Achievements of the ATLAS Upgrade Planar Pixel Sensors R&D Project

Abstract : In the framework of the HL-LHC upgrade, the ATLAS experiment plans to introduce an all-silicon inner tracker with the HL-LHC upgrade to cope with the elevated occupancy. To investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Planar Pixel Sensor R&D Project (PPS) was established comprising 19 institutes and more than 90 scientists. Main areas of research are performance assessment and improvement of planar pixel sensors at HL-LHC fluences the achievement of slim or active edges to provide low geometric inefficiencies without the need for shingling of modules establishment of reliable device simulations for severely radiation-damaged pixel detectors the exploration of possibilities for cost reduction to enable the instrumentation of large areas with pixel detectors. The presentation will give an overview of the R&D project and highlight accomplishments, among them beam test results with planar sensors up to innermost layer fluences (>1016neq/cm2) measurements obtained with irradiated thin edgeless n-in-p pixel assemblies recent studies of the SCP technique to obtain almost active edges by post-processing already existing sensors based on scribing, cleaving and edge passivation update on prototyping efforts for large areas: sensor design improvements, 6" wafer production experience, 8" wafer production possibilities, concepts for low-cost hybridisation. Together, these results will allow an assessment of the state-of-the-art with respect to radiation-hard position-sensitive tracking detectors suited for the instrumentation of large areas.