Stilbene Cell Analysis for Radioxenon Monitoring

Radioxenon monitoring is one component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty. The systems in the field use hollow plastic scintillators for beta detection and NaI(Tl) detectors for gamma detection, where the plastic cell also contains the radioxenon gas sample. To advance the current detection systems, a stilbene cell is being developed to replace the plastic cell. The benefits of developing a new detector that uses stilbene include increased resolution of the beta spectrum and removal of radon interferences using pulse shape discrimination. This work compares measurements, to analyze the detector characteristics, made by a prototype stilbene cell with that of the presently used plastic cell. MCNPX-PoliMi modeled the experiment, and produced simulations will be used to optimize the final design of the stilbene cell.