An alpha particle detector for a portable neutron generator for the Nuclear Materials Identification System (NMIS)

摘要

A recoil alpha particle detector has been developed for use in a portable neutron generator. The associated particle sealed tube neutron generator (APSTNG) will be used as an interrogation source for the Nuclear Materials Identification System (NMIS). With the coincident emission of 14.1 MeV neutrons and 3.5 MeV alpha particles produced by the D-T reaction, alpha detection determines the time and direction of the neutrons of interest for subsequent use as an active nuclear materials interrogation source. The alpha particle detector uses a ZnO(Ga) scintillator coating applied to a fiber optic face plate. Gallium-doped zinc oxide is a fast ( < 1 ns), inorganic scintillator with a high melting point (1975℃). One detector has been installed in an APSTNG and is currently being tested. Initial results include a measured efficiency for 3.5 MeV alphas of 90%.