Scattering of 13 MeV neutrons from 11B and 28Si

Differential cross sections for elastic and inelastic scattering of 13 MeV neutrons from 11B and 28Si were measured by using the JAERI tandem accelerator. Scattered neutrons were observed by a time-of-flight spectrometer with an array of four 20 cmφ x 35 cm NE213 liquid scintillator detectors. Neutron time-of-flight spectra were taken at scattering angles from 20deg to 140deg for 11B, and from 15deg to 140deg for 28Si. Inelastic scattering cross sections of neutrons leading to the 1/2-(2.125 MeV), 5/2-(4.445 MeV) and 3/2-(5.021 MeV) states, and the 2+(1.779 MeV) and 4+(4.618 MeV) states, of 11B and 28Si, respectively, were measured simultaneously with the elastic cross sections. The experimental cross sections were analyzed in terms of a spherical optical model potential, DWBA and coupled channel calculations using collective model. (author)