Speaker
Description
The High Luminosity LHC (HL-LHC) upgrade requires that the planned Inner Tracker (ITk) of the ATLAS detector must be tolerant to extremely high radiation doses. Specifically, the innermost parts of the pixel system will have to withstand radiation fluences above $1\times10^{16}n_{eq}cm^{-2}$. Novel 3D silicon pixel sensors offer a superior radiation tolerance compared to conventional planar pixel sensors, and are thus excellent candidates for the innermost parts of the ITk. This talk presents studies of 3D pixel sensors with pixel size $50 \times 50 \mu m^2$ mounted on the RD53A prototype readout chip. Test beam results are presented for unirradiated as well as heavily irradiated sensors. For particles passing at perpendicular incidence, it is shown that efficiencies above 96% are reached for sensors exposed to fluences of $1\times10^{16}n_{eq}cm^{-2}$ when biased to 80V.
