Combined test beam results on the alignment of Muon chambers and Muon reconstruction in the 2004 ATLAS H8 setup

ATLAS detector is designed to exploit the full discovery potential of the LHC proton–proton collider at CERN, at an energy of 14 TeV. The detector, which is optimized for operating at high luminosity, features an inner tracker, Electromagnetic and Hadronic calorimeters and a Muon Spectrometer. The ATLAS Muon Spectrometer is composed of tracking and trigger detectors, which span a total area of 5500 m2. The design of the spectrometer provides very good momentum resolution that varies between 2% and 10% for momentum ranging from 5 GeV to 1 TeV. To achieve this resolution, the 1200 individual tracking chambers composed of Monitored Drift Tubes (MDT) are constructed with mechanical precision better than 20 μm, while the position and deformation of individual chambers will be monitored with an optical alignment system to be better than 40 μm during data taking. In 2004, a combined systems test of a ϕ sector of the following ATLAS sub-detectors: the Inner Detector, the Liquid Argon Calorimeter, the Tile Hadronic Calorimeter and the Muon Spectrometer, was performed in the H8 beam line at the CERN SPS. Results obtained on the alignment of the MDT chambers in the Muon Spectrometer setup, the performance of the MDT chambers and the reconstruction of Muon tracks using the combined information from both the Inner Detector and the Muon Spectrometer are presented here.