Description
Silicon sensors have been used in experiments for several dozen years, mainly for the accurate measurement of the position of charged particles. However, to deal with the increasing luminosity of particle physics experiments and, therefore, increasing particle track densities, research and development of those sensors have recently also been focussing on precise time measurements, enabling simultaneous particle tracking with µm resolution and time-of-arrival measurement with tens of ps resolution, so-called 4D-tracking. Currently, the most promising 4D-tracking detectors are based on the Low Gain Avalanche Diode (LGAD) technology, which will be widely used in the construction/upgrades of experimental systems at high and low energy nuclear physics frontiers. E.g. the main LHC experiments, ATLAS and CMS, have decided to use this technology for the upcoming high-luminosity LHC upgrades. Also, at the HADES experiment at GSI, LGAD sensors will be employed for the start of reaction time and beam profile measurement. A prototype system for the latter experiment has just recently achieved a time resolution of 50 ps showing the capability of this new detector concept.
Due to the growing interest in this detector technology, LGADs have been continuously advancing, making 4D-tracking also more accessible to other applications, e.g. medical applications such as ion beam therapy (IBT). Especially, the development of large-area LGAD-based systems would open up the possibility of incorporating 4D-tracking into the imaging and beam monitoring processes for IBT. With a suitable apparatus, this combination of advantages could be leveraged into a change of the current ion treatment workflow and have a high impact on ion beam therapy.