A new method for analysis of beta-gamma radioxenon spectra

Abstract

A new method for calculation of isotope-specific activities and activity concentrations in measurement systems for atmospheric radioxenon is presented. The method results in simple matrix-vector equations, and requires the definition of fewer spectral regions-of-interest than previous algorithms. The most important difference compared to the current method is however the calculation of decision limits, which results in false detection rates closer to the selected confidence level of 95% compared to the methods used today. This is achieved by introducing a Bayesian correction of the background estimate. The results have implications for the understanding of the atmospheric radioxenon background, for example for the observed low levels of 133mXe, an important isotope in the area of nuclear explosion detection.