oa Performance Of The Gas Electron Multiplier For Cms Muon Chambers Upgrade

The international GEM collaboration is working on instrumenting the high-? region of the CMS endcap with Gas Electron Multiplier (GEM), a candidate detection system for muon particles that could resist the high luminosity and strong magnetic field present in that region. It consists of a thin polymer foil, metal coated on each side and pierced by a high density of holes (see figures). The potential difference between the electrodes and the high electric field in the holes will cause an electron generated by ionzing radiation or a charged particle crossing the detector to multiply and form an avalanche. This will further amplify the signal and provide a better detection system. Texas A&M University at Qatar is involved in the development and upgrade of the muon system. In this work, we present the results of the spatial resolution and efficiency studies of the GEM prototype tested at the CERN facilities using pion and muon beams.