Elastic and Inelastic Scattering of Fast Neutrons fromTh232

Abstract

The elastic and inelastic scattering of neutrons from thorium is studied throughout the incident neutron energy interval 0.3 to 1.6 Mev. Fast time-of-flight techniques are utilized in conjunction with an electro-magnetic pulsing and bunching system for the production of short and very intense neutron bursts. The differential elastic cross section is determined as a function of incident neutron energy. The cross sections for inelastic scattering resulting in the excitation of residual nuclear levels at 50\ifmmode\pm\else\textpm\fi{}2, 170\ifmmode\pm\else\textpm\fi{}10, 720\ifmmode\pm\else\textpm\fi{}20, 790\ifmmode\pm\else\textpm\fi{}20, 820\ifmmode\pm\else\textpm\fi{}20, 1050\ifmmode\pm\else\textpm\fi{}50, and 1150\ifmmode\pm\else\textpm\fi{}50 kev are measured. The angular distribution of inelastically scattered neutrons resulting in the excitation of the lower two nuclear levels is determined. The measured individual inelastic excitation functions are combined to obtain the total inelastic scattering cross section as a function of incident neutron energy. The experimental results are compared with the results of other measurements.