Performance of the ALICE muon trigger RPCs during LHC Run I

TL;DR

This paper evaluates the performance and stability of the ALICE muon trigger RPCs during LHC Run I, focusing on efficiency, noise rates, and operational consistency across different collision types.

Contribution

It provides a comprehensive analysis of RPC performance metrics over three years of LHC operation, highlighting stability and operational effectiveness.

Findings

RPCs maintained high efficiency throughout Run I

Dark counting rates remained within acceptable limits

Stable operation across different collision systems

Abstract

ALICE (A Large Ion Collider Experiment) studies the transition of nuclear matter to a deconfined phase known as Quark Gluon Plasma, in ultra-relativistic heavy-ion collisions at the LHC. ALICE is equipped with a muon spectrometer for the detection of quarkonia and heavy flavour particles. The trigger system of the spectrometer consists of 72 RPCs arranged in four detection planes, with a total area of 140 m^{2}. In the first three years of LHC operation, the muon trigger system was fully operational in data-taking in pp, Pb-Pb and p-Pb collisions. The RPC performance and stability throughout the whole data-taking period is presented and discussed, for the parameters such as the efficiency, the dark counting rate, the dark current and the cluster size.