Polaris-H measurements and performance

Polaris-H, a compact Compton camera designed by H3D, Inc. has been characterized and tested in field measurements at nuclear power plants. Polaris-H integrates a 3D-position-sensitive pixelated CZT detector (20 mm × 20 mm × 15 mm), associated readout electronics, an embedded computer, a 5-hour battery, and an optical camera all within a portable water-resistant case. The total mass is about 4 kg. Start-up time is 2 minutes. Additionally, there is a connection for a tablet, which displays a real-time gamma-ray spectrum (near 1% FWHM at 662 keV) and isotope-specific images of the radiation distribution in all 4π in real time. The newest design of Polaris-H features the capability to control data acquisition without using a tablet interface, a higher energy dynamic range, and a higher maximum count rate. Absolute efficiency, imaging efficiency, energy resolution, and detection and identification performance are presented. Measurements are shown for applications of decontamination and detection of previously unknown contamination regions.