90-Th-228
90-TH-228 KINKI U. EVAL-JUN87 T.OHSAWA
DIST-SEP89 REV2-JUN94
----JENDL-3.2 MATERIAL 9028
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
81-04 EVALUATION FOR JENDL-2 WAS MADE BY T. OHSAWA* AND M. OHTA
(KYUSHU UNIVERSITY). DETAILS OF THE EVALUATION ARE
DESCRIBED IN REF. /1/. (*PRESENT ADDRESS: KINKI UNIVERSITY)
83-11 FISSION SPECTRUM WAS ADDED. RESONANCE FORMULA WAS CHANGED
TO MLBW FORMULA. THE TOTAL, (N,2N) AND (N,3N) CROSS SEC-
TIONS WERE MODIFIED.
87-06 ALMOST OF JENDL-2 DATA WERE ADOPTED FOR JENDL-3.
(MF3,MT17), (MF3,MT91) AND (MF3,MT102) WERE SLIGHTLY
MODIFIED IN HIGH ENERGY REGION.
COMPILATION WAS MADE BY T.NAKAGAWA (JAERI).
94-06 JENDL-3.2.
NU-P, NU-D AND NU-TOTAL WERE MODIFIED.
COMPILED BY T.NAKAGAWA (NDC/JAERI)
***** MODIFIED PARTS FOR JENDL-3.2 ********************
(1,452), (1,455), (1,456)
***********************************************************
MF=1 GENERAL INFORMATION
MT=451 COMMENT AND DICTIONARY
MT=452 NUMBER OF NEUTRONS PER FISSION
SUM OF NU-P NAD NU-D.
MT=455 DELAYED NEUTRONS PER FISSION
AVERAGE VALUES OF SYSTEMATICS BY TUTTLE/2/, BENEDETTI ET
AL./3/ AND WALDO ET AL./4/ DECAY CONSTANTS WERE ASSUMED
TO BE THE SAME AS THOSE OF TH-229 EVALUATED BY BRADY AND
ENGLAND/5/.
MT=456 PROMPT NEUTRONS PER FISSION
BASED ON THE SEMI-EMPIRICAL FORMULA OF HOWERTON /6/.
MF=2 RESONANCE PARAMETERS
MT=151 RESOLVED RESONANCES
RESONANCE REGION IS BELOW 7.798 EV. PARAMETERS WERE GIVEN
FOR THE MLBW FORMULA. ONLY TWO RESONANCES WERE OBSERVED BY
SIMPSON ET AL./7/. AN ADDITIONAL TERM WITH 1/V DEPENDENCE
WAS ASSUMED TO REPRODUCE THE THERMAL CAPTURE CROSS SECTION.
FISSION CROSS SECTION WAS ALSO ASSUMED TO HAVE 1/V BEHAVIOR.
CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEG.(BARNS)
2200-M/S RES. INTEG.
ELASTIC 12.81 -
CAPTURE 119.9 1170
FISSION 0.300 1.02
TOTAL 133.0 -
MF=3 NEUTRON CROSS SECTIONS
BELOW 7.798 EV IS THE RESONANCE REGION. BACKGROUND DATA
WERE GIVEN. THE CROSS SECTIONS WERE EVALUATED IN THE ENERGY
REGION ABOVE 7.798 EV AS FOLLOWS.
MT=1 TOTAL CROSS SECTION
OPTICAL MODEL CALCULATION WITH THE FOLLOWING PARAMETERS:
V = 41.0 - 0.05*E (MEV),
WS = 6.4 + 0.15*SQRT(E) (MEV), -- DER. WOODS-SAXON --
VSO= 7.0 (MEV),
R0 = RSO = 1.31 (FM),
RS = 1.38 (FM),
A = B = ASO= 0.47 (FM).
THESE PARAMETERS WERE TAKEN FROM THOSE FOR TH-232 /8/.
MT=2 ELASTIC SCATTERING CROSS SECTION
BASED ON STATISTICAL AND OPTICAL MODEL CALCULATIONS USING
THE CODE CASTHY /9/.
MT=4,51-62,91 INELASTIC SCATTERING CROSS SECTION
STATISTICAL AND OPTICAL MODEL CALCULATIONS.
LEVEL SCHEME OF TH-228 /10/.
NO. ENERGY(MEV) SPIN-PARITY
G.S. 0.0 0 +
1 0.0576 2 +
2 0.1869 4 +
3 0.328 1 -
4 0.3961 3 -
5 0.5193 5 -
6 0.8317 0 -
7 0.8746 2 +
8 0.9441 2 +
9 0.952 1 -
10 0.9688 2 +
11 1.016 3 -
12 1.0224 3 +
LEVELS ABOVE 1.025 MEV WERE ASSUMED TO BE OVERLAPPING.
MT=16,17 (N,2N) AND (N,3N) CROSS SECTIONS
CALCULATED BY MEANS OF THE EVAPORATION MODEL OF SEGEV AND
CANER /11/.
MT=18 FISSION CROSS SECTION
THE DATA OF VOROTNIKOV ET AL./12/ WERE ADOPTED UP TO 5 MEV.
THE FISSION CROSS SECTION OF THE NEIGHBORING EVEN-EVEN
ISOTOPE TH-230 NORMALIZED TO JOIN SMOOTHLY TO THE DATA OF
VOROTNIKOV ET AL. WAS ADOPTED ABOVE 5 MEV.
MT=102 CAPTURE CROSS SECTION
STATISTICAL AND OPTICAL MODEL CALCULATIONS WITH GAMMA-RAY
STRENGTH FUNCTION OF 0.00791.
MT=251 MU-BAR
CALCULATED WITH OPTICAL MODEL.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2,51-62,91
STATISTICAL AND OPTICAL MODEL CALCULATIONS.
MT=16,17,18
ASSUMED TO BE ISOTROPIC IN THE LABORATORY SYSTEM.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,17,91
EVAPORATION SPECTRA
MT=18
FISSION SPECTRUM ESTIMATED FROM Z**2/A SYSTEMATICS BY SMITH
ET AL./13/.
REFERENCES
1) OHSAWA T. AND OHTA M.: MEMOIRS FACULTY OF ENGINEERING,
KYUSHU UNIV. 40, 149 (1980).
2) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, P.29 (1979),
3) BENEDETTI G. ET AL.: NUCL. SCI. ENG., 80, 379 (1982).
4) WALDO R. ET AL.: PHYS. REV., C23, 1113 (1981).
5) BRADY M.C. AND ENGLAND T.R.: NUCL. SCI. ENG., 103, 129(1989).
6) HOWERTON R.J.: NUCL. SCI. ENG. 62, 438 (1977).
7) SIMPSON O.D. ET AL.: IBID. 29, 423 (1967).
8) OHSAWA T. AND OHTA M.: J. NUCL. SCI. TECHNOL. 18, 408 (1981).
9) IGARASI S. AND FUKAHORI T.: JAERI 1321 (1991).
10) LEDERER C.M. AND SHIRLY V.S. (ED.): TABLE OF ISOTOPES,
7TH EDITION (1978).
11) SEGEV M. AND CANER M.: ANN. NUCL. ENERGY 5, 239 (1978).
12) VOROTNIKOV ET AL.: SOV. J. NUCL. PHYS. 16, 505 (1973).
13) SMITH A.B. ET AL.: ANL/NDM-50 (1979).