Measurement Of Gamma Ray Production Cross Sections For Nitrogen And Oxygen PDF Download

An integral experiment, designed to provide high-sensitivity tests for gamma-ray production and neutron-scattering cross sections, has been performed. The experiment is based on the white-source, pulsed-neutron, time-of-flight method with the sample at the detector end of the flight path. Measurements were made with a single 5 x 5 cm cylindrical NE-213 detector positioned at 30, 55, 90, and 125 degrees relative to the incident neutron beam. Pulse-shape discrimination was used to separate neutron and gamma-ray counts. Measured count rates due to secondary gamma rays and scattered neutrons from two sample materials, graphite and liquid nitrogen, are reported here as functions of time and incident neutron energy. Differences between calculated gamma-ray and neutron count rates and those reported here should be readily interpreted in terms of specific cross-section deficiencies at well defined incident neutron energies in the 1.5- to 20-MeV range. (Author).