[en] A method is proposed for determining the absolute sputtering coefficients for the components of alloys in a hollow-cathode hydrogen plasma with sputtering particles having energies on the order of several hundred eV, based on the standard spectral-probe method used for determining the selective sputtering coefficients in plasmas of atomic gases. The distribution functions of the particles bombarding the surface of the hollow cathode are calculated. It is shown that the main contribution to sputtering under typical discharge conditions in a hollow cathode gas pressures of several torr, current densities of order 10 mA/cm² is from H³ ions. 15 refs

[en] Short note

[en] The investigation is devoted to theoretical and experimental study of sputtering and surface composition changes of structural materials being of potential use in chambers of first generation thermonuclear reactors. Physical foundations of a probe method to determine the sputtering coefficients in a gaseous discharge are outlined. Presented are the selective sputtering coefficients of major components of borosilicon graphite, titanium alloys, iron-nickel-base and nickel base alloys, pure titanium, iron and nickel in a deuterium plasma at the ion energy of approximately 300 eV. It is concluded, that the absolute sputtering coefficients of alloying elements can variate, whereas the relative ones remain constant. In terms of the plasma radiative losses the nickel base alloys are superior to the type Ch18N10T stainless steel and to the type ChN38VT nickel base alloys. A semiphenomenological theory of the surface structure reconstruction under low-energy ion irradiation is put forward. In a closed discharge the surface is shown to be enriched by the light-sputtered components. It increases the total sputtering coefficient and, as a consequence, the radiative plasma losses

[en] Physical model describing the process of transition layer formation, when producing ion beam coatings was based. Mass transfer equation was obtained and solved. Calculation results were correlated with profiles of element distribution on the interface of carbon films with aluminium. titanium and iron substrates, obtained experimentally by the method of X-ray photoelecron spectroscopy in combination with argon ion etching

[en] The advantages of a method of hollow-cathode discharge for modelling sputtering of the first wall of a fusion reactor, are discussed. The results of the theory of sputtered atom motion to a probe in the diffusion mode and formulae for calculation of the fracture of cathode-sputtered atoms arriving on the probe are presented. The relations are given for determination of the selective coefficients of sputtering of material components and their concentration in spectral-probe investigation

[en] Results of studies of erosion of 19 structural materials are presented. These data (together with results of other studies) allow to optimally select thermonucleor material structural elements. The obtained values of selective sputtering coefficients enable calculation in time of near-surface layer composition and selective sputtering coefficients of thermonuclear material components, selection of optimal regimes of reactor operation from the view point of erosion characteristics, and evaluation of time, during which the first wall comes up to steady-state sputtering regime

[en] Selective coefficients of sputtering of austenitic steels Kh18N10T and heat resistant alloy KhN75MBTYu have been measured. It is shown that a spectral probe method can be used to determine selective sputtering coefficients of the components containing in small quantity (2-3 at %). A novel method of determination of concentrations of the main components of construction materials is proposed and employed. The theory is developed and model calculations of change of the composition and erosion of the surface of austenitic steels are conducted in conditions of carbon sputtering from other construction materials of the reactor

[en] Results are presented from a study of the erosion of 19 construction materials. These data (together with the results of other studies) make it possible to select the best material for the structural components of a thermonuclear reactor. The measured values of the selective sputtering coefficients can be used to calculate the time variation in the composition of the surface layers and the selective sputtering coefficients of the components of materials in a thermonuclear reactor, to choose the optimum operating regimes for reactors from the standpoint of erosion characteristics, and to estimate the time over which the first wall will enter a steady-state sputtering regime