PNNL

Abstract

This paper discusses the ongoing development of a compact, unattended, and low-power radiation detection system designed for deployment to the front lines of nuclear proliferation. Current countermeasure deployments aim to detect nuclear threats by screening cargo containers abroad or at ports of entry, but the defensive nature of these systems means that they face the immense challenge of detecting intentionally-concealed materials. A complementary strategy places countermeasures closer to the source of nuclear proliferation, but deployments to these regions often must operate autonomously and in the absence of infrastructure. This application motivates our development of a low-power system capable of detecting gamma-ray and neutron emissions while operating autonomously for extended periods of time. Many challenges are present when developing radiation-detection systems for this application, and this paper describes work focused on two of them: the development of compact, low-power electronics for gamma-ray-spectrometer and 3He- tube signal processing, and analysis algorithms capable of distinguishing threats from benign sources in mid-resolution gamma-ray spectrometers. We discuss our development efforts on these fronts and present results based on implementation in a proof-of-principle system comprised of two 5 cm x 10 cm x 41 cm NaI(Tl) crystals and eight 40-cm 3He tubes.