PSI run report of the micromegas detector-March 28-April 13 1999

99-020 A Micromegas prototype has been tested at PSI in a high flux pion beam. The main goal was the study of the rate of discharges in this environment, but we also report results on time resolution and pulse height distribution measurements. Discharge probabilities per particles of 4x10<SUP>-5</SUP> for a pure pi<SUP>-</SUP> beam of 215 MeV/c momentum and 10<SUP>-4</SUP> for a mixed pi<SUP>+</SUP> and protons beam of 350 MeV/c momentum have been measured. It turned out to be constant up to high rates of 48 MHz in the chamber. These results on the discharges may have been worsened by the gas mixture used for this run, namely argon and CO<SUB>2</SUB>. Micromegas doesn't seem to be LHC compliant in it's actual form, in spite of its many qualities, which merit more investigation.