTHY CODE/2/.
MT=16, 22, 28
ISOTROPIC IN THE LABORATORY SYSTEM.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16, 22, 28, 91
CALCULATED WITH THE GNASH CODE/6/.
REFERENCES
1) MUGHABGHAB S.F. AND GARBER D.I. :"NEUTRON CROSS SECTIONS", VOL.
1, PART B (1984).
2) IGARASI S. : J. NUCL. SCI. TECH. 12, 67 (1975).
3) KUNZ P.D. : UNPUBLISHED.
4) ENSDF(EVALUATED NUCLEAR STRUCTURE DATA FILE)
5) BORMANN M. ET AL. : 1966 PARIS CONF. VOL.1, 225 (1967).
6) YOUNG P.G. AND ARTHUR E.D. : LA-6947 (1977).