Optimization and Performance of the ATLAS Tau Trigger with Cosmics Data

Cosmics data are providing a valuable handle to optimize and commission the ATLAS detector before beam collissions. In this process the ATLAS Tau Trigger is also exercising and adjusting its different components, namely the hardware based first level trigger, and the second and third levels, implemented with software. In this contribution we summarize the performance at the different stages with cosmics events, and compare with Monte Carlo simulation and offline reconstructed muon candidates. We also describe the prospects for initial running with beam collisions, focusing on the commission of the second and third level tau triggers and the strategy to measure the first trigger efficiencies with data.