# GEM Foil Quality Assurance For The ALICE TPC Upgrade

## TL;DR

This paper discusses the development and implementation of a comprehensive quality assurance scheme for GEM foils used in the upgraded ALICE TPC detector, enabling higher data rates at CERN's LHC.

## Contribution

It introduces a detailed QA process for GEM foil production, ensuring performance standards for the ALICE TPC upgrade.

## Key findings

- Successful QA scheme for GEM foils established
- Enhanced detector performance and data rate capabilities
- Reliable production process for over 800 GEM foils

## Abstract

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) -based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.