(НИЯУ МИФИ, 2021) OGORODNIKOVA, O. V.; KLIMOV, N. S.; GASPARYAN, YU. M.; EFIMOV, V. S.; KOVALENKO, D.; GUTAROV, K.; POSKAKALOV, А. G.; KHARKOV, M. M.; KAZIEV, A. V.; Казиев, Андрей Викторович; Гаспарян, Юрий Микаэлович; Ефимов, Виталий Сергеевич; Огородникова, Ольга Вячеславовна; Харьков, Максим Михайлович
Tungsten and dense nano-structured tungsten (W) coatings are used as plasma-facing materials in current tokamaks and suggested to be used for future fusion devices. In this regard, a study of accumulation of deuterium (D) and helium (He) in W materials and corresponding material 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, sequential and simultaneous (with 10% of He seeding) D/He plasma exposure of W-based samples (polycrystalline W, nano-structured W coating and W with He-induced W ‘fuzz’) in quasi-stationary high-current plasma gun QSPA-T below and above the melting threshold with a pulse duration of 1 ms and number of pulses from one to thirty was performed and compared with stationary plasma loads. Material modification was investigated using an electron microscope equipped with a focused ion beam for in-situ cross sectioning and an x-ray diffractometer.