Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

The CMS Precision Proton Spectrometer timing system: Run 2 performance and Run 3 upgrade status and perspective

Jul 9, 2022, 6:00 PM
Room 6 (Bianca)

Room 6 (Bianca)

Parallel Talk Operation, Performance and Upgrade (Incl. HL-LHC) of Present Detectors Operation, Performance and Upgrade (Incl. HL-LHC) of Present Detectors


Edoardo Bossini (University of Pisa-INFN Pisa)


Fast timing detectors have become more and more important for high energy physics and other technological application, with their development being crucial for several aspect of the High Luminosity LHC program. 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-flight with high precision. The time information is used to reconstruct the longitudinal position of the proton interaction vertex and to suppress pile-up background. Special movable vacuum chambers placed in the LHC beam pipe, the Roman Pot, allow the PPS detector hosted inside to be be moved close to the circulating beams. 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. 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. In Run 2 detectors were exposed to a highly non-uniform irradiation, with local peaks above $10^{16}neq/cm^2$, a similar value is expected in the future in Run 3. LHC data and subsequent test beam results show that the observable radiation damage only led to a moderate decrease of the detector timing performance. After a desciption of the PPS detector, the performance in Run2 will be reported, inclusive of the recent studies of radiation effects. The timing system has been upgraded 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.

In-person participation Yes

Primary author

Edoardo Bossini (University of Pisa-INFN Pisa)

Presentation materials