Comparative study of pulsed X-ray and y-ray radiation-induced effects in pure-silica-core optical fibers

S. Girard, Benoît Brichard, J. Baggio, Francis Berghmans, Marc Decréton, Andrei Goussarov

    Research outputpeer-review


    We have investigated the variation of the optical absorption induced by pulsed and continuous y-ray exposures in pure-silica-core optical fibers. Tested multimode waveguides, designed with well-defined concentrations of hydroxyl groups and chlorine impurity, are possible candidates for integration in the plasma diagnostics of LMJ and ITER facilities. We evaluated their radiation-tolerance to low dose levels in the visible and near-infrared parts of teh spectrum. We measure the time dependent changes of the radiation-induced attenuation (RIA) at fixed wavelengths and we complete these measurements with a spectral analysis of these losses in the time range from 10-2 to 103s. We compared the responses obtained under transient exposures with measurements done at same dose levels with lower dose rate. We showed that the radiation-induced changes are strongly dose rate dependent for this kind of optical fibers. Depending on the hydroxyl group concentration in the silica-glass, different point defects are shown to alter the fiber transmission after both irradiation types. The self-trapped holes play a particular role in the transient responses of optical fibers whereas non-bridging oxygen hole centers are mainly responsible for y-ray radiation-induced losses. The consequences of these different behaviors for the integration of optical fiber in the LMJ are discussed.
    Original languageEnglish
    Title of host publicationConférence RADECS 2005 Proceedings
    Place of PublicationFrance
    StatePublished - Sep 2007
    EventRADECS - Cap d'Agde
    Duration: 19 Sep 200523 Sep 2005


    CityCap d'Agde

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