The LHCb Muon detector commissioning and first running scenarios

The LHCb muon detector, part of the first LHCb trigger level (L0), has been built to provide a fast and efficient identification of the muons produced in pp collisions at the LHC. The expected performances are: 95% L0 trigger efficiency within a 25 ns time window and muon identification in L0 with a Pr resolution of 20%. The detector has been built using Multi-Wire Proportional Chambers and Gas Electron Multiplier technology. The chambers are arranged in five stations, interspersed with iron filter placed along the beam pipe. The results obtained in the commissioning of all the installed chambers and the measured performances are presented. The strategies foreseen for the detector calibration, the results of the space and time alignment efforts and few first running scenarios are discussed.