The ATLAS Liquid Argon Calorimeter: Construction, Integration, Commissioning

The ATLAS liquid argon (LAr) calorimeter system consists of an electromagnetic barrel calorimeter and two end caps with electromagnetic, hadronic and forward calorimeters. The liquid argon sampling technique, with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the end cap (EMEC). The hadronic end cap calorimeter (HEC) uses a copper‐liquid argon sampling technique with flat plate geometry and is subdivided in depth in two wheels per end‐cap. Finally, the forward calorimeter (FCAL) is composed of three modules employing cylindrical electrodes with thin liquid argon gaps.The construction of the full calorimeter system is complete since mid‐2004. Production modules constructed in the home institutes were integrated into wheels at CERN in 2003–2004, and inserted into the three cryostats. They passed their first complete cold test before the lowering into the ATLAS cavern. Results of quality checks (e.g. electrical, mechanical, …) performed on all the 190304 rea...