Performance of Upgraded Thermal Neutron Counters (TNCs)

Operators at the Los Alamos National Laboratory Plutonium Facility use thermal neutron coincidence counters (TNCs) to quantify the nuclear material in a sample. The TNCs use passive non-destructive assay (NDA) methods to detect coincidence neutrons from sample items1. The TNCs in our facility have been upgraded to new operating software and hardware. This report provides a contrast between the old and new TNC systems. To facilitate the contrast, NDA measurements were made using plutonium oxide standards. The factors compared between the old and new TNC systems are ease of use, functionality, and instrument performance.