3D Simulation of Electron and Ion Transmission of GEM-based Detectors

TL;DR

This paper uses 3D Garfield simulations to analyze electron and ion transmission in GEM detectors, proposing a new triple GEM configuration with low ion backflow for future TPC applications.

Contribution

It introduces a novel triple GEM configuration with optimized parameters to reduce ion backflow while maintaining electron transmission, enhancing TPC detector performance.

Findings

Triple GEMs with different hole pitches studied under various fields.

A new triple GEM configuration with low ion backflow proposed.

Simulation results show improved ion suppression and electron transmission.

Abstract

Time Projection Chamber (TPC) has been chosen as the main tracking system in several high-flux and high repetition rate experiments. These include on-going experiments such as ALICE and future experiments such as PANDA at FAIR and ILC. Different $\mathrm{R}\&\mathrm{D}$ activities were carried out on the adoption of Gas Electron Multiplier (GEM) as the gas amplification stage of the ALICE-TPC upgrade version. The requirement of low ion feedback has been established through these activities. Low ion feedback minimizes distortions due to space charge and maintains the necessary values of detector gain and energy resolution. In the present work, Garfield simulation framework has been used to study the related physical processes occurring within single, triple and quadruple GEM detectors. Ion backflow and electron transmission of quadruple GEMs, made up of foils with different hole pitch under different electromagnetic field configurations (the projected solutions for the ALICE TPC) have been studied. Finally a new triple GEM detector configuration with low ion backflow fraction and good electron transmission properties has been proposed as a simpler GEM-based alternative suitable for TPCs for future collider experiments.