ABSTRACT
This chapter describes the ionizing radiation produces a number of charge carriers in semiconductor detectors. X-rays interact inelastically with matter in three ways: photoelectric, Compton, and pair production. These energy loss mechanisms all eventually produce thermalized electron–hole pairs in the conduction and valence bands of the semiconductors. The modality for detecting x-rays is very different. In most cases, it is impossible to focus the x-rays, and large-area detectors are required. Detectors can have thousands or millions of contacts and similar numbers of amplifier channels. A full application-specific integrated circuits (ASIC) development can easily cost over a million euro and extend over two years, which can be a significant problem for the budget of some scientific experiments. There are several intrinsic noise processes that limit the performance of pixelated detectors. The cooling takes place in exactly the space that one would like to route interconnections to control and take data from the ASICs.
