Tridimensional Event Visualization for the ATLAS Calorimeter

The ATLAS detector has been commissioned with cosmic rays. For this commissioning phase, a bunch of software tools has been developed for supporting data analysis. Among ATLAS subdetectors, commissioning the calorimeter system demanded a considerable effort due to its segmentation into seven detection layers, which produces more than a hundred thousand readout channels. Tasks like performance evaluation of the calorimeter, calibration and noisy or dead channel detection benefit a lot from cosmic muon track visualization, which facilitates the identification of the activated cells in the calorimeter. The coherence of the reconstructed data can be visually checked and potential problems can be detected in a easier way. This work presents a 3-D visualization tool for the ATLAS calorimeter system, which provides a smooth integration with analyses currently performed by the ATLAS community. The tool structure and some applications with reconstructed data are presented. Due to its 3-D graphical interface, the proposed tool has been providing a simple and intuitive way to analyze event reconstructions. As a consequence, the ATLAS hadronic calorimeter collaboration is now using this visualization tool online in the control room.