<title>Attenuation of silica optical fibers in nuclear environment and its dependence on the properties of materials for fiber preparation</title>

Abstract

The radiation-induced light absorption in bulk quartz, Polymer Clad Silica (PCS) and Gradient-Index (GI) fibers is studied. The radiation-induced absorption spectra of four kinds of bulk quartz samples in UV wavelength region are measured. The new absorption band around 215 nm is found, the increase of the sample absorption is attributed to the impurity content. Radiation-induced attenuation spectra of PCS fibers drawn from the bulk quartz materials are shown. The dependence the radiation-induced attenuation on the fiber diameter in the PCS fibers is related to the changes in the silicone optical cladding. The radiation- induced light attenuation in GI fibers is studied in the wavelength range of 450 to 1000 nm. The radiation-induced absorption band centered around 560 nm and the shift of the UV absorption edge towards the longer wavelengths are found. Simple experimental schemes are proposed on the base of these results and tested for radiation dosimetry purposes including the measurements in the nuclear power plant Dukovany.