Investigation of optical and structural properties of quartz optical fibers and Ce doped scintillation fibers under radiation

In this thesis, the behavior of quartz and Ce doped optical fibers under Co-60 gamma radiation was investigated. In this study, we used four quartz and six Ce doped optical fibers which have different core structures and various elemental contributions. These optical fibers were irradiated with low and high dose radiation by on-line and off-line measurement methods. In these measurements, the spectra were obtained in the wavelength range of 400-1000 nm. Radiation-attenuated attenuation (RIA) and the recovery processes of the optical fibers were achieved by selecting specific wavelengths from the spectra. RIA and the recovery processes were evaluated according to parameters such as the structure of the optical fiber, Ce dope concentrations, radiation dose rates and total dose amounts. The quartz optical fibers used in the experiment were found to be resistant to the applied radiation, and it was determined that this strength was due to the high amount of OH- ions in their structure. It was concluded that the presence of Al and P elements in the structure of the Ce doped optical fibers caused a decrease in their radiation hardness. An optical fiber has been proposed by us within the scope of the results obtained from the measurements of the optical fibers, and was manufactured by Polymicro Technologies. The analyses of this optical fiber are presented in this thesis and indicate better radiation hardness than other optical fibers with Ce doped in the study. The recovery processes of the optical fibers were determined by the second order growth kinetic model, and the consistency of the predictions of the model with the experimental results was shown. In addition, the radiation effect in the optical fibers with the photoluminescence and the numerical aperture (NA) measurements were investigated.