Investigation of pixellated HgI2 γ-ray spectrometers

HgI2 gamma-ray spectrometers having small pixel anodes and a thickness of 4–5 mm have been investigated. An energy resolution of 2.9% FWHM was obtained on a 4 mm thick detector using the three-dimensional position sensitive single polarity charge sensing technique. Typical phenomena observed on two detectors are reported and their characteristics are discussed. The results indicate that it is possible to construct efficient gamma-ray spectrometers using commercially available HgI2 materials if the three-dimensional position sensitive single polarity charge sensing method is implemented.