CdTe and CdZnTe X-ray and gamma-ray detectors for imaging systems

This review paper presents the current state of the art imaging systems using room-temperature CdTe and CdZnTe X-ray and gamma-ray detectors. Imaging systems composed of both single elements and monolithic segmented CdTe and CdZnTe arrays are used in medical diagnostics, astronomy, research and industry. This paper is divided into two sections: The first section describes different types and configurations of CdTe or CdZnTe detectors used in imaging systems, with the emphasis on single charge carrier collection detectors and front-end read-out electronics in the form of application specific integrated circuits associated with these detectors. It also discusses the advantages, disadvantages and limitations with respect to the efficiency and area of the imaging systems using CdTe and CdZnTe detectors compared to other types of X and gamma ray detectors. The second section describes several examples of imaging systems utilizing CdZnTe detectors: 1) a large area imaging telescope for the detection of gamma ray bursts using a coded aperture collimator; 2) a large area medical nuclear camera for cardiology and scintimammography using a parallel hole collimator; 3) a large field of view gamma camera based on a rotating slat collimator; and 4) a prototype of an electronically collimated Compton camera.