68-ER-167 TIT EVAL-SEP00 A.K.M.HARUN-AR-RASHID+
DIST-MAR02 20020205
----JENDL-3.3 MATERIAL 6840
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
2000-09 Evaluation was performed by A.K.M.Harun-ar-Rashid (tit),
M.Igashira (tit), T.Ohsaki (tit), and K.Shibata (jaeri).
2001-02 Compiled by K.Shibata (jaeri).
mf=1 General information
mt=451 Descriptive data and dictionary
mf=2 Resonance parameters
mt=151
** Resolved resonances
Resonance region = 1.0e-5 eV to 591.0 eV
The multilevel Breit-Wigner formula was used. Resolved
resonance parameters from Ref. 1 or 2 (Ehi=591.0 eV).
Values of Gamma-gamma not given in Ref.1 or 2 are set to
0.089 eV. 30 resonances did not have values given for "J",
21 are assigned to J= 3 and the remaining 9 to J= 4 by random
method. The value for the scattering radius is 8.2fm, taken
from Ref.3 with small change with in the given error, so as
to produce the close value of the thermal neutron scattering
cross section recommended by Mughabghab (Ref. 3). Highest
energy resonance included is 590.1 eV. No background cross
sections were given.
** Unresolved resonance:
Unresolved resonance range: 591.0 to 1.0000e+04 eV
Scattering radius set to 8.2fm (same as resolved range).
Gamma-gamma set to 0.089 eV (same as resolved range).
Calculated 2200-m/s cross sections and res. integrals
2200-m/s res. integ.
elastic 1.335 b -
capture 642.274 b 2962.04 b
total 643.609 b -
mf=3 Neutron cross sections
mt=1 Total cross section
Spherical optical model calculation was made by using
casthy code [4]. Parameters are as follows,
V = 48.2-0.25*E-16.0*(N-Z)/A , r0=1.18, a0=0.63
Ws = 7.84-0.51*E , rs=1.29, as=0.63
Vso= 6.0 , rso=1.26, aso=0.63
(energies in MeV, lengths in fm).
mt=2 Elastic scattering cross section
The cross sections were obtained by subtracting a sum of
reaction cross sections from the total cross sections.
mt=4,51,52,.,73,91 Inelastic scattering cross sections
Calculated by using egnash code [5,6].
The direct-process component was considered for mt=51,52,62,
64,66 from dwba calculation by dwucky code [5,7] with a
weak coupling model.
The level scheme is given as follows:
no. energy(MeV) spin-parity
gs 0.0000 7/2 +
1 0.0793 9/2 +
2 0.1780 11/2 +
3 0.2078 1/2 -
4 0.2649 3/2 -
5 0.2816 5/2 -
6 0.2949 13/2 +
7 0.3466 5/2 -
8 0.4133 7/2 -
9 0.4300 7/2 -
10 0.4344 15/2 +
11 0.4420 9/2 -
12 0.5315 3/2 +
13 0.5358 9/2 -
14 0.5738 5/2 +
15 0.5874 17/2 +
16 0.6408 7/2 +
17 0.6452 11/2 -
18 0.6624 11/2 -
19 0.6679 5/2 -
20 0.6833 13/2 -
21 0.7110 11/2 +
22 0.7111 9/2 +
23 0.7453 7/2 +
Levels above 0.750MeV are assumed to be overlapping
mt=16,17,22,28,32,103,104,105,107 (n,2n), (n,3n), (n,n'a),
(n,n'p), (n,n'd)), (n,p), (n,d), (n,t), (n,a)
Calculated using egnash [5,6].
mt=102 Capture cross section
The capture cross section is based on the statistical model
calculations. The measured data of Ref.8 were taken into
account. The direct and semidirect capture cross sections
were added above 2 MeV by using the quick gnash code [6,9].
mf=4 Angular distributions of secondary neutrons
mt=2
Calculated with the casthy code.
mt=16,17,22,28,32,
Assumed to be isotropic in the laboratory system.
mt=51,---,73,91
Calculated with the casthy code.
For mt=51, the dwba component was taken into account.
mf=5 Energy distributions of secondary neutrons
mt=16,17,22,28,32,91
Calculated with the egnash code.
mf=12 Photon production multiplicities
mt=16,17,22,28,51-73,91,102,103,104,107
Calculated with the egnash code.
mf=14 Photon angular distributions
mt=16,17,22,28,51-74,91,102,103,104,107
Assumed to be isotropic.
mf=15 Photon energy distributions
mt=16,17,22,28,91,102,103,104,107
Calculated with the egnash code.
For mt=102, the measured data [10] are included at 45 and
550 keV.
References
1. Landolt-Boernstein New Series I/16B (Aug 1998).
2. Y. Danon et al.: Nucl. Sci. Eng., 128, 61 (1998).
3. S. F. Mughabghab: "Neutron Cross Sections: Vol. 1,
Neutron Resonance Parameters and Thermal Cross Sections,
Part B: Z=61-100," Academic press (1984).
4. S. Igarasi, T. Fukahori: JAERI 1321 (1991).
5. N. Yamamuro: JAERI-M 90-006 (1990).
6. P.G. Young et al.: LA-12343-MS, UC-413 (July 1992).
7. P.D. Kunz: Program DWUCK4, Computational Nuclear
Physics 2: Nuclear Reaction; edited by K. Langanke et al.
Published by Springer-Verlag (1992).
8. A.K.M. Harun-ar-Rashid et al.: J. Nucl. Sci. Technol., 37,
421 (2000).
9. N. Yamano: Private communication.
10. M. Igashira: Private communication (2001).