Operational Experience and Performance with the ATLAS Pixel detector at the Large Hadron Collider

The tracking performance of the ATLAS detector at the LHC relies critically on its 4-layer Pixel detector, that has undergone significant hardware and readout upgrades to meet the challenges imposed by the higher collision energy, pileup and luminosity. The record breaking instantaneous luminosity of 2×10^34cm^{−2} s^{−1}, corresponding to an average number of 60 proton-proton collisions for bunch crossing was reached in 2017 and regularly achieved in 2018. The consequent Pixel strategy to contain the readout bandwidth limitations is discussed. The key status and performance metrics of the ATLAS Pixel Detector in Run 2 are summarised and the operational experience and requirements to ensure optimum data quality and data taking efficiency are described. A special emphasis is given to radiation damage effects showing signs of degradation which are visible but which are not impacting yet the tracking performance: dE/dX, occupancy reduction with integrated luminosity, under-depletion and annealing effects that are not insignificant for the inner-most layers.