Impact of GEM foil hole geometry on GEM detector gain

A Karadzhinova,I Kassamakov,R Veenhof,E Tuominen,A Nolvi,E Hæggström

doi:10.1088/1748-0221/10/12/p12014

Abstract

Detailed 3D imaging of Gas Electron Multiplier (GEM) foil hole geometry was realized. Scanning White Light Interferometry was used to examine six topological parameters of GEM foil holes from both sides of the foil. To study the effect of the hole geometry on detector gain, the ANSYS and Garfield ++ software were employed to simulate the GEM detector gain on the basis of SWLI data. In particular, the effective gain in a GEM foil with equally shaped holes was studied. The real GEM foil holes exhibited a 4% lower effective gain and 6% more electrons produced near the exit electrode of the GEM foil than the design anticipated. Our results indicate that the GEM foil hole geometry affects the gain performance of GEM detectors.

Highlights

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The real Gas Electron Multiplier (GEM) foil holes exhibited a 4% lower effective gain and 6% more electrons produced near the exit electrode of the GEM foil than the design anticipated
3.1 GEM foil hole parameters examined with Scanning White Light Interferometer (SWLI) Figure 12 illustrates the GEM foil sample hole #8, scanned by SWLI and compared with the corresponding optical scanning system (OSS) image

Summary

Introduction

This content has been downloaded from IOPscience. 2015 JINST 10 P12014 (http://iopscience.iop.org/1748-0221/10/12/P12014) View the table of contents for this issue, or go to the journal homepage for more. You may be interested in: Gas Electron Multiplier foil holes: a study of mechanical and deformation effects L. To study the effect of the hole geometry on detector gain, the ANSYS and Garfield ++ software were employed to simulate the GEM detector gain on the basis of SWLI data. The effective gain in a GEM foil with shaped holes was studied. The real GEM foil holes exhibited a 4% lower effective gain and 6% more electrons produced near the exit electrode of the GEM foil than the design anticipated. Our results indicate that the GEM foil hole geometry affects the gain performance of GEM detectors

Methods

Results

Discussion

Conclusion