| 시설장비 설명 |
Polaris-H was designed to perform gamma spectroscopy and imaging throughout nuclear power plants. It integrates a 3D position sensitive pixelated CZT detector (20 mm x 20 mm x 15 mm), associated readout electronics, an embedded computer, a 5-h battery, and an optical camera in a portable water-proof enclosure. The total mass is about 4 kg, and the system startup time is 2 min. In addition, it has a connection for a tablet, which displays a gamma-ray spectrum and isotope specific images of the gamma-ray distribution in all directions in real time. List-mode data is saved to an external USB memory stick. Based on pixelated depth sensing technology, spectroscopy is routinely better than 1.1% FWHM at 662 keV, and imaging efficiency at 662 keV varies less than a factor of two for all directions, except through the battery. Measurements have been performed in contaminated environments, in high radiation fields, and in cramped quarters. Polaris-H has been used in environments of 100 mrem/h with no noticeable spectral or image degradation. Measurements can be made in crawl spaces. Some nuclear power plants have also used Polaris-H to look for gaps in shields and to locate isotopes in shipping containers as they arrive or depart the site. Polaris-H was designed specifically for measurements in nuclear power plants, which drove design decisions. The instrument is portable, so it can be moved about the plant easily, including into cramped areas like crawl spaces and manholes. |
