CMS Silicon Strip Tracker Commissioning and Preliminary Performances

The Silicon Strip Tracker (SST) of the Compact Muon Solenoid (CMS) Experiment at the CERN Large Hadron Collider (LHC) is the world’s largest silicon microstrip detector. The SST is composed of four subdetectors which were integrated into the Tracker Support Tube (TST) at the CERN Tracker Integration Facility (TIF) in March 2007. After the insertion of the TST into CMS in December 2007, the first data taking of CMS with the SST included took place in July 2008 without magnetic field and one month later with a magnetic field of 3.8 Tesla. The SST was ready for the LHC start-up of September 10, 2008. The main aspects of the SST commissioning and a description of the problems encountered and solved so far are summarized here together with some preliminary performance evaluation