Fiber Bragg Grating strain sensors for Tracking Particle Detector

This work is devoted to a feasibility analysis of the use of Fiber Bragg Grating (FBG) sensing technology for real-time deformation monitoring of a gaseous tracking particle detector. Our attention is focused on a micromegas (an abbreviation for "micro mesh gaseous structure" (MM)), that is a micro pattern gas detector to be applied in Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN) in the ATLAS experiment. One mandatory issue for the correct operation of the MM detector is a precise monitoring of its panels' flatness/deformation. To this aim, FBG real-time sensing technology is proposed for its capability to meet important requirements in terms of radiation hardness and insensitivity to magnetic fields and to offer local strain detection with high sensitivity (resolution of 1 mu epsilon). As a demonstrative target, in this work some FBG sensors have been integrated (surface attached) with a miniature MM detector support panel in order to investigate their potentialities/capabilities in detecting local strain and thus bending. The obtained experimental results confirm that FBG sensors, that tolerate high radiation, are able to monitor deformation and curvature in accord with high energy physics requirements.