Fiber optic sensors structural monitoring of the beam pipe in the CMS experiment at the CERN

In this paper, the results of the temperature and strain monitoring of the central beam pipe of the Compact Muon Solenoid Experiment (CMS) at CERN are presented. The measurements are carried out by means of a system of Fiber Bragg Grating (FBG) sensor arrays glued on the central Beam Pipe of CMS. The system consisting of FBG sensors represents the ideal solution to manufacture a reliable and accurate sensing system to be used 24/7 in the harsh environment in CMS. The sensing principles of the FBG sensor and its temperature characteristics are introduced. First temperature and strain measurements data are presented. They were recorded during last period of CMS maintenance and first period of LHC collision started in April 2015.