The CMS Precision Proton Spectrometer: Precision timing with scCVD diamond crystals

The CMS Precision Proton Spectrometer (PPS), operating at the LHC, makes use of timing detectors based on planar single crystal CVD diamonds to measure the time of arrival of protons scattered in the very forward region. The time information is used to reconstruct the longitudinal position of the proton interaction vertex and to suppress pile-up background. The timing system, used during the LHC Run 2, has been upgraded for the Run 3, with the goal of reaching an ultimate timing resolution of better than 30 ps for protons in the TeV energy range. Here an overview of the PPS timing system is provided and the detector performance in Run 2 are briefly reported. The Run 3 upgrade will be outlined.