The Atlas Tile Calorimeter performance at LHC

The Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. Due to the very good muon signal to noise ratio it assists the spectrometer in the identification and reconstruction of muons. TileCal is built of steel and scintillating tiles coupled to optical fibers and read out by photomultipliers. The calorimeter is equipped with systems that allow to monitor and to calibrate each stage of the read-out system exploiting different signal sources: laser light, charge injection and a radiactive source. The performance of the calorimeter has been measured and monitored using calibration data, random triggered data, cosmic muons, splash events and most importantly the large sample of pp collision events acquired in 2011. Results on the absolute energy scale calibration precision, on the energy an timing uniformity and on the synchronization precision are presented. These results demonstrate that the Tile Calorimeter is performing well within the design requirements and to giving essential input to the physics results.