Performance of Irradiated RD53A 3D Pixel Sensors

The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of (50x50) μm2 and (25x100) μm2 compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to 5×1015 neq/cm2. An operation voltage of only 50 V is needed to achieve a 97% hit efficiency after this fluence.