Speaker
Description
The High-Luminosity LHC (2030+) will operate at unprecedented intensities and radiation levels, with up to 200 overlapping proton-proton collisions per LHC bunch crossing, requiring significant upgrades to the CMS detector to maintain its physics performance. As part of the Phase-2 upgrade of CMS, the electromagnetic calorimeter (ECAL) readout electronics will be upgraded, providing a 160 MHz sampling rate that enables improved timing reconstruction and enhanced Level-1 Trigger capabilities. These upgrades also allow for greatly improved rejection of unwanted ECAL signals from APD spikes, which arise from highly ionising particles directly striking the avalanche photodiodes used for the light readout.
APD spikes can mimic high-energy electromagnetic deposits and, if not effectively suppressed, may saturate the Level-1 trigger bandwidth. This work focuses on the study of two spike-tagging algorithms for Phase-2 operation of CMS ECAL using test beam data from electron and pion beams provided by the CERN SPS.
Preliminary performance results are presented using datasets from ECAL Phase-2 test beam campaigns collected in 2021 and 2025. These studies assess the spike-tagging performance in detector configurations representative of the upgraded ECAL, providing input to the development of robust spike-mitigation strategies for HL-LHC conditions.