A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
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. A first approach aims at reducing the discharge probability to an acceptable level by lowering the charge density in the amplification region is abandoned. A second option is that of using single-stage resistive Micromegas. In this case, no attempt is made to reduce the discharge probability, which remains the same as in a standard Micromegas. The purpose is instead that of mitigating the undesired effects of streamers, and in particular the dead time. With efficiencies above 98% this approach shows good results.
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. A first approach aims at reducing the discharge probability to an acceptable level by lowering the charge density in the amplification region is abandoned. A second option is that of using single-stage resistive Micromegas. In this case, no attempt is made to reduce the discharge probability, which remains the same as in a standard Micromegas. The purpose is instead that of mitigating the undesired effects of streamers, and in particular the dead time. With efficiencies above 98% this approach shows good results.
Developing and evaluating new micropattern gas detectors
Villa, Marco (author)
2014
197 Seiten, Bilder, Tabellen, Quellen
Theses
English
Guiding Cell Migration Using One-Way Micropattern Arrays
| British Library Online Contents | 2007
Hexagonal Surface Micropattern for Dry and Wet Friction
| British Library Online Contents | 2009
Development of Apatite Micropattern Test Specimen for Cell Operation
| British Library Online Contents | 2006
Reprogramming Directional Cell Motility by Tuning Micropattern Features and Cellular Signals
British Library Online Contents | 2010
| British Library Online Contents | 2006