2024, Tumarkin, A. V., Kolodko, D. V., Kharkov, M. M., Stepanova, T. V., Kaziev, A. V., Samotaev, N. N., Oblov, K. Yu., Тумаркин, Александр Владимирович, Колодко, Добрыня Вячеславич, Харьков, Максим Михайлович, Степанова, Татьяна Владимировна, Казиев, Андрей Викторович, Самотаев, Николай Николаевич, Облов, Константин Юрьевич

Thispaper aims to investigate the quality of thin alumina films deposited on glass samples using magnetron sputtering in the reactive modulated pulsed power mode (MPPMS) and evaluate the process productivity. The aluminum target was sputtered in Ar/O2 gas mixtures with different fractions of oxygen in the total gas flow, in the fixed pulsed voltage mode. The pulse-on duration was varied between 5 and 10 ms, while the pulse-off time was 100 or 200 ms. The dependences of mass deposition rate and discharge current on the oxygen flow were measured, and the specific deposition rate values were calculated. Prepared coatings had a thicknesses of 100ў??400 nm. Their quality was assessed by scratch testing and by measuring density, refractory index, and extinction coefficient for different power management strategies. The strong influence of pulse parameters on the coating properties was observed, resulting in a maximum density of 3.6 g/cm3 and a refractive index of 1.68 for deposition modes with higher duty cycle values. Therefore, adjusting the pulse-on and pulse-off periods in MPPMS can be used not only to optimize the deposition rate but also as a tool to tune the optical characteristics of the films. The performance of the studied deposition method was evaluated by comparing the specific growth rates of alumina coatings with the relevant data for other magnetron discharge modes. In MPPMS, a specific deposition rate of 200 nm/min/kW was obtained for highly transparent Al2O3, without using any dedicated feedback loop system for oxygen pressure stabilization, which makes MPPMS superior to short-pulse high-power impulse magnetron sputtering (HiPIMS) modes.

2020, Kaziev, A. V., Leonova, K. A., Kharkov, M. M., Tumarkin, A. V., Kolodko, D. V., Khomyakov, A. Y., Ageychenkov, D. G., Казиев, Андрей Викторович, Харьков, Максим Михайлович, Тумаркин, Александр Владимирович, Колодко, Добрыня Вячеславич, Агейченков, Дмитрий Григорьевич

© Published under licence by IOP Publishing Ltd.The magnetron discharge with hot (uncooled) target in an impulse mode has been experimentally investigated. The I-V characteristics have been measured depending on the magnetic field strength for three target materials: copper, chromium, and silicon. For melted copper and hot chromium targets, stable gasless (no argon) operation of the magnetron has been demonstrated with maximum impulse power densities about 2.5 kW/cm2 (averaged over the racetrack area). For silicon target, maximum impulse power density was 1.5 kW/cm2 at low argon pressure (0.1 Pa). The magnetic field dependences of discharge parameters have shown the associated changes in differential plasma impedance.

2020, Sorokin, I. A., Kolodko, D. V., Luzanov, V. A., Shustin, E. G., Сорокин, Иван Александрович, Колодко, Добрыня Вячеславич

A technique for growing thin graphite films on a dielectric substrate by annealing the Al2O3(0001)/Ni(111)/ta-C structure has been optimized. This technique is based on catalytic decomposition of hydrocarbons on the surface of a single-crystal catalyst metal film on a dielectric substrate and subsequent diffusion and crystallization of carbon between the metal film and the substrate. A thin graphite film with a low density of crystal-structure defects is obtained on the dielectric substrate after chemical etching of the metal film.

2020, Tarakanov, V. P., Shustin, E. G., Kolodko, D. V., Sorokin, I. A., Колодко, Добрыня Вячеславич, Сорокин, Иван Александрович

© 2020, Pleiades Publishing, Ltd.Abstract—: Results are presented of the particle-in-cell numerical simulations by the KARAT code of the formation of a plasma–beam discharge in the absence of both the longitudinal magnetic field and the initial plasma. Oscillations of the electric field generated by the plasma–beam instability in the electron beam region almost do not affect the plasma at the periphery of the system. Simulation results are compared to the results obtained earlier by a simplified model and to the results of test experiments. The spatial distributions of the plasma density and electron temperature qualitatively agree with the experimental results.

2019, Kolodko, D, V., Ageychenkov, D. G., Kaziev, A, V., Leonova, K. A., Kharkov, M. M., Tumarkin, A. V., Колодко, Добрыня Вячеславич, Агейченков, Дмитрий Григорьевич, Казиев, Андрей Викторович, Харьков, Максим Михайлович, Тумаркин, Александр Владимирович

We studied the ion fluxes on metal surfaces in the inductively coupled plasma reactor as a test facility. The gas mixture of argon and nitrogen was used, with 0.44 Pa total pressure. The radiofrequency power was varied in a wide range (250-2000 W). The ion fluxes were sampled in situ using a specially designed electrostatic extractor and then analyzed with a custom-built magnetic sector mass-separator. The gas composition was independently monitored by the quadrupole analyzer. All measurements were accompanied by optical emission spectroscopy (OES). The correlations of measured optical and corpuscular data are discussed. The conversion function linking optical and corpuscular intensities for Ar/N-2 radiofrequency discharge was determined.

2020, Sorokin, I. A., Kolodko, D. V., Krasnobaev, K. I., Сорокин, Иван Александрович, Колодко, Добрыня Вячеславич

© 2020, Pleiades Publishing, Inc.Abstract—A simple technique is presented for producing diamond-like films with copper impurity by sputtering the surface of a copper cathode with argon ions in a glow discharge with a hollow cathode with simultaneous chemical deposition diamond-like films on its surface. It was shown that a small (up to 1: 1000) admixture of propane at the pressure of the plasma forming gas of 40 Pa does not affect the plasma parameters, however, it allows you to vary the relative copper content in the diamond-like film.

2015, Sinelnikov, D., Kurnaev, V., Kolodko, D., Solovev, N., Колодко, Добрыня Вячеславич, Синельников, Дмитрий Николаевич

Tungsten is the main candidate for plasma facing material in the divertor zone of a thermonuclear reactor due to high melting temperature, high thermal conductivity and low sputtering erosion yield. However, its surface can be modified by "fuzz" nanostructure, which can form in linear simulators and tokamaks [1] under helium irradiation fluence as high as ~1025m-2and sample temperature in the range of 1000-2000 K. Such structure significantly changes the plasma-wall interaction balance, which results in higher probability of unipolar arc ignition. In the case of arcing, erosion yield sharply increases, especially if arcing takes place on a fuzzy surface [2]. Tungsten fuzz is also characterized by high pre-breakdown current intensity, which could indicate the initial stage of unipolar arc ignition [3]. Prebreakdown currents are usually initiated by field emission due to amplification of electric field on sharp cathode relief. So, an investigation of emission properties dependence on surface relief during fuzz formation and destruction seems to be important for the prediction of unipolar arcing.

2024, Kharkov, M. M., Tumarkin, A. V., Prosolov, A. A., Kabanov, G. A., Kolodko, D. V., Tarasov, B. A., Irmagambetova, S. M., Kaziev, A. V., Харьков, Максим Михайлович, Тумаркин, Александр Владимирович, Кабанов, Глеб Алексеевич, Колодко, Добрыня Вячеславич, Тарасов, Борис Александрович, Ирмагамбетова, Сауле Муханбетовна, Казиев, Андрей Викторович

2020, Chernyh, N. A., Kharkov, M. M., Kaziev, A. V., Danilyuk, D. V., Kukushkina, M. S., Tumarkin, A. V., Kolodko, D. V., Харьков, Максим Михайлович, Казиев, Андрей Викторович, Кукушкина, Маргарита Сергеевна, Тумаркин, Александр Владимирович, Колодко, Добрыня Вячеславич

© 2020 Elsevier B.V.VT1-0 (Russian equivalent of Grade 2) titanium surfaces were modified under argon ion bombardment from the low-pressure inductively coupled plasma (ICP). The ion processing allowed us to prepare various types of structures on titanium with controlled characteristic dimensions at nano- and miscroscale (from tens of nm to 3 µm). The hillock, porous, conical, wall/cell structures as well as their combinations have been obtained. The topology type and the characteristic dimensions of surface features depend on the current density js, Ar ion energy Ei, irradiation fluence Φ (or processing time t), and the sample temperature T during the treatment. The microstructures appear on the surface provided the titanium sample is irradiated at temperatures below 900 °C. The sample temperature was determined by both the average current density (jsav from 0.2 to 20 mA/cm2) and the ion energy (Ei from 150 to 1500 eV). A certain fluence is required for uniform surface coverage with microstructures. We suppose that the titanium surface texturing is a result of a complex interplay of the following mechanisms: sputtering, re-sputtering (shadowing), crystal lattice transformation, accumulation and annihilation of defects, and hypothetically, argon retention.

2020, Kaziev, A. V., Kolodko, D. V., Kharkov, M. M., Rykunov, G. I., Sergeev, N. S., Tumarkin, A. V., Казиев, Андрей Викторович, Колодко, Добрыня Вячеславич, Харьков, Максим Михайлович, Сергеев, Никита Сергеевич, Тумаркин, Александр Владимирович

© 2021 IEEEImpulse magnetron discharges with millisecond-scale pulses-extended duration modes of technological high-power impulse magnetron sputtering (HiPIMS)-have promising applications in pulsed plasma facilities of different kinds due to high ionization degree (up to 90%), suitable duration, and scalable hardware design. Depending on operating conditions, at the same power level, two distinct diffuse regimes can be distinguished: the one with intense target sputtering-long HiPIMS (L-HiPIMS),-and the non-sputtering low-voltage one (non-sputtering magnetron discharge). The majority of existing studies of these discharge forms were made for argon working gas. For a number of prospective high-power pulsed plasma applications (e. g. pulsed plasma accelerators and thrusters), however, the option of using light gases is preferable. Here, the operation of a millisecond-scale impulse magnetron discharge (L-HiPIMS) in helium has been examined. The plasma parameters (electron density, electron temperature) were measured in a time-resolved fashion with a Langmuir probe. The electrical measurements were accompanied with optical emission spectroscopy. The use of the long pulsed modes enables achieving high plasma density and accelerating the ion flux with a peak energy of ~ 10 eV.