35-Br- 81
35-BR- 81 JNDC EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.
DIST-MAR02 REV3-FEB02 20020222
----JENDL-3.3 MATERIAL 3531
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
===========================================================
JENDL-3.2 data were automatically transformed to JENDL-3.3.
Interpolation of spectra: 22 (unit base interpolation)
(3,251) deleted, T-matrix of (4,2) deleted, and others.
===========================================================
HISTORY
90-03 NEW EVALUATION FOR JENDL-3 WAS COMPLETED BY JNDC FPND
W.G./1/
93-03 JENDL-3.2 WAS MADE BY JNDC FPND W.G.
***** MODIFIED PARTS FOR JENDL-3.2 ********************
(2,151) UNRESOLVED RESONANCE PARAMETERS RE-ADJUSTED
SO AS TO REPRODUCE THE RE-NORMALIZED CAPTURE
CROSS SECTION.
(3,102) RE-NORMALIZED.
(3,4), (3,51-91) AND ANGULAR DISTRIBUTIONS
SMALL EFFECTS OF THE RE-NORMALIZATION OF THE
CAPTURE CROSS SECTION.
***********************************************************
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 13 KEV
RESONANCE ENERGIES FOR THE 304 LEVELS AND FOR THE REMAINING 3
LEVELS WERE BASED ON THE MEASUREMENTS BY MACKLIN/2/ AND BY
OHKUBO ET AL./3/, RESPECTIVELY. NEUTRON AND RADIATION WIDTHS
WERE DETERMINED BY DIFFERENT METHODS ACCORDING TO THE
FOLLOWING THREE CONDITIONS, RESPECTIVELY.
1) IN CASES WHERE TOTAL WIDTH AND NEUTRON CAPTURE AREA
MEASURED BY MACKLIN WERE GIVEN FOR A RESONANCE LEVEL, THE
NEUTRON AND RADIATION WIDTHS WERE SIMULTANEOUSLY OBTAINED BY
SOLVING A QUADRATIC EQUATION.
2) IN CASES WHERE NEUTRON CAPTURE AREA MEASURED BY MACKLIN AND
G*(REDUCED NEUTRON WIDTH) MEASURED BY OHKUBO ET AL. WERE
AVAILABLE, THE RADIATION WIDTHS WERE DERIVED FROM THE BOTH
DATA.
3) IN CASES WHERE ONLY NEUTRON CAPTURE AREA BY MACKLIN WAS
AVAILABLE, OR G*(NEUTRON WIDTH) BY OHKUBO ET AL. WAS SMALLER
THAN NEUTRON CAPTURE AREA BY MACKLIN FOR A RESONANCE LEVEL,
THE AVERAGE RADIATION WIDTH OF 279 MEV GIVEN BY MACKLIN WAS
ADOPTED. THE NEUTRON WIDTH WAS DERIVED FROM THIS AVERAGE
RADIATION WIDTH AND THE NEUTRON CAPTURE AREA. IN ADDITION,
IF THE VALUE OF G*(AVERAGED RADIATION WIDTH) WAS SMALLER THAN
NEUTRON CAPTURE AREA FOR SOME RESONANCE LEVELS, THE AVERAGE
RADIATION WIDTH WAS INCREASED DEPENDING ON THE VALUE OF
NEUTRON CAPTURE AREA, SO AS TO SATISFY THE FOLLOWING CONDI-
TION:
G*(AVERAGE RADIATION WIDTH) > NEUTRON CAPTURE AREA.
TOTAL SPIN J OF SOME RESONANCES WAS TENTATIVELY ESTIMATED
WITH A RANDOM NUMBER METHOD. NEUTRON ORBITAL ANGULAR
MOMENTUM L WAS ASSUMED TO BE 0 FOR ALL RESONANCE LEVELS.
SCATTERING RADIUS WAS TAKEN FROM THE GRAPH (FIG. 1, PART A)
GIVEN BY MUGHABGHAB ET AL./4/ A NEGATIVE RESONANCE WAS
ADDED SO AS TO REPRODUCE THE THERMAL CAPTURE CROSS SECTION
GIVEN BY MUGHABGHAB ET AL.
UNRESOLVED RESONANCE REGION : 13 KEV - 100 KEV
THE NEUTRON STRENGTH FUNCTION S0 WAS BASED ON THE COMPILATION
OF MUGHABGHAB ET AL., AND S1 WAS BASED ON THE SYSTEMATICS OF
MUGHABGHAB ET AL., AND S2 WAS CALCULATED WITH OPTICAL MODEL
CODE CASTHY/5/. 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. THE RADIATION
WIDTH WAS BASED ON THE COMPILATION OF MUGHABGHAB ET AL.
TYPICAL VALUES OF THE PARAMETERS AT 70 KEV:
S0 = 0.800E-4, S1 = 2.000E-4, S2 = 0.690E-4, SG = 17.3E-4,
GG = 0.300 EV, R = 7.334 FM.
CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)
2200 M/S RES. INTEG.
TOTAL 6.307 -
ELASTIC 3.616 -
CAPTURE 2.690 46.7
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/6/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP
EVAPORATION MODEL. THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE
DETERMINED TO REPRODUCE A SYSTEMATIC TREND OF THE TOTAL CROSS
SECTION BY CHANGING R0, RS AND RSO OF IIJIMA-KAWAI POTENTIAL/7/.
THE OMP'S FOR CHARGED PARTICLES ARE AS FOLLOWS:
PROTON = PEREY/8/
ALPHA = HUIZENGA AND IGO/9/
DEUTERON = LOHR AND HAEBERLI/10/
HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/11/
PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT
AND CAMERON/12/ WERE EVALUATED BY IIJIMA ET AL./13/ 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
/14/.
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 BASED ON EVALUATED NUCLEAR
STRUCTURE DATA FILE (1987 VERSION)/15/ AND NUCLEAR DATA
SHEETS/16/.
NO. ENERGY(MEV) SPIN-PARITY
GR. 0.0 3/2 -
1 0.2760 5/2 -
2 0.5362 9/2 +
3 0.5382 1/2 -
4 0.5660 3/2 -
5 0.6499 3/2 -
6 0.7672 3/2 -
7 0.7925 3/2 +
8 0.8150 1/2 +
9 0.8283 3/2 -
10 0.8324 1/2 -
11 0.8364 7/2 -
12 1.1047 1/2 -
13 1.1899 5/2 -
14 1.2666 3/2 -
15 1.3228 5/2 -
16 1.3275 5/2 -
17 1.3525 1/2 -
18 1.3757 7/2 +
19 1.5428 1/2 -
20 1.5870 1/2 +
21 1.9499 7/2 +
22 1.9852 3/2 +
23 2.0559 1/2 -
24 2.0846 7/2 +
25 2.1225 3/2 +
26 2.1641 1/2 -
LEVELS ABOVE 2.193 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 (1.65E-03) WAS ADJUSTED TO
REPRODUCE THE CAPTURE CROSS SECTION OF 119 MILLI-BARNS AT 90
KEV MEASURED BY MACKLIN/2/.
MT = 16 (N,2N) CROSS SECTION
MT = 17 (N,3N) CROSS SECTION
MT = 22 (N,N'A) CROSS SECTION
MT = 28 (N,N'P) CROSS SECTION
MT = 32 (N,N'D) CROSS SECTION
MT = 33 (N,N'T) CROSS SECTION
MT =103 (N,P) CROSS SECTION
MT =104 (N,D) CROSS SECTION
MT =105 (N,T) 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 (= 120.9) 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) 21.50 MB (RECOMMENDED BY FORREST/19/)
(N,ALPHA) 5.00 MB (RECOMMENDED BY 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 = 5.7 A0 = 0.62
WS = 7.0 RS = 6.2 AS = 0.35
VSO= 7.0 RSO= 5.7 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
---------------------------------------------------------------
33-AS- 77 1.300E+01 8.440E-01 4.637E+00 7.951E+00 1.470E+00
33-AS- 78 1.150E+01 7.500E-01 5.001E+00 3.894E+00 0.0
33-AS- 79 1.290E+01 8.230E-01 3.020E+00 7.585E+00 1.570E+00
33-AS- 80 1.150E+01 7.250E-01 4.181E+00 3.535E+00 0.0
34-SE- 78 1.287E+01 8.750E-01 1.163E+00 9.882E+00 2.900E+00
34-SE- 79 1.412E+01 8.000E-01 5.994E+00 7.842E+00 1.430E+00
34-SE- 80 1.334E+01 8.130E-01 6.129E-01 9.136E+00 3.000E+00
34-SE- 81 1.368E+01 7.490E-01 2.463E+00 6.614E+00 1.430E+00
35-BR- 79 1.293E+01 8.690E-01 5.790E+00 8.381E+00 1.470E+00
35-BR- 80 1.318E+01 7.950E-01 1.882E+01 5.695E+00 0.0
35-BR- 81 1.290E+01 8.310E-01 3.275E+00 7.733E+00 1.570E+00
35-BR- 82 1.266E+01 6.900E-01 5.789E+00 3.665E+00 0.0
---------------------------------------------------------------
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 3.192 FOR BR- 81 AND 5.0 FOR BR- 82.
REFERENCES
1) KAWAI, M. ET AL.: J. NUCL. SCI. TECHNOL., 29, 195 (1992).
2) MACKLIN, R.L.: NUCL. SCI. ENG., 99, 133 (1988).
3) OHKUBO, M., KAWARASAKI, Y., AND MIZUMOTO, M.:
NUCL. SCI. TECH. 18, 745 (1981).
4) MUGHABGHAB, S.F. ET AL.: "NEUTRON CROSS SECTIONS, VOL. I,
PART A", ACADEMIC PRESS (1981).
5) IGARASI, S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).
6) IIJIMA, S. ET AL.: JAERI-M 87-025, P. 337 (1987).
7) IIJIMA, S. AND KAWAI, M.: J. NUCL. SCI. TECHNOL., 20, 77
(1983).
8) PEREY, F.G: PHYS. REV. 131, 745 (1963).
9) HUIZENGA, J.R. AND IGO, G.: NUCL. PHYS. 29, 462 (1962).
10) LOHR, J.M. AND HAEBERLI, W.: NUCL. PHYS. A232, 381 (1974).
11) BECCHETTI, F.D., JR. AND GREENLEES, G.W.: POLARIZATION
PHENOMENA IN NUCLEAR REACTIONS ((EDS) H.H. BARSHALL AND
W. HAEBERLI), P. 682, THE UNIVERSITY OF WISCONSIN PRESS.
(1971).
12) GILBERT, A. AND CAMERON, A.G.W.: CAN. J. PHYS., 43, 1446
(1965).
13) IIJIMA, S., ET AL.: J. NUCL. SCI. TECHNOL. 21, 10 (1984).
14) GRUPPELAAR, H.: ECN-13 (1977).
15) ENSDF: EVALUATED NUCLEAR STRUCTURE DATA FILE (JUNE 1987).
16) NUCLEAR DATA SHEETS, 46, 487 (1985).
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).