The charged particle response of CdZnTe radiation detectors

A series of experiments has determined the response of CdZnTe radiation detectors to electrons and alpha particles. Densely ionising particles result in an “S-shaped” pulse which is somewhat different in shape to those generated during photon interactions. A preliminary analysis of these pulse shapes is presented and the impact of this on possible schemes for pulse-shape discrimination is discussed. By altering the position of interaction of the alpha-particle beam in the detector, it is possible to analyse the non-uniformity of the electric field present in these detectors. Results are presented to demonstrate these effects, and the implications of these for operation of CdZnTe detectors in charged particle beams will be discussed.