Behavior of developed radiation-resistant silica-core optical fibers under fission reactor irradiation

Oxyhydrate (OH) doped and fluorine (F) doped fused-silica core optical fibers were irradiated in a fission reactor at 370–380 K with a fast neutron flux of about 5×1016n/m2s and a gamma-ray dose rate of about 500 Gy/s for about 24 days. Oxyhydrate and fluorine dopings improved radiation resistance of optical fibers especially in the visible range. A fluorine doped and heat-treated optical fiber showed best radiation resistance and its radiation induced loss in a visible range is about 20 dB/m after it was irradiated up to a fast neutron fluence of 1×1023 n/m2. Results are implying that fused silica core optical fibers can be used nearer to a burning plasma for plasma diagnostics and remote sensing.