Large Room Temperature Cd1-xZnxTe Detectors

40169 W. Peter Trower Applications such as medical tomography, x-ray defectometry, and metallurgical processing require high resolution spectrometric detectors. At present, the desired resolution can only be achieved using germanium crystals cooled to cryogenic temperatures, conditions which severely limit applicability. This project will develop x-ray and gamma-ray detectors that operate at room temperature, but with the energy resolution of cryogenic germanium detectors. The detectors will be more efficient than similar sized germanium or silicon, will produce larger signals than scintillator-photodiodes, and will be radiation tolerant because of their growth induced compensation mechanism. Phase I will: (1) develop a modified Vapor Phase Growth technology for single Cd1-xZnxTe solid solution crystals; (2) synthesize and distill Cd1-xZnxTe, from which solid solution Cd1-xZnxTe single crystals will be grown; (3) measure the Cd1-xZnxTe luminescent, optical, structural, and electrical properties; and (4) construct and evaluate prototype X- and ¿-ray single Cd1-xZnxTe crystal detectors. Anticipated Results/Potential Commercial Applications as described by the awardee: Large, high-resistivity Cd1-xZnxTe crystal spectrometric detectors will have room temperature energy resolution approaching that of cryogenic germanium detectors. Therefore they hold commercial promise in medical tomography, x-ray defectometry dosimetry, metallurgical processing, ore assaying, oil well logging, etc.