Quality of the CMS Tracker End Cap Silicon Strip Modules
Veröffentlicht am 14.02.2007 in
The Large Hadron Collider (LHC) at CERN, a 2×7 TeV proton-proton collider, is planned to be operable in 2007 and will run for at least 10 years. The Compact Muon Solenoid (CMS), a huge multipurpose detector, is one of the four major experiments at the LHC. The construction of the Inner Tracker of CMS required more than 15.000 silicon micro-strip detector modules including about 24.000 large area silicon strip sensors.
This diploma thesis has been composed at the Institute for High Energy Physics (HEPHY) of the Austrian Academy of Sciences. It reviews the quality assurance for the 6.400 silicon micro-strip detector modules, built of one or two silicon strip sensors, in the Tracker End Caps (TEC), one out of four subsystems of the Inner Tracker. In the production laboratories, including our institute, the main steps during the fabrication of these modules are reception tests of the industrially produced module parts, their precise mechanical assembly, application of thin wire micro-bond connections and electrical functionality tests of the finalised modules.
This diploma thesis begins with a short overview of the Large Hadron Collider taking a deeper look at the CMS experiment. Then an overview of silicon sensors and the basic elements of the TEC silicon strip modules are provided. Afterward the quality assurance program during the module production and its results are presented.
At HEPHY Vienna the complete production of the Tracker End Cap Ring 2 modules was performed. My first task was to review the module assembly precision at our institute, where some problems had to be solved. At the same time I became responsible for the testing of the frames and front-end hybrids before the module assembly and the tests of the finalised modules. This included the fine-tuning of the cuts for the fault finding algorithm of the automated setup for the hybrid and module tests and the repair of different faults. I investigated the problem of the conductive glue on the sensor backplane and developed a solution.
Later on I started to monitor the quality of the whole TEC module production and to supervise the repairs and the sensor recuperation of the faulty modules together with Marko Dragicevic and Thomas Bergauer. We characterised every faulty module and with the help of a specially created data base we could produce a statistic on them. Finally I became responsible for characterising and repairing of the TEC spare modules.
Autoren: Stephan Hänsel