EVALUATION OF NEUTRON NUCLEAR DATA OF B-11
Japan Atomic Energy Research Institute
Tokai-mura, Naka-gun, Ibaraki 319-11, Japan
Nuclear data of B-11 have been evaluated in the energy range from 0.01 meV to 20 MeV. The evaluated quantities are cross sections, angular distributions and energy spectra of secondary neutrons. The evaluation was performed by using the R-matrix theory below 7 MeV and multistep statistical model above 7 MeV. Below 7 MeV, R-matrix parameters of Koehler et al. were modified to fit experimental data of the total cross section. For calculation of the multistep statistical model, the optical model and the level density parameters were chosen to reproduce experimental data of charged particle emission and elastic scattering cross sections. Direct inelastic scattering processes for seven excited levels were considered with DWBA calculation. The results of present work are in good agreement with the experimental data of cross sections, angular distributions of secondary neutrons and double differential cross sections. They were compiled for JENDL-3 in the ENDF/B-V format.
KEYWORDS: Evaluation, B-11, Neutron Nuclear Data, R-matrix, Optical Model, DWBA, JENDL-3