14-Si- 28
14-SI- 28 TIT,JAERI EVAL-MAR88 H.KITAZAWA,Y.HARIMA,T.FUKAHORI
DIST-SEP89 REV2-JAN94
----JENDL-3.2 MATERIAL 1425
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
88-03 NEW EVALUATION WAS PERFORMED FOR JENDL-3 BY KITAZAWA,
HARIMA (TOKYO INSTITUTE OF TECH.) AND FUKAHORI (JAERI).
DETAILS ARE GIVEN IN REF./1/.
88-03 COMPILED BY FUKAHORI.
94-01 JENDL-3.2.
COMPILED BY T.NAKAGAWA (NDC/JAERI)
***** MODIFIED PARTS FOR JENDL-3.2 ********************
(3,2) EFFECTS OF MODIFICATION OF INELASTIC
SCATTERING CROSS SECTIONS.
(3,4), (3,51-66) CROSS-SECTION CURVES WERE SMOOTHED.
(4,16-28), (4,91) TAKEN FROM JENDL FUSION FILE
(5,16-91) TAKEN FROM JENDL FUSION FILE
(12,102)
***********************************************************
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JENDL FUSION FILE /2/ (AS OF JAN. 1994)
EVALUATED AND COMPILED BY S.CHIBA (NDC/JAERI)
CROSS SECTIONS, ANGULAR DISTRIBUTIONS AND ENERGY DISTRI-
BUTIONS WERE TAKEN FROM JENDL-3.1. MF=6 OF MT=16, 22, 28,
AND 91 WERE CREATED BY F15TOB PROGRAM/2/ BY USING KUMABE'S
SYSTEMATICS/3/. THE PRECOMPOUND/COMPOUND RATIO WAS TAKEN
FROM THE SINCROS-II CALCULATION/4/.
OPTICAL-MODEL, LEVEL DENSITY AND OTHER PARAMETERS USED
IN THE SINCROS-II CALCULATION ARE DESCRIBED IN REF./4/.
-------------------------------------------------------------
MF=1 GENERAL INFORMATION
MT=451 DESCRIPTIVE DATA AND DICTIONARY
MF=2 RESONANCE PARAMETERS:
MT=151
RESOLVED RESONANCES : 1.0E-5 EV - 1.81 MEV
THE RESONANCE PARAMETERS WERE SEARCHED, USING MLBW FORMULA.
AN INITIAL GUESS OF THE PARAMETERS WAS TAKEN FROM REF./5/.
CALCULATED 2200-M/S CROSS SECTIONS AND RESONANCE INTEGRALS
2200-M/SEC RES. INTEG.
ELASTIC 2.149 B -
CAPTURE 0.177 B 0.085 B
TOTAL 2.325 B -
MF=3 NEUTRON CROSS SECTIONS
MT=1 TOTAL CROSS SECTION
BETWEEN 1.81 AND 12.5 MEV, THE CROSS SECTIONS WERE OBTAINED BY
AN EYE-GUIDE SO AS TO FOLLOW THE EXPERIMENTAL DATA. ABOVE 12.5
MEV, THE CROSS SECTIONS WERE CALCULATED WITH THE STATISTICAL-
MODEL CODE CASTHY./1,6/
MT=2 ELASTIC SCATTERING CROSS SECTIONS
OBTAINED BY SUBTRACTING PARTIAL CROSS SECTIONS FROM THE TOTAL
CROSS SECTIONS.
MT=4,51-66,91 INELASTIC SCATTERING CROSS SECTIONS
CALCULATED WITH THE STATISTICAL-MODEL CODE CASTHY /6/ AND THE
COUPLED-CHANNEL MODEL CODE ECIS /7/ OR JUPITOR-1 /8/, TAKING
ACCOUNT OF COMPETITIVE PROCESSES FOR NEUTRON, PROTON, ALPHA-
PARTICLE AND GAMMA-RAY EMISSION./1/ BELOW 11 MEV, THE IMAGINARY
POTENTIAL STRENGTH OF THE NEUTRON SPHERICAL OPTICAL POTENTIAL
WAS MODIFIED FROM THAT IN REF./1/ TO BE W = 1.09 + 0.55*E
(MEV).
LEVEL SCHEME WAS TAKEN FROM REF./9/.
NO. ENERGY(MEV) SPIN-PARITY
G.S. 0.0 0 +
1. 1.7789 2 +
2. 4.6178 4 +
3. 4.9791 0 +
4. 6.2765 3 +
5. 6.6914 0 +
6. 6.8786 3 -
7. 6.8888 4 +
8. 7.3807 2 +
9. 7.4173 2 +
10. 7.7988 3 +
11. 7.9334 2 +
12. 8.2590 2 +
13. 8.3280 1 +
14. 8.4133 4 -
15. 8.5430 6 +
16. 8.5890 3 +
CONTINUUM LEVELS WERE ASSUMED ABOVE 8.9 MEV. LEVEL DENSITY WAS
CALCULATED, USING THE GILBERT-CAMERON FORMULA. THE LEVEL
DENSITY PARAMETERS WERE OBTAINED FROM A CUMULATIVE PLOT OF
OBSERVED LEVELS/1/.
FOR JENDL-3.2, CROSS SECTIONS AT THRESHOLD ENERGIES OF THE
LEVELS WERE INSERTED BY INTERPOLATING THE CALCULATED CROSS
SECTIONS.
MT=16 (N,2N) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH
CODE/1,10/. BELOW 11 MEV, THE IMAGINARY POTENTIAL STRENGTH OF
THE NEUTRON SPHERICAL OPTICAL POTENTIAL WAS MODIFIED FROM THAT
IN REF./1/ TO BE W = 1.09 + 0.55*E (MEV).
MT=22 (N,NA) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH
CODE/1,10/. OPTICAL POTENTIAL FOR ALPHA-PARTICLES WAS
DETERMINED, USING THE DISPERSION THEORY./11/
MT=28 (N,NP) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH CODE.
MT=102 CAPTURE
CALCULATED WITH THE STATISTICAL-MODEL CODE CASTHY /6/ AND THE
DIRECT-SEMIDIRECT-MODEL CODE HIKARI /12/. THE STATISTICAL-
MODEL CALCULATIONS WERE NORMALIZED TO 0.6 MB AT 2.0 MEV.
MT=103 (N,P) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH CODE. THE
IMAGINARY POTENTIAL STRENGTH OF THE PROTON SPHERICAL OPTICAL
MODEL WAS MODIFIED FROM THAT IN REF./1/ TO BE W = 11.0 MEV
BETWEEN 11 AND 20 MEV AND W = 8.8 + 0.2*E (MEV) BELOW 11 MEV.
THE STRENGTH WAS DETERMINED SO AS TO REPRODUCE OBSERVED VALUES
/13/.
MT=107 (N,A) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH CODE.
OPTICAL POTENTIAL FOR ALPHA-PARTICLES WAS DETERMINED, USING
THE DISPERSION THEORY/11/.
MT=111 (N,2P) CROSS SECTIONS
CALCULATED BY THE STATISTICAL MODEL, USING THE GNASH CODE.
MT=251 MU-BAR
CALCULATED WITH STATISTICAL-MODEL CODE CASTHY /1,6/.
MF=4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=2
CALCULATED WITH THE STATISTICAL-MODEL CODE CASTHY /1,6/.
MT=51-66
INCOHERENT SUM OF THE STATISTICAL MODEL AND COUPLED-CHANNEL
MODEL CALCULATIONS./1/ CALCULATED WITH CASTHY AND ECIS OR
JUPITOR-1.
MT=16,22,28,91
TAKEN FROM JENDL FUSION FILE.
MF=5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
MT=16,22,28,91
TAKEN FROM JENDL FUSION FILE.
MF=12 GAMMA-RAY MULTIPLICITIES (BELOW 9.22088 MEV)
MT=51-66,102,103,107
CALCULATED BY USING THE GNASH CODE/1,10/. MULTIPLICITIES OF
MT=102 WERE DETERMINED FROM ENERGY BALANCE.
MF=13 GAMMA-RAY PRODUCTION CROSS SECTIONS (ABOVE 9.22088 MEV)
MT=3
CALCULATED BY THE STATISTICAL MODEL AND COUPLED-CHANNEL MODEL,
USING THE GNASH CODE /10/ AND THE ECIS /7/ OR JUPITOR-1 CODE
/8/. BRANCHING RATIOS FOR TRANSITIONS BETWEEN DISCRETE LEVELS
WERE TAKEN FROM REF./9/. GAMMA-RAY TRANSITION STRENGTH IN
THE CONTINUUM WAS CALCULATED BY THE BRINK-AXEL GIANT RESONANCE
MODEL FOR E1 TRANSITION AND BY THE WEISSKOPF SINGLE-PARTICLE
MODEL FOR E2 AND M1 TRANSITION./1/
MF=14 GAMMA-RAY ANGULAR DISTRIBUTIONS
MT=3,51-66,102,103,107
ISOTROPIC DISTRIBUTION WAS ASSUMED.
MF=15 GAMMA-RAY SPECTRA
MT=3,102,103,107
CALCULATED WITH THE GNASH CODE./1,10/
REFERENCES
1) KITAZAWA H. ET AL.: PROC. INT. CONF. NUCLEAR DATA FOR SCIENCE
AND TECHNOLOGY, MITO, 1988, P.473, (1988).
2) CHIBA S. ET AL.: JAERI-M 92-027, P.35 (1992).
3) KUMABE I. ET AL.: NUCL. SCI. ENG., 104, 280 (1990).
4) YAMAMURO N.: JAERI-M 90-006 (1990).
5) MUGHABGHAB S.F. ET AL.: "NEUTRON CROSS SECTIONS, VOL. 1 PART
A", ACADEMIC PRESS (1981).
6) IGARASI S. AND FUKAHORI T.: JAERI 1321 (1991).
7) RAYNAL J.: COMPUTER PROGRAM ECIS79 FOR COUPLED-CHANNEL
CALCULATIONS, 1979 (UNPUBLISHED).
8) TAMURA T.: REV. MOD. PHYS., 37, 679 (1965).
9) ENDT P.M. AND VAN DER LEUN C.: NUCL. PHYS., A310, 1 (1978).
10) YOUNG P.G. AND ARTHUR E.D.: LA-6947 (1977).
11) KITAZAWA H. ET AL.: UNPUBLISHED.
12) KITAZAWA H.: COMPUTER PROGRAM HIKARI FOR DIRECT-SEMIDIRECT
CAPTURE CALCULATIONS, 1980 (UNPUBLISHED).
13) IKEDA Y.: JAERI 1312 (1988).