Differential Neutron Production Cross Sections and Neutron Yields from Stopping-Length Targets for 113-MeV Protons

Abstract

Differential cross sections from thin targets and absolute neutron yields from stopping-length targets at angles of 7.5, 30, 60, and 150 deg for the 113-MeV proton bombardment of elemental beryllium, carbon, aluminum, iron, and depleted uranium are measured. Additional cross-section measurements are reported for oxygen, tungsten, and lead. Time-of-flight techniques are used to identify and discriminate against backgrounds and to determine the neutron energy spectrum. Comparisons of the experimental data with intranuclear-cascade evaporation model calculations with the HETC code show discrepancies as high as a factor of 7 in the differential cross sections. These discrepancies make it possible to identify some of the good agreement seen in the stopping length yield comparison as fortuitous cancellation of incorrect production estimates in different energy regimes.