ABSTRACT
The properties of compound semiconductors such as gallium arsenide (GaAs), mercuric iodide (HgI2), thallium bromide (TlBr), cadmium telluride (CdTe), and cadmium zinc telluride (CdZnTe) are desirable for the production of high-energy x-ray imaging detectors. Due to the poor charge transport properties of holes in CdTe and CdZnTe material, different electrode geometries have been developed to screen out the hole contribution to the detector signal. These single-charge sensing geometries include coplanar grids, Frisch-collar detectors and small pixel detectors. When processing data produced by small pixel detectors, the effects of charge sharing must be considered. The HEXITEC ASIC was developed for imaging applications in which important additional information regarding the object's properties is contained within the energy spectrum of the absorbed, transmitted, and emitted x-rays. The chapter concludes with a number of case studies that demonstrate the use of spectroscopic imaging with the HEXITEC detector in different application areas.
