Reconstruction of a radiation point source’s radial location using goodness-of-fit test on spectra obtained from an HPGe detector

Abstract

High purity germanium (HPGe) detectors are ubiquitous in nuclear physics experiments and are also used in numerous low radioactive background detectors. The effect of the position of 60Co and 137Cs point sources on the shape of spectra were studied with Monte Carlo and HPGe detector measurements. We briefly confirm previous work on the position dependence of relative heights of peaks. Spectra taken with the radiation sources placed at locations around the detector were then compared using the Kolmogorov–Smirnov (K–S) goodness-of-fit test. We demonstrate that with this method the Compton continuum spectral shape has good sensitivity to the radial location of a point source, but poor angular resolution. We conclude with a study of the position reconstruction accuracy as a function of the number of counts from the source.