Commissioning and performance of the ALICE-TRD

The Transition Radiation Detector (TRD) for ALICE at the Large Hadron Collider (LHC) is designed to identify electrons and to provide a Level-1 (L1) trigger decision based on fast online tracking in the high multiplicity environment of heavy ion collisions. Currently 10 super modules are installed and are fully operational. We describe the design of the detector and its integration into the ALICE setup. Commissioning and calibration procedures of the TRD are discussed as well as results on its performance.