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63-Eu-154 ORNL,BNL EVAL-MAY89 R.Q.WRIGHT, H.TAKAHASHI
DIST-JAN09 20090105
----JEFF-311 MATERIAL 6334
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
*************************** JEFF-3.1.1 *************************
** **
** Original data taken from: JEFF-3.1+New Eval **
** Modification: New MT=102 res par, G. Noguere **
******************************************************************
JEFF-3.1.1 Revision, March 2008, G.Noguere (CEA)
MF=2 RESONANCE PARAMETERS (Revised, Atlas of Neutron Resonance)
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ENDF/B-VI MOD 2 Revision, March 1998, R.Q. Wright (ORNL)
MF=2 RESONANCE PARAMETERS (Revised)
A negative level at -0.71 eV is added and the parameters for
the first positive resonance at 0.19 eV are revised. The
parameters for this resonance are now very nearly the same as
those of Anufriev [27].
The revised thermal cross sections are as follows:
2200 m/sec cross sections (barns)
total 1853.14
elastic 6.65
capture 1846.49
Capture resonance integral = 1357 barns
The thermal capture cross section in the revised evaluation is
in good agreement with the measured value of Sekine [28],
1840 +/- 90 barns.
*****************************************************************
ENDF/B-VI MOD 1 Evaluation, May 1989, R.Q. Wright (ORNL)
ENDF/B-V material converted to ENDF-6 format by NNDC
The ENDF/B-V evaluation, MAT 1293, has been revised below
10 keV.
MF= 2 RESONANCE PARAMETERS
RESOLVED RESONANCE PARAMETERS, are revised, taken from
Mughabghab [26] and are used to delfine the total, elastic,
and capture cross sections for energies between 0.00001 and
27.8 eV. A MLBW formalism is used. The original resonance
parameters in the energy range 27.8 to 63.0 eV are modified
as follows.
E0 same as ENDF/B-V (MAT 1293)
GN = GN/(2.0*G) (to keep same value of 2G*GN)
GG = GG*1.3125 (to get average width= 0.126)
GT = GN+GG
Average reduced neutron width = 4.44540E-04
Average gamma width = 1.25926E-01
Strength function = 2.19309E-04
UNRESOLVED RESONANCE RANGE, UPPER LIMIT IS 10 KEV
The unresolved resonance parameters are based on the data
of Mughabghab [26].
Average gamma width = 0.1260 EV
D0 (Maughabghab 0.92 EV) = 0.9752 EV
S0 (not given in Mughabghab) = 2.5709E-04
MF= 3 SMOOTH CROSS SECTIONS
Elastic and capture backgrounds are zero below 10 keV.
MT= 1 Total cross section was revised by small amounts at 21
points between 8.7 and 11.8 MeV to agree with the sum of the
partial cross sections.
MT= 2 Elastic cross section at 10 keV was reduced to 13.8
barns.
MT=102 Capture cross section at 30 keV is 2920 mb (unchanged).
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ENDF/B-V MAT 1293 Translation, December 1978, F. Mann and
R. Schenter (HEDL)
****************************************************************
ENDF/B-IV MAT Evaluation, December 1973, H. Takahashi (BNL)
Almost no experimental data are available for 154Eu, so the
evaluations was mostly carried out by nuclear model calculations.
MT= 2 RESONANCE PARAMETERS
Replaced in ENDF/B-VI.
MT= 3 SMOOTH CROSS SECTIONS
MT= 1 Total cross section
Between 10 keV and 2.5 MeV, the total cross sections were
calculated using ABACUS-2 [6] Optical Model code. The
Optical Model parameters used in the calculation will be
shown in a later section. Above 2.5 MeV, the total cross
sections were assumed to be the same as the experimental
values of natural europium measured by Foster [7].
MT= 2 Elastic scattering cross sections
The elastic scattering cross sections in the energy higher
than the unresolved resonance energy were obtained by
substructing the non elastic cross section from the evaluated
total cross section.
MT= 3 Nonelastic scattering cross section
The nonelastic scattering cross section was calculated by
summing up all cross sections except the elastic scattering
cross section.
MT= 4,51,52...,91 Inelastic scattering cross sections
The inelastic scattering cross sections are given as total
(MT=4), discrete level excitation cross section (MT=51...) for
the first 5 levels and continuum level excitation cross
section (MT=91). The level scheme for these discrete level is
taken from Refs. [9,10,11,12,13].
Since no experimental data are available for the individual
level excitation cross sections, they were calculated using
COMNUC-3 [14] for energies up to 3 MeV. Above 3 MeV,
inelastic scattering is mostly the excitation of the
continuum of levels, so that the inelastic scattering cross
section for discrete level excitation above this energy was
neglected and the inelastic scattering cross section for
continuum level excitation was calculated by the Cascade
calculation using GROGI-3 [15]. The level density parameters
for the continuum of levels were taken from Cook's data [17]
for the deformed nuclei using the Gilbert-Cameron formula [18]
MT= 16,17 (n,2n), (n,3n) cross sections
These cross sections were calculated by using GROGI-3. The
Optical Model parameters described in the later section were
used.
MT=102 Radiative capture cross section
The radiative capture cross sections at low energy range were
calculated from the File 2 resonance parameters and are given
as smooth cross sections. The cross sections between 100 eV
and 10 keV are presented as unresolved resonance parameters.
For energy higher than 10 keV, the cross sections were
calculated using COMNUC-3. The calculation was done similarly
to the ones for Eu151 and Eu153 [7], that is, Moldauer's
Q value was assumed to be zero, and the correlation correction
factor due to the degrees of freedom associated with open
channels was taken into account. From 3 MeV to 20 MeV, the
capture cross section was obtained by GROGI-3 for the compound
process, by Cvelbar's formula [21] based on Lane-Lynn [22]
and Brown's [23] formula for the direct and semi-direct
reaction.
MT=103,28 (n,p) and (n,n',p) cross sections
No experimental values were available, so that we calculated
these by nuclear model codes. For (n,p) reaction, the semi-
empirical Statistical Model code THRESH [20] was used. But
the evaluation [7] of Eu151 and Eu153 indicated that the
cross sections around 14 MeV calculated by this code were
small compared to the experimental values. thus, the
calculated cross sections were normalized by the factors
obtained for Eu151. The (n,n'p) cross sections were
calculated using GROGI-3.
MT=104,105,107 (n,d), (n,t), (n,He3) reaction cross sections
The cross sections calculated by THRESH were adopted.
MT=107,22 (n,alpha) and (n,n'd) cross sections
These cross sections were obtained in a similar manner to the
(n,p) and (n,n'p) reactions.
MT= 4 ANGULAR DISTRIBUTION OF SECONDARY NEUTRONS
MT= 2 Elastic scattering
Calculated by ABACUS-2 (NABAK PDP-10 version) [6]. The
Legendre coefficients calculated by CHAD (NUCHAD in PDP-10
version) [24] were given. Since the elastic scattering due
to the nuclear compound process is small in the energy range
above 3 MeV, the elastic angular distribution of was
calculated by taking only the shape elastic scattering into
account above 3 MeV.
MT= 51,...,91,16,17,22,23 Inelastic scattering,(n,2n),(n,3n),
(n,n'p), and (n,n'alpha)
Assumed to be isotropic in the center-of-mass system.
MT= 5 ENERGY DISTRIBUTION OF SECONDARY NEUTRONS
MT= 16,16,91 (n,2n),(n,3n),(n,n')
Energy distributions of neutron were assumed to be
Maxwellian. The effective temperatures were obtained by the
Weiskopf formula [25].
****************************************************************
REFERENCES
1. J.L. Cook, report AAEC/TM-549 (1969)
2. D.W. Barr and J.H. Devaney, report LA-3643 (1967)
3. R.J. Hayden et. al., Phys.Rev. 75, 1500 (1949)
4. W.H. Walker, Chalk River report AECL-3037, Part I (1969)
5. S.F. Mughabghab and D. Garber, report BNL-325, 3rd Ed.,
Vol.1 (1973)
6. E.H. Auerbach, report BNL-6562 (1962)
7. H. Takahashi, report BNL-19455 (1974) [ENDF-213]
8. D.G. Foster Jr. and D.W. Glasgow, Phys.Rev.C 3, 576 (1971)
9. T. Lewis and R. Graetzer, Nucl.Phys. A162, 145 (1971)
10. A. Faessler and H.G. Wahsweiler, Nucl.Phys. 59, 202 (1964)
11. L.V. Groshev et al., Nucl.Data Table A5, 1 (1968)
12. D.J. Horen et al., "Nuclear Level Scheme A=45 through A=257,"
to be published in Nucl.Data Tables
13. C. Lederer, J. Hollander and I. Perlman, Table of Isotopes,
6th Ed. (1967)
14. C. Dunford, report AI-AEC-12931 (1970) and private
communication (COMNUC-3 code) (1971)
15. H. Takahashi, GROGI-III, modified from GROGI-2. (1 7)
16. J. Gilat, report BNL-50246 (1970)
17. J.L. Cook, H. Ferguson and A.R. de L. Musgrove, report
AAEC/TM-392 (1967)
18. A. Gilbert and A.G.W. Cameron, Can.J.Phys. 43, 1446 (1965)
19. T. Tamura, Rev.Mod.Phys. 37, 679 (1965)
20. S. Pearlstein, J.Nucl.En. 27, 81 (1973)
21. F. Cvelbar et al., NIJS report T-529 (1968)
22. A.M. Lane and J.E. Lynn, Peaceful Uses of Atomic Energy,
Proc. Conf., Geneva, 1958, Vol.15 (United Nations, 1958) p.38
23. G.E. Brown, Nucl.Phys. 57, 339 (1964)
24. R.F. Berland, Atomics Int. report NAA-SR-11231 (1965)
25. A. Weinberg and E. Wigner, The Physical Theory of Reactors
(U. of Chicago Press, 1959)
26. S.F. Mughabghab, Neutron Cross Sections, Vol. 1, Part B,
Z=61-100 (Academic Press 1984)
27. V.A. Anufriev et al., Sov.At.En. 46, 182 (1979); translated
from At.En. 46, 158 (1979). [Data from EXFOR40484]
28. T. Sekine, S. Ichikawa and S. Baba, Appl.Rad.Isotopes 38,
513 (1987)
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