HgI2 X- and γ-ray camera with spectrometric capabilities

A HgI2 microstrip two-dimensional array with total area of 10 × 10 mm2 and a thickness of 0.5 mm has been tested. By using a coincidence-anticoincidence technique the effective pixel area has been identified and spectroscopic performance and some indications about the spatial resolution have been extracted. Values like 25% (FWHM) at 6 keV and 8.5% at 32 keV for the energy resolution have been obtained. For the X-ray energies used, ranging from 32 to 81 keV, the absence of an intense lateral diffusion of the produced charge allows performing the position readout in a quantized fashion, where the event position is that of the struck strip, leading to a spatial resolution corresponding to the pixel size.