DISCHARGE PHENOMENA IN MICRO-PATTERN GASEOUS DETECTORS

• Piotr Gasik (GSI)

Room: Kreuzbergweg 24/0.052 (FTD) - Präsentationsraum The history of gas discharge physics dates back to the early 1800s when V.V. Petrov discovered arc discharge. Since then, the physics of gas discharges is presumably one of the best-studied fields in modern science. Yet, after more than two hundred years of experience, the fundamental questions about discharge phenomena are still vivid, especially within the gaseous particle detector community. Despite 30 years of experience in the production and successful operation of Micro Pattern Gaseous Detectors (MPGD), the high demands of modern experiments, which particularly concern the substantial increase in active detector area, require further developments and improvements. Constantly increasing luminosity demands operation in a harsh, high-rate environment posing stringent requirements on the performance of MPGDs. The key parameters for long-term operation are radiation hardness, aging resistance, and stability against electrical discharges. The latter in particular pose a threat to the integrity of a detector and its readout electronics, as they may cause irreversible damage to the amplification structure, ranging from enhanced leakage currents to permanent electric short circuits that render the detector effectively blind and lead to a loss in its acceptance. It is, therefore, of the highest importance to further study and optimize this particular aspect of detector operation. A brief summary of gas discharge physics and its relevance for MPGDs will be given during the seminar. Discharge phenomena occurring in MPGDs will be discussed. The most common mitigation strategies, new ideas, and possible ways towards the development of a spark-less gaseous detector will be presented.