The Silicon Inner Tracker of CMS: Construction, Organization and Future Upgrade

The silicon Inner Tracker is the innermost detector part of the CMS experiment at CERN. This detector contains about 200 m 2 of precision silicon sensors, fast and radiation hard electronics, an optical readout and many more highly sophisticated components. The total number of sensor elements amounts to 9.3 million strips and 66 millions pixels. The strip detector is completely assembled and has been commissioned at the operating temperature of about—15 °C. A collaboration consisting of about 500 members coming from 51 institutes worldwide has designed and constructed this detector in a period of more than 12 years. The different components for the tracker were developed in cooperation with industrial partners. The Inner Tracker was installed in the CMS experiment at the end of 2007. A discussion on the upgrade of CMS and the Inner Tracker has already started in view of an increase in performance of the LHC collider. To cope with the even more demanding requirements expected for the next generation apparatus an extensive R&D period is about to start with many opportunities opening up for new collaboration members to join the effort.