Tracker alignment

One of the most demanding calibration activities for the CMS Tracker is the geometrical alignment of its 15148 modules with respect to each other. Detector alignment has been a highly important issue for the physics discoveries, and it will be one of the essential ingredients again in 2015 when the Large Hadron Collider restarts operation, since alignment needs to be carried out from scratch. In 2013 the HIP team continued its long-term participation in the alignment work of the CMS Tracker focusing in questions of monitoring and validation. Tapio Lampén was in charge of maintenance and development of the offline track-based alignment validation tools, and contributed to the validation process of alignment constants as well as studies of time-dependent changes of Lorentz Angle calibration of the Pixel detector.