Fiber and Fiber Cable reliability after radiation to High Luminosity Large Hadron Collider (HL-LHC) doses

摘要

The Large Hadron Collider is planning an upgrade to its luminosity which will require the detectors' fiber-optic data acquisition systems to be qualified for operation at much higher particle fluences. Three candidate optical fibers; Corning SMF-28e (single-mode), DrakaElite™ Super Radhard MMF (multimode), and Corning Clearcurve™ MMF were exposed to radiation doses (gamma rays) in excess of 500kGy (Si). The fibers were pull-tested to breakage at various elongation speeds which allowed their stress corrosion susceptibilities to be measured. Results indicate that the stress corrosion susceptibilities of the Draka and SMF-28e fibers are mechanically radiation hard for this application but that Clearcurve™ fiber showed significant changes in its mechanical behaviour after irradiation. SMF-28e fiber was also exposed to a neutron fluence of 8×10~(14) n/cm~2 and no measurable difference was observed in its stress corrosion susceptibility. Two different standard polyethylene cable jackets, manufactured by Ericsson and Fujikura, were subjected to proton irradiation amounting to a fluence of 5×10~(14) 27MeV protons and significant changes in the jackets' mechanical properties were observed. DrakaElite Super Radhard multimode and single-mode fibers were subjected to microbend tests before and after exposure to a 500 kGy(Si) dose of gamma rays and no measureable change in their attenuation was observed.