68-Er-162 TIT EVAL-SEP00 A.K.M. HARUN-AR-RASHID+
DIST-MAY10 20090902
----JENDL-4.0 MATERIAL 6825
-----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).
Evaluation was performed for jendl-3.3.
2009-09 Unresolved resonance parameters were obtained by K.Shibata
(jaea).
mf=1 General information
mt=451 Descriptive data and dictionary
mf=2 Resonance parameters
mt=151 Resolved and unresolved resonance parameters
Resolved resonance parameters (MLBW formula): below 250 eV
Resolved resonance parameters were taken from ref. 1
The bound level at -32.5 eV has Gamma-n = 0.11967 eV and
Gamma-gamma = 0.1 eV. This choice gives the desired
value for the thermal capture cross section, 19+-2 b [2].
Values of Gamma-gamma not given in Ref.1 are set to 0.1 eV.
The value for the scattering radius is 8.1fm. Highest
energy resonance included is 250.0 eV. No background cross
section is given.
Unresolved resonance region: 250 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 2.6946E+01
Elastic 8.0278E+00
n,gamma 1.8918E+01 4.5195E+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,.,67,91 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 0.1020 2 +
2 0.3295 4 +
3 0.6670 6 +
4 0.9007 2 +
5 1.0019 3 +
6 1.0871 0 +
7 1.0968 8 +
8 1.1280 4 +
9 1.1710 2 +
10 1.2863 4 +
11 1.3521 1 -
12 1.3567 3 -
13 1.4123 2 +
14 1.4204 0 +
15 1.4299 2 +
16 1.4597 6 +
17 1.4691 5 -
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 cross section was normalized to 253 mb
at 500 keV [6]. The direct and semidirect capture cross
sections were added above 2 MeV by using the quick gnash
code [7,8].
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,---,67,91
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=16,17,51-67,91,102,103,107
Calculated with the egnash code.
mf=14 Photon angular distributions
mt=16,17,51-67,91,102,103,107
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. Yu.N. Trofimov: Yadernye Konstanty, (2), 11 (1989).
7. P.G. Young et al.: LA-12343-MS, UC-413 (1992).
8. N. Yamano: Private communication.