Performance of a triple-GEM detector for high rate charged particle triggering

We report the results of a systematic study of the performance of 10×10 cm2 triple-GEM detectors operated with several gas mixtures. revious paper, we pointed out that adding CF4 to the standard Ar/CO2 gas mixture allows to improve the time resolution of the detector from ∼10 ns down to ∼6 ns (r.m.s.). In this paper, we discuss the results obtained with CF4 and iso-C4H10-based gas mixtures, during a beam test at the πM1 beam facility of the Paul Scherrer Institute (PSI). inary results concerning the discharge probability of triple-GEM detector, when exposed to both high intensity pion/proton beam and α-particles from a radioactive source are presented. Gain measurements and aging tests, using a high intensity 5.9 keV X-ray tube, are eventually discussed.