X-RAY-IMAGING USING A PIXEL GAAS DETECTOR

The electrical characteristics, charge collection efficiency 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 mu m thick crystal; each pixel had an area of 200 X 200 mu m(2) with 20 mu m spacing between adjacent pixels. This detector showed a charge collection efficiency 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 affecting the uniformity of the measurement. It was successful in recording (60 keV photon energy) the image of a wolframium slab, 100 mu m thick.