A study of the timing properties of Cd{sub 0.9}Zn{sub 0.1}Te

Abstract

CdZnTe has become a material of great interest in the field of X- and {gamma}-ray imaging, and shows great promise as a highly efficient, room-temperature operation detector. However, data on the timing resolution obtainable with this material is scarce. It is known that CdZnTe, in common with all compound semi-conductors, gives pulses of varying rise-time depending on the interaction location, hence causing a broadening of the time spectrum. We therefore assembled and characterized an appropriate electronic measuring set-up and took data with 2 different sets of detectors, varying the experimental parameters such as bias voltage, threshold and temperature during the course of the experiment. The results obtained with planar detectors of 9 mm{sup 2} {times} 2 mm thick were superior to the results obtained with detectors of 25 mm{sup 2} {times} 10 mm thick, even when the difference in effective bias field strength is considered. Timing resolutions of 5.3 ns and 20.9 ns (FWHM) respectively were obtained. Reducing the temperature to 0{degree}C reduced the resolution to 4.5 ns, thereby indicating that the performance is limited by signal-to-noise ratio considerations