Discriminating nuclear threats from benign sources in gamma-ray spectra using a spectral comparison ratio method

This manuscript presents a method for categorizing gamma-ray spectra as indicative of benign or threat sources. Reported here is a method of spectral comparison ratios (SCR), which is useful in the targeted detection of specific gamma-ray signature classes. SCRs discriminate between benign and target sources by comparing counts in broad energy bins that are pre-determined using statistical discrimination criteria. The integral component of the SCR method is the location and interdependence of the energy bins, and this work discusses the statistical methods used for choosing their locations along with decision criteria that maximally separate targets from benign sources.