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Information × Registration Number 0216U006695, 0115U004256 , R & D reports Title Critical issues of plasma-surface interaction in international fusion reactor ITER popup.stage_title Head Garkusha Igor Evgenevich, Доктор фізико-математичних наук Registration Date 26-04-2016 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 The results of experiments on high-power plasma interactions with different targets surfaces under the conditions typical for ITER Type I ELMs were received with QSPA Kh-50 repetitive pulses of the duration of 0.25 ms and the heat loads in the range of 0.2- 2.5 MJ/m2, which simulate the ELM impact in ITER. The experiments include the measurements of plasma energy load to compound targets and estimation of surface damage under repetitive ITER ELM relevant plasma exposures. The difference between the values of heat load reaching the different parts of the combined target is due to the formation of the plasma shielding layer. For inclined irradiation, thickness of the shielding layer is smallest at the upper edge of the sample. This layer of cold plasma is responsible for decreasing part of incident plasma energy which is delivered to the surface. It is shown that melt dynamics on the structure edges, droplet splashing and molten bridges through the slits are determining processes in macroscopic erosion of castellated surface structures. Degradation of optical properties was observed of W and Mo mirror specimens fabricated from fine-grain metals subjected to bombardment by ions of argon and deuterium plasma, correspondingly. Step by step sputtering procedures were realized in a DSM-2M stand with measuring after each exposure in plasma the reflectance at normal incidence and weight loss. After sputtering process was finished, the characteristics of surface roughness were analyzed by atomic force microscope. The analysis of different mechanisms of wave excitation with shielded strap antenna and incorporation of them into the numerical model for plasma production had been performed. The analysis carried out reveal three important phenomena which are not described by the divergence-free antenna model. The first one is the electrostatic field enhancement and its penetration through the Faraday shield. The second phenomenon is shielding of the magnetic field perpendicular to the shield surface. The third phenomenon is the unidirectional currents in the shield elements caused by the electrostatic fields. The currents are closed to the strap by the displacement currents. To account for these phenomena the corresponding charges and currents flowing over the shield elements are prescribed. Product Description popup.authors І.Є. Гаркуша І.В. Рижков І.М. Панкратов І.О. Місірук А.А. Тюпа А.Н.Шаповал В.Є. Моісеєнко В.Б. Коровін В.В. Стальцов В.В. Чеботарьов В.В. Яковлєва В.О. Махлай В.С. Войценя В.С. Таран В.Ю. Красюк Е.Д. Крамский К.К. Трерьяк М.Є. Мазніченко М.В.Кулик М.М. Козуля М.М. Махов Н.М. Агаркова О.О. Скорик Р.О. Павличенко С.М. Мазніченко popup.nrat_date 2020-04-02 Close