Dmitry Terentyev

Optical fibres are considered for applications in various nuclear environments in the presence of radiation exposure. Under irradiation, the properties of the optical fibres are modified. In the present paper we investigate the influence of gamma radiation on the magneto-optical properties of the Corning SMF-28e optical fibre. The stability of the Verdet constant is an important requirement for performing current measurements under radiation, for example, in magnetic fusion installations during nuclear (deuterium–tritium) plasma operation, where radiation at MGy dose levels can be accumulated. Our results demonstrate that radiation-induced changes in the Verdet constant are within its measurement accuracy (0.56%) for gamma radiation doses up to 770 kGy.

In this study, the results of transmission electron microscopy (TEM) examinations of neutron-irradiated (2.5 dpa at 150 °C, 350 °C, and 450 °C) CuCrZrV and ODS(Y₂O₃)-Cu alloys are presented. These materials were developed for application as heat sink materials in fusion technology. This study includes TEM imaging and quantitative analysis of neutron radiation-induced defects such as dislocation loops and voids as well as the determination of the conditions for their formation. It was found that dislocation loops of a₀½⟨110⟩ type form in both alloys at all irradiation temperatures. The formation of voids in CuCrZrV alloy is effectively suppressed. The neutron irradiation causes a redistribution of Cr, Zr, and V in the CuCrZrV alloy. A particular focus was on the investigation of the distribution of the transmutation products Ni and Zn. Ni tends to segregate at the Cr-rich clusters and forms a shell around them, while Zn is evenly distributed.