Neutron Yields from Stopping-Length Targets for 256-MeV Protons

Absolute neutron yields from stopping-length targets at angles of 7.5, 30, 60, and 150 deg for the 256-MeV proton bombardment of elemental beryllium, carbon, aluminum, and iron are measured. Time-of-flight techniques are used to identify and discriminate against backgrounds and to determine the neutron energy spectrum. Comparison of the experimental data with intranuclear-cascade evaporation-model calculations using the HETC code showed good agreement, indicating that transport probably dominates production effects in the calculations.