Digirad proposes to develop a new class of solid-state detector arrays with microelectronics readout circuitry for two-dimensional imaging of x-ray and gamma ray fields in support of next-generation Earth and space science mission requirements. The approach uses cadmium zinc telluride (CZT), a new room temperature detector material first developed by Digirad. Recent results show that CZT detector arrays can exhibit high detection efficiencies and superior energy resolution from below 1 kev to above 600 kev. CZT detectors are robust and lightweight; and can be patterned in a variety of array structures, with pixel dimensions to well below 100 æm. The innovation of producing CZT imagers suitable for space applications has not yet been accomplished, although at least three proposals accepted by NASA'S recent New Mission Concepts for Astrophysics program recommended their use. Thus CZT imager development responds directly to Section 8.04 of the SBIR solicitation, and particularly to the needs of NASA small missions initiatives. Phase I goals are to demonstrate the feasibility of achieving performance goals by analyzing the performance of specific array structures and studying their tolerances to the vibration, temperature variation and radiation conditions of launch and space environments.Commercial Applications:CZT imager technology improvements developed in this project should directly benefit Digirad's new gamma camera for nuclear medicine and other imaging products under development by providing improved performance and reliability, and lower manufacturing costs.
