Fast Photoneutron Detection

Abstract: The purpose of this project was to investigate fast photoneutron production from a series of materials commonly used for backing neutron beam guides. Fast neutrons were knocked out of these materials by exposing them to to high-energy photons at the Tagged-Photon Facility at MAX-lab in Lund, Sweden. Liquid scintillator detectors at different angles around the targets registered the photoknockout neutrons. These fast-neutron detectors were energy calibrated using two well-understood gamma-ray sources. The energy calibrations were used to establish the hardware detector thresh- olds. The hardware thresholds server as input to an absolute neutron-detection efficiency Monte Carlo simulation known as STANTON, which was used to establish the best-case neutron-detection efficiency achieved in the measurement. Finally, the detector thresh- olds were increased in software to study the reduction in detection efficiency as a function of the increase in threshold. A complete overview of the project is presented.