Development of segmented semiconductor arrays for quantum imaging

The field of pixel detectors has grown strongly in recent years through progress in CMOS technology, which permits many hundreds of transistors to be implemented in an area of 50-200 um2. Pulse processing electronics with noise of the order of 100 e- RMS permits to distinguish photons of a few keV from background noise. Techniques are under development, which should allow single chip systems (area ~1 cm2) to be extended to larger areas. This paper gives an introduction into the concept of quantum imaging using direct conversion in segmented semiconductor arrays. An overview of projects from this domain using strip, pad and in particular hybrid pixel detectors will be presented. One of these projects, the Medipix project, is described in more detail. The effect of different correction methods like threshold adjustment and flat field correction is illustrated and new measurement results and images presented.