95-Am-242G MINSK+ EVAL-FEB97 V.M.Maslov et al.
INDC(BLR)-008/G DIST-MAR02 REV2-APR00 20000420
----JENDL-3.3 MATERIAL 9546
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
80-03 New evaluation was made by T.Nakagawa and S.Igarasi /Na80/
88-03 Since no recent experimental data were available, the data
of JENDL-2 were adopted for JENDL-3.
00-04 JENDL-3.3 was compiled by T.Nakagawa
Evaluated data of Maslov et al. /Ma97/ were extensively
adopted.
***** Modified parts from JENDL-3.2 *******************
All data
*******************************************************
=================================================================
Description on modified parts from Maslov's evaluation.
=================================================================
MF=2 Resonance Rapameters
MT=151
Unresolved resonance parameters
The level spacing was modified to keep consistency with
that of L=0 and J=0.5. The neutron width was also modified
with the same factor of the level spacing. Interpolation
of cross sections was changed to 5 (log-log).
Calculated Thermal cross sections and Resonance integral
at .0253 eV (b) Res. Integ. (b)
Total 2319.8 -
Elastic 7.66 -
Fission 2093.3 997
Capture 218.8 187
MF=3 Neutron Cross Sections
MT=19, 20, 21 Fission
Maslov's elavualtion was not adopted.
MT=102 Capture
Direct and semi-direct capture cross section was calculated
with DSD code /Ka99/, and added to Maslov's calculation.
MF=5 Energy Distributions of Secondary Neutrons
MT=16, 17, 91
At the threshold energies, the same shape of distributions at
the second incident energy was assumed. Interpolation was
replaced with 22.
Other parts are the same as Maslov's evaluation.
=================================================================
References
Ka99) Kawano T.: private communication (1999).
Ma97) Maslov V.M. et al.: INDC(BLR)-8 (1997).
Na80) Nakagawa T. and Igarasi S.: JAERI-M 8903 (1980). in Japanese
========== Description given in Maslov's data ===================
95-Am-242G MINSK BYEL EVAL-FEB97
DIST-MAR97
V.M. MASLOV, E.Sh. SUKHOVITSKIJ,
Yu.V. PORODZINSKIJ, G.B. MOROGOVSKIJ
STATUS
EVALUATION WAS MADE UNDER THE PROJECT AGREEMENT CIS-03-95
WITH INTERNATIONAL SCIENCE AND TECHNOLOGY CENTER (MOSCOW).
FINANCING PARTY OF THE ISTC FOR THE PROJECT IS JAPAN.
EVALUATION WAS REQUESTED BY Y.KIKUCHI (JAERI, TOKAI)
DOCUMENTED IN INDC(BLR)-008, 1997.
MF=1 GENERAL INFORMATION
MT=451 COMMENTS AND DICTIONARY
MT=452 TOTAL NUMBER OF NEUTRONS PER FISSION
SUM OF MT=455 AND MT=456.
MT=455 DELAYED NEUTRON DATA
NUMBER OF DELAYED NEUTRONS AND
DECAY CONSTANTS FROM BRADY ET AL./1/
MT=456 NUMBER OF PROMPT NEUTRONS PER FISSION ADOPTED TO BE
IDENTICAL TO THAT FOR AM-242M, WHICH WAS OBTAINED
WITH MADLAND-NIX MODEL CALCULATIONS /2/ FITTED TO
THE MEASURED DATA OF HOWE ET AL./3/
ABOVE EMISSIVE FISSION THRESHOLD
SUPERPOSITION OF NEUTRON EMISSION
IN (N,XNF) REACTIONS /4/ AND PROMPT FISSION
NEUTRONS IS EMPLOYED.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS (MLBW)
RESOLVED RESONANCE REGION : 1.0E-5 - 100 EV
GENERATED FROM AVERAGE RESONANCE RAMETERS BASED ON
OPTICAL MODEL CALCULATIONS AND FISSION LEVEL DENSITY,
BARRIER PARAMETERS AND TRANSITION STATES STRUCTURE,
FIXED FOR AM-242M.
CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE
INTEGRALS ARE:
2200 M/SEC RES.INTEG.
TOTAL 2319.73 b -
ELASTIC 7.66 b -
FISSION 2093.23 b 997.81
CAPTURE 218.83 b 187.01
UNRESOLVED RESONANCE REGION :
ENERGY INDEPENDENT PARAMETERS:
R=9.42 FM FROM OPTICAL MODEL CALCULATIONS
S1=2.046*10-4 FROM OPTICAL MODEL CALCULATIONS
S2=1.924*10-4 FROM OPTICAL MODEL CALCULATIONS
ENERGY DEPENDENT PARAMETERS:
S0-DECREASES FROM 1.363-4(0.10KEV) TO 1.267-4(44.2838
keV)
D - SPIN DEPENDENT, NORMALIZED TO =0.877 EV
CORRESPONDENT LEVEL DENSITY PARAMETER WAS FITTED TO
=0.271 EV FOR AM-242M, THEN GROUND STATE
DIFFERENCES ARE TAKEN INTO ACCOUNT.
WF -SPIN DEPENDENT AS DEFINED BY THE TRANSITION STATE
SPECTRA AT INNER AND OUTER BARRIER HUMPS, DETERMINED
FOR AM-242M
WG-WITH ACCOUNT OF FISSION COMPETITION =0.050 EV
MF=3 NEUTRON CROSS SECTIONS
MT=1,4,51-75,91,102. TOTAL, ELASTIC AND INELASTIC
SCATTERING, CAPTURE CROSS SECTION
TOTAL,DIRECT ELASTIC AND DIRECT INELASTIC FOR MT=53,57,
66 AND OPTICAL TRANSMISSION COEFFICIENTS FROM
COUPLED CHANNELS CALCULATIONS.
THE DEFORMED OPTICAL POTENTIAL USED:
VR=(46.10-0.3*E) MEV RR=1.26 FM AR=0.615 FM
WD=(3.53+0.4*E) MEV E < 10 MEV RD=1.24 FM
WD= 7.50 MEV E=> 10 MEV AD=0.5 FM
VSO=6.2 MEV RSO=1.12 FM ASO=0.47 FM B2=0.206 B4=0.092
FOUR LEVELS OF GROUND STATE ROTATIONAL BAND
ARE COUPLED.
CAPTURE,COMPOUND ELASTIC AND INELASTIC BY STATISTICAL
MODEL, SEE MT=18-21.
ABOVE NEUTRON ENERGY 5 MEV CAPTURE IS ASSUMED TO BE
CONSTANT.
ADOPTED LEVEL SCHEME OF AM-242 FROM NUCLEAR DATA
SHEETS /7/.
No ENERGY(MEV) SPIN-PARITY K
g.s. 0.00000 1 - 0
1 0.04410 0 - 0
2 0.04863 5 - 5
3 0.05290 3 - 0
4 0.07580 2 - 0
5 0.11400 6 - 5
6 0.14000 6 - 6
7 0.14800 5 - 0
8 0.14990 4 - 0
9 0.19000 7 - 5
10 0.19760 3 -
11 0.21700 7 - 6
12 0.22000 1 - 1
13 0.23050 2 + 1
14 0.24200 2 - 1
15 0.24410 3 - 3
16 0.26300 6 - 0
17 0.26310 7 - 0
18 0.27010 2 +
19 0.27500 3 - 1
20 0.28330 3 +
21 0.28840 4 - 3
22 0.29180 2 - 2
23 0.30500 8 - 6
24 0.30690 3 -
25 0.31900 4 - 1
OVERLAPPING LEVELS ARE ASSUMED ABOVE 0.320 MEV
LEVEL DENSITY PARAMETERS: SEE MT 18-21
MT=16,17. (N,2N) AND (N,3N) CROSS SECTION
FROM STATISTICAL MODEL CALCULATIONS /8/ WITH THE
ACCOUNT OF PRE-EQUILIBRIUM NEUTRON EMISSION:SEE MT=18-21
MT=18,19,20,21. FISSION CROSS SECTION IS CALCULATED WITHIN
STATISTICAL MODEL /9,10/. THE FISSION BARRIER PARAMETERS
ARE FIXED BY FITTING MEASURED DATA FOR AM-242M BY
BROWNE ET AL./5/ AND FURSOV ET AL./11/.
THE FIRST CHANCE FISSION MT=19 IS CALCULATED WITH
THE CONTRIBUTION OF EMISSIVE FISSION TO TOTAL FISSION
CROSS SECTION ACCORDING TO /9,12/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
FOR MT=2, 53, 57, 66 FROM COUPLED CHANNELS CALCULATIONS
WITH ADDED ISOTROPIC STATISTICAL CONTRIBUTION.
MT=16,17,18-21,51-52,54-56,58-65,67-75,91 - ISOTROPIC
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
ENERGY DISTRIBUTIONS FOR MT=16,17 WERE
CALCULATED BY STATISTICAL MODEL OF CASCADE NEUTRON
EMISSION TAKING INTO ACCOUNT THE HISTORY OF THE DECAY
WITH THE ALLOWANCE OF PRE-EQUILLIBRIUM EMISSION OF
THE FIRST NEUTRON /4/
ENERGY DISTRIBUTIONS FOR MT=18,19,20,21 WERE ADOPTED TO
BE IDENTICAL TO THAT OF AM-242M, WHICH WERE CALCULATED
BY MADLAND-NIX MODEL /2/ WITH ACCOUNT OF COMPETITION
BETWEEN MULTIPLE-CHANCE FISSION PROCESSES UP THROUGH
THIRD-CHANCE FISSION WITH THE ALLOWANCE OF PRE-EQUILIBRIUM
EMISSION OF THE FIRST NEUTRON /4,8/
REFERENCES
1. Brady M.C., Wright R.Q., England T.R., Report
ORNL/CSD/TM-226(1991), IAEA-NDS-102, 1992.
2. Madland D.G., Nix J.R., Nucl. Sci. Engng. 81, 213 (1982).
3. Howe R.E., Browne J.C., Dougan R.J., Dupzyk R.J., Landrum J.H.
Nucl. Sci. Eng.,77, 454 (1984).
4. Maslov V.M., Porodzinskij Yu.V., Sukhovitskij E.Sh., Proc.
Int. Conf. on Neutron Physics, 14-18 Sept., Kiev, USSR,
V.1, p.413, 1988.
5. Browne J.C., White R.M., Howe R.E. et al., Phys. Rev. C,
29, 2188 (1984).
6. Porodzinskij Yu.V., Sukhovitskij E.Sh., Nuclear Constants,
4, p.27, 1987 (in Russian).
7. ENSDF, 1995.
8. Ignatjuk A.V., Maslov V.M., Pashchenko A.B. Sov. J. Nucl.
Phys. 47, 224 (1988).
9. Ignatjuk A.V., Maslov V.M., Proc. Int. Symp. Nuclear Data
Evaluation Methodology, Brookhaven, USA, October 12-16, 1992,
p.440, World Scientific, 1993.
10. Maslov V.M. Sov. J. At. Energy 64, 478 (1988).
11. Fursov B.I., Samylin B.F., Smirenkin G.N., Polynov V.N.,
Nuclear Data for Science and Technology, Proc. Int. Conf.,
Gatlinburg, Tennessee, USA, May 9-13, 1994, v.1,p.269.
12. Maslov V.M., Kikuchi Y. JAERI-Research 96-030, 1996.
========== Description given in Maslov's data (end) =============