Small-strip thin gap chambers wedge-0 testbeam

The Large Hadron Collider (LHC) at CERN will undergo an extensive luminosity upgrade with the goal of extending sensitivity to study new physics in the multi-TeV range. The current forward muon-tracking detectors of the Muon Spectrometer of the ATLAS experiment are currently unable to cope with anticipated triggering rates and have a high false muon trigger rate. In order to handle the expected increase in background noise after the luminosity upgrade, the current muon small wheels must be replaced with the New Small Wheel (NSW) technology, which will be capable of simultaneous precision tracking and triggering under high luminosity LHC conditions. The NSW will use both small-strip thin gap chambers (sTGC) and micromegas (MM) technologies. A high energy muon testbeam was performed on the sTGC Wedge-0 at the CERN H8 facility to examine the efficiency of the sTGCs with different electronics configurations. The pads were found to be fully efficient for both configurations. However the total length of deadtime increased with the presence of a radioactive source, raising the question if the chambers will maintain high efficiency in the large radiation background environment of the high luminosity ATLAS experiment. A sTGC quadruplet fully equipped with electronics on all four layers has been installed and commissioned in the CERN Gamma Irradiation Facility (GIF++) to address this question.