Antiproton beam profile measurements using Gas Electron Multipliers

TL;DR

This paper presents a novel, lightweight Gas Electron Multiplier (GEM) detector for precise antiproton beam profile measurements at CERN, overcoming limitations of previous multi-wire proportional chambers and demonstrating successful deployment.

Contribution

Introduction of a lightweight GEM-based detector for antiproton beam profiling, offering improved accuracy and reliability over traditional MWPC systems at CERN.

Findings

Successful prototype testing in 2010

Deployment of five detectors in CERN beam lines

Potential for widespread upgrade of beam profile monitors

Abstract

The new beam profile measurement for the Antiproton Decelerator (AD) at CERN is based on a single Gas Electron Multiplier (GEM) with a 2D readout structure. This detector is very light, ~0.4% X_0, as required by the low energy of the antiprotons, 5.3 MeV. This overcomes the problems previously encountered with multi-wire proportional chambers (MWPC) for the same purpose, where beam interactions with the detector severely affect the obtained profiles. A prototype was installed and successfully tested in late 2010, with another five detectors now installed in the ASACUSA and AEgIS beam lines. We will provide a detailed description of the detector and discuss the results obtained. The success of these detectors in the AD makes GEM-based detectors likely candidates for upgrade of the beam profile monitors in all experimental areas at CERN. The various types of MWPC currently in use are aging and becoming increasingly difficult to maintain.