Development of Micromegas detectors for the upgrade of the ATLAS Muon Spectrometer

The Muon Sepctrometer of the ATLAS detector will undergo a major change in view of the LHC upgrade foreseen in 2018. In particular the two most internal detector wheels of the endcap part of the muon spectrometer (Small Wheels) need to be rebuilt with detectors capable to cope with the higher particle rate. We propose Micromegas detectors to be used both as trigger and tracking devices for the new Small Wheels. The most recent developments of Micromegas tailored to the ATLAS spectrometer upgrade will be illustrated: the development of resistive strip detectors to reduce the discharge probability, the construction of largesize (∼ m2) chambers, the optimization of working parameters and the innovative μTPC working mode that allows a local reconstruction of track segments