Event filter monitoring with the ATLAS tile calorimeter

The ATLAS Tile Calorimeter detector is presently involved in an intense phase of subsystems integration and commissioning with muons of cosmic origin. Various monitoring programs have been developed at different levels of the data flow to tune the set-up of the detector running conditions and to provide a fast and reliable assessment of the data quality already during data taking. This paper focuses on the monitoring system integrated in the highest level of the ATLAS trigger system, the Event Filter, and its deployment during the Tile Calorimeter commissioning with cosmic ray muons. The key feature of Event Filter monitoring is the capability of performing detector and data quality control on complete physics events at the trigger level, hence before events are stored on disk. In ATLAS’ online data flow, this is the only monitoring system capable of giving a comprehensive event quality feedback.