A STUDY OF TRAPPING LEVELS IN SOME RED MERCURIC IODIDE SINGLE-CRYSTALS FOR NUCLEAR RADIATION DETECTION

Photon-stimulated currents (PSC) and thermally stimulated currents (TS C) have been measured in red mercuric iodide (alpha-Hgl(2)) single cry stals grown in our laboratory from tetrahydrofurane-alpha-Hgl(2) satur ated solution, dimethyl sulphoxide-methanol-alpha-Hgl(2) saturated sol ution and from a polymer-controlled vapour phase. PSC measurements hel ped in determining uniquely the activation energies and nature (electr on or hole) of different trapping levels in these crystals. Subsequent ly, by a comparative study of TSC and PSC measurements, the capture cr oss sections have been determined uniquely. Finally, after estimating the trap densities, an attempt has been made to predict the influence of different trapping levels on the performance of the detectors fabri cated out of the three types of crystal.