Modeling beta-gamma coincidence spectra of Xe-131m, Xe-133, Xe-133m, and Xe-135

摘要

In support of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), improvements have been made to the model of the Automated Radioxenon Sampler/Analyzer (ARSA) beta-gamma coincidence detector for radioxenon monitoring. MCNPX is used to simulate the detector response for all the electrons and photons emitted from Xe-131m, Xe-133, Xe-133m, Xe-135, and Cs-137 signals. A MatLab code was written to incorporate the MCNPX results in the calculation of beta-gamma coincidence spectra. These will aid in the development of the Spectral Deconvolution Analysis Tool (SDAT)(1) and to calibrate beta-gamma coincidence systems. The models developed for this work include improvements over previous models in their ability to address Compton scattering in the beta-cell, and the beta-distribution offset in the 31 keV gamma-ray region for (133)xe.