95-AM-242MJAERI EVAL-MAR88 T.NAKAGAWA
JAERI-M 89-008 DIST-SEP89
----JENDL-3.2 MATERIAL 9547
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
80-03 NEW EVALUATION WAS MODE BY T.NAKAGAWA AND S.IGARASI (JAERI).
DETAILS ARE GIVEN IN REF. /1/.
88-03 RE-EVALUATION WAS MADE FOR JENDL-3 BY T.NAKAGAWA (JAERI)/2/.
MF=1 GENERAL INFORMATION
MT=451 COMMENT AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF PROMPT AND DELAYED NEUTRONS.
MT=455 DELAYED NEUTRON DATA
ESTIMATED FROM TUTTLE'S SEMI-EMPIRICAL FORMULA /3/.
MT=456 NUMBER OF PROMPT NEUTRONS PER FISSION
BASED ON THE RELATIVE MEASUREMENTS /4,5/ TO THE U-235
DATA, AND ON THE EMPIRICAL FORMULA BY HOWERTON /6/.
MF=2 RESONANCE PARAMETERS
MT=151 RESONANCE PARAMETERS
RESOLVED RESONANCE PARAMETERS : BELOW 20 EV
PARAMETERS FOR 48 LEVELS DEDUCED BY BROWNE ET AL./7/
AND THE SINGLE LEVEL BREIT-WIGNER FORMULA WERE ADOPTED.
UNRESOLVED RESONANCE PARAMETERS : 20 EV - 30 KEV
PARAMETERS WERE DETERMINED SO AS TO REPRODUCE THE
FISSION CROSS SECTION OF BROWNE ET AL./7/. BACKGROUND
SIG WAS GIVEN TO THE FISSION AT LOW ENERGIES.
AVERAGE WG = 0.05 EV, AVERAGE WF = 1.28 EV,
D-OBS = 0.4 EV, S0 = 1.07E-4, S1 = E-DEPENDENT,
R = 9.59 FM
CALCULATED 2200M/S CROSS SECTIONS AND RESONANCE INTEGRALS.
2200 M/SEC RES. INTEG.
TOTAL 7969. B -
ELASTIC 5.667 B -
FISSION 6409. B 1560 B
CAPTURE 1254. B 246 B
MF=3 NEUTRON CROSS SECTIONS
BELOW 30 KEV: CROSS SECTIONS WERE REPRESENTED WITH THE
RESONANCE PARAMETERS.
ABOVE 30 KEV:
MT=1,2 TOTAL AND ELASTIC SCATTERING CROSS SECTIONS
CALCULATED WITH OPTICAL AND STATISTICAL MODEL CODE
CASTHY/8/.
THE SPHERICAL OPTICAL POTENTIAL PARAMETERS (MEV, FM) :
V= 42.0 - 0.107*E , R= 1.282 , A= 0.6
WS= 9.0 - 0.339*E + 0.0531*E**2 , R= 1.29 , A= 0.5
VSO= 7.0 , R= 1.282 , A= 0.6
MT=4,51-72,91 INELASTIC SCATTERING CROSS SECTIONS
CALCULATED WITH CASTHY/8/. THE LEVEL SCHEME WAS TAKEN
FROM THE COMPILATION BY ELLIS AND HAESE /9/, WITH
SHIFTED ENERGY ORIGIN AT -49 KEV.
NO. ENERGY(MEV) SPIN-PARITY
G.S. -0.049 1 -
1 -0.005 0 -
2 0.0 3 -
3 0.0 (META STABLE) 5 -
4 0.025 2 -
5 0.064 6 -
6 0.099 4 -
7 0.099 5 -
8 0.141 7 -
9 0.193 3 -
10 0.214 6 -
11 0.214 7 -
12 0.239 4 -
13 0.239 2 -
14 0.276 3 -
15 0.292 5 -
16 0.323 4 -
17 0.361 6 -
18 0.381 5 -
19 0.439 7 -
20 0.451 6 -
21 0.532 7 -
22 0.630 8 -
OVERLAPPING LEVELS WERE ASSUMED ABOVE 0.632 MEV.
THE LEVEL DENSITY PARAMETERS WERE DETERMINED ON THE
BASIS OF NUMBER OF EXCITED LEVELS/10/ AND RESONANCE
LEVEL SPACING/11/.
AM-243 AM-242
A(1/MEV) 31.3 29.6
T(MEV) 0.355 0.342
C(1/MEV) 11.71 22.98
E-X(MEV) 3.278 2.323
SPIN-CUTOFF(1/MEV**0.5) 31.81 30.85
PAIRING E(MEV) 0.5 0.0
MT=16,17 (N,2N) AND (N,3N) CROSS SECTIONS
TAKEN FROM JENDL-2 CALCULATED WITH THE EVAPORATION MODEL
BY PEARLSTEIN /12/.
MT=18 FISSION CROSS SECTION
DETERMINED BY CUBIC SPLINE-FITTING TO THE DATA MEASURED
BY BROWNE ET AL./7/
MT=102 CAPTURE CROSS SECTION
CALCULATED WITH CASTHY/8/. THE GAMMA-RAY STRENGTH
FUNCTION WAS ESTIMATED FROM WG=0.05 EV AND D-OBS=0.4 EV.
MT=251 MU-L BAR
CALCULATED WITH CASTHY/8/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-72,91
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 WITH NUCLEAR TEMPERATURE
CALCULATED FROM LEVEL DENSITIES.
MT=18 FISSION SPECTRUM ESTIMATED FROM Z**2/A SYSTEMATICS BY
SMITH ET AL. /13/ BY ASSUMING E(CF-252) = 2.13 MEV.
REFERENCES
1) NAKAGAWA T. AND IGARASI S.: JAERI-M 8903 (1980), IN JAPANESE.
2) NAKAGAWA T.: JAERI-M 89-008 (1989).
3) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, 29 (1979).
4) JAFFEY A.H. AND LERNER J.L.: NUCL. PHYS., A145, 1 (1970).
5) KROSHKIN N.I. AND ZAMYATNIN YU.S.: ATOM. ENERG., 29, 95
(1970), SOV. ATOM. ENERGY, 29, 790 (1970).
6) HOWERTON R.J.: NUCL. SCI. ENG. 62, 438 (1977).
7) BROWNE J.C. ET AL.: PHYS. REV., C29, 2188(1984).
8) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
9) ELLIS Y.A. AND HAESE R.L.: NUCL. DATA SHEETS 21, 615 (1977).
10) ENSDF, EVALUATED NUCLEAR STRUCTURE DATA FILE (1988).
11) MUGHABGHAB S.F.: "NEUTRON CROSS SECTIONS, VOL. 1, PART B",
ACADEMIC PRESS, INC. (1984).
12) PEARLSTEIN S.: NUCL. SCI. ENG., 23, 238 (1965).
13) SMITH A.B. ET AL. : ANL/NDM-50 (1979).