Achievements of the ASTRO-E Hard X-ray Detector development

The ASTRO-E Hard X-ray Detector utilized GSO/BGO well-type phoswich counters in compound-eye configuration, to achieve an extremely low background level of a few /spl times/10/sup -5/ counts s/sup -1/ cm/sup -2/ keV/sup -1/. The GSO scintillators installed in the BGO active shield wells observes 30-600 keV photons, while silicon PIN diodes of 2 mm thick placed in front of each GSO crystal covers 10-60 keV photons with energy resolution of /spl sim/3.5 keV FWHM. The design goals both of low background and high energy resolution in the hard X-ray bands were confirmed to be achieved through the preflight calibration experiments.