58-Ce-141 JAEA EVAL-FEB10 S.Kunieda, A.Ichihara, K.Shibata+ DIST-DEC21 20100223 ----JENDL-5 MATERIAL 5840 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 10-02 Re-evaluation was performed for JENDL-4 (compiled by S. Kunieda). 21-11 revised by O.Iwamoto (MF8/MT4,16,17,22,28,32,102-107) added 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 40 eV For JENDL3.3, experimental data measured by Anufriev et al./1/ for 6 resonances below 335 eV were used. Resonance energies, neutron and radiation widths obtained by Anufriev et al. were adopted. Total spin J was determined with a random number method. Finally, a negative resonance was added so as to reproduce the thermal capture cross section given by Mughabghab et al./2/ For JENDL-4.0, the neutron width of 7.4-eV resonance was modified. That of JENDL-3.3 was 10 times larger than reported value. Total spin J of each resonance was re-evaluated. Neutron width of -5.0-eV resonance was adjusted to reproduce the capture cross section of 29+-3 b /3/. Upper boundary of the resolved resonance region was set to 40 eV instead of 350 eV of JENDL-3.3, because level- missing was seen above this energy. - Unresolved resonance region: 40 eV - 200 keV The parameters were obtained by fitting to the total and capture cross sections calculated by the POD code /4/. The ASREP code /5/ 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 3.23139E+01 Elastic 3.28994E+00 n,gamma 2.90240E+01 1.48336E+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 /6/ & POD calculations /4/. MT= 3 Non-elastic cross section Sum of partial non-elastic cross sections. MT= 4,51-91 (n,n') cross section The OPTMAN /6/ & POD calculations /4/. 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 MT=102 Capture 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,a) cross section Calculated by the POD code /4/. 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 /4/. 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 /6/ & POD calculations /4/. 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 /4/. MT= 51-90 (n,n') reaction Neutron angular distributions calculated by OPTMAN /6/ & POD /4/. MT= 91 (n,n') reaction Neutron spectra calculated by the POD code /4/. 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 /4/. 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 /4/. *************************************************************** * Nuclear Model Calculations with POD Code /4/ * *************************************************************** 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 /6/ was employed for neutrons, while the ECIS code /7/ was adopted for charged particles. 2. Optical model & parameters Neutrons: Model: Coupled-channel model based on the rigid-rotor model OMP : Based on the Coupled-channel optical potential /8/ The original Parameters were slightly modified as listed below to reproduce experimental total cross sections measured by Camarda et al /9/. ------------------------------------------------------------ - Real-volume term VR0= -3.85E+1 MeV VR1= 2.70E-2 MeV VR2= 1.20E-4 MeV VR3= 3.50E-7 MeV VRLA= 9.49E+1 MeV ALAVR= 4.22E-3 r= 1.21E+0 a= 6.30E-1 - Imaginary-surface term WDBW= 1.30E+1 MeV WDWID= 1.40E+1 MeV ALAWD= 1.40E-2 r= 1.21E+0 a= 6.75E-1 - Imaginary-volume term WCBW= 1.70E+1 MeV WCWID= 1.05E+2 MeV r= 1.21E+0 a= 6.75E-1 - Spin-orbit term VS= 6.34E+0 MeV ALASO= 5.00E-3 WSBW= -3.10E+0 MeV WSWID= 1.60E+2 MeV r= 1.06E+0 a= 5.90E-1 - Isospin coefficients CISO= 2.43E+1 WCISO= 1.80E+1 CCOUL= 9.00E-1 - Deformation parameter Beta2= -1.00E-1 ------------------------------------------------------------ Protons: Model: Spherical OMP : Koning and Delaroche /10/ Deuterons: Model: Spherical OMP : Bojowald et al. /11/ Tritons: Mode: Spherical OMP : Becchetti and Greenlees /12/ He-3: Model: Spherical OMP : Becchetti and Greenlees /12/ Alphas: Model: Spherical OMP : A simplified folding model potential /13/ (The nucleon OMP was taken form Ref./8/.) 3. Level scheme of Ce-141 ------------------------------------ No. Ex(MeV) J PI CC ------------------------------------ 0 0.00000 7/2 - * 1 0.66206 3/2 - 2 1.13700 1/2 - 3 1.35452 9/2 - * 4 1.36870 13/2 + 5 1.37800 9/2 - 6 1.49700 5/2 - 7 1.62650 3/2 + 8 1.69330 11/2 - 9 1.73900 7/2 - 10 1.78500 1/2 + 11 1.80870 3/2 - 12 1.81200 5/2 - 13 1.91500 9/2 - 14 1.94200 1/2 + ------------------------------------ Levels above 1.95200 MeV are assumed to be continuous. 4. Level density parameters Energy-dependent parameters of Mengoni-Nakajima /14/ were used ---------------------------------------------------------- Nuclei a* Pair Esh T E0 Ematch Elv_max 1/MeV MeV MeV MeV MeV MeV MeV ---------------------------------------------------------- Ce-142 17.282 2.014 -0.311 0.610 0.530 6.671 2.365 Ce-141 17.686 1.011 -1.072 0.493 0.659 3.613 1.942 Ce-140 17.074 2.028 -1.942 0.640 0.903 6.384 2.481 Ce-139 17.607 1.018 -1.120 0.492 0.694 3.570 1.985 La-141 16.464 1.011 -0.489 0.665 -0.737 6.277 0.929 La-140 17.665 0.000 -1.411 0.615 -1.257 4.391 0.602 La-139 16.263 1.018 -2.218 0.812 -1.629 8.151 1.257 Ba-139 20.276 1.018 -2.224 0.511 0.373 4.093 2.038 Ba-138 16.830 2.043 -3.130 0.710 0.829 6.866 3.155 Ba-137 18.884 1.025 -2.239 0.463 0.926 3.110 1.908 ---------------------------------------------------------- 5. Gamma-ray strength functions M1, E2: Standard Lorentzian (SLO) E1 : Generalized Lorentzian (GLO) /15/ 6. Preequilibrium process Preequilibrium is on for n, p, d, t, He-3, and alpha. Preequilibrium capture is on. References 1) B.A.Anufriev et al. : 1980 Kiev, Vol.2, p.136 (1980). 2) S.F.Mughabghab et al.: "Neutron Cross Sections, Vol. I, Part A," Academic Press (1981). 3) P.M.Lantz et al.: Nucl. Sci. Eng., 20, 302 (1964). 4) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007). 5) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999) [in Japanese]. 6) E.Soukhovitski et al., JAERI-Data/Code 2005-002 (2005). 7) J.Raynal, CEA Saclay report, CEA-N-2772 (1994). 8) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007). 9) Camarda et al., Phys. Rev. C 29, 2106 (1984). 10) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003). 11) Bojowald et al., Phys. Rev. C 38, 1153 (1988). 12) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization Phenomena in Nuclear Reactions," p.682, The University of Wisconsin Press (1971). 13) D.G.Madland, NEANDC-245 (1988), p. 103. 14) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151 (1994). 15) M.Brink, Ph.D thesis, Oxford University, 1955.