High Rate Proton Irradiation of 15mm Muon Drifttubes

TL;DR

This paper presents the development and testing of a new 15mm diameter drift tube detector designed to withstand high background hit rates expected in future LHC upgrades, demonstrating improved performance under proton irradiation.

Contribution

A novel high rate capable drift tube detector with reduced diameter was developed and experimentally tested using proton irradiation to evaluate its performance.

Findings

The 15mm drift tubes maintain efficiency under high proton hit rates.

Pulse height and spatial resolution are affected by proton irradiation but remain within acceptable limits.

The new design shows promise for future high-luminosity collider environments.

Abstract

Future LHC luminosity upgrades will significantly increase the amount of background hits from photons, neutrons and protons in the detectors of the ATLAS muon spectrometer. At the proposed LHC peak luminosity of 5*10^34 1/cm^2s, background hit rates of more than 10 kHz/cm^2 are expected in the innermost forward region, leading to a loss of performance of the current tracking chambers. Based on the ATLAS Monitored Drift Tube chambers, a new high rate capable drift tube detecor using tubes with a reduced diameter of 15mm was developed. To test the response to highly ionizing particles, a prototype chamber of 46 15mm drift tubes was irradiated with a 20 MeV proton beam at the tandem accelerator at the Maier-Leibnitz Laboratory, Munich. Three tubes in a planar layer were irradiated while all other tubes were used for reconstruction of cosmic muon tracks through irradiated and non-irradiated parts of the chamber. To determine the rate capability of the 15mm drift-tubes we investigated the effect of the proton hit rate on pulse height, efficiency and spatial resolution of the cosmic muon signals.