High spatial resolution HgI2 linear array based on resistive charge division

Newly designed HgI2 linear arrays based on resistive charge division, obtained by depositing a Ge surface resistive layer (with typical interstrip resistances of ∼4 and 6 MΩ) between the read-out Pd strips, have been fabricated. These detectors, coupled with specially designed front-end electronics, have shown a high detection efficiency over a large active detection area and an energy resolution of 20% for X-ray energy Ex = 22 keV, estimated to become < 5% at Ex > 100 keV. Further, a spatial sensitivity of ∼ 10 μm and a spatial resolution of ∼ 100 μm have been obtained at 30 keV, by making use, for a fine spatial characterization of the devices, of a laser beam spot 50 μm in diameter with wavelength tuned to match the crystal band gap (582 nm). These devices could be successfully employed in basic research (for example Bragg X-ray spectrometry) and for radiological and high-energy (Ex > 100 keV) astrophysical applications. (orig.)