54-Xe-131 JAEA EVAL-FEB22 S.Kunieda, A.Ichihara, K.Shibata+
DIST-MAY10 20100316
----JENDL-4.0 MATERIAL 5446
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
History
09-11 Re-evaluation was performed for JENDL-4.0
10-03 Compiled by S.Kunieda
MF= 1 General information
MT=451 Descriptive data and directory
MF= 2 Resonance parameters
MT=151 Resolved and unresolved resonance parameters
- Resolved resonance region (MLBW formula): below 2.25 keV
Resonance parameters of JENDL-3.3 were mainly based on the
data measured by Ribon et al./1/. The neutron orbital
angular momentum l was assumed to be 0 for all the 40
resonance levels up to 4 keV. The neutron widths of the 40
levels were derived from the g*(neutron width) data measured
by Ribon et al. However, the value of total spin j for each
resonance level was unknown except 24 levels assigned by
Ribon et al. In JENDL-3.3, the total spin j of 16 resonance
levels was tentatively estimated with a random number
method. The radiation widths of 24 resonance levels were
given by Ribon et al.; those of 6 levels were obtained from
the difference between total and neutron widths. For the
remaining 10 levels, the weighted average radiation width of
111.94 meV was derived from the above 24 radiation widths,
and was assigned to them. A negative resonance level was
added at -84 eV so as to reproduce the thermal capture cross
section of 85+-10 barns given by Mughabghab et al./2/
The scattering radius was also taken from the graph (fig. 1,
Part A) given by Mughabghab et al.
In JENDL-4, the values of total spin j at 49.508 eV,
992.98 eV, 1884.6 eV, and 2082.7 eV were changed in order to
keep the consistency among the neutron, radiation, and total
widths. With the change of the j-values, the widths at some
resonance levels were modified. The weighted average value
of radiation widths was also slightly modified from 111.94
eV to 111.84 eV. The data of p-wave resonance measured at
3.2 eV by Skoy et al./3/ were compiled in this edition.
Moreover, the parameters at 14.41 eV were replaced with
those at 14.47 eV obtained by Skoy et al./4/
The negative resonance level was modified so as to reproduce
the thermal capture cross section of 100+-6 barns at 0.0253
eV measured by lucas et al./5/.
- Unresolved resonance region: 3.6 keV - 150 keV
The parameters were obtained by fitting to the total and
capture cross sections calculated by the POD code /6/.
The ASREP code /7/ was employed in this evaluation.
The unresolved parameters should be used only for
self-shielding calculation.
Thermal cross sections & resonance integrals at 300 K
----------------------------------------------------------
0.0253 eV res. integ. (*)
(barns) (barns)
----------------------------------------------------------
Total 1.31493E+02
Elastic 3.18080E+01
n,gamma 9.96848E+01 9.09207E+02
----------------------------------------------------------
(*) Integrated from 0.5 eV to 10 MeV.
MF= 3 Neutron cross sections
MT= 1 Total cross section
Sum of partial cross sections.
MT= 2 Elastic scattering cross section
The OPTMAN /8/ & POD /6/ calculations.
MT= 3 Non-elastic cross section
Sum of partial non-elastic cross sections.
MT= 4,51-91 (n,n') cross section
The OPTMAN /8/ & POD /6/ calculations.
MT= 16 (n,2n) cross section
MT= 17 (n,3n) cross section
MT= 22 (n,na) cross section
MT= 28 (n,np) cross section
MT= 32 (n,nd) cross section
Calculated by the POD code /6/.
MT=102 Capture cross section
Calculated by the POD code /6/. The value of gamma-ray
strength function was set to the recomendation value by
Mughabghab /9/.
MT=103 (n,p) cross section
MT=104 (n,d) cross section
MT=105 (n,t) cross section
MT=106 (n,He3) cross section
MT=107 (n,a) cross section
Calculated by the POD code /6/.
MT=203 (n,xp) cross section
Sum of (n,np) and (n,p)
MT=204 (n,xd) cross section
Sum of (n,nd) and (n,d)
MT=205 (n,xt) cross section
MT=206 (n,xHe3) cross section
Calculated by the POD code /6/.
MT=207 (n,xa) cross section
Sum of (n,na) and (n,a)
MF= 4 Angular distributions of emitted neutrons
MT= 2 Elastic scattering
The OPTMAN /8/ & POD /6/ calculations.
MF= 6 Energy-angle distributions of emitted particles
MT= 16 (n,2n) reaction
MT= 17 (n,3n) reaction
MT= 22 (n,na) reaction
MT= 28 (n,np) reaction
MT= 32 (n,nd) reaction
Neutron spectra calculated by the POD code /6/.
MT= 51-90 (n,n') reaction
Neutron angular distributions calculated by
OPTMAN /8/ & POD /6/.
MT= 91 (n,n') reaction
Neutron spectra calculated by the POD code /6/.
MT= 203 (n,xp) reaction
MT= 204 (n,xd) reaction
MT= 205 (n,xt) reaction
MT= 206 (n,xHe3) reaction
MT= 207 (n,xa) reaction
Light-ion spectra calculated by the POD code /6/.
MF=12 Gamma-ray multiplicities
MT= 3 Non-elastic gamma emission
Calculated by the POD code /6/.
MF=14 Gamma-ray angular distributions
MT= 3 Non-elastic gamma emission
Assumed to be isotropic.
MF=15 Gamma-ray spectra
MT= 3 Non-elastic gamma emission
Calculated by the POD code /6/.
***************************************************************
* Nuclear Model Calculations with POD Code /6/ *
***************************************************************
1. Theoretical models
The POD code is based on the spherical optical model, the
distorted-wave Born approximaiton (DWBA), one-component exciton
preequilibrium model, and the Hauser-Feshbach-Moldauer statis-
tical model. With the preequilibrium model, semi-empirical
pickup and knockout process can be taken into account for
composite-particle emission. The gamma-ray emission from the
compound nucleus can be calculated within the framework of the
exciton model. The code is capable of reading in particle
transmission coefficients calculated by separate spherical or
coupled-channel optical model code. In this evaluation, the OPTMAN
code /8/ was employed for neutrons, while the ECIS code
/10/ was adopted for charged particles.
2. Optical model & parameters
Neutrons:
Model: The coupled-channel method based on the rigid-rotor
model was adopted. Deformation parameter beta2 was
taken from ref./11/
OMP : Coupled-channel optical potential /12/ was applied.
Protons:
Model: Spherical
OMP : Koning and Delaroche /13/
Deuterons:
Model: Spherical
OMP : Bojowald et al. /14/
Tritons:
Mode: Spherical
OMP : Becchetti and Greenlees /15/
He-3:
Model: Spherical
OMP : Becchetti and Greenlees /15/
Alphas:
Model: Spherical
OMP : A simplified folding model potential /16/
(The nucleon OMP was taken from Ref./12/.)
3. Level scheme of Xe-131
------------------------------------
No. Ex(MeV) J PI CC
------------------------------------
0 0.00000 3/2 + *
1 0.08019 1/2 +
2 0.16393 11/2 -
3 0.34114 9/2 -
4 0.36449 5/2 + *
5 0.40481 3/2 +
6 0.56519 1/2 +
7 0.63699 7/2 +
8 0.66693 7/2 -
9 0.69990 3/2 +
------------------------------------
Levels above 0.70990 MeV are assumed to be continuous.
4. Level density parameters
Energy-dependent parameters of Mengoni-Nakajima /17/ were used
----------------------------------------------------------
Nuclei a* Pair Esh T E0 Ematch Elv_max
1/MeV MeV MeV MeV MeV MeV MeV
----------------------------------------------------------
Xe-132 16.240 2.089 -1.146 0.723 0.006 8.026 2.425
Xe-131 16.786 1.048 -0.172 0.686 -1.237 7.025 0.700
Xe-130 16.030 2.105 0.158 0.675 0.108 7.673 2.544
Xe-129 16.580 1.057 0.970 0.676 -1.490 7.279 0.589
I -131 15.458 1.048 -1.637 0.769 -1.003 7.186 1.623
I -130 15.945 0.000 -0.675 0.824 -3.544 8.206 0.070
I -129 15.256 1.057 -0.097 0.711 -0.934 6.797 1.204
Te-129 20.892 1.057 -1.456 0.590 -0.837 6.047 0.360
Te-128 15.820 2.121 -0.935 0.757 -0.307 8.631 2.488
Te-127 18.544 1.065 0.107 0.594 -0.817 6.052 0.764
----------------------------------------------------------
5. Gamma-ray strength functions
M1, E2: Standard Lorentzian (SLO)
E1 : Generalized Lorentzian (GLO) /18/
6. Preequilibrium process
Preequilibrium is on for n, p, d, t, He-3, and alpha.
Preequilibrium capture is on.
References
1) Ribon, P. et al.: CEA-N-1149 (1969).
2) Mughabghab, S.F. et al.: "Neutron Cross Sections, Vol. I,
Part A", Academic Press (1981).
3) Skoy, V.R. et al. Phys. Rev., C53, 2573 (1996).
4) Skoy, V.R. et al.: Nucl. Instrum. Meth. Phys. Res., B267,
2351 (2009).
5) Lucas, M. et al.: 77Paris, 1, 431 (1977).
6) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007).
7) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999)
[in Japanese].
8) E.Soukhovitski et al., JAERI-Data/Code 2005-002 (2005).
9) S.F.Mughabghab, "Atlas of Neutron Resonances",
Elsevier (2006).
10) J.Raynal, CEA Saclay report, CEA-N-2772 (1994).
11) S.Raman et al., At. Data and Nucl. Data Tables 78, 1 (1995)
12) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007).
13) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003).
14) Bojowald et al., Phys. Rev. C 38, 1153 (1988).
15) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization
Phenomena in Nuclear Reactions," p.682, The University
of Wisconsin Press (1971).
16) D.G.Madland, NEANDC-245 (1988), p. 103.
17) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151
(1994).
18) M.Brink, Ph.D thesis, Oxford University, 1955.