High-Resolution Micromegas Telescope for Pion- and Muon-Tracking J. Bortfeldt et al. – LMU Munich goal: track reference system with <20μm track resolution for detector tests with high-energy pions and muons 4 Micromegas detectors 9cm x 10cm active area, 360 copper strips, 250μm pitch gas: Ar:CO2 85:15 @ 1013mbar segmented trigger scintillators → 3rd track coordinate readout: Gassiplex based frontend modules, 1500 channels in total synchronization with other DAQ systems via external 12 bit trigger counter → 12ch TDC detector calibration using 160GeV pions at the H6 beamline @ SPS, CERN

High-Resolution Micromegas Telescope for Pion- and Muon-Tracking J. Bortfeldt et al. – LMU Munich best value of efficiency: 98.5% (fully efficient) discharge probability: 1.5 x 10-5 per pion → 0.66% dead time @ 22kHz particle rate → negligible best value of single detector spatial resolution: 35μm → track resolution <20μm with 2 x 2 detectors only weak influence of gas gain and diffusion on spatial resolution spatial resolution depends on number of primary electrons, reaching the amplification region