Radiation tests of the prototypes of the fiber-optic collector for ITER plasma diagnostics

•Radiation test of the fiber-optic collector prototypes have been made at Co-60 gamma source.•Each sample consisted of 1904 WF200 silica fibers glued together with Epo Tek 353ND high-temperature epoxy.•Transmittance of the sample decreased about of 1 % in the spectral range of 450−700 nm after the irradiation up to 2.5 kGy.•There was no loss of the structural integrity or a damage of the single fibers.•Such type of the fiber-optic collector could be used for plasma diagnostics in ITER. Fiber bundles will be subjected to gamma-neutron irradiation in ITER Port Interspace & Cell areas, and the highest radiation dose will be accumulated in their head parts (collectors). Radiation tests have to be done to prove their radiation hardness. The paper is devoted to the radiation test of the fiber-optic collector prototypes at Co-60 gamma source. The collectors were manufactured using Epo-Tek 353ND optical glue, which is intended for a long-term use at temperatures up to 300 °C (decay temperature 412 °C). The irradiation was performed in the Kurchatov Institute in the continuous mode of the Co-60 gamma source. The aim of the tests was to investigate the influence of gamma-irradiation on the samples’ transparency and integrity. The test results showed that the fiber collector prototype based on silica fibers and EPO-Tek 353ND epoxy has a sufficient radiation resistance after the irradiation up to dose of a few kGy.