An evaluation of the possible use of CdTe microdetectors for astrophysical, biomedical and industrial imaging

Various imaging techniques in fields as diverse as astrophysical research, biomedical diagnostics and industrial tomography are closely related to the development of γ-ray detectors with improved spectral and imaging performances. From this point of view, cadmium telluride solid state detectors are very promising due to their capability to operate at room temperature, their high stopping power and their possibility of miniaturization. The necessity to have contemporaneously good efficiency and high spatial resolution demands that these microdetectors are produced in a novel manner, where the polarization of the applied electric field is perpendicular to the direction of the incoming radiation. In this way, it is possible to achieve a good charge collection efficiency and hence a high energy resolution, together with a high absorption thickness while at the same time having a spatial resolution commensurate with the detector size of about 2x2 mm2. The result of measurements regarding the energy resolution of various sizes of μdetector from 2x2x2 mm3 to 2.5x2.5x20 mm3, are presented and discussed. (orig.)