An evaluation of HgI2 detectors for x-ray computed tomography

Mercuric iodide (HgI2) presents a set of attractive features as a semiconductor x-ray detector for computed tomography (CT). Its response is stable, it operates at room temperature, and thin detectors have a high detection efficiency. The properties of HgI2 permit the assembly of high spatial resolution detectors in a compact configuration. On the other hand, HgI2 exhibits a long memory, and some detectors also exhibit polarization effects, both of which are detrimental in CT. A pulse-shaping technique has been used to overcome these effects, thus demonstrating the suitability of HgI2 for use in CT.