Effect of Reactor Irradiation on Nitrogen-Doped Silica-Core Fibers and Fiber Bragg Gratings Based on Them

We report results of an experimental study of radiation-resistant photosensitive nitrogen-doped silica-core fibers and fiber Bragg gratings based on them under the influence of intense reactor radiation in the presence of neutron and gamma photon fluxes. The total dose of gamma radiation received by the Bragg elements reaches a value of 0.5 GGy in the experiment. A quasi-linear radiation-induced increase in the Bragg wavelength of the sensors is observed, as well as a decrease in the level of reflection of the elements, which should be taken into account in designing sensors. An example is presented of the use of radiation-resistant Bragg sensors based on nitrogen-doped silica-core fibers to monitor the parameters of the core of a nuclear power reactor.