State-of-the-art of crystal growth and nuclear spectroscopic evaluation of mercuric iodide radiation detectors

The procedure of preparing starting materials of HgI 2 pre-treated with iodine and crystal growth from the vapor phase using the temperature oscillation method, TOM, in both a horizontal and vertical furnace is reviewed. The nuclear radiation detector properties of two of the best representative crystals grown in a horizontal furnace from iodized material and in a vertical furnace from non-iodized material are shown and discussed. The smallest full width half-maximum, fwhm, so far detected with a 10×8×0.5 mm 3 mercuric iodide detector is 4.5 keV for the 662 keV photopeak of 137 Cs.