MDT Monitored Drift Tubes

A mock-up of the precision wire chambers (Monitored Drift Tubes) used by the ATLAS experiment to detect muons. The chambers consist of several layers of 3 cm aluminum tubes. The electrons created by the muons passing through the tubes drift to a wire situated in the middle of the tube. By measuring the arrival times in several tubes as shown below, muon tracks can be reconstructed with an accuracy of 80 μm. These tracks, bent by the magnetic field, are used to measure the electric charge and the momentum of the muons.