Large precision muon detector for ATLAS

The ATLAS muon spectrometer is designed to exploit the full physics discovery potential at the Large Hadron Collider in a stand-alone mode. The precision muon detector is made of monitored drift tubes with tracking precision better than 50 mum to measure the muon track sagitta in the toroidal magnetic field. A world-wide intensive construction work of the ATLAS muon detector is under way. We report the precision muon detector mass production experience, including the R&D results on the long tube operation stability and the impact on the momentum resolution due to wire sag. The quality control data in mass production are presented. Cosmic ray test results show that the MDT chambers have tracking efficiency close to 100% and single wire resolution is better than 80 mum.