Characterization with test beams of ITk pixel detectors for the upgrade of the ATLAS Inner Detector

The ATLAS Inner Detector will be replaced with an all-silicon tracking detector (ITk) to cope with the new challenging conditions arising with the High-Luminosity Large Hadron Collider (HL-LHC), where the instantaneous luminosity will increase by three times compared to that of the LHC, and bring higher radiation damage. The pixel detector will be the innermost part of the ITk, consisting of five radial layers. The sensors in different positions are designed with different geometries and technologies, and are procured from different vendors. $n^+\text{-in-}p$ planar hybrid modules with $150\,{\rm \mu m}$ and $100\,{\rm \mu m}$ thickness will instrument the outer layers, and 3D sensor technology was chosen to instrument the innermost layers due to its radiation hardness. Additionally, the production of the sensors is distributed among four different vendors: HPK, Micron, FBK and SINTEF, with HPK producing the majority of the sensors. As soon as pre-production modules and sensors of different types and produced by different vendors become available, they are being tested with test beams before and after irradiation to assess their performance at the fluence expected at the end of their life during HL-LHC. An overview of the current test beam results is given. The results shown are for pre-production modules equipped with ITkPixV1.1 (RD53B) readout chips. The reconstruction and analysis were done with the Corryvreckan software.