The CMS Precision Proton Spectrometer precision timing with scCVD diamond crystals.

The CMS Proton Precision Spectrometer (PPS), operating at the LHC, makes use of 3D silicon tracking stations to measure the kinematics of protons scattered in the very forward region, as well as timing detectors based on planar single crystal CVD diamond to measure the proton time-of-arrival with high precision. The time information is used to reconstruct the longitudinal position of the proton interaction vertex and to suppress pile-up background. A novel architecture with two diamond sensors read out in parallel by the same electronic channel had been used to enhance the timing performance of the detector and a dedicated amplification and readout chain had been developed to sustain particle fluency of ~1 MHz/channel. The PPS timing detector has operated demonstrating its capability to reconstruct the interaction vertex and to be used to suppress pile-up background. Here an overview of the PPS timing system will be provided and the detector performance in Run 2 will be reported. The timing system has been upgraded for the LHC Run 3 and new detectors packages are currently being installed, with the goal of reaching an ultimate timing resolution of better than 30 ps on protons in the TeV energy range.