Characterization of Lithium-6 as a Commercial Helium-3 Alternative for Nuclear Safeguards and Security

Helium-3 detectors are efficient, reliable neutron detectors, but their high demand has reduced their supply to a very miniscule level, making them very expensive. The goal of this project is to test and evaluate an alternative produced by industry. Current testing is being done with a Lithium Zinc Sulfide (⁶LiF:ZnS(Ag)) detector from Aspect used in their portal monitors.

There are three basic requirements for neutron detectors used in nuclear safeguards and security: 1) high absolute detection efficiency, 2) maintaining neutron detection efficiency when simultaneously exposed to a high gamma ray exposure rate, and 3) the ability to maintain neutron detection rate in all operational temperature ranges. All of these requirements will be tested with the detector mentioned above, including comparisons to a helium-3 slab counter from Rapiscan. This thesis describes the results of said detector systems, which were tested at Oak Ridge National Laboratory.