Study of the performance of the ATLAS muon spectrometer

The ATLAS muon spectrometer consists of three large air-core superconducting toroids and of systems of both trigger and precise position measurement chambers of various technologies. The aim of the spectrometer is to provide a measurement of the muon transverse momenta with a resolution below 10% from 3 GeV up to 1 TeV. The system is also designed to trigger on muons in a wide angular region. The precision tracking chambers are Monitored Drift Tube chambers (MDT) covering most of the detector, and the Cathode Strip Chambers (CSC) are located in a small part of the forward region. Resistive Plate Chambers (RPC) and Thin Gap Chambers (TGC) are used for triggering. The performance of the spectrometer in terms of trigger and track reconstruction efficiency and in terms of resolution are continuously measured using collision data. The methods developed to assess the spectrometer performance will be presented and discussed.