56-Ba-136
56-Ba-136 JNDC EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.
DIST-MAY10 20091217
----JENDL-4.0 MATERIAL 5643
-----INCIDENT NEUTRON DATA
------ENDF-6 FORMAT
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Resonance parameters in JENDL-3.3 were revised for JENDL-4.
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JENDL-3.2 data were automatically transformed to JENDL-3.3.
Interpolation of spectra: 22 (unit base interpolation)
(3,251) deleted, T-matrix of (4,2) deleted, and others.
===========================================================
History
84-10 Evaluation for JENDL-2 was made by JNDC FPND W.G./1/
90-03 Modification for JENDL-3 was made/2/.
10-03 JENDL-4.0 was made.
Resoloved resonance parameters were evaluated by K.Shibata.
Unresolved resonance parameters were evaluated by S.Kunieda.
The LSSF=1 was applied.
Compiled by S.Kunieda
***** modified parts for JENDL-4.0 ********************
(1,451) Updated.
(2,151) Updated.
(3,1) Re-calculated from partial cross sections.
(3,2) Calculated from URP in lower energy range.
(3,4) Re-calculated from partial cross sections.
(3,102) Calculated from URP in lower energy range.
***********************************************************
mf = 1 General information
mt=451 Comments and dictionary
mf = 2 Resonance parameters
mt=151 Resolved and unresolved resonance parameters
Resolved resonance parameters for MLBW formula (below 34.49 keV)
The parameters are the same as JENDL-2 evaluated by Kikuchi et
al./3/ on the basis of experimental data of Alves et al./4/,
Van de Vyver and Pattenden/5/ and Musgrove et al./6/ The
average radiation width of 0.125 eV/7/ was assumed. Below 3
keV, 6 artificial levels were generated with stat/8/ by
assuming d = 225 eV, S0 = 0.8e-4/7/, S1 = 0.8e-4 and the
radiation width of 0.125 eV. A negative resonance was added
by referring to Ref./7/ in order to reproduce the capture
cross section of 0.4 barns at 0.0253 eV/7/.
*************************************************************
Resolved resonance paramters were taken from the work of
Koehler et al./28/ A total spin J was determined by a
random number method. A negative resonance was added so
as to reproduce the thermal capture cross section
recommended by Mughabghab./29/
*************************************************************
Unresolved resonance region : 34.49 keV - 100 keV
Unresolved resonance parameters were adopted from JENDL-2.
The neutron strength functions, S0, S1 and S2 were calculated
with optical model code CASTHY/9/. The observed level spacing
was determined to reproduce the capture cross section
calculated with CASTHY. The effective scattering radius was
obtained from fitting to the calculated total cross section at
100 keV.
Typical values of the parameters at 70 keV:
S0 = 0.520e-4, S1 = 0.850e-4, S2 = 0.550e-4, Sg = 1.32e-4,
Gg = 0.112 eV, R = 5.288 fm.
***************************************************************
For JENDL-4.0, the unresolved resonance parameters were
re-evaluated by the ASREP /30/ code so as to reproduce the
total and capture cross sections given in JENDL3.3 in the
energy region from 34.49 keV to 200 keV. The parameters
should be used only for self-shielding calculations.
***************************************************************
Thermal cross sections & resonance integrals at 300 K
----------------------------------------------------------
0.0253 eV res. integ. (*)
(barns) (barns)
----------------------------------------------------------
Total 3.44386E+00
Elastic 2.76338E+00
n,gamma 6.80477E-01 1.91575E+00
----------------------------------------------------------
(*) Integrated from 0.5 eV to 10 MeV.
mf = 3 Neutron cross sections
Below 100 keV, resonance parameters were given.
Above 100 keV, the spherical optical and statistical model
calculation was performed with CASTHY, by taking account of
competing reactions, of which cross sections were calculated
with PEGASUS/10/ standing on a preequilibrium and multi-step
evaporation model. The OMP's for neutron given in Table 1 were
determined to reproduce a systematic trend of the total cross
section by changing Ws and rso of Iijima-Kawai potential/11/.
The OMP's for charged particles are as follows:
proton = Perey/12/
alpha = Huizenga and Igo/13/
deuteron = Lohr and Haeberli/14/
helium-3 and triton = Becchetti and Greenlees/15/
Parameters for the composite level density formula of Gilbert
and Cameron/16/ were evaluated by Iijima et al./17/ More
extensive determination and modification were made in the
present work. Table 2 shows the level density parameters used
in the present calculation. Energy dependence of spin cut-off
parameter in the energy range below E-joint is due to Gruppelaar
/18/.
mt = 1 Total
Spherical optical model calculation was adopted.
mt = 2 Elastic scattering
Calculated as (total - sum of partial cross sections).
mt = 4, 51 - 91 Inelastic scattering
Spherical optical and statistical model calculation was
adopted. The level scheme was taken from Ref./19/.
no. energy(MeV) spin-parity dwba cal.
gr. 0.0 0 +
1 0.8186 2 + *
2 1.5505 2 +
3 1.5792 0 +
4 1.8663 4 +
5 2.0540 4 +
6 2.0799 2 +
7 2.1280 2 +
8 2.1402 5 -
9 2.1415 0 +
10 2.2071 6 +
Levels above 2.284 MeV were assumed to be overlapping.
For the levels with an asterisk, the contribution of direct
inelastic scattering cross sections was calculated by the
DWUCK-4 code/20/. Deformation parameter (beta2 = 0.1242) was
based on the data compiled by Raman et al./21/
mt = 102 Capture
Spherical optical and statistical model calculation with
CASTHY was adopted. Direct and semi-direct capture cross
sections were estimated according to the procedure of Benzi
and Reffo/22/ and normalized to 1 milli-barn at 14 MeV.
The gamma-ray strength function (1.22e-04) was adjusted to
reproduce the capture cross section of 45 milli-barns at 70
keV measured by Musgrove et al./23/
mt = 16 (n,2n) cross section
mt = 17 (n,3n) cross section
mt = 22 (n,n'a) cross section
mt = 28 (n,n'p) cross section
mt =103 (n,p) cross section
mt =104 (n,d) cross section
mt =105 (n,t) cross section
mt =107 (n,alpha) cross section
These reaction cross sections were calculated with the
preequilibrium and multi-step evaporation model code PEGASUS.
The Kalbach's constant k (= 257.1) was estimated by the
formula derived from Kikuchi-Kawai's formalism/24/ and level
density parameters.
Finally, the (n,2n), (n,p) and (n,alpha) cross sections were
normalized to the following values at 14.5 MeV:
(n,2n) 1670.00 mb (systematics of Wen Den Lu+/25/)
(n,p) 6.00 mb (measured by Ikeda+/26/)
(n,alpha) 2.04 mb (systematics of Forrest/27/)
mt = 251 mu-bar
Calculated with CASTHY.
mf = 4 Angular distributions of secondary neutrons
Legendre polynomial coefficients for angular distributions are
given in the center-of-mass system for mt=2 and discrete inelas-
tic levels, and in the laboratory system for mt=91. They were
calculated with CASTHY. Contribution of direct inelastic
scattering was calculated with DWUCK-4. For other reactions,
isotropic distributions in the laboratory system were assumed.
mf = 5 Energy distributions of secondary neutrons
Energy distributions of secondary neutrons were calculated with
PEGASUS for inelastic scattering from overlapping levels and for
other neutron emitting reactions.
TABLE 1 NEUTRON OPTICAL POTENTIAL PARAMETERS
DEPTH (MEV) RADIUS(FM) DIFFUSENESS(FM)
---------------------- ------------ ---------------
V = 41.8 R0 = 6.89 A0 = 0.62
WS = 2.95+0.789E RS = 7.098 AS = 0.35
VSO= 7.0 RSO= 6.89 ASO= 0.62
THE FORM OF SURFACE ABSORPTION PART IS DER. WOODS-SAXON TYPE.
TABLE 2 LEVEL DENSITY PARAMETERS
NUCLIDE A(1/MEV) T(MEV) C(1/MEV) EX(MEV) PAIRING
---------------------------------------------------------------
54-XE-132 1.563E+01 6.500E-01 5.485E-01 6.600E+00 2.160E+00
54-XE-133 1.600E+01 6.250E-01 2.327E+00 5.284E+00 1.120E+00
54-XE-134 1.400E+01 6.300E-01 3.184E-01 5.224E+00 1.820E+00
54-XE-135 1.550E+01 5.565E-01 7.506E-01 4.010E+00 1.120E+00
55-CS-133 1.750E+01 6.000E-01 3.784E+00 5.352E+00 1.040E+00
55-CS-134 1.598E+01 6.450E-01 1.710E+01 4.505E+00 0.0
55-CS-135 1.343E+01 6.537E-01 1.831E+00 4.203E+00 7.000E-01
55-CS-136 1.400E+01 6.000E-01 4.424E+00 2.967E+00 0.0
56-BA-134 1.800E+01 6.100E-01 4.177E-01 7.309E+00 2.620E+00
56-BA-135 1.902E+01 5.820E-01 2.277E+00 6.108E+00 1.580E+00
56-BA-136 1.610E+01 6.500E-01 5.721E-01 6.928E+00 2.280E+00
56-BA-137 1.645E+01 5.640E-01 5.394E-01 4.905E+00 1.580E+00
---------------------------------------------------------------
Spin cutoff params were calculated as 0.146*sqrt(a)*a**(2/3).
In the CASTHY calculation, spin cutoff factors at 0 MeV were
assumed to be 6.925 for Ba-136 and 5.625 for Ba-137.
References
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and Applied Science, Santa Fe., Vol. 2, p.1627 (1985).
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(1971).
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Part A", Academic Press (1981).
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(1983).
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W. Haeberli), p. 682, the University of Wisconsin Press.
(1971).
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(1965).
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interscience Publication (1978).
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(1987)
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Physics and Nucl. Data for Reactors, Harwell 1978, 449.
24) Kikuchi, K. and Kawai, M.: "Nuclear Matter and Nuclear
Reactions", North Holland (1968).
25) Wen Den Lu and Fink, R.W.: Phys. Rev., C4, 1173 (1971).
26) Ikeda, Y. et al.: JAERI 1312 (1988).
27) Forrest, R.A.: AERE-R 12419 (1986).
28) Koehler, P.E. et al.: Phys. Rev., C54, 1463 (1996).
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(2006).
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[in Japanese].