Quality Assurance and Performance Tests of Silicon Detector Modules for the CMS/Tracker

After providing a short overview of the LHC accelerator, the CMS experiment and it’s various detector systems, we will have an in-depth look on silicon semiconductor particle detectors. Various important aspects like theoretical principles, radiation damage and actual design considerations are discussed and the quality assurance scheme for the sensor and module production is introduced. A strong emphasis is made on the ARC module teststand which was set up and operated be the author. Another important aspect in establishing a good quality assurance scheme is flexibility and keeping an eye on the unexpected. At one such occasion, the author had to gather custom made test equipment, to investigate certain effects in silicon sensors manufactured by ST Microelectronics. Conclusions from these measurement could only be drawn very cautiously, as the manufacturing process and many of its subtle changes, remained a well kept secret of the company. Nevertheless, the investigations proofed to be useful and ST Microelectronics was able to remedy the problems. A manufacturing, assembly and quality assurance process can only be declared successful, when the final product in the end is working within the specifications. To prove that this is true for the CMS tracker detector modules, the author joined a collaboration of young physicists to examine the performance of a selection of modules in a testbeam at the DESY research facility in Hamb urg, Germany. As a novelty, fully irradiated CMS detector modules where put into a testbeam for the very first time. It will be shown, that module types used in this testbeam are capable of working well within specs even after experiencing the full 10 years of LHC lifetime.