Measurement Results Using the Polaris 3D-Position-Sensitive CdZnTe Imaging Spectrometer Array System

摘要

A new semiconductor-based radiation-detection system has been designed by the Orion team at the University of Michigan. The Polaris system uses eighteen 6-cm3 CdZnTe detectors grown by Redlen Technologies attached to read-out electronics designed by Gamma Medica-ldeas to record gamma-ray interactions over a dynamic range from approximately 30 keV to 3 MeV. The first prototype has achieved below 1.5% FWHM at 662 keV for all events and near 1.0% FWHM at 662 keV for single-interaction events. The high atomic number of the CdZnTe crystals leads to high detection efficiency, and recent advances in event reconstruction produce a greater percentage of recorded events for Compton imaging using our UMImaging software. UMImaging is a gamma-ray imaging software primarily for imaging Compton scattering but also including coded aperture imaging algorithms. Coded aperture imaging extends source localization to lower energies where Compton scattering is less probable. The system has been tested to show its effectiveness for gamma-ray imaging and spectroscopy of nuclear materials.