Test and Alignment of the ATLAS Precision Muon Chambers

The muon spectrometer of the ATLAS experiment is equipped with so-called Monitored Drift Tube (MDT) Chambers as precise tracking detectors. 88 of these chambers were built by the Max-Planck-Institut (MPI) fuer Physik in Munich. The present diploma thesis was written in the course of this project. It consists of two parts: The first part deals with the final tests of the MPI muon chambers at CERN before their installation in ATLAS. The complete test programme is discussed and the results are given. After that, the installation procedure and the precise mechanical positioning of the chambers in the detector is described, as well as the first steps of the commissioning after installation. It is shown that all MPI muon chambers exhibit very low failure rates and fulfil the very high ATLAS quality requirements. The needed precision of their initial mechanical positioning could be achieved. In the second part of this work, a new method for the alignment of the muon chambers was developed. The aim is to monitor the relative chamber positions in the spectrometer using curved tracks reconstructed in the spectrometer itself during operation in the magnetic field. The method makes use of redundant momentum measurements in the spectrometer which exploit the capability of the muon chambers to measure also the direction along with the position of a track. It could be shown for the first time that a sufficient alignment precision can be achieved with such a strategy