11-Na- 23 JAERI EVAL-AUG00 K.SHIBATA (JAERI)
DIST-MAY10 20100312
----JENDL-4.0 MATERIAL 1125
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
HISTORY
2000-8 New evaluation was performed by K.Shibata (JAERI) for
JENDL-3.3.
2002-1 Covariances were taken from JENDL-3.2 covariance file.
2010-3 Covariances for MF/MT=3/1,51-58,102 were re-estimated.
mf=1 General information
mt=451 Descriptive data and dictionary
mf=2 Resonance parameters
mt=151 Resolved resonance parameters
Resolved parameters for MLBW formula were given in the energy
region from 1.0e-5 eV to 350 keV. Parameters were mainly taken
from the recommended data of BNL /2/, and the data for some
levels were modified so that the calculated total cross sec-
tions for Na-23 were fitted to the experimental data. The
scattering radius was assumed to be 5.2 fermi. Calculated 2200
m/sec cross sections and resonance integrals are as follows:
2200 m/s cross section(b) res. integral(b)
elastic 3.024
capture 0.531 0.3122
total 3.555
This part was taken from JENDL-3.2 without any modification.
mf=3 Neutron cross sections
Below 350 keV, background cross section was given for the total
and elastic scattering cross sections. The cross-section data
are reproduced from the evaluated resolved resonance parameters
with MLBW formula. Above 350 keV, the total and partial cross
sections were given pointwise.
mt=1 Total
In the energies between 350 keV and 14 MeV, evaluated based on
the experimental data of Cierjacks/3/ by tracing their fine
structures. Above 14 MeV, based on the experimental data of
Langsford/4/, Stoler/5/ and Larson/1/. Modefication was done by
T.Fukahori(jaeri) to be based on the experimental data of only
Larson/1/ above 1 MeV.
The total cross section was taken from JENDL-3.2 without any
modification.
mt=2 Elastic scattering
Obtained by subtracting the sum of the partial cross sections
from the total cross section.
mt=4, 51-78, 91 Inelastic scattering
The cross sections were calculated by using the TNG code /6/.
The direct cross sections were taken into account for mt=51,52,
53,56. The deformation parameters were estimated by a weak
coupling model.
For mt=51, the TNG calculations were replaced with the following
data:
Threshold - 2.15 MeV: Maerten et al./7/ multiplied by 1.25
The factor of 1.25 was derived from
a benchmark test made by N. Yamano/8/.
2.15 - 4.0 MeV : JENDL-3.2 mt=51
The neutron optical potential parameters used are:
V = 45.82 - 0.2497*Ecm , Vso = 5.5 (MeV)
Ws = 7.4162 + 0.0049*Ecm (MeV)
r = 1.2572, rs = 1.1393, rso = 1.2687 (fm)
a = 0.61646, as = 0.60349, aso = 0.6198 (fm)
The level data used in the above calculations were taken
from RIPL /9/ as follows:
mt level energy(MeV) spin-parity
0.0 3/2+
51 0.440 5/2+
52 2.076 7/2+
53 2.391 1/2+
54 2.640 1/2-
55 2.704 9/2+
56 2.982 3/2+
57 3.678 3/2-
58 3.848 5/2-
59 3.914 5/2+
60 4.430 1/2+
61 4.775 7/2+
62 5.379 5/2+
63 5.534 11/2+
64 5.742 5/2+
65 5.766 3/2+
66 5.927 7/2+
67 5.964 3/2-
68 6.042 7/2-
69 6.115 5/2+
70 6.195 5/2-
71 6.236 9/2+
72 6.308 1/2+
73 6.354 9/2-
74 6.578 5/2+
75 6.618 5/2+
76 6.735 3/2+
77 6.820 5/2-
78 6.868 3/2+
Levels above 6.9 MeV were assumed to be overlapping.
mt=16, 22, 28, 103, 107 (n,2n),(n,na),(n,np),(n,p),(n,a)
Calculated with the TNG code. For mt=103, the TNG calculations
were replaced with the JENDL-3.2 data below 11 MeV.
mt=102 capture
In the energy region from 350 keV to 10 MeV, the cross
sections were calculated by TNG. Above 10 MeV, a constant
cross section of was assumed.
mf=4 Angular distributions of secondary neutrons
mt=2
Calculated with the optical model.
mt=51-78
Calculated with the TNG code and the DWUCK code/10/.
mf=6 Energy-angle distributions of secondary particles
mt=16, 22, 28, 91, 103, 107
Calculated with the TNG code.
mf=12 Photon production multiplicities
mt=4, 16, 22, 28, 51-78,102, 103, 107
Calculated with the TNG code.
For mt=102, the measured data /11/ were taken into account
between 50 keV and 400 keV.
mf=14 Photon angular distributions
mt=4, 16, 22, 28, 51-78, 102, 103, 107
Assumed to be isotropic.
mf=15 Continuous photon energy spectra
mt=4, 16, 22, 28, 102, 103, 107
Calculated with the TNG code.
For mt=102, the measured data /11/ were taken into account
between 50 keV and 400 keV.
mf=33 Covariances of cross sections (ref.12)
mt=1
Based on experimental data. A chi-value was 1.887.
mt=2
Constructed from mt=1, 16, 22, 28, 51-91, 102, 103, and 107.
mt=4
Constructed from mt=51-91.
mt=16
Based on experimental data. A chi-value was 1.36.
mt=22
The covariances were obtained by using kalman. A chi-value
was 2.54.
mt=28
The covariances were obtained by using kalman. A chi-value
was 2.54.
mt=51-91
The covariances were obtained by using kalman. A chi-value
was 3.72.
mt=102
Based on experimental data. A chi-value was 3.97.
mt=103
Based on experimental data. A chi-value was 2.3.
mt=107
Based on experimental data. A chi-value was 2.61.
=================================================================
For JENDL-4.0, variances for MT=1,51-58,102 were re-estimated by
considering the difference between the evaluated and measured
data.
=================================================================
mf=34 Covariances of angular distributions (ref.12)
mt=2
The covariances were obtained by using kalman. A chi-value
was 1.01.
References
1) Larson D.C. et al. : ORNL/TM-5614 (1976).
2) Mughabghab S.F. et al.:"Neutron Cross Sections", Vol. 1,
Part A (1981).
3) Cierjacks S. et al. : KfK-1000 (1969).
4) Langsford A. et al. : 1965 Antwerp Conf. 529 (1965).
5) Stoler P. et al. : 1971 Knoxville Conf. Vol.1, 311 (1971).
6) Shibata K. and Fu C.Y.: ORNL/TM-10093 (1986).
7) Maerten H. et al.: Taken from EXFOR (1994).
8) Yamano N.: Private communication (2001).
9) IAEA: "Handbook for Calculations of Nuclear Reaction Data:
Reference Input Parameter Library", IAEA-TECDOC-1034 (1998).
10) Kunz P.D.: Unpublished.
11) Igashira M.: Private communication (2000).
12) Shibata K. et al.: JAERI-Research 97-074 (1997).