X-Ray Luminescence of Mercuric Iodide Nuclear Detectors

The luminescence of HgI2 crystals excited by x-rays has been measured over the temperature range 9-350°K. The emission spectrum was found to consist of 3 main band groups: at 5320, 5600 and a group of wide bands covering the range 6000-8000 A. Each group showed considerable substructure particularly at low temperatures. Thermal ionization energies, shifts of the band peaks with temperature and some other characteristics of the various emission bands were measured. The samples were also examined as x-ray detectors. Results are discussed including possible correlation between the nature of the luminescence and the properties of the crystals as x-ray detectors.