Comparative study on the degradation of UV optical fibers subjected to electron beam and gamma ray irradiation

The present paper continues our previous research on the degradation of UV optical fibers under irradiation and reports, as a novelty in the filed, a comparative study on the radiation induced optical attenuation in three commercial available, UV optical fibers subjected to electron beam, gamma ray and bremsstrahlung irradiation. The purposes of these investigations were on one side to evaluate the radiation sensitivity of UV optical fibers under conditions not reported previously in the literature and, on the other side, to estimate the possible use of various types of such optical fibers for radiation detection/monitoring. The dependency of the optical attenuation at specific wavelengths was measured as a function of the optical fiber type and irradiation conditions, such as dose rate, total dose, and temperature stress applied during the irradiation. In this paper, we investigate also the behavior of H2-loaded UV optical fiber with metal coating when irradiation and heating are applied simultaneously. H2-loading of UV optical fibers proved to be a reliable mean to increase the radiation hardness in the case of UV optical fibers, and sample heating during the irradiation affect less the Al coated optical fibers than polyimide coated ones. A linear dependency of the optical attenuation on the total dose was observed for H2-loaded samples and in the case of solarisation resistant optical fibers. We suggest that a proper balance between radiation hardening and sensitivity to radiation of UV optical fibers can pave the way towards their use in radiation monitoring.