Unattended sensors for nuclear threat detection

This paper discusses the ongoing development of a compact, unattended low-power radiation detection system designed for autonomous operation in regions with limited or no supporting infrastructure. This application motivates our focus on two of the more challenging system development problems: (1) the development of compact, low-power electronics for gamma-ray spectrometers and neutron detectors, and (2) analysis algorithms capable of distinguishing special nuclear material from benign sources in the opaque signatures of mid-resolution spectrometers. We discuss our development efforts on these fronts and present results based on implementation in a proof-of-principle system composed of two 5-cm × 10-cm × 41-cm NaI(Tl) crystals and eight 40-cm 3 He tubes.