Speaker
Description
Facing the high luminosity phase of the LHC (HL-LHC) to start operation around 2026, a major upgrade of the tracker system is in preparation for the ATLAS experiment. Thanks to the small material budget and their high charge collection efficiency after irradiation, thin planar pixel modules are the baseline option to instrument all layers of the pixel system beginning from the second layer.
To optimise the sensor layout towards the decreased pixel cell size of $50\times50\;\mu$m$^2$, TCAD device simulations are being performed before and after irradiation to investigate charge collection efficiency and electrical field properties. Two different common irradiation models will be compared regarding these observables.
In addition, sensors of 100-150$\;\mu$m thickness, interconnected to FE-I4 read-out chips featuring the previous generation pixel cell size of 50x250$\;\mu$m$^2$, are characterised at testbeams at the CERN-SPS. The performance of sensors irradiated up to a fluence of 1e16$\;$n$_\text{eq}$/cm$^2$ is compared in terms of charge collection and hit efficiency before and after annealing. This study aims to reproduce the effects of storage time at room temperature of high energy physics pixel detectors during maintenance periods.
