Recent developments using GaAs as an x-ray detector

Recent developments in the manufacture of GaAs detectors for high energy physics applications and dark matter searches have resulted in working devices made from LEC and HB starting material This offers the promise of routine manufacture of reproducible devices at a modest cost. The most advanced of the techniques is that of Schottky diodes on LEC material. Results are presented demonstrating the performance of such devices (3.0 mm X 5.0 mm X 200 micrometers ) as x-ray detectors, including their low temperature operation. An alternative technique using charge collection in bulk HB material at temperatures down to liquid helium also is briefly described.