Mitigation of high X-ray dose radiation-induced attenuation in optical fibers at 15 K: effect of cumulative dose

The radiation tolerance of optical fibers at cryogenic temperatures is low, but some work has shown that this radiation-induced attenuation can be mitigated via photo bleaching. We explore the effect of high-power X-ray radiation (320 kV accelerating voltage - 10 mA anode current) on optical fibers at 15 K and the photobleaching effect of a secondary beam of light at 1050 nm. We studied the effectiveness of the photobleaching light at recovering transmission at 1550 nm with three different optical powers of the photobleaching light in the range 0.1 to 4 mW. We focused on how pre-irradiated fibers differ from pristine fibers and what is the effect of cumulative dose on parameters such as the saturation radiation-induced attenuation.