Abstract— A microwave beam (wavelength 4 mm, power 150–300 kW) generates an ionization wave in air in the subthreshold field in the shape of a conglomerate of thread-like channels that moves toward the beam. The periphery of the beam refracts in the plasma of the non-self-sustained discharge in the UV halo of the thread-like discharges and self-focuses in the recombining plasma behind the front of

Abstract— The effect of electrode polarity in the pin-to-rod geometry on the development of pulsed electric discharge in water with specific electrical conductivity of (90 ± 10) µS/cm with and without air microbubbles was experimentally studied. It was found that the initiation of the plasma channel at the anode in water occurs near the metal–liquid–insulation contact in both anode geometries under

Abstract A four-channel scheme of an experiment aimed at obtaining optical and X-ray spectra and images of radiation generated in optical breakdown plasma channels in Bessel beams formed by focusing electromagnetic radiation by means of axicon-type conoid focusing systems is developed.

Abstract For plasma heating and stabilization in open magnetic traps, the high-power neutral beam injector with tunable beam energy was developed at Budker Institute of Nuclear Physics. The initial energy of the beam particles is 15 keV, and it can be subsequently increased to 40 keV. In this case, the neutral beam power increases from 1.7 to 3.5 MW. A distinctive feature of this injector is the fact

Abstract A method is proposed for tomography of the distribution function of energetic ions that are adiabatically trapped in an open magnetic trap, according to the diagnostic data by the method of collective Thomson scattering. This method is based on measurements of the scattering spectra from successive plasma cross sections corresponding to different values of the magnetic-field strength along

Abstract Experimental and theoretical studies of plasma parameters of the positive column of a direct current glow discharge in xenon were carried out. In the experiments, a discharge tube with a radius of 2 cm and a distance between the electrodes of 56 cm was used. The experiments were carried out for the gas pressure of 0.1 and 1 Torr, and the discharge current was varied in the range of 10–50 mA

Abstract A pulse-periodic cesium discharge is studied in a wide range of its parameters in two lamps with burners of the same diameter (5 mm), but with different interelectrode spacings (55 and 22 mm). It is found that such a decrease in the length of the plasma column leads to a significant change in the properties of the discharge. In the longer burner, contraction of the discharge column occurs

Abstract The process and applications of a specific type of gaseous discharge—beam–plasma discharge (BPD)—are reviewed. A brief survey of the BPD theory is presented. The basic features of BPD in active geophysical experiments with injection of electron beams into Earth’s ionosphere are discussed. Studies of the physics of BPD have revealed the effects successively applied in plasma technology for

Abstract Temperatures of singly and doubly charged krypton ions, along with electron temperature, were determined as functions of time in current sheets formed in the 2D and 3D magnetic configurations with an X-line. It is established that maximum temperature of krypton ions exceeds maximum electron temperature by more than an order of magnitude, and these temperatures exhibit different dependence

Abstract We study theoretically a non-stationary positive corona developing in free space from a system of grounded wires suspended at the same height and placed in a uniform thundercloud electric field growing with time. To calculate the corona characteristics, a two-dimensional computer model has been developed. The discharge is described by an equation for the density of positive ions of a single

Abstract Propagation and structure of the pulsed microplasma discharge initiated on the titanium sample surface covered with a thin dielectric film with a thickness of approximately 10 nm was studied experimentally. The discharge duration was 100 μs; the amplitude of the discharge electric current was 200 A. The microplasma discharge was initiated by the plasma flow with wide aperture, a plasma density

Abstract The dust–ion–acoustic (DIA) solitary wave (SW) propagation in a magnetized dusty plasma consisting of mobile positive and heavy negative ions, nonthermal electrons and positrons is presented. By using reductive perturbation technique, three dimensional Zakharov–Kuznetsov (Z–K) equation is derived and the solution is obtained by using the tan-hyperbolic method. Here, the dust grain charging

Abstract A coaxial electrodynamic system for the amplification of microwaves with plasma filling, through which a relativistic electron beam moves, is studied theoretically. The dependences of the increments of the spatial amplification of the beam–plasma instability on the external signal frequency and the amplifier parameters are obtained. The nonlinear dynamics of the development of instability

Abstract— Results of experiments on a linear facility with a helicon plasma source operating at a frequency of 13.56 MHz and a power of up to 15 kW are reported. In the experiments, different antennas (coil, NAGOYA TYPE III, and half-wave helicon) with azimuthal wavenumbers of m = 0, ±1 were used. Plasma density and electron temperature radial profiles for antennas of these types were measured as a

Abstract A new type of scrape-off layer plasma instability associated with radial inhomogeneity of plasma density, contact of plasma with conducting material surfaces, and neutral recycling is presented. In order to elucidate the physics of this instability, the simplest possible setup is analyzed.

Abstract— Studies of the composition of the products of chemical reactions in the afterglow of a new type of atmospheric discharge, the microwave self-non-self-sustained discharge in air with admixtures of methane, were carried out. A detailed kinetic model was developed that describes the kinetics of reactions with polyatomic nitrogen oxides at the stage of intensive cooling of the discharge channel

Abstract An analysis of a set of experiments on studying subthreshold microwave self/non-self-sustained (SNSS) discharges made it possible to estimate the volume of the active zone of self-sustained thread-like discharges resulting from the development of the ionization–overheating instability. It is shown that this volume is 0.04–0.1 of the wave beam volume. It is shown that in the processes of the

Abstract Quasiperiodic and chaotic features of the dust ion acoustic (DIA) waves in a magnetized dusty plasma is studied. Reductive perturbation technique (RPT) is used to derive the damped forced Kadomtsev–Petviashvili (KP) equation. The effect of the dust ion collisional frequency (νid0) on the quasiperiodic and chaotic motion of the DIA waves is studied. It is observed that in absence of dust–ion

Abstract Observations of two successive prolonged dipolarizations in the geomagnetic tail (at a distance of X ~ –18.3RE from the Earth, where RE is the Earth’s radius) according to the data obtained by the MMS mission are presented and analyzed. Eight dipolarization fronts (DF) were identified during these dipolarizations, and their propagation velocities and spatial scale were determined. The DF propagation

Abstract Surface waves in layered systems consisting of material media with different frequency dispersions are considered: dielectric–plasma–vacuum, vacuum–plasma–plasma, and dielectric–vacuum–plasma. It is shown that in such systems, one of the surface waves can be radiative into a medium that does not form an interface for the surface wave under consideration, in view of which the wave becomes decaying

Abstract Results are presented from studies of the stability of the plane dust clusters in the form of a regular polygon with the number of particles from two to five. It is assumed that the particles are placed in the plasma consisting of Maxwellian electrons and a directed flow of cold ions. It is shown that, in such clusters, the oscillatory instabilities can develop along with the aperiodic instabilities

Abstract Operation of the plasma relativistic microwave generator is considered in a frequency range of 1‒5 GHz. From data on the generation frequencies and resonator parameters, the following fundamental characteristics of the longitudinal modes are determined: the wavelength, phase velocity and the effective resonator length. A method was suggested for calculating and determining these parameters

Abstract The subthreshold self-non-self-sustained discharge in air was studied as the basis of the system for cleaning urban air from ecologically harmful admixtures. A cycle of experiments was carried out and the efficiency of the destruction of small amounts of hydrogen sulfide mixed with air (about 8 ppm) introduced into the processed air volume was determined. Experiments demonstrated a relatively

Abstract Studies of samples of graphite heat-shielding facing of the T-15MD tokamak chamber with stationary plasma loads in the PLM plasma device and high-power electron beams simulating loads during ELMs and transient processes were carried out. When the graphite facing samples were tested with plasma loads up to 2 MW/m2, their surface temperature reached more than 1200°C, the surface heating did

Abstract— A scheme of a spacecraft thruster based on pulsed plasma railgun with capillary–porous electrodes is proposed. Electrodes of this kind are renewable and do not degrade while their lifetime is limited by the stored amount of the filler metal of the capillary–porous electrode. Operating regimes in which capillary–porous electrodes are efficient are found. In these regimes, the proposed railgun

Abstract The experiments at the FT-2 tokamak are described that were focused on clearing up the role of the parametric decay instabilities in decreasing the generation efficiency of the non-inductive current excited by the electromagnetic waves in the lower hybrid frequency range. The most discussed instability of such kind is the decay of the pump wave into the daughter high-frequency waves and the

Abstract A model of spherical pulsed ion diode with laser-plasma anode for generation of neutrons in nuclear fusion reaction between deuterium and tritium is proposed. Formation and acceleration of deuteron packet in the diode is analyzed taking into account adiabatic mechanism of laser-plasma expansion in the form of the Riemann shock wave and the influence of electrostatic oscillations in the region

Abstract A theoretical investigation is made to study the properties of dust–acoustic (DA) waves, and corresponding dust–acoustic rogue waves (DARWs) in a magnetized electron-depleted dusty plasma that contains opposite polarity warm dust grains, external magnetic field, and nonextensive distributed ions. By using a multiscale reductive perturbation technique (RPT), the nonlinear Schrödinger (NLS)

Abstract The dynamics of an electron avalanche starting from the flat cathode surface and from the tops of microtips of different heights on the cathode surface is compared. The dynamics of avalanches was simulated in a changing electric field of the forming cathode sheath of a self-sustained high-pressure volume discharge with preliminary ionization of the gaseous medium. The aim of this work was

Abstract In modern large-sized tokamaks and those under construction, for example, in ITER, when measuring the average plasma electron density using the refractometry technique, it becomes necessary to study different effects that affect the measurement accuracy. This paper presents the results from studies of the high-temperature effects that can affect the interpretation of delay time measurements

Abstract A grid anode glow discharge is a promising source of plasma for absorbing electromagnetic radiation. This paper presents an experimental study of a large-area dc grid anode glow discharge in helium. The behavior of the helium discharge was studied at pressures in the range of 2–50 Torr and discharge voltages up to 1500 V. It was observed that the discharge completely covered the cathode surface

Abstract— In electromagnetic generators of the terawatt range with current pulse of 1–30 MA, electric explosion of the surface of current-carrying electrodes takes place. One of the options for protecting the electrodes is covering the current-carrying surface with different materials. In this work, we present experimental data and results of numerical simulations of the processes that take place in

Abstract The pulse-periodic operation regime of a plasma relativistic microwave generator is considered. The reasons for the increase of average frequency of the output microwave radiation in a pulse train created in the same conditions of initial plasma generation are analyzed. The effect of solid body erosion that occurs due to the interaction of the relativistic electron beam with the collector

Abstract The basic physical methods of disinfection of air, water, and surfaces, such as filtration, ozonation, exposure to ultraviolet radiation, photocatalysis, cold plasma, electric discharges, and electroporation in an electric field are reviewed. The main attention is paid to the consideration of traditional and new methods of air disinfection. Recommendations on application of pulsed UV radiation

Abstract Linear and nonlinear propagation of electrostatic waves is studied in electron-depleted bi-ion plasmas where positive and negative ions have different masses and charge states. The two-fluid model is used. The Korteweg–de Vries equation is obtained using the reductive perturbation technique. The results of the numerical calculations show that in K–fullerene plasma for the experimentally obtained

Abstract Localized plasma formations called space leaders are observed in streamer coronas of negative leaders of long laboratory sparks. The main leader completes a step when the space leader comes into contact with the head of the main leader. In the present work, we discuss the creation mechanism of local plasma formations (henceforth, generally, referred to as the hot spots) that are able to initiate

Abstract The formation and evolution of a Korteweg–de Vries (KdV) soliton in a dense quantum plasma consisting of electrons and ions is studied. The solitary profile is first obtained and the external force is applied to study the effect of force on the stationary formation. Further, a new technique based on the MacCormack Predictor Corrector scheme is designed to study the plasma species individual

Abstract— Electrodynamic characteristics of a low-pressure (electron collision frequency much lower than the field frequency) capacitive HF discharge maintained by an electromagnetic field with a frequency between 13 and 900 MHz are studied analytically and numerically. It is demonstrated that the field of both the fundamental mode (the field in the metal–space-charge sheath–plasma–space-charge sheath–metal

Abstract The ratio of the radiation energy of the plasma relativistic microwave amplifier at a frequency of the input signal to the noise energy is measured. In the absence of the input signal, the noise radiation is detected. It is shown that, under certain conditions, the amplifier noise energy sharply decreases, as compared to the noise energy measured in the absence of the input signal.

Abstract— A magnetized inductively coupled plasma ion beam etcher (MICP-IBE) was designed by employing electromagnets around the etcher (IBE). A magnetic field can be set up such that the magnitude of the magnetic flux density on the screen grid increases or decreases with the radial distance from the screen grid center. Four different types of magnetic field conditions were considered. The plasma

Abstract The results of the studies of the compression of the plasma of cone-cylindrical nested arrays of mixed composition at current flow through them of up to 3 MA at the Angara-5-1 facility are presented. The outer array of the nested array is a conical array of thin nylon fibers or tungsten wires, while the inner one is a cylindrical tungsten wire array. The implosion of current in this type of

Abstract The specificity of the development of a counter discharge from a grounded electrode in the field of a negative stepped lightning leader has been established. It is shown that high-voltage control pulses are effective only when acting directly on a counter leader. Analytical expressions are derived for estimating the conditions for the start of the counter discharge directly in the streamer

Abstract— Hydrogen glow discharge cleaning (H-GDC) is a routine conditioning procedure for the modern tokamaks and the future fusion machines, including ITER. Due to the low energy of hydrogen ions in glow discharge plasmas, the probability of any considerable damage to the plasma-facing components was mainly ignored. In this work, Tungsten, as the primary candidate for the plasma-facing materials

Abstract— The paper presents a review of modern works on gasdynamic flow control using a highly nonequilibrium pulsed plasma. The main attention is paid to the effects based on ultrafast (on the nanosecond time scale for atmospheric pressure) local gas heating, since, at present, the main successes in controlling high-speed flows by means of gas discharges are associated with this thermal mechanism

Abstract The parametric decay instability of microwaves with extraordinary polarization is analyzed that leads to their anomalous scattering by oscillations of the intermediate frequency range, localized in the edge transport barrier of a fusion installation. This effect can occur during electron cyclotron heating of the plasma at the second harmonic of the resonance frequency by multi megawatt microwave

Abstract The nonlinear development stage is studied of the instability of coupled waves in the planar plasma crystal in the external confining force field. It is assumed that the particles are located in plasma consisting of the Maxwellian electrons and the directed flow of cold ions. It is demonstrated that the effect of nonlinearity results either in acceleration of the instability development or

Abstract— In a device with a plasma focus, the possibility of improving the initial azimuthal uniformity of the current plasma shell is realized by enhancing the stabilizing action of the skin effect at an increase in the initial rate of the discharge current rise. An additional current source is used, which is switched on before the operation of the vacuum discharger triggering the capacitor bank

Abstract In this work, evolution of dust grains from different materials used in fusion energy installations was studied and a model was constructed that describes the generation of dust. The model accounts for the thermochemical, electrical, and other properties of the materials of the fusion reactor wall. It was shown that the dominant process that leads to the decrease in dust grain mass is the

Abstract The effect of a shielding gas on the plasma flow of an electric arc and molten metal is studied. The effect of the shielding gas on the plasma flow of the electric arc of molten metal is simulated, and a mathematical model is developed that describes the flow of the plasma-forming gas inside a device that forms the necessary directions of plasma flows to form a droplet of molten electrode

Abstract The work is devoted to the study of thermophysical and radiation processes during the formation of a plasma channel under the passage of a series of current pulses of pulsed-periodic cesium–xenon–mercury discharge. The influence of the auxiliary discharge mode, temperature, and vapor pressure of metals on the development and relaxation of the plasma channel is shown. The spectral characteristics

Abstract– In this work, systems with serial and alternating electrical connection of three electrohydrodynamic cells based on corona discharge in atmospheric pressure air were studied. Numerical simulations of the systems was conducted. The volume force acting in the drift regions of the multi-cascade system was calculated and a good agreement was obtained between experimental and theoretical data

Abstract The results of modeling a nanosecond discharge in a uniform electric field in argon at atmospheric pressure based on two kinetic models are compared: with one and with six excited states, respectively. The analysis of the development of ionization waves in a centimeter gap in a two-dimensional axisymmetric geometry is performed. It is shown that the obtained result is influenced by the choice

Abstract Raman scattering instability (RSI) is investigated in a magnetized quantum electron–ion plasma by applying the separate spin evolution-quantum hydrodynamic (SSE-QHD) model. The governing differential equations of large amplitude transverse electromagnetic waves (TEM) and electron plasma waves (EP) are derived in spin polarization effect. The nonlinear interaction of spin polarized TEM and

Abstract Electrodynamic characteristics of a low pressure (electron collision frequency much lower than the field frequency) capacitive high frequency (HF) discharge maintained by electromagnetic field with a frequency between 10 and 1000 MHz are studied analytically and numerically. The discharge is assumed to fill completely a cylindrical metallic discharge chamber that contains a large area active

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

Abstract— Theoretical and numerical investigations are carried out for the instability of the dust–acoustic waves (DAWs) under the transverse perturbation in a magnetized dusty plasma with two-temperature nonthermal ions. By the reductive perturbation technique, the Zakharov–Kuznetsov (ZK) equation and modified ZK equation of the DAWs are derived. Under the higher-order transverse perturbations, the

Abstract The results of investigations of a spark discharge in air in the gap between the tip (anode) and a 1.5‑mm-long plane are presented. It is shown that, after breakdown, the discharge develops in the form of a beam of individual microchannels that close the discharge gap, then, after 20–30 ns, a continuous outer boundary of the channel forms and its radial expansion begins. The electron concentration

Abstract The plasmaphysical code is presented that makes it possible to simulate the energy distributions of atoms escaping from plasma of the toroidal facilities. The code includes calculations of the particle spatial distributions in the charge-exchange plasma target consisting of atoms and hydrogen-like impurity ions. The calculations of the charge-exchange target are performed in two ways: using

Abstract The results of studying the self/non-self-sustained gas discharge (SNSS discharge) excited by microwave beams at high gas pressure (atmospheric or higher than atmospheric) under conditions of a substantially subthreshold radiation power are presented. The discharge has a number of properties that distinguish it from all microwave discharges described in literature. The physical model of the

Abstract The cumulative impact of the inhomogeneous distribution of the plasma temperature and electromagnetic effects on dynamics of plasma filaments in the hot edge plasma of a tokamak, characterized by small values of the parameter \(\beta < {{m}_{e}}{\text{/}}{{m}_{i}}\), is analyzed. The physical model describing the filament dynamics is presented. Estimates of the scrape-off-layer plasma parameters