Fast High Resolution Position-Sensitive Gaseous Detectors

Abstract

The present review describes a new coordinate detectors based on gas micro-pattern technology, which are applied in experiments in elementary particle physics and with SR beams. The microstrip gas chambers (MSGC) on substrates with electronic conductivity are presented in the paper. Such detectors are shown to have spatial resolution better than 100 micron and to be able to effectively operate at particle rates up to 106 s-1mm-2, that at least by two orders of magnitude higher than rate capability of multiwire proportional chambers. Essential part of the review is devoted to studies of the cascades of gas electron multipliers (GEM). In particular, the dependence of gas amplification and conditions of a discharge occurrence on the number of GEMs in cascade, on the distribution of potentials between GEMs in cascade and on gas mixture in the presence of hadron flux are discussed. Gas micro-pattern technology is widely used for the development of coordinate detectors. In the present review we describe as an example the detectors with triple GEM cascades for the tagging system of the KEDR experiment at the VEPP-4M collider