56-Ba-135 JNDC EVAL-MAR90 JNDC FP NUCLEAR DATA W.G. DIST-MAY10 20091217 ----JENDL-4.0 MATERIAL 5640 -----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/. 93-11 JENDL-3.2 was made by JNDC FPND W.G. ***** modified parts for JENDL-3.2 ******************** (2,151) Resolved resonance parameters. Negative resonance parameters were slightly modified. *********************************************************** 10-03 JENDL-4.0 was made. 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) Unresolved resonance parameters were 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 region (MLBW formula) : below 5.96 keV the evaluation for JENDL-2 was made by Kikuchi/3/. For the resonances below 1.4 keV, neutron widths were obtained from the experimental data of Alves et al./4/ and Van de Vyver and Pattenden/5/. Radiation widths were based on the data of Alves et al. or average value of 0.15 eV by Musgrove et al./6/ above 3 keV, parameters were determined from the data of Musgrove et al. In the energy range below 3 keV, many artificial levels were generated with stat/7/ by assuming d=39.3 eV, S0=0.8e-4, S1=0.48e-4 and average radiation width of 0.15 eV. A negative resonance was added so as to reproduce the capture cross section of 5.8+-0.9 barns at 0.0253 eV/8/. For JENDL-3, the JENDL-2 data were modified on the basis of the latest experimental data of Mizumoto/9/. Resonance energies and neutron widths of JENDL-2 were partially modified with Mizumoto's data in the energy range form 404.5 eV to 4.95 keV. Total spin J of some resonances was tentatively estimated with a random number method. The parameters of negative level were adjusted to the capture cross section recommended by Mughabghab et al./8/ For JENDL-3.2, a slight modification of the negative level was made. Unresolved resonance region : 5.96 keV - 100 keV Parameters were adjusted to reproduce the capture cross section calculated with CASTHY/10/ (JENDL-2 value) below 40 keV, and the capture cross section measured by Musgrove et al./11/ above 40 keV. The initial values of neutron strength functions, S0 and S1, were adopted from the recommendation by Mughabghab et al., and S2 was taken from calculation with CASTHY/10/. The effective scattering radius was obtained from fitting to the calculated total cross section at 100 keV. The radiation width Gg was based on the compilation of of Mughabghab et al. Typical values of the parameters at 70 keV: S0 = 0.922e-4, S1 = 0.491e-4, S2 = 0.584e-4, Sg = 70.2e-4, Gg = 0.150 eV, R = 5.232 fm. *************************************************************** For JENDL-4.0, the unresolved resonance parameters were re-evaluated by the ASREP /26/ code so as to reproduce the total and capture cross sections given in JENDL3.3 in the energy region from 5.96 keV to 250 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 7.60237E+00 Elastic 1.80455E+00 n,gamma 5.79783E+00 1.31270E+02 ---------------------------------------------------------- (*) 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/12/ 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/13/. The OMP's for charged particles are as follows: proton = Perey/14/ alpha = Huizenga and Igo/15/ deuteron = Lohr and Haeberli/16/ helium-3 and triton = Becchetti and Greenlees/17/ Parameters for the composite level density formula of Gilbert and Cameron/18/ were evaluated by Iijima et al./19/ 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 /20/. 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./21/. no. energy(MeV) spin-parity gr. 0.0 3/2 + 1 0.2210 1/2 + 2 0.2682 11/2 - 3 0.4806 5/2 + 4 0.5879 3/2 + 5 0.8550 3/2 + 6 0.8745 7/2 + 7 0.9800 3/2 + Levels above 1.17 MeV were assumed to be overlapping. 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 (5.93e-03) was adjusted to reproduce the capture cross section of 250 milli-barns at 100 keV measured by Musgrove et al./11/ 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 = 32 (n,n'd) cross section 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,alpha) cross section These reaction cross sections were calculated with the preequilibrium and multi-step evaporation model code PEGASUS. The Kalbach's constant k (= 268.3) was estimated by the formula derived from Kikuchi-Kawai's formalism/23/ 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) 1630.00 mb (systematics of Wen Den Lu+/24/) (n,p) 5.88 mb (systematics of Forrest/25/) (n,alpha) 2.64 mb (systematics of Forrest) 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. For other reactions, isotropic distri- butions 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 to 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 SYST A(1/MEV) T(MEV) C(1/MEV) EX(MEV) PAIRING --------------------------------------------------------------- 54-XE-131 1.740E+01 6.000E-01 3.176E+00 5.394E+00 1.120E+00 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 55-CS-132 * 1.676E+01 5.726E-01 1.123E+01 3.569E+00 0.0 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 56-BA-133 1.941E+01 5.930E-01 3.357E+00 6.465E+00 1.580E+00 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 --------------------------------------------------------------- syst: * = ldp's were determined from systematics. Spin cutoff parameters were calculated as 0.146*sqrt(a)*a**(2/3). In the CASTHY calculation, spin cutoff factors at 0 MeV were assumed to be 5.285 for Ba-135 and 6.925 for Ba-136. References 1) Aoki, T. et al.: Proc. Int. Conf. on Nuclear Data for Basic and Applied Science, Santa Fe., Vol. 2, p.1627 (1985). 2) Kawai, M. et al.: J. Nucl. Sci. Technol., 29, 195 (1992). 3) Kikuchi, Y. et al.: JAERI-M 86-030 (1986). 4) Alves, R.N., et al.: Nucl. Phys., A134, 118 (1969). 5) Van de Vyver, R.E., Pattenden, N.J.: Nucl. Phys., A177, 393 (1971). 6) Musgrove, A.R. de L., et al.: AAEC/E325 (1974). 7) Kikuchi, Y.: JAERI-M 6248 (1975). 8) Mughabghab, S.F. et al.: "Neutron Cross Sections, Vol. I, Part A", Academic Press (1981). 9) Mizumoto, M: J. Nucl. Sci. Technol., 25, 757 (1988). 10) Igarasi, S. and Fukahori, T.: JAERI 1321 (1991). 11) Musgrove, A.R. de L., et al.: Proc. Int. Conf. on Neutron Physics and Nucl. 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Rev., C4, 1173 (1971). 25) Forrest, R.A.: AERE-R 12419 (1986). 26) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999) [in Japanese].