Design and Performance of the ATLAS Muon Detector Control System

Muon detection plays a key role at the Large Hadron Collider. The ATLAS Muon Spectrometer includes Monitored Drift Tubes (MDT) and Cathode Strip Chambers (CSC) for precision momentum measurement in the toroidal magnetic field. Resistive Plate Chambers (RPC) in the barrel region, and Thin Gap Chambers (TGC) in the end-caps, provide the level-1 trigger and a second coordinate used for tracking in conjunction with the MDT. The Detector Control System of each subdetector technology is required to monitor and safely operate tens of thousand of channels, which are distributed on several subsystems, including low and high voltage power supplies, trigger and front-end electronics, currents and thresholds monitoring, alignment and environmental sensors, gas and electronic infrastructure. The system is also required to provide a level of abstraction for ease of operation as well as specific tools allowing expert actions and detailed analysis of archived data. The hardware architecture and the software solutions adopted are shown along with results from the commissioning phase and the routine operation with colliding beams at 3.5 + 3.5 TeV. Design peculiarities of each subsystem and their use to monitor the detector and the accelerator performance are discussed along with the effort for a simple and coherent operation in a running experiment. The material presented can be a base to future test facilities and projects.