A miniature, self-contained, CdZnTe gamma spectrometer for use in unattended nuclear material monitoring

A small, self-contained, CdZnTe-based data-acquisition system has been developed at Los Alamos National Laboratory that can be used for the unattended monitoring of gaseous uranium hexafluoride (UF₆) processes. The miniature device uses a twin-detector design with a unique collimation and shielding system to assist with gaseous UF₆ wall-deposit characterization. The detectors are fully supported with bias voltages, read-out electronics, a multichannel analyzer, and a microprocessor, all within a compact package that can be run on DC power. First-generation, automated data collection and analysis software provides change-of-state detection capability and the unattended measurement of UF₆ gas enrichment. Significant changes in the detector count rate trigger new gas measurements. All information and analysis results are stored onboard and may be accessed later. The software has been developed and tested using actual UF₆ material in a test loop at Oak Ridge National Laboratory. This paper discusses the system hardware and software specifications and capabilities, and reports on the UF₆ gas measurement results