Yoshimaro Yamanouti, Masayoshi Sugimoto, Yutaka Furuta and Motoharu Mizumoto

Japan Atomic Energy Research Institute
Tokai, Ibaraki 319-11, Japan

Mikio Hyakutake

Department of Nuclear Engineering, Kyushu University
Hakozaki, Fukuoka 812, Japan

Thamrong Methasiri

Department of Physics, Chulalongkorn University
Bangkok 10500, Thailand

Differential cross sections for elastic and inelastic scattering of 13MeV 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 20cmφ × 35cm NE213 liquid scintillator detectors. Neutron time-of-flight spectra were taken at scattering angles from 20° to 140° for 11B, and from 15° to 140° 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.

KEYWORDS: elastic and inelastic scattering, 13MeV, neutron, 11B, 28Si, tandem accelerator, DWBA, coupled-channel formalism, compound nuclear contribution