70-Yb-168 JAEA EVAL-FEB10 S.Kunieda, A.Ichihara, K.Shibata+ DIST-DEC21 20100222 ----JENDL-5 MATERIAL 7025 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 10-02 New evaluation was done (compiled by S. Kunieda). 21-11 revised by O.Iwamoto (MF8/MT4,16,17,22,24,28,32,41,102-104,107) JENDL/AD-2017 adopted (MF8/MT105,106) added (MF9/MT102) JENDL/AD-2017 adopted MF= 1 General information MT=451 Descriptive data and directory MF= 2 Resonance parameters MT=151 Resolved and unresolved resonance parameters - Resolved resonance region: below 190 eV The parameters (MLBW formula) were taken from the compilation of Mughabghab /1/. - Unresolved resonance region: 190 eV - 250 keV The parameters were obtained by fitting to the total and capture cross sections calculated by the POD code /2/. The ASREP code /3/ 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 2.31095E+03 Elastic 2.98415E+00 n,gamma 2.30796E+03 2.13543E+04 ---------------------------------------------------------- (*) 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 /4/ & POD calculations /2/. MT= 3 Non-elastic cross section Sum of partial non-elastic cross sections. MT= 4,51-91 (n,n') cross section The OPTMAN /4/ & POD calculations /2/. 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 /2/. 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 /2/. 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 /4/ & POD calculations /2/. 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 /2/. MT= 51-90 (n,n') reaction Neutron angular distributions calculated by OPTMAN /4/ & POD /2/. MT= 91 (n,n') reaction Neutron spectra calculated by the POD code /2/. 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 /2/. 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 /2/. *************************************************************** * Nuclear Model Calculations with POD Code /2/ * *************************************************************** 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 /4/ code was employed for neutrons, while the ECIS code /5/ was adopted for charged particles. 2. Optical model & parameters Neutrons: Model: Coupled-channel model based on the rigid-rotor model OMP : Coupled-channel optical potential /6/ Deformation parameters were taken from FRDM /7/. Protons: Model: Spherical OMP : Koning and Delaroche /8/ Deuterons: Model: Spherical OMP : Bojowald et al. /9/ Tritons: Mode: Spherical OMP : Becchetti and Greenlees /10/ He-3: Model: Spherical OMP : Becchetti and Greenlees /10/ Alphas: Model: Spherical OMP : A simplified folding model potential /11/ (The nucleon OMP was taken form Ref./6/.) 3. Level scheme of Yb-168 ------------------------------------ No. Ex(MeV) J PI CC ------------------------------------ 0 0.00000 0 + * 1 0.08773 2 + * 2 0.28655 4 + * 3 0.58525 6 + * 4 0.97002 8 + * 5 0.98385 2 + 6 1.06695 3 + 7 1.09800 0 + 8 1.15400 0 + 9 1.16100 0 + 10 1.17120 4 + 11 1.19700 0 + 12 1.23100 0 + 13 1.23318 2 + 14 1.27700 2 + ------------------------------------ Levels above 1.28700 MeV are assumed to be continuous. 4. Level density parameters Energy-dependent parameters of Mengoni-Nakajima /12/ were used ---------------------------------------------------------- Nuclei a* Pair Esh T E0 Ematch Elv_max 1/MeV MeV MeV MeV MeV MeV MeV ---------------------------------------------------------- Yb-169 20.623 0.923 2.335 0.513 -1.057 5.756 0.851 Yb-168 19.954 1.852 2.450 0.547 -0.443 7.235 1.277 Yb-167 20.425 0.929 2.859 0.552 -1.713 6.742 0.079 Yb-166 19.750 1.863 2.801 0.567 -0.787 7.768 1.343 Tm-168 19.816 0.000 2.068 0.501 -1.571 4.279 0.347 Tm-167 19.043 0.929 2.438 0.564 -1.337 6.372 0.291 Tm-166 19.615 0.000 2.801 0.617 -3.381 7.029 - Er-166 19.750 1.863 2.177 0.529 -0.073 6.724 1.938 Er-165 19.711 0.934 2.574 0.556 -1.477 6.498 0.467 Er-164 19.546 1.874 2.669 0.542 -0.316 7.095 1.806 ---------------------------------------------------------- 5. Gamma-ray strength functions M1, E2: Standard Lorentzian (SLO) E1 : Generalized Lorentzian (GLO) /13/ 6. Preequilibrium process Preequilibrium is on for n, p, d, t, He-3, and alpha. Preequilibrium capture is on. References 1) S.F.Mughabghab, "Atlas of Neutron Resonances", Elsevier (2006). 2) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007). 3) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999) [in Japanese]. 4) E.Soukhovitski et al., JAERI-Data/Code 2005-002 (2005). 5) J.Raynal, CEA Saclay report, CEA-N-2772 (1994). 6) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007). 7) P.Moller et al., At. Data and Nucl. Data Tables 59, 185 (1995). 8) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003). 9) Bojowald et al., Phys. Rev. C 38, 1153 (1988). 10) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization Phenomena in Nuclear Reactions," p.682, The University of Wisconsin Press (1971). 11) D.G.Madland, NEANDC-245 (1988), p. 103. 12) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151 (1994). 13) M.Brink, Ph.D thesis, Oxford University, 1955.