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 =========================================================== Resonance parameters in JENDL-3.3 were revised for JENDL-4. =========================================================== =========================================================== 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). 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