FAST-NEUTRON SCATTERING CROSS-SECTIONS AT SMALL ANGLES AND OPTICAL-MODEL PARAMETERS

A position sensitive neutron detector was used to measure the differen tial cross sections of 14.8 MeV (or 14.7 MeV) neutrons scattered from U-238, Pb, Ni, Fe, Cr, Al, and O between 2.5-degrees and 16-degrees an d that of 12 MeV neutrons from U-238 and Fe. The data were corrected f or neutron flux attenuation, multiple neutron scattering, and finite g eometry with a Monte Carlo simulation. The angular distributions are a nalyzed with a spherical optical model or coupled channels model (code ECIS79) and a set of global optical model parameters were obtained at approximately 14.8 MeV neutron energy for mass number between 27 and 238. The measured and calculated results are compared and discussed.