FOS4CMS: More than a decade of uninterrupted FBG monitoring in the CMS Experiment at CERN

Abstract

This paper provides an extensive overview of more than a decade of continuous data collected by the Fiber Optic Sensing for CMS (FOS4CMS) network, featuring over 1000 Fiber Bragg Grating (FBG) sensors. These FBG sensors have been instrumental in monitoring temperature and strain within the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). Their strategic placement allowed for observation of crucial components, including the central beam pipe, silicon tracker, RPC muon detectors, and the underground cavern. Operational since 2009, the monitoring system underwent expansions during LHC Long Shutdowns (LS1 and LS2) and upgrades for LHC Run3. Leveraging Wavelength Division Multiplexing, the FBG sensors demonstrated reliability, seamlessly integrating into the CMS Detector Control System. In summary, the presented data robustly affirm the resilience of FBG sensors in the challenging High Energy Physics environment, with the FOS4CMS system's uninterrupted 24/7 operation over a decade marking a significant milestone in the successful application of FBG technology within the CMS experiment at CERN.