HIGH-ENERGY TOMOGRAPHY USING CADMIUM ZINC TELLURIDE DETECTORS

Cadmium zinc telluride (Cd0.8Zn(0.2)Te) is nowadays one of the most pr omising room temperature semiconductors for X- and gamma-ray detection . Indeed, its physical characteristics make this detector very suitabl e for operating under high-intensity fluxes, such as those produced by linear accelerators. For this reason, CdZnTe has been chosen for the set-up of a tomographic facility based on a 12-MeV linear accelerator. This system is a first generation tomograph; it has already been used for preliminary phantoms image acquisition, showing rather good imagi ng capabilities. The polychromaticity of the source may induce severe beam-hardening artifacts in the final tomographic images. Extensive ex perimental studies have been carried out to optimize correction algori thms able to reduce such artifacts. A set of images of relevant sample s have been acquired in order to evaluate the relationship between the absorption coefficients and the resulting CT numbers.