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Акишев, Юрий Семенович

Организационные подразделения

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Институт лазерных и плазменных технологий

Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.

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Акишев

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Юрий Семенович

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Теперь показываю 1 - 10 из 14

Только метаданные
The "memory" effect of microdischarges of a barrier discharge in airflow Эффект "памяти" микроразрядов барьерного разряда в потоке воздуха
(2019) Usenov, E. A.; Petryakov, A. V.; Ramazanov, T. S.; Gabdullin, M. T.; Akishev, Yu. S.; Акишев, Юрий Семенович
© 2019 Federal Informational-Analytical Center of the Defense Industry. All rights reserved.The experimental results on the dynamics of microdischarges of the volume barrier discharge in rail electrode geometry along which the atmospheric pressure airflow was blown are presented. The aim of this work is the clarification of a role of volume plasma and surface charges in the “memory” effect of microdischarges. On the basis of the analysis of the microdischarges images taken with the use of the high-speed camera, it is established that transportation of plasma channels by a gas flow defines the localization of emergence of every microdischarge in each subsequent half-cycle of the sinusoidal voltage. An important role plays the turbulence of airflow and existence in it of whirlwinds which determine both the speed of plasma channels transportation and the possibility for the appearance of microdischarges in a concrete half-cycle. Results show a possibility to control the parameters of a barrier discharge by gas dynamics.
Только метаданные
On the Development of Ionization Waves Preceding Breakdown in a Long Capillary Tube Filled with Helium at Low Pressure
(2021) Karal'nik, V. B.; Petryakov, A. V.; Ionikh, Y. Z.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2021, Pleiades Publishing, Ltd.Abstract: Experiments that revealed the main trends in the development of complete breakdown in a long capillary tube for different electrode configurations are reported. It is demonstrated that, in the presence of an additional external electrode around the tube, a fast stage completing the breakdown is preceded by a slow stage caused by development of a weak-current surface barrier discharge inside the tube. This discharge is realized due to propagation of forward (from the high-voltage electrode) and backward (from the grounded electrode) surface ionization waves. The presence of preliminarily, locally deposited charge of the sign opposite to polarity of the voltage pulse leads to acceleration of propagation of ionization waves in the tube. In the absence of the external electrode, the breakdown occurs much faster but is characterized by a large scatter in the delay time (up to complete lack of breakdown) relative to the applied voltage pulse. Unstable operation of the gas-discharge device determined by development of breakdown represents a much more serious problem in many applications compared to the situation in which it turns on slowly but stably. Therefore, the results demonstrating the possibility of controlling the breakdown are of great scientific and practical value.
Только метаданные
Radial current distribution along the ionization wave propagating in a long dielectric capillary tube filled with a low-pressure helium
(2021) Karalnik, V. B.; Petryakov, A. V.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2021 Institute of Physics Publishing. All rights reserved.The experimental results on the study of the ionization wave propagating along a long capillary tube are presented. The ionization wave was initiated by high-voltage pulse of positive or negative polarity. The propagation of this surface ionization wave precedes and influences the establishment of complete electric breakdown within the tube. The spreading of this wave is accompanied by the surface charge deposition. The usage of the fine-sectioned outer electrode allows one to find out the general features of the ionization waves.
Только метаданные
Features of a negative ionization wave development preceding the full breakdown in a long capillary tube wrapped with a continuous or fine-sectioned grounded electrode
(2021) Karalnik, V. B.; Petryakov, A. V.; Akishev, Yu. S.; Акишев, Юрий Семенович
© 2021 Institute of Physics Publishing. All rights reserved.The experimental results on the study of negative ionization wave propagating along a long capillary tube are presented. The ionization wave was initiated by high-voltage pulse of negative polarity. The propagation of this surface ionization wave precedes and influences the establishment of complete electric breakdown within the tube. The spreading of this wave is accompanied by the surface charge deposition. The usage of the fine-sectioned outer electrode allows one to find out the general features of a negative ionization wave. The main of them is the tight correlation between local currents determining the formation of local surface charge and visual discharge images taken by the fast camera characterizing the pace of the ionization wave propagation.
Только метаданные
Gas-discharge source of coaxial and opposite directed plasma jets based on a barrier discharge in radially converging gas flow Газоразрядныи источник соосных и разнонаправленных плазменных струи на основе барьерного разряда в радиально-сходящемся потоке
(2020) Petryakov, A. V.; Trushkin, N. I.; Akishev, Yu. S.; Акишев, Юрий Семенович
© 2020 Federal Informational-Analytical Center of the Defense Industry. All rights reserved.An original source of non-equilibrium low-temperature plasma jets based on a barrier discharge in radially converging flow of atomic and molecular gases at atmospheric pressure was developed and created. The electrode discharge system consists of two parallel quartz disks, in the geometric center of which are made two coaxial identical holes. A metal foil in the form of a wide ring aligned with the holes is glued to the outside of each disk. The gas flow is directed from the periphery of the disks to their center and goes out normal to the surface of the disks through narrow openings. As a result, two coaxial plasma jets are formed, perpendicular to the disks and directed in different directions. In the published literature there are no analogues of the developed source of two coaxial and opposite directed plasma jets. The source was tested for plasma treatment of dielectric yarns, which were pulled through holes in barriers and were constantly enveloped by non-thermal plasma jets. The results of the work show the practical possibility of using the created gas-discharge source for continuous “roll-to-roll” plasma treatment of polymer filaments in order to improve their hydrophilicity.
Только метаданные
Ionization wave propagation in a long capillary tube in the presence of a low-current glow discharge in low-pressure helium
(2021) Karalnik, V. B.; Petryakov, A. V.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2021 Institute of Physics Publishing. All rights reserved.The experimental results on the study of the positive ionization wave propagating along a long capillary tube are presented. The ionization wave was initiated by eigther highvoltage pulse of positive polarity applied over a long capillary tube with helium or high-voltage pulse applied over the same tube but in presence of low-current glow discharge. The spreading of this wave is accompanied by the surface charge deposition. The usage of the fine-sectioned outer electrode allows one to find out the features of the positive ionization wave in both cases (with or without low-current discharge).
Открытый доступ
Effect of the speed of the flat substrate movement on the air plasma jet transversal spreading at its impinging the surface
(2020) Balakirev, A. A.; Medvedev, M. A.; Petryakov, A. V.; Trushkin, N. I.; Akishev, Yu. S.; Акишев, Юрий Семенович
© 2020 Published under licence by IOP Publishing Ltd.Low-temperature plasma jets are used to treat both the motionless and moving objects (targets or substrates). The gas-dynamic aspects of the plasma jet's interaction with the target are important and have to be taken into account in selecting the most efficient plasma processing parameters. Clearly, the spreading of plasma jet over a fast-moving surface is significantly different from its spreading over a fixed target. This question is investigated by the example of the interaction of an air plasma jet with a surface of fast-rotating dielectric disk. It is shown the change in the shape of the jet striking perpendicularly the moving substrate happens due to the movement of a thin layer of the ambient air adjacent to the fast-moving surface. This effect can have a noticeable influence on the reactive particles transfer from the plasma jet onto the surface to be treated.
Открытый доступ
Relation of electric conditions between a source of Ar plasma jet and a substrate with a configuration of a plasma sheet on a target
(2019) Balakirev, A. A.; Karalnik, V. B.; Petryakov, A. V.; Trushkin, N. I.; Akishev, Yu. S.; Акишев, Юрий Семенович
© Published under licence by IOP Publishing Ltd.The paper presents the experimental results relevant to the external electrical influence on the structure of a thin plasma sheet formed atop a substrate surface by Ar plasma jet that is being generated by a coaxial sinusoidal barrier discharge (BD) in an argon flow. The electrical influence on the target is being created due to connecting of a high-voltage or grounded electrode of the BD to the metal plate on which the dielectric or metallic substrate to be treated is located. Such an approach ensures a synchronism of the interaction of the external auxiliary electric field with the own electric field of the ionization wave (plasma bullet) propagating along the argon plasma jet toward the substrate during each period of the BD alternating voltage. An image of the structure of the plasma sheet on the substrate surface averaged over many periods of sinusoidal voltage was recorded in the experiments.
Открытый доступ
Dielectric barrier discharge in radially converging gas flow generating two coaxial and opposite directed nonthermal plasma jets
(2020) Petryakov, A. V.; Trushkin, N. I.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2020 Institute of Physics Publishing. All rights reserved.An original source of non-equilibrium low-temperature plasma jets based on a barrier discharge in a radially converging flow of atomic and molecular gases at atmospheric pressure was developed and created. The discharge electrode system consists of two parallel and coaxial quartz disks, in the geometric center of those two coaxial identical holes were made. On the outer side of each disk a metal foil in the form of a wide ring is glued coaxially to the holes. The gas flow is directed from the periphery of the disks to their center and exits normally to the disks surfaces through narrow holes. As a result, two coaxial and opposite directed plasma jets are formed, which are perpendicular to the disks. There are no analogs of the developed source in literature. The source has been tested for plasma treatment of dielectric yarns that are transported through holes in dielectric barriers and are constantly enveloped in plasma jets. The results show practical possibility of using the developed gas-discharge source for continuous "roll-to-roll" plasma treatment of polymer filaments with the aim to improve their hydrophilicity.
Открытый доступ
Influence of the sign and magnitude of a surface charge on the breakdown voltage of a barrier corona discharge in Ar
(2019) Balakirev, A. A.; Medvedev, M. A.; Petryakov, A. V.; Trushkin, N. I.; Akishev, Y. S.; Акишев, Юрий Семенович
© Published under licence by IOP Publishing Ltd.The topic of this article is related to the breakdown phenomena in the surface dielectric barrier discharge (SDBD). The surface charge, locally deposited on the dielectric barrier, changes markedly the configuration and intensity of the electric field both on the barrier and in the gas gap. In turn, a change in the local electric field affects the rate of ionization multiplication of electrons in this area and, accordingly, influences the breakdown conditions of both volume and surface barrier discharges. In the case of sinusoidal SDBD, the first breakdown in each next half-cycle will be controlled by the charge deposited on the barrier during the previous half-cycle. Contrariwise, if there are several successive breakdowns in the half-cycle, each next breakdown after the first one will be controlled predominantly by the charge and plasma created by the previous breakdown in this half-cycle but not only by the charge deposited in the previous half-cycle. These features of the SDBD breakdown were investigated by the example of the barrier corona in argon at atmospheric pressure in the pinto-plane configuration. This discharge allows us the controlling of the location of the deposited charge. Surface charge was deposited in advance and by the SDBD itself.