The CMS Tracker

With the CMS Tracker the tracks of charged particles can be precisely reconstructed. Near the interaction point in the very center of the detector, these tracks are very dense. Furthermore, the LHC produces over 800 Million collisions per second requiring very fast and precise sensors. Only semiconductor sensors made from silicon have shown adequate performance and radiation hardness to operate in such an environment.

Similar to a digital photo camera which only takes a few two dimensional picture per second, the CMS Tracker can record three dimensional pictures of charged particle tracks using 25 000 silicon strip sensors placed on several planes of concentric cylinders. The total surface is more than 200 m2 and the CMS Tracker his the largest scientific device using semiconductor sensors.