Der ATLAS Pixelsensor

The innermost subdetector of the ATLAS Experiment is a hybrid pixel detector which consists of about 150 million pixel on roughly 2000 modules for a high resolution tracking and b-tagging in the LHC enviroment. The scope of this theses is the successful development of silicon pixel sensors for the ATLAS Pixel Detector. The main attention for the design was given to survivability in the harsh radiation enviroment of LHC up to a fluence 10^{15} n_{eq}/cm^2during 10 years of operation. This leads to the need of long term operation at several hundreds of volts, partially depleted while maintaining good charge collection, small cell size and thin sensors reducing multiple scattering. Additionally, a punch through bias grid for testing the sensors before assembly under realistic bias conditions is implemented to allow a quality assurance. The design of the ATLAS pixel sensor is explained in detail and the results of the prototype sensors showing the capability of the chosen sensor design to cope with the challenging requirements of an operation in the LHC enviroment are presented. Furthermore the possibility of transfering this silicon sensor design approach to biomedical or other applications is discussed.