The ATLAS jet trigger

The ATLAS jet trigger system has a 3-level structure, and was designed based on the concept of Regions Of Interest, where only regions of the detector around interesting Level-1 objects are reconstructed at the higher levels. This philosophy has changed during 2011, and there now exists the possibility to unpacking the full calorimeter at Event Filter. In 2012, full calorimeter unpacking is also available at Level-2, in addition jet energies are now calibrated to jet energy scale, and cleaning cuts are applied to reduce rate spikes. This paper presents the performance of the jet trigger in 2011 and an overview of the new features available for 2012.