Speaker
Mr
Ivan Ovtin
(NSU, BINP)
Description
The Compact Muon Solenoid (CMS) detector is a large general-purpose detector at the Large Hadron Collider (LHC). The Electromagnetic Calorimeter (ECAL) is an important part of CMS to accurately measure the energies of electrons and photons. The ECAL is made of 75848 lead-tungstate (PbWO4) scintillating crystals. The ECAL response changes over time mainly because of crystal transparency variations due to radiation damage and recovery. The laser monitoring system is designed to measure the transparency changes for each ECAL crystal over time. High-Luminosity running at the LHC, which is planned for 2025 and beyond, will imply an order of magnitude increase in radiation levels and particle fluences with respect to the present LHC running conditions. The mitigation of aging is an important goal for the upgrade of the laser light monitoring system. This talk describes the evolution the transparency of the ECAL crystals in Run 2 data, the components of the ECAL monitoring system, and its proposed upgrade.
Primary author
Mr
Ivan Ovtin
(NSU, BINP)
