Production of [beta-gamma] coincidence spectra of individual radioxenon isotopes for improved analysis of nuclear explosion monitoring data
Radioactive xenon gas is a fission product released in the detonation of nuclear devices that can be detected in atmospheric samples far from the detonation site. In order to improve the capabilities of radioxenon detection systems, this work produces [beta-gamma] coincidence spectra of individual isotopes of radioxenon. Previous methods of radioxenon production consisted of the removal of mixed isotope samples of radioxenon gas released from fission of contained fissile materials such as ²³⁵U. In order to produce individual samples of the gas, isotopically enriched stable xenon gas is irradiated with neutrons. The detection of the individual isotopes is also modeled using Monte Carlo simulations to produce spectra. The experiment shows that samples of [superscript 131m]Xe, ¹³³Xe, and ¹³⁵Xe with a purity greater than 99% can be produced, and that a sample of [superscript 133m]Xe can be produced with a relatively low amount of ¹³³Xe background. These spectra are compared to models and used as essential library data for the Spectral Deconvolution Analysis Tool (SDAT) to analyze atmospheric samples of radioxenon for evidence of nuclear events.