Персона: Огородникова, Ольга Вячеславовна
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МОДЕЛИРОВАНИЕ РАДИАЦИОННЫХ ПОВРЕЖДЕНИЙ В СПЛАВАХ ВОЛЬФРАМА С ИСПОЛЬЗОВАНИЕМ ИОННОГО ОБЛУЧЕНИЯ
In this work, a comprehensive study of a W-6Re and W-10Cr alloys after accelerated irradiation with ions to a damage dose of 10 displacements per atom at temperatures of 300 and 500 °C was carried out. A detailed chemical analysis of radiation induced defects acquired by means of transmission electron microscopy and atom probe tomography. It is shown that, as a result of irradiation, nanosclae clusters enriched in rhenium and chromium are formed. In addition, a high density (of the order of 1024 m-3) of clusters of point defects was found in the area of material damage.
HYDROGEN AND HELIUM RETENTION IN TUNGSTEN UNDER ION IRRADIATION
Interaction of helium and hydrogen ions with tungsten is intensively investigated during last decades in relation to construction of fusion reactor. Tungsten has the high melting temperature and the energy threshold for sputtering and, therefore, is considered as plasma facing material (PFM) in fusion devices in the area of largest heat loads and small energies of ions (divertor area). In particular, tungsten will be used in the international experimental reactor ITER, which is now under construction.
SURFACE MODIFICATIONS OF W-BASED MATERIALS UNDER HELIUM AND DEUTERIUM ION IMPLANTATION
In a thermonuclear reactor, materials will be irradiated with hydrogen isotopes and helium (He), neutrons, and heat fluxes. Tungsten (W) and dense nano-structured tungsten (CMSII) coatings are used as plasma-facing materials in current tokamaks and suggested to be used for future fusion devices. In this regard, the study of the accumulation of He and deuterium (D) in W based materials and corresponding surface modifications under normal operation conditions and transient events appears necessary for assessment of safety of fusion reactor due to the radioactivity of tritium and material performance and for the plasma fuel balance. Therefore, in this work, irradiation of W-based materials with D and He ions in stationary regime and in quasi-stationary high-current plasma gun QSPA-T below and above the melting threshold has been performed. In QSPA-T, a pulse duration was 1 ms and number of pulses was varied from one to thirty. In stationary plasma loads, ion energy was varied from 20 to 3 keV, temperature 300-1200 K and flux/fluence 1017-1021 at/m2s/1020-1025 at/m2.
CORRELATION OF DEUTERIUM RETENTION WITH CRYSTALLINE STRUCTURE IN DENSE AND DISORDERED TUNGSTEN COATINGS
Dense nano-structured tungsten (W) coatings are used as plasma-facing materials in current tokamaks and thick coatings are suggested to be used also for the future fusion devices, ITER and DEMO. In this study, deuterium (D) retention in various W coatings was investigated to understand dependences of the D retention on the crystalline structure of each W coating and on the substrate material.
DEUTERIUM RE-EMISSION AND THERMAL DESORPTION FROM IRON AND EUROFER
Reduced-activation ferritic-marthensitic (RAFM) steels, such as Eurofer, are considered as candidates for structural materials in fusion reactors due to the high thermal conductivity, the low thermal expansion coefficient and good resistance to radiation swelling. There are also some concepts of fusion reactors, where RAFM steels also considered as material for plasma-facing components. In this regard, the key aspects of hydrogen (H) isotopes interaction with RAFM steels, such as tritium (T) retention and migration in these materials are particularly important as a point of safety concern.