Operation of the ATLAS Semiconductor Tracker: commissioning and performance results with cosmic ray data

The Semiconductor Tracker (SCT) is one of the three sub-systems of the ATLAS internal tracker. Its complete installation and sign-off took about 18 months and was finished at the beginning of 2008. Since then, the SCT has been run successfully taking data in combined mode with the other ATLAS sub-systems. The major problems related with cooling failures and the mortality of off-detector opto-chips have been solved. As in summer 2009, more than 99% of the main detector components are fully working. Detailed calibration procedures have been applied to optimize the detector performance. An initial alignment has been achieved using cosmic ray real data. Some results in terms of tracking performance and Lorentz angle measurements are also shown.