Testbeam Measurements with the RD53A Hybrid Pixel Readout Chip

The high luminosity upgrade of the LHC (HL-LHC) at CERN poses new requirements on its detectors. In order to cope with the high radiation and high hit occupancy resulting from the high luminosity at the HL-LHC, new pixel readout chips need to be developed for the ATLAS and CMS phase 2 upgrades. RD53A is the first large-scale prototype which was developed within the RD53 collaboration, a joint effort of the ATLAS and CMS experiments. This hybrid pixel readout chip is processed in 65 nm CMOS technology with 50 um $\times$ 50 um pixel size and features better data rate capabilities and better radiation tolerance. Besides the characterization of the chip in the lab, testbeam studies using high-energy beams are important as well. For this, a sensor has been bump-bonded to the chip, which can then be tested in a testbeam. Using a high resolution beam telescope facilitates the possibility of in-pixel studies. In this talk testbeam measurements using the RD53A readout chip with a 120 GeV pion beam at SPS (CERN) are presented.