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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 10

Только метаданные
Effect of High-Voltage Electrode Potential Bias on the Breakdown Induced by Ionization Wave in Discharge Tube
(2020) Meshchanov, A. V.; Ionikh, Y. Z.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2020, Pleiades Publishing, Ltd.Abstract—: An experimental study has been done of the bias effect of the active (high-voltage) electrode potential on the breakdown characteristics in a discharge tube 15 mm in diameter, filled with neon, argon, or their mixture (3 : 1) at a pressure of ~1 Torr. The bias of the potential is carried out by parallel connection to the electrode with an additional constant voltage or additional pulses with an amplitude less than the voltage for maintaining self-sustained discharge. In this case, a change in the breakdown voltage, the velocity of the pre-breakdown ionization wave, and the brightness of radiation from its front is observed. In particular, the breakdown voltage can increase up to 1.5–2 times, and this state of the discharge gap can be maintained for tens of minutes. The observed effects are assumed to be caused by the appearance of a charge on the tube wall and a change in its potential near the electrode, which affect the characteristics of the primary breakdown between the electrode and the wall and, in turn, the processes of discharge ignition. The mechanisms of appearance of the surface charge on the wall when feeding a bias voltage to electrode are investigated.
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
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
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.
Открытый доступ
Spectroscopic determination of the composition and spatial distribution of active particles in a plasma jet of helium and argon being blown out into atmospheric air
(2020) Karalnik, V. B.; Petryakov, A. V.; Trushkin, N. I.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2020 Institute of Physics Publishing. All rights reserved.Optical emission spectroscopy was used to determine the composition and spatial distribution of reactive species along a non-thermal plasma jet in a stream of argon and helium, expanding in the ambient air. It was shown that the composition and spatial distribution of reactive species in argon and helium plasma jets differ significantly. The geometric dimensions of the Ar and He plasma jets are also noticeably different. The features of the observed patterns of the composition and spatial distribution of active particles are discussed.
Только метаданные
The Memory Effect of Microdischarges in the Barrier Discharge in Airflow
(2020) Usenov, E. A.; Petryakov, A. V.; Ramazanov, T. S.; Gabdullin, M. T.; Akishev, Y. S.; Акишев, Юрий Семенович
© 2020, Pleiades Publishing, Ltd.Abstract: The paper devoted to the research of the microdischarge dynamics in the dielectric barrier discharge. The discharge between rail electrodes in airflow along the electrodes at atmospheric pressure was studied. The aim of this work is to clarify the role of volume plasma and surface charges in the memory effect of microdischarges. Based on the analysis of microdischarge images obtained using high-speed camera, it is established that the transport of microdischarge plasma by a gas flow determines the microdischarge localization in each subsequent half-cycle of the applied voltage. An important part is played by the turbulence and the presence of vortices in the airflow. They determine both the speed of plasma channel transfer and the probability of the microdischarge appearence in a specific half-cycle. The results of the work show the possibility of the gas-dynamic control for parameters of a barrier discharge.
Только метаданные
Formation of Extended Tubular Plasma in Argon at Low Pressure and in a Weak Longitudinal Magnetic Field
(2024) Akishev, Y. S.; Bakhtin, V. P.; Buleyko, A. B.; Loza, O. T.; Акишев, Юрий Семенович
Только метаданные
Pin-to-plane self-pulsing discharge in transversal airflow: interaction with a substrate of plasma filaments blown out from the discharge zone
(2020) Akishev, Y. S.; Balakirev, A. A.; Grushin, M. E.; Karalnik, V. B.; Акишев, Юрий Семенович
The pin-to-plane electrode system for the multi-sectioned discharge in the transversal airflow at atmospheric pressure has been developed. The airflow is directed perpendicularly to the electric current. As it was revealed, all sections of the multi-sectioned discharge operate identically and independently to each other. For this reason, the spatial-temporal behavior of the discharge excited only in a single section was investigated. The pin-to-plane discharge (PPD) was powered by a positive polarity DC voltage that induces the spontaneously repeating streamer-spark breakdowns in a discharge gap. Each breakdown forms the plasma filament (PF) which is being further blown out of the discharge zone and stretched by the airflow. The PF impacts a dielectric plate located in the path of the airflow at different distances away from the discharge zone. Two modes in the behavior of the blown-out PF have been revealed. When the plate is close to the discharge zone, the blown-out PF is tightly pressed by the flow to the plate. In this case, both the brightness and electric current of the PF are periodically pulsing with a high frequency up to the plasma filament breaking up due to its strong elongation by the flow. If the plate is far away, the quasistationary regime happens. During the PF elongation in this regime, plasma filament keeps both the brightness and current approximately changeless till the filament breaking up. At In this regime, the blown-out PF is being stretched in parallel to the surface without contacting it. The release of energy into the PF continues also in the course of its blowing out until its impinging the object located in the path of airflow. Due to that, the PPD pulsing mode generates a lot of reactive species inside the PF up to its impinging the object to be treated. This is a reason why the self-pulsing PPD can be highly effective for surface processing by non-thermal plasma.