The 40×40cm2 gaseous microstrip detector Micromegas for the high-luminosity COMPASS experiment at CERN

The measurements in the COMPASS experiment at CERN require high-resolution tracking detectors, with low radiation length and high-rate capability. For this purpose we have developed and optimized a gaseous microstrip detector `Micromegas'. Twelve planes with 1024 strips each, assembled in 3 stations of 4 views XYUV, are now being operated with success in the COMPASS environment. We describe here the performances and results obtained.