X - Ray Imaging using a Pixel GaAs Detector

The electrical characteristics,charge collection eeciency and energy resolution of a GaAs detector made out of LEC material have been studied. A matrix of 36 square pixels was deposited on a 70 m thick crystal; each pixel had an area of 200x200 m 2 with 20 m spacing between adjacent pixels. This detector showed a charge collection eeciency uniformity among the pixels better than 88% when exposed to 60 keV photons, which ensures that a comfortable common threshold setting can be adopted without aaecting the uniformity of the measurement. It was successful in recording (60 keV photon energy) the image of a wolframium slab, 100 m thick.