| ABSTRACT: |
Pixel Array Detectors (PADs) are finding wide application in synchrotron science. Pixel Array Detectors consist of a silicon detector (diode) layer and a CMOS logic layer, where each pixel in the silicon detector is connected by bump bond to a corresponding pixel in the CMOS, or "ASIC". The custom integrated circuit logic in each pixel in the ASIC processes the signal from an X-ray striking the detector. The pixel logic might integrate incoming signal, count photons, or do a combination of the two. The basic unit of the detector, a PAD module, might be 2cm by 2cm or 2cm x 8cm in area; larger area detectors are made up by tiling modules. Pixel sizes are approximately 150 microns. It is the active processing of detector signals with custom logic that differentiates a Pixel Array Detector from other detectors such as CCD detectors. Pixel Array Detectors generally have very fast read out (1-2 milliseconds) and very low point spread. Depending on the pixel design used, PADs also can have other attributes such as very high dynamic range, individual photon counting, recording of extremely high count rates, or recording extremly short bursts of x-rays.
In this talk, an overview of Pixel Array Detectors will be presented. Pixel design will be described and their strengths and weaknesses considered for
some chosen applications. |
