GEM Single/Double Mask and Sensitivity Studies

Abstract

The Gas Electron Multiplier (GEM) is a gas based detector used to detect charged particles in high-energy physics applications. It amplifies signals related to particle interaction within a detector and provides high gas gain, detection efficiency and time resolution. Layers of GEM are expected to be installed in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN. This research aims to optimize GEM operation and efficiency by comparing the effect of two different etching techniques-- double mask and single mask—on the detector gain. In the double mask technique, a standard GEM foil is manufactured with photoresist laminations on the upper and lower copper layers. A new manufacturing process called the single mask was developed to improve detector gain. Better structural uniformity is attained in this case as only one of the copper layers are chemically etched. On the other hand, this results in an asymmetrical double-conical hole shape instead of the symmetrical one resulting from the double mask manufacturing process. In this project, we will explore the impact of different hole diameters on the GEM efficiency and gain by simulating detector conditions using a combination of three software tools HEED, ANSYS, and Garfield++.