Neutron Energy Distribution and Energy-Corrected Spatial Distribution Around a Sealed-Tube DT Fusion Neutron Generator

Neutron irradiation of a molten salt tritium breeder is planned to evaluate tritium accountancy in the liquid immersion blanket robust accountancy (LIBRA) project at MIT. A sealed-tube deuterium-tritium (DT) fusion neutron generator (NG) will be used for the irradiation. Hence, the NG's characterization is necessary to evaluate the tritium accountancy. Specifically, the neutron profile, energy, and flux are essential factors for the analysis in the irradiation experiment. This study aims to investigate the neutron distribution around the NG for the characterization of a DT fusion neutron environment. First, neutrons on the outer surface of the generator were measured using an imaging plate (IP) and aluminum (Al) activation foils. The obtained image reflected the beta-ray emission from Al activated by fast neutrons. Next, the single-crystal chemical vapor deposition (sCVD) diamond detector was also employed to measure the angular dependence of neutron energy from the generator axis of symmetry. Using the angular distribution of neutron energy, the IP image was corrected. The neutron energy distribution and the energy-corrected spatial distribution around the generator were obtained by these methods. The image contains information about the neutron profile which can be utilized for the analysis of the fusion neutron field.