PNNL

Abstract

Several computationally simple methods are presented for determining the direction to one or more point sources using the GammaTracker handheld radioisotope identifier. GammaTracker will display a heading indicating the direction to one or more sources; no gamma-ray images will be displayed to the user. The details of each directionality method are presented and performance is compared using radiation transport simulations of gamma-ray point sources at varying activity levels on a natural background. All methods achieved sufficiently high pointing accuracy and precision in the tested scenarios, which included background-to-source ratios up to 10:1. The prospects for implementation in the GammaTracker firmware architecture are discussed.