Performance of GEM Detectors for MUSE*

The Muon Scattering Experiment (MUSE) at Paul Scherrer Institute (PSI) is designed to simultaneously measure the proton charge radius with elastic scattering of electrons and muons of either charge polarity. Due to the large emittance of the secondary beam, it is necessary to have a beamline detector for event-by-event beam particle tracking. A telescope of Gas Electron Multipliers (GEM), exposed to a high flux of beam particles is used to reconstruct the incoming tracks with high spatial resolution while presenting minimal material for the beam to pass through. In this presentation, I will discuss the effects of noise suppression techniques such as channel flagging, interpolation, and cross-talk suppression that are used to improve the GEM beam tracker performance. In addition, the multi-sample readout allows to reconstruct the time dependence of proper GEM signals and to further reject backgrounds.