The PPS tracking system: performance in LHC Run2 and prospects for LHC Run3

The CT-PPS (CMS TOTEM Precision Proton Spectrometer, now PPS) system consists of tracking and timing detectors installed along the LHC beam line between 210 and 220 m from the interaction point on both sides of the CMS experiment. The aim of the apparatus is to measure with high precision the position, direction and time-of-flight of protons which emerge intact from the pp collision. Fully integrated in the CMS data acquisition system, PPS has taken data at high luminosity during the years of the LHC-Run2 (2016-2018), with slightly different detector configurations. The tracking system consists of 4 detector stations (two per side) and was instrumented with edgeless silicon strips (2016-2017) and 3D pixel sensors bump-bonded to the PSI46dig ROC (2017-2018). In this contribution commissioning, operation and performance of the CT-PPS tracking system during Run2 will be discussed, with focus on the challenges posed by the fact that detectors were operated at few millimeters from the beam, in highly non-uniform irradiation environment. Prospects for LHC-Run3 will be also presented.