Radiation tolerant sensors for the ATLAS pixel detector

The pixel detector in the ATLAS experiment at the LHC, Geneva, is an important detector component for high resolution tracking and vertex identification. For this demanding task the hybrid pixel detector with silicon sensors has to work in a very harsh radiation environment with up to 3.5×1014 neq/cm2 per year. On the basis of the known radiation effects a dual-track strategy was followed for the development of radiation tolerant silicon pixel sensors. The ATLAS pixel collaboration successfully developed the radiation hard sensor design which meets the challenging requirements for the ATLAS pixel detector. In parallel, the hardening of the silicon itself was followed within the ROSE collaboration, which developed the radiation tolerant DOFZ-silicon with oxygen enrichment by diffusion. Taking all the results together the radiation tolerant silicon sensors have been designed, produced and showed excellent performance before and after irradiation.