Design, Construction and Commissioning of the CMS Tracker at CERN and Proposed Improvements for Detectors at the Future International Linear Collider

The CMS (Compact Muon Solenoid) detector is a huge particle physics experiment located at one of the four proton-proton interaction points of the Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). With 27 km circumference it is the not only the largest particle accelerator in size, but with a center of mass energy of 2x7 TeV it will also set the world record in terms of energy. The inner tracking system of the CMS experiment has a diameter of 2.4 m and a length of 5.4 m and is representing the largest silicon tracker ever built. About 15,000 detector modules consisting of more than 24,000 silicon sensors create a silicon area of 206 m2 to detect charged particles from proton collisions. They are placed on a rigid carbon fibre structure in the center of the experiment, and have to operate reliably within a harsh radiation environment and the working conditions of a 3.8 Tesla solenoid magnetic field at -10 degree C temperature. This thesis was conducted at the Institute of High Energy Physics of the Austrian Academy of Sciences (HEPHY), which has been involved in the design and construction of the CMS Tracker for more than 10 years. It reviews the quality assurance scheme established for testing the silicon sensors and describes the measurements done within this framework, which were developed and supervised mostly by myself. Furthermore, the Tracker Construction Database is presented, which was used to store not only these measurement results, but also helped with the logistics of the approximately 200 000 components of the CMS Tracker. I was involved in its design and developed tools for data retrieval. In the next chapter, the modules for the Tracker End Caps (TEC) are presented and problems during their construction are discussed. The tools which I developed for supervision and production steering are presented. After a short overview about larger TEC substructures called petals, the tests of a fraction of the whole tracker (called slice test) at CERN - to which I also contributed - are reviewed. The stringent requirements imposed on the quality and performance of the CMS Tracker required the solution of various problems and led to rich experience in semiconductor detectors for high energy physics experiments and its related large-scale quality assurance. To preserve this knowledge for new future detectors at the proposed International Linear Collider (ILC), this thesis concludes with a discussion about conceptual problems in the current design and proposes potential improvements.