38-Sr- 87
38-SR- 87 JNDC EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.
DIST-NOV90
----JENDL-3.2 MATERIAL 3834
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
84-10 EVALUATION FOR JENDL-2 WAS MADE BY JNDC FPND W.G./1/
90-03 MODIFICATION FOR JENDL-3 WAS MADE/2/.
MF = 1 GENERAL INFORMATION
MT=451 COMMENTS AND DICTIONARY
MF = 2 RESONANCE PARAMETERS
MT=151 RESOLVED AND UNRESOLVED RESONANCE PARAMETERS
RESOLVED RESONANCE REGION (MLBW FORMULA) : BELOW 14.08 KEV
RESONANCE PARAMETERS OF JENDL-2 WERE MODIFIED AS FOLLOWS:
EVALUATION OF JENDL-2 WAS PERFORMED ON THE BASIS OF THE
MEASUREMENTS BY CAMARDA ET AL./3/ AND MUSGROVE ET AL./4/
NEUTRON WIDTHS WERE DERIVED FROM THE DATA OF 2G*(NEUTRON
WIDTH) AND NEUTRON CAPTURE AREAS. NEUTRON ORBITAL ANGULAR
MOMENTUM L WAS ASSUMED TO BE 0 FOR ALL RESONANCE LEVELS EXCEPT
THE 2ND LEVEL (L=1) AT 35.27 EV. HOWEVER, THE VALUES OF TOTAL
SPIN J WERE UNKNOWN FOR ALL RESONANCE LEVELS. THUS, TARGET
SPIN OF 4.5 WAS ADOPTED AS J VALUE. AVERAGE RADIATION WIDTH
OF 180.4 MEV WAS OBTAINED BY AVERAGING THE GIVEN RADIATION
WIDTHS. HOWEVER, THIS VALUE WAS REDUCED TO 110.72 MEV SO AS
TO REPRODUCE THE NEUTRON CAPTURE RESONANCE INTEGRAL OF 118+-30
BARNS GIVEN BY MUGHABGHAB ET AL./5/ A NEGATIVE RESONANCE WAS
ALSO ADDED AT -50 EV, AND THE PARAMETERS WERE ADJUSTED SO AS
TO REPRODUCE THE THERMAL CAPTURE CROSS SECTION OF 16+-3 BARNS
GIVEN BY MUGHABGHAB ET AL.
FOR JENDL-3, THE VALUES OF TOTAL SPIN J WERE TENTATIVELY
ESTIMATED WITH A RANDOM NUMBER METHOD. NEUTRON WIDTHS WERE
MODIFIED ON THE BASIS OF THE ESTIMATED J-VALUES. RADIATION
WIDTH OF THE NEGATIVE LEVEL WAS SLIGHTLY ADJUSTED SO AS TO
REPRODUCE THE THERMAL CAPTURE CROSS SECTION ACCORDING TO THE
MODIFICATION OF THE POSITIVE LEVELS. SCATTERING RADIUS WAS
TAKEN FROM THE GRAPH (FIG. 1, PART A) GIVEN BY MUGHABGHAB ET
AL.
UNRESOLVED RESONANCE REGION : 14.08 KEV - 100 KEV
UNRESOLVED RESONANCE PARAMETERS WERE ADOPTED FROM JENDL-2.
THE NEUTRON STRENGTH FUNCTIONS, S0, S1 AND S2 WERE CALCULATED
WITH OPTICAL MODEL CODE CASTHY/6/. THE OBSERVED LEVEL SPACING
WAS DETERMINED TO REPRODUCE THE CAPTURE CROSS SECTION
CALCULATED WITH CASTHY. THE EFFECTIVE SCATTERING RADIUS WAS
OBTAINED FROM FITTING TO THE CALCULATED TOTAL CROSS SECTION AT
100 KEV.
TYPICAL VALUES OF THE PARAMETERS AT 70 KEV:
S0 = 0.300E-4, S1 = 4.000E-4, S2 = 0.360E-4, SG = 4.72E-4,
GG = 0.116 EV, R = 7.414 FM.
CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)
2200 M/S RES. INTEG.
TOTAL 22.90 -
ELASTIC 6.897 -
CAPTURE 16.00 121
MF = 3 NEUTRON CROSS SECTIONS
BELOW 100 KEV, RESONANCE PARAMETERS WERE GIVEN.
ABOVE 100 KEV, THE SPHERICAL OPTICAL AND STATISTICAL MODEL
CALCULATION WAS PERFORMED WITH CASTHY, BY TAKING ACCOUNT OF
COMPETING REACTIONS, OF WHICH CROSS SECTIONS WERE CALCULATED
WITH PEGASUS/7/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP
EVAPORATION MODEL. THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE
DETERMINED BY IIJIMA AND KAWAI/8/ TO REPRODUCE A SYSTEMATIC
TREND OF THE TOTAL CROSS SECTION. THE OMP'S FOR CHARGED
PARTICLES ARE AS FOLLOWS:
PROTON = PEREY/9/
ALPHA = HUIZENGA AND IGO/10/
DEUTERON = LOHR AND HAEBERLI/11/
HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/12/
PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT
AND CAMERON/13/ WERE EVALUATED BY IIJIMA ET AL./14/ MORE
EXTENSIVE DETERMINATION AND MODIFICATION WERE MADE IN THE
PRESENT WORK. TABLE 2 SHOWS THE LEVEL DENSITY PARAMETERS USED
IN THE PRESENT CALCULATION. ENERGY DEPENDENCE OF SPIN CUT-OFF
PARAMETER IN THE ENERGY RANGE BELOW E-JOINT IS DUE TO GRUPPELAAR
/15/.
MT = 1 TOTAL
SPHERICAL OPTICAL MODEL CALCULATION WAS ADOPTED.
MT = 2 ELASTIC SCATTERING
CALCULATED AS (TOTAL - SUM OF PARTIAL CROSS SECTIONS).
MT = 4, 51 - 91 INELASTIC SCATTERING
SPHERICAL OPTICAL AND STATISTICAL MODEL CALCULATION WAS
ADOPTED. THE LEVEL SCHEME WAS TAKEN FROM REF./16/.
NO. ENERGY(MEV) SPIN-PARITY
GR. 0.0 9/2 +
1 0.3883 1/2 +
2 0.8730 3/2 -
3 1.2290 5/2 +
4 1.2570 5/2 -
5 1.7390 13/2 +
6 1.7710 5/2 +
7 1.9210 7/2 +
LEVELS ABOVE 1.997 MEV WERE ASSUMED TO BE OVERLAPPING.
MT = 102 CAPTURE
SPHERICAL OPTICAL AND STATISTICAL MODEL CALCULATION WITH
CASTHY WAS ADOPTED. DIRECT AND SEMI-DIRECT CAPTURE CROSS
SECTIONS WERE ESTIMATED ACCORDING TO THE PROCEDURE OF BENZI
AND REFFO/17/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.
THE GAMMA-RAY STRENGTH FUNCTION (4.71E-04) WAS ADJUSTED TO
REPRODUCE THE CAPTURE CROSS SECTION OF 42 MILLI-BARNS AT 70
KEV MEASURED BY MUSGROVE ET AL./4/
MT = 16 (N,2N) CROSS SECTION
MT = 22 (N,N'A) CROSS SECTION
MT = 28 (N,N'P) CROSS SECTION
MT = 32 (N,N'D) CROSS SECTION
MT =103 (N,P) CROSS SECTION
MT =104 (N,D) CROSS SECTION
MT =105 (N,T) CROSS SECTION
MT =106 (N,HE3) CROSS SECTION
MT =107 (N,ALPHA) CROSS SECTION
THESE REACTION CROSS SECTIONS WERE CALCULATED WITH THE
PREEQUILIBRIUM AND MULTI-STEP EVAPORATION MODEL CODE PEGASUS.
THE KALBACH'S CONSTANT K (= 394.6) WAS ESTIMATED BY THE
FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/18/ AND LEVEL
DENSITY PARAMETERS.
FINALLY, THE (N,P) AND (N,ALPHA) CROSS SECTIONS WERE
NORMALIZED TO THE FOLLOWING VALUES AT 14.5 MEV:
(N,P) 20.60 MB (SYSTEMATICS OF FORREST/19/)
(N,ALPHA) 6.81 MB (SYSTEMATICS OF FORREST)
MT = 251 MU-BAR
CALCULATED WITH CASTHY.
MF = 4 ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS
LEGENDRE POLYNOMIAL COEFFICIENTS FOR ANGULAR DISTRIBUTIONS ARE
GIVEN IN THE CENTER-OF-MASS SYSTEM FOR MT=2 AND DISCRETE INELAS-
TIC LEVELS, AND IN THE LABORATORY SYSTEM FOR MT=91. THEY WERE
CALCULATED WITH CASTHY. FOR OTHER REACTIONS, ISOTROPIC DISTRI-
BUTIONS IN THE LABORATORY SYSTEM WERE ASSUMED.
MF = 5 ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS
ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS WERE CALCULATED WITH
PEGASUS FOR INELASTIC SCATTERING TO OVERLAPPING LEVELS AND FOR
OTHER NEUTRON EMITTING REACTIONS.
TABLE 1 NEUTRON OPTICAL POTENTIAL PARAMETERS
DEPTH (MEV) RADIUS(FM) DIFFUSENESS(FM)
---------------------- ------------ ---------------
V = 46.0-0.25E R0 = 5.893 A0 = 0.62
WS = 7.0 RS = 6.393 AS = 0.35
VSO= 7.0 RSO= 5.893 ASO= 0.62
THE FORM OF SURFACE ABSORPTION PART IS DER. WOODS-SAXON TYPE.
TABLE 2 LEVEL DENSITY PARAMETERS
NUCLIDE A(1/MEV) T(MEV) C(1/MEV) EX(MEV) PAIRING
---------------------------------------------------------------
36-KR- 83 1.483E+01 6.700E-01 2.532E+00 5.589E+00 1.170E+00
36-KR- 84 9.970E+00 9.600E-01 4.942E-01 8.590E+00 2.630E+00
36-KR- 85 1.024E+01 8.900E-01 1.570E+00 6.261E+00 1.170E+00
36-KR- 86 9.052E+00 8.686E-01 2.185E-01 5.874E+00 2.100E+00
37-RB- 84 1.106E+01 8.060E-01 5.598E+00 4.438E+00 0.0
37-RB- 85 1.190E+01 8.690E-01 2.827E+00 7.561E+00 1.460E+00
37-RB- 86 1.002E+01 8.500E-01 3.954E+00 4.312E+00 0.0
37-RB- 87 8.806E+00 9.410E-01 1.125E+00 5.465E+00 9.300E-01
38-SR- 85 1.134E+01 9.100E-01 3.646E+00 7.608E+00 1.240E+00
38-SR- 86 1.120E+01 8.900E-01 5.328E-01 8.599E+00 2.700E+00
38-SR- 87 1.030E+01 8.610E-01 1.186E+00 5.938E+00 1.240E+00
38-SR- 88 9.160E+00 7.510E-01 8.288E-02 4.550E+00 2.170E+00
---------------------------------------------------------------
SPIN CUTOFF PARAMETERS WERE CALCULATED AS 0.146*SQRT(A)*A**(2/3).
IN THE CASTHY CALCULATION, SPIN CUTOFF FACTORS AT 0 MEV WERE
ASSUMED TO BE 6.928 FOR SR- 87 AND 5.839 FOR SR- 88.
REFERENCES
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AND APPLIED SCIENCE, SANTA FE., VOL. 2, P.1627 (1985).
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AND TECHNOLOGY, MITO, P. 569 (1988).
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PHYSICS AND NUCL. DATA FOR REACTORS, HARWELL 1978, 449.
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PART A", ACADEMIC PRESS (1981).
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(1983).
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INTERSCIENCE PUBLICATION (1978).
17) BENZI, V. AND REFFO, G.: CCDN-NW/10 (1969).
18) KIKUCHI, K. AND KAWAI, M.: "NUCLEAR MATTER AND NUCLEAR
REACTIONS", NORTH HOLLAND (1968).
19) FORREST, R.A.: AERE-R 12419 (1986).