Results of prototyping for the Phase-II upgrade of the pixel detector of the ATLAS experiment

The current inner tracker of the ATLAS experiment is foreseen to be replaced for the High-Luminosity era of the LHC to cope with the increase in occupancy, bandwidth and radiation damage. The new tracker consists of an all-silicon system, the Inner Tracker (ITk). It is built of both silicon pixel and silicon strip sub-systems aiming to provide tracking coverage up to vertical bar eta vertical bar = 4. For a high tracking performance, radiation hard and high-rate capable silicon sensors and readout electronics are important. Moreover, services and stable, low mass mechanical structures are essential and present challenges for the system design. Currently, a large prototyping programme is ongoing within the ITk pixel detector community. Components for larger structures with multiple modules based on the FE-I4 readout chips were produced and are in assembly and evaluation. This way the system integration and design is prototyped and validated. In the report, the latest evaluation and results of thermo-mechanical prototypes and fully electrical prototypes are presented. Important system relevant aspects and their application will be discussed.