THE USE OF HGI2 PHOTODETECTORS COMBINED WITH SCINTILLATORS FOR GAMMA-RAY SPECTROSCOPY

Gamma-ray spectrometers using mercuric iodide (HgI2) photodetectors (P Ds) combined with scintillators have been designed, fabricated and tes ted. The technology developed makes it possible to reliably produce hi gh quality HgI2 PDs with a relatively high yield. The energy resolutio n of 4.58% FWHM for 662 keV Cs-137 gamma-ray photons has been obtained . The HgI2 PD configuration, packaging and encapsulation is described in the paper. After successfully developing the technology for making high quality detectors, the emphasis of our effort has been placed on making large area detectors, i.e., increasing detector diameters from 0.5 in, to between 1 and 2 in. HgI2 PD characteristics, which include energy resolution, electronic noise, leakage current, detector capacit ance, and long term stability have been evaluated and are reported in the paper.