Advanced Alignment of the ATLAS Tracking System

In order to reconstruct the trajectories of charged particles, the ATLAS experiment exploits a tracking system built using different technologies, planar silicon modules or microstrips (PIX and SCT detectors) and gaseous drift tubes (TRT), all embedded in a 2T solenoidal magnetic field. Misalignments and deformations of the active detector elements deteriorate the track reconstruction resolution and lead to systematic biases on the measured track parameters. The alignment procedures exploits various advanced tools and techniques in order to determine for module positions and correct for deformations. For the LHC Run II, the system is being upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL).