Gaseous Detectors

Abstract

Over the course of the last 50 years, the advances and breakthrough in instrumentation, leading to the development of new, cutting-edge technologies, drove the progress in experimental particle physics. A true innovation in detector concepts came in 1968, with the development of a fully parallel readout for a large array of sensing elements – the Multi-Wire Proportional Chamber (MWPC), which earned Georges Charpak a Nobel Prize in Physics in 1992. This invention revolutionized particle detection, which moved from optical-readout devices (cloud chamber, emulsion or bubble chambers) to the electronics era. Since then, radiation detection and imaging with gaseous detectors, capable of economically covering large detection volume with low mass budget, have been playing an important role in many fields of science. Over the past three decades, advances in photo-lithography, microelectronics, and printed-circuit board (PCB) techniques triggered a major transition in the field of gaseous detectors from wire structures to the Micro-Pattern Gaseous Detector (MPGD) concepts. The excellent spatial and time resolution, high rate capability, low mass, large active areas, and radiation hardness make them an invaluable tool to confront future detector challenges at the frontiers of research. Modern technologies have been also derived from original MPGD structures; hybrid approaches, combining different elements in a single device, gaseous with non-gaseous detectors, as it is the case for optical read-out, or novel concepts, where MPGDs are directly coupled to the CMOS pixel chip, have emerged. Important consolidation of some better-established MPGD structures has been reached within the RD51 collaboration, often driven by the working conditions of large collider experiments. The design of the new micro-pattern devices appears suitable for industrial production. This chapter provides an overview of the state of the art in gaseous detectors, various areas of their application, and summarizes some of the future R&D activities for advanced MPGD concepts.