68-Er-164 TIT EVAL-SEP00 A.K.M. HARUN-AR-RASHID+
DIST-MAY10 20091112
----JENDL-4.0 MATERIAL 6831
-----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).
2009-09 The resolved resonance paramters were modified by
T.Murata. The unresolved resonance parameters were
obtained by K.Shibata. The data were compiled by
K. Shibata.
mf=1 General information
mt=451 Descriptive data and dictionary
mf=2 Resonance parameters
mt=151 Resolved and unresolved resonance parameters
Resolved resonance region: below 800.0 eV
Resolved resonance parameters were taken from Ref. 1
The bound level at -24.4 eV has Gamma-n = 0.0738159 eV and
Gamma-gamma = 0.096 eV. This choice gives the desired
value for the thermal capture cross section, 13+-2 b [2].
Values of Gamma-gamma not given in Ref.1 are set to 0.096
eV. The value for the scattering radius is 8.1 fm.
Highest energy resonance included is 750.22 eV.
No background cross section is given.
In JENDL-4.0, the parameters for 7.92-eV resonance were
replaced with those for 7.90-eV resonance measured by
Danon et al./8/
Unresolved resonance region: 800 eV - 100 keV
The parameters were obtained by fitting to the calculated
total and capture cross sections. The unresolved resonance
parameters obtained should be used only for self-shielding
calculation.
Thermal cross sections and resonance integrals at 300 K
----------------------------------------------------------
0.0253 eV res. integ. (*)
(barns) (barns)
----------------------------------------------------------
Total 2.2013E+01
Elastic 9.1367E+00
n,gamma 1.2876E+01 1.6618E+02
----------------------------------------------------------
(*) Integrated from 0.5 eV to 10 MeV.
mf=3 Neutron cross sections
mt= 1 Total cross section
Spherical optical model calculation was made by using
casthy code [3]. 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,.,66,91 Inelastic scattering cross sections
Calculated by using egnash code [4].
The direct-process component was considered for mt=51
from dwba calculation by dwucky code. [4,5]
The level scheme is given as follows:
no energy(MeV) spin/parity
gs 0.0000 0 +
1 0.0914 2 +
2 0.2995 4 +
3 0.6144 6 +
4 0.8603 2 +
5 0.9464 3 +
6 1.0246 8 +
7 1.0583 4 +
8 1.1975 5 +
9 1.2460 0 +
10 1.3146 2 +
11 1.3586 6 +
12 1.3868 1 -
13 1.4166 4 +
14 1.4340 3 -
15 1.4699 4 +
16 1.4839 2 +
Levels above 1.500 MeV are assumed to be overlapping
mt= 16,17,22,28,103,104,105,107
(n,2n), (n,3n), (n,n'a), (n,n'p),
(n,p), (n,d), (n,t), (n,a)
Calculated using egnash [4].
mt=102 Capture cross secton
The capture cross section is based on the statistical model
calculations [3]. The direct and semidirect capture cross
sections were added above 2 MeV by using the quick gnash
code [6,7].
mf=4 Angular distributions of secondary neutrons
mt=2
Calculated with the casthy code.
mt=16,17,22,28
Assumed to be isotropic in the laboratory system.
mt=51,---,66,91
Calculated with the casthy code.
For mt=51, the dwba component was taken into account.
mf=5 Energy distributions of secondary neutrons
mt=16,17,22,28,91
Calculated with the egnash code.
mf=12 Photon production multiplicities
mt=16,17,51-66,91,102,103,107
Calculated with the egnash code.
mf=14 Photon angular distributions
mt=16,17,51-66,91,102,103,107
Assumed to be isotropic.
mf=15 Photon energy distributions
mt=16,17,91,102,103,107
References
1. Landolt-Boernstein New Series I/16B (Aug 1998).
2. S.F. Mughabghab: "Neutron Cross Sections: Vol. 1,
Neutron Resonance Parameters and Thermal Cross Sections,
Part B: Z=61-100," Academic Press (1984).
3. S. Igarasi, T. Fukahori: JAERI 1321 (1991).
4. N. Yamamuro: JAERI-M 90-006 (1990).
5. P.D. Kunz: Unpublished.
6. P.G. Young et al.: LA-12343-MS, UC-413 (1992).
7. N. Yamano: Private communication.