Source Detection with Position-Sensitive Gamma-Ray Detectors

Gamma-ray detectors have applications in security, medicine, and nuclear non-proliferation. Some gamma-ray detectors are position-sensitive, meaning that the recorded data contains
information about the position of the gamma-ray source. We use asymptotic statistics to address the question of whether or not a position-sensitive detector can more reliably detect a gamma-ray point source than a detector that only counts the number of recorded photons. We prove that position-sensitive capability increases the
area under the receiver operating characteristic curve (AUC) when the background is known, the detector sensitivity is uniform, and the
system model is known exactly. We also propose a method for evaluating detection performance in terms of the receiver operating characteristic (ROC) when these assumptions are not met. The proposed method requires a modest amount of data and computation compared to empirical ROC computation. We validate the proposed method with
simulated and measured data.