Alignment of the Muon Spectrometer in ATLAS

The ATLAS muon spectrometer is designed to measure the momentum of a 1 TeV/c muon to an accuracy of 10%. A muon of this momentum bends less than 500 μm in the toroidal field of ATLAS and the position of the muon chambers must be known to better than 50 microns. ATLAS uses a combination of an optical system and alignment with tracks to achieve such a precise alignment. Several analyses to monitor and validate the alignment were quite successful in the first year of LHC operation. This report provides a brief overview of the motivation, building and commissioning of the optical system, performance, and validation of the alignment of the muon spectrometer.