Development of Wet-Media Alpha Detector for Field Survey

Abstract

The emission of alpha particles from nuclear contamination sources poses a challenge for conventional alpha counters, which have limited detection capabilities in wet media due to water shielding. These instruments are typically designed for use in dry media and keep a one or two centimeter gap between the probe and the media during survey. However, CNL's experimental results have demonstrated that the using silver-activated zinc sulphide (ZnS:Ag) scintillator in powder form can overcome this problem.

As the first step, a commercial alpha counter probe was modified to evaluate the feasibility of using this technique for field applications, and promising results were obtained. Over the last two years, an in-house product has been developed based on this breakthrough technology, which provides in-situ alpha radiation measurement for wet soil and other wet media. The development involved designing an enclosure, electronics, and software from scratch. CNL owns the full intellectual property of this product. This development has significant implications for detecting and monitoring of alpha contamination in wet environments.