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 mum(2). Pulse processing electronics with noise of the order of 100e(-) RMS permits to distinguish photons of a few kilo-electron-Volts from background noise. Techniques are under development, which should allow single chip systems (area similar to 1 cm(2)) 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 are presented. (C) 2003 Elsevier B.V. All rights reserved.