LPE GAAS AS AN X-RAY-DETECTOR FOR ASTRONOMY

Gallium arsenide detectors offer an attractive alternative to silicon for high energy X-ray (> 10 keV) astrophysics. Thick (130 mum) detecto rs fabricated from GaAs grown using the liquid phase epitaxy (LPE) pro cess are now achieving an energy resolution which is approaching that needed in astrophysics. At the same time progress continues to be made in the field of true imaging optics at these high energies using mult i-layer reflective surfaces and it is now not unreasonable to imagine a hard X-ray astrophysics mission with grazing incidence optics and a GaAs solid state position sensitive spectrometer in the focal plane. A brief introduction to hard X-ray astrophysics and optics is given. Re sults obtained with an LPE GaAs device are presented including both de tector performance and the electrical characteristics. At room tempera ture a resolution of approximately 2.8 keV HWHM was achieved.