Developing and evaluating new micropattern gas detectors

Micropattern gas detectors (MPGDs) were introduced in the late 1980s in order to overcome the limited rate capability of traditional proportional counters. Thanks to their microscopic electrode structures, MPGDs are faster and more precise than the previous gas detectors and soon gained popularity. Two of the most successful MPGDs are the gas electron multiplier (GEM) and the micro-mesh gaseous structure (Micromegas). In this thesis I present the features of GEMs and Micromegas, some of their current applications and the research and development that I have done on these technologies. My activity covered two main topics: the test and enhancement of single-mask GEMs for large-area applications and the study of spark-tolerant Micromegas for the upgrade of the ATLAS Small Wheels.