Radiation Induced Point Defects In Ultra-Low Loss Pure Silica Core Optical Fibers
Project content and funding
The project is focused on the phenomenon of radiation-induced attenuation (RIA) affecting the transmission properties of optical fibers (OF). RIA is affecting and degrading the properties of OF when they are exposed to radiations, either photons (UV, X-rays, Gamma) or electrons (from KeV to MeV range). The understanding of the mechanism at the base of RIA is therefore important in several fields where OF are used: space and aeronautics industry, nuclear industry, military, high energy physics facilities (fusion, synchrotrons, ..), etc.
The project activity focus specifically on the RIA observed on ultra-low loss (ULL) OFs. These OFs display excellent transmission properties, i.e. extremely low attenuation in the IR ranges typically used for telecommunication. Recent results shown that, in some cases, they display significant RIA under irradiation, both in the UV-visible range and in the IR range. Still, the mechanism at the origin of this degradation is not clearly understood.
The aim of this project is to investigate further and finally clarify the origin of the RIA in the ULL fibers, exploring different kind of radiations (X-rays, Gamma and high-energy electrons) and different irradiation parameters (dose, dose rate, energy). The results will shed light on RIA mechanisms, i.e. creation of defects, which are relevant not only for ULL fibers, but also for other OFs.
Financing
The project is a bilateral ARIS-CEA project financed by the Slovenian Research And Innovation Agency (project number NC-24005) and by the French Alternative Energies and Atomic Energy Commission (CEA).
Duration of the project: 01/01/2024 - 31/12/2025
Project Team at UNG
Partner insitution: Laboratoire des solides irradiés, UMR 7642 / CNRS - CEA - Ecole polytechnique (France)
Project phases
1) characterization of morphology and compositional mapping of the OF
2) characterization of emitting point defects (also spatial distribution) by Cathodoluminescence spectro-microscopy
3) characterization of paramagnetic point defects by EPR
4) defect identification, comparison with literature and/or with theoretical calculations
5) irradiation of the selected OFs with different radiations (electrons, X-rays, gamma)
6) characterization of the effect of irradiation by CL, EPR and possibly other techniques
7) characterization of RIA during and after irradiation.
8) study of time evolution (kinetic) of point defects under KeV electron irradiation
9) explanation of the effect on RIA of the point defects irradiation-induced evolution
