Commissioning the ATLAS silicon microstrip tracker

The completed SemiConductor Tracker (SCT) has been installed inside ATLAS. Quick tests were performed last year to verify the connectivity of the electrical and optical services. Problems observed with the heaters for the evaporative cooling system have been resolved. This has enabled extended operation of the full detector under realistic conditions. Calibration data has been taken and analyzed to determine the noise performance of the system. In addition, extensive commissioning with cosmic ray events has started. The cosmic muon data has been used to align the detector, to check the timing of the front-end electronics as well as to measure the hit efficiency of modules. The current status of the SCT will be reviewed, including results from the latest data-taking periods. The commissioning experience will be used to extract lessons for future silicon detector projects.