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New, high spatial resolution CdZnTe (CZT) and silicon (Si) pixel detectors are developed for high angular and high energy resolution X-ray astronomy. These detectors can be used for wide field-of-view all-sky X-ray, and gamma-ray monitors such as the AXGAM instrument and focusing X-ray imagers such as the high energy detector (HXT) proposed for the CONSTELLATION mission. The high stopping power of CZT detectors combined with low-noise front-end readout electronics ASIC (application specific integrated circuit) makes possible an order of magnitude improvement in spatial (angular) and energy resolution in X-ray detection. If silicon pixel detectors are used the energy threshold can be lowered. The preliminary test results obtained from our first silicon and CZT pixel detectors are presented. These detectors may also be used with or without modification for medical and industrial imaging.

A linear CdZnTe pad detector array with approximately 1 mm/sup 2/ pad area has been developed. The detector has a wide energy range from about 20 to 200 keV. A fast, low-noise monolithic mixed signal ASIC chip has been developed to read out these detector arrays. A prototype X-ray imaging system consisting of the CdZnTe detector array and the monolithic ASIC chip has been fabricated and tested. In this system, the detectors are abutted against each other to form an approximately 1 m long linear array. The system has been used to take preliminary scanned images of complex objects at various energies. New results obtained from this system is discussed.