Münster 2017 – wissenschaftliches Programm
T 117.6: Vortrag
Donnerstag, 30. März 2017, 18:05–18:20, VSH 06
Studies on Discharge Behaviour in Thick-GEMs — •Bernhard Flierl1, Otmar Biebel1, Theo Goldfuss1, Ralf Hertenberger1, Phillipp Lösel1, and Andre Zibell2 — 1Ludwig-Maximilians-Universität München — 2Julius-Maximilians-Universität Würzburg
Gaseous Electron Multipliers (GEMs) have shown great performance in different applications. Their intrinsic high rate capability might be lowered in hostile environment, where strongly ionizing particles occur simultaneously to minimum ionizing particles to be detected. Very high charge deposition creates discharges, which are in general harmless for the GEM, but create dead time until the initial voltages are recreated. Here the discharge characteristics of Thick-GEMs made from 1 mm PCB-Material and 35 µm copper cladding in contrast to standard GEMs of 50 µm Kapton with 5 µm copper cladding is studied and different approaches of discharge prevention are discussed. An optical read-out is used to locate and count artificially induced discharges, which lead to a visible spark. We present results of characterization with different drift gases by measurements with cosmic muons and an α-source in order to trigger discharges by high local energy deposition of 5.5 MeV. The main focus is on the minimization of the effects of a discharge, e.g minimization of voltage drop on the GEM-electrodes and dead time after a discharge.