Neutron Detector Sensitivity Measurements and Their Variation

Historically Helium-3 based neutron detectors have been utilized for many applications including Radiation Portal Monitors and various Nuclear Safeguard applications. With the reduced amount of Helium-3 available alternative technologies are being evaluated and employed for use in these applications. In this study, the performance of Boron-10 lined proportional counters is evaluated experimentally in gamma-ray fields relevant to these applications. The method used to define and measure neutron sensitivity is evaluated, and effects of the ambient gamma field on the measured sensitivity are studied for a variety of detector configurations. Based on the results of this study, a repeatable method of defining and measuring detector sensitivity is reported, and the change in sensitivity that may be observed by systems integrators after incorporating the detectors into completed systems is assessed.