Performance and Operation of the ATLAS Resistive Plate Chambers Detector in 2011

Resistive Plate Chambers provide the barrel region of the ATLAS detector with an independent muon trigger and a two-coordinate measurement. The chambers, arranged in three concentric double layers are operated in a strong magnetic toroidal field and cover a surface area of about 4000m2. During 2011 the LHC has provided proton-proton collisions at 7 TeV in the center-of-mass frame with a steady increase in instantaneous luminosity over several orders of magnitude, summing up to about 5 f b