ABSTRACT
The next generation of space-based hard X-ray (dened here as the energy range from 10 to several hundred kiloelectron volts) telescopes for astrophysical observations will include both large-area coded aperture imaging systems for synoptic studies over a wide eld of view and focusing telescopes to reach faint ux limits over more limited regions of the sky. Both applications require detectors with good (a few percentage points) energy resolution and two-dimensional position resolution of a millimeter or better. In addition, space-based telescopes in this energy band benet from compact detector geometries that can be well shielded from the intense background radiation produced in the atmosphere and spacecraft by cosmic rays. The ability to measure the depth of interaction is also desirable for background rejection.
