Spatial resolution in Micromegas detectors

The performance of a telescope of Micromegas detectors has been studied in a pion beam at the CERN PS. With a gas filling of CF/sub 4 / and 20% isobutane and with a strip pitch of 100 mu m an accuracy of 14+or-3 mu m on the spatial resolution has been measured at normal incidence. A simulation demonstrates that the resolution is limited by the size of the holes of the mesh of the detector and could be reduced to 11 mu m in the same conditions with smaller holes. Even further improvement down to 8.5 mu m is feasible for the same gas with an optimized 75 mu m strip pitch. (5 refs).