The aim of this work is to apply a parametric statistical methodology to the radioxenon activity concentrations measured at noble gas stations of the International Monitoring System of the CTBTO, in order to investigate the radioxenon atmospheric background and the radioxenon anomalous values. The proposed parametric statistical methodology is based on the “Statistical Process Control” method and it consists of using two “Control Charts”. The “Single Observation Control” Chart, sensitive to large variation of the measured values, could be useful for periodic monitoring of the phenomenon at the noble gas stations; the “Exponentially Weighted Moving Average” Chart, sensitive to small variations of the measured values, could be used to perform specific studies on the atmospheric background and on the anomalies of radioxenon activity concentrations.
Radioxenon is useful to potentially reveal underground nuclear explosions (UNEs) but it is also emitted by civil sources. To discriminate signals, advanced statistical methods are used to understand the background and the anomalous values that could be reasonably related to UNEs.