Digital x-ray imaging with energy sensitivity using
micropattern gas detectors

Gene Barasch
Brookhaven National Laboratory
March 4, 2002

Abstract:
Multi-Wire Proportional Chambers (MWPCs) have been the workhorse energy and position sensitive detectors in particle physics applications since the late 60's and their development led to the Nobel Prize in Physics for George Charpak in 1992. However, they are rate-limited and could not be used for full-field, full intensity x-ray imaging. In 1987, Anton Oed of the Institut Laue Langevin in Grenoble, France constructed the first Micro-Strip Gas Counter (MSGC) by mimicing the electric field configuration of a wire chamber using instead of wires strips lithographed on a substrate. These and other related devices not only can maintain function at medical imaging rates but demonstrate superb position/object resolution and energy resolution. Thus, for the first time, 2-D gas detectors have become strong candidates for medical applications. Recent advances in pixel electronics and pixel chip fabrication now allow the development of a full size, full field x-ray imaging device that may have unique capabilities in such energy-sensitive applications as dual-energy digital subtraction.