Portable, Fieldable, Non- Helium-3 Based Neutron Multiplicity Counter

Neutron coincidence counters are currently based on 3H technology. A worldwide 3He shortage plus the need for significant improvements in performance necessitate the development of a new class of neutron detectors. We propose the use of boron-coated straw (BCS) detectors, consisting of 4 mm diameter copper tubes lined with 10B-enriched boron carbide (10B4C). Previous studies have shown that BCS detectors can competitively replace 3He tubes in the commercially available High Level Neutron Coincidence Counter (HLNCC-II). BCS benefits include operation with low gas pressure (1 atm or less), optimal gas mixture for fast signals, operation at low voltage bias, low power consumption, simple electronic readout, easy fabrication, and low cost. BCS also shares many of the benefits of the 3He medium, including high detection efficiency, good gamma ray discrimination, and high reliability. We propose the development of a portable multiplicity counter for use by the military in the field, similar in physical dimensions to an existing 3He-based design, but replacing the 3He tubes with the BCS detection technology. Because of the wide commercial availability of enriched 10B BCS detectors are not encumbered in any manner by supply chain issues and with assembly line production development can be produced very economically.