Construction and Testing of a Pixellated CZT Detector and Shield for a Hard X-ray Astronomy Balloon Flgiht

摘要

We report on the construction and laboratory testing of pixellated CZT detectors mounted in a flip-chip, tiled fashion and read out by an ASIC, as required for proposed hard X-ray astronomy missions. Two 10 mm x 10 mm x 5 mm detectors were fabricated, oen out of standard eV Products high-presusre Bridgman CZT and one out of IMARAD horizontal Bridgman CZT. Each was fashioned with a 4 x 4 array of gold pixels on a 2.5 mm pitchw ith a surrounding guard ring. The detectors were mounted sid by side on a carrier card, such that the pixel pitch was preserved, and read out by a 32-channel VA-TA ASIC from IDE AS Corp. controlled by a PC/104-single-board computer. A passive shield/collimator surrounded by plastic scintillator encloses the detectors on five sides and provides a approx 40 deg field of view. Thus this experiment tests key techniques required for future hard X-ray survey instruments. The experiment was taken to Ft Sumner, NM in May 2000 in preparation for a scientific balloon flight aboard the joint Harvard-MSFC EXITE2/HERO payload. Although we did not receive a flight opportunity, and are currently shceduled to fly in September 2000, we present our calibration data in the flight configuration together with data anlysis techniques and simulations fo the expected flight background spectrum.