Prototype performance and design of the ATLAS pixel sensors

Silicon pixel sensors for the ATLAS pixel detector have been successfully developed. The main attention for the design was given to survivability in the harsh radiation environment of LHC up to a fluence of 10/sup 15/n/sub eq//cm/sup 2/ during 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 the multiple scattering. Additionally, a bias grid for testing the sensors before assembly under realistic bias conditions is implemented to allow a quality assurance. (14 refs).