Abstract Here we report the results of the turbulence study in the high-confinement mode (H-mode) with and without edge localized modes (ELMs). The study was performed by the Doppler backscattering (DBS) method on the Globus-M tokamak. Two types of ELMs were observed in the Globus-M tokamak during NBI heating and accordingly, two different transitions to transient ELM-free modes were discovered. It

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

Abstract Distinctive features of the drift motion of a nonrelativistic charged particle in slowly varying magnetic and strong electric fields, for which the assumption that the electric drift velocity is small as compared to the total particle velocity is non-applicable, are studied. The variational principles of the drift motion are extended to the case of the strong electric field. The generalized

Abstract The propagation of planar and nonplanar electron-acoustic waves composed of stationary ions, cold electrons, superthermal hot electrons, and positrons is studied by using Korteweg–de Vries (KdV) equation in the planar and nonplanar coordinates. The analytical and numerical solutions of KdV equation reveal that the nonplanar electron-acoustic solitons are modified significantly with positron

Abstract— So far, the detailed experimental effect of the inductance on the X-ray yield in the Filippov-type plasma focus devices has not been documented in literature. In this paper, a 90 kJ Filippov-type plasma focus device is used to investigate the effect of three different external inductances (20, 40, and 60 nH) on the pinch current and neon soft X-ray (SXR) yield experimentally. The obtained

Abstract A specificity of the boundary between the photosphere and the chromosphere of the Sun consists in considerable acceleration of plasma spicules above this boundary and appearance of wave motions (predominantly Alfvén waves). Analytical solution to the equations of magnetic hydrodynamics is constructed in the vicinity of this boundary from the chromosphere side. Expressions describing the growth

Abstract In the paper, experimental results concerning the dynamics of the counter interaction of high-energy plasma flows in a magnetic field with an induction of up to 2 T are presented and discussed. Plasma flows with velocities (2–4) × 107 cm/s, ion density (2–4) × 1015 cm–3, and energy content of 70–100 kJ were formed by two electrodynamic coaxial accelerators with pulsed gas injection. Nitrogen

Abstract Modification of the beam tracing method for numerical simulations is proposed that allows one to use it in the zones of the microwave beam bifurcation, which is accompanied by the linear mode transformation. The theoretical basis for this modification is the switching over to the hybrid spatial-spectral representation of two beams, within which both the beam axes coincide and, therefore, the

Abstract Globus-M2—a new 1-Tesla spherical tokamak—was recently launched. The main features and research directions of this machine in scope of fusion–fission reactor development are described. Main results of the first experimental campaign with toroidal magnetic field up to 0.73 T and plasma current up to 0.33 MA are discussed. Significant improvement of the discharge parameters as compared to Globus-M

Abstract The etching characteristics of a patterned amorphous carbon layer (ACL) in a magnetized inductively coupled plasma (MICP) etcher were investigated. The etch rate and etched profile dependences on the source power, the neutral gas pressure and the dual bias power ratio were investigated. We measured the ion energy distribution (IED), the ion flux, plasma density and electron temperature using

Abstract With allowance for the centrifugal and gradient drifts of ions, a new approximate dispersion equation is obtained for the ion Bernstein (IB) wave propagating strictly transverse to the external inhomogeneous magnetic field. Using this equation, it is shown that if, in the high-temperature plasma, the drift of ions is taken into account, the resonance frequency ranges in the vicinities of the

Abstract We studied the propagation of small-amplitude dust ion acoustic (DIA) solitary waves in four-component relativistic plasma comprised of nonthermal electrons, mobile positively charged ions, positron beam and negatively charged massive dust particles. By using the reductive perturbation method, the Korteweg–de-Vries (KdV) nonlinear wave equation is derived numerically. In this work, we have

Abstract The analysis is based on the relations characterizing charged particles’ motion in the drift approximation (D. V. Sivukhin, in Reviews of Plasma Physics, Ed. by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 1; B. A. Trubnikov, Introduction toPlasma Theory (Mos. Inzh. Fiz. Inst., Moscow, 1968) [in Russian]). It is noted that the particles can be accelerated using the device

Abstract— The dissipative divertor for the power and particle exhaust in a tokamak relies heavily on strong impurity radiation inside the divertor volume. In the present paper, the influence of the cross-field transport inside the divertor volume on the radiation loss by nitrogen and neon impurity seeding is studied in the SOLPS4.3 2D transport code. The study is carried out in a simplified tokamak

Abstract Two stable operating mode, which were called “jet” and “bell” mode, were observed for Hall thrusters. These modes are distinguished from each other by the shape of the plasma plume and the anode efficiency. This paper presents the results of the measurements of the high-frequency floating potential oscillations using a Langmuir probe and of the relative erosion rate of boron nitride ceramic

Abstract— The formation of plasma on the surface of a current-carrying electrode of a high-current facility when a current flows through it with a linear density of up to 4 MA/cm and is coated with lead foil or ceramic is studied. The propagation velocity of a dense plasma from a stainless steel electrode is 2–10 km/s, and when the electrode is coated with lead, it is 1–6 km/s. In these experiments

Abstract To better understand the arc plasma axial motion under an axial magnetic field, a high-speed charge-coupled device camera was used to observe the arc plasma images in a magnetically rotating arc plasma generator. Experimental results indicate that the arc plasma moves towards the cathode bottom as the magnetic field strength increases, while a higher arc current facilitates the cathode arc

Abstract Floating potential fluctuations (FPF) of the direct current magnetron sputtering plasma as a function of discharge voltage were observed. The system behaves chaotic to quasi periodic transition as the discharge voltage is increased. Detailed quantify examination is carried out using time series analyzing techniques such as Lyapunov exponent and statistical estimation to explore the dynamics

Abstract— The cathode plasma of a discharge in an electrolyte based on sodium carbonate and sodium hydroxide is studied as well as its interaction with the surface of electrolytes made from tungsten, tantalum, and titanium. The electrotechnical properties of the discharge are measured by spectral methods and the electron temperature of the near-cathode plasma is determined. When tungsten electrodes

Abstract— A self-consistent fluid simulation of inductively coupled plasma-enhanced chemical vapour deposition (ICP-CVD) using silane, argon, and hydrogen mixture is presented. The model solves the continuity equations for charged species, the drift-diffusion equations to describe their transport and the electron energy balance equation, coupled with Maxwell’s and Poisson’s equations, using COMSOL

Abstract The study of a diffuse vacuum arc (DVA) is of interest in connection with the developing methods of plasma processing of the spent nuclear fuel (SNF). This type of discharge can provide a high degree of ionization of the vapors of the cathode material in the absence of droplets and multiply charged ions. This work is devoted to the study of the ion composition of the arc discharge plasma at

Abstract A method is proposed for producing microwave generation in a relativistic magnetically insulated vircator in the under-limit mode of an electron beam. The method is implemented if the repeated or multiple passage of the electron beam of the drift tube is organized. In this case, a virtual cathode is formed in the vircator and the powerful microwave generation occurs. Using the particle-in-cell

Abstract— Factors affecting the calculation of the electrical conductivity of hot dense nonideal plasma systems are revisited and scrutinized. Essential features relevant to truncation of the internal partition function, Coulomb strong coupling, electronic excited states, in addition to high ionization boundary and Coulomb logarithm, are thoroughly investigated and assessed. Particular interest has

Abstract The structure of high-frequency oscillations in the plasma of a Hall thruster (HT) is studied experimentally in two different stable discharge modes: the “jet” mode and the “bell” mode. The discharge modes under study differ in the geometrical shape of the plasma plume and in the main integral characteristics of the thruster, such as the anode efficiency, driving force, and the specific momentum

Abstract— The generation of accelerated electron beams in a high-current Z-pinch formed by the implosion of wire cylindrical tungsten arrays on an Angara-5-1 facility is studied. The most intense characteristic and bremsstrahlung X-ray radiation of fast electrons is recorded from the central region of the pinch at the pin-ching stage. The transverse size of the radiation source in the characteristic

Abstract We have investigated the propagation characteristics of Ion-Acoustic Solitary Waves (IASWs) in a magnetized, cometary plasma consisting of hydrogen ions, positively and negatively charged oxygen ions, kappa described hot solar electrons, and slightly colder cometary electrons. The effects of q-nonextensive distributions, on both lighter and heavier ions have been studied by deriving the Zakharov–Kuznetsov

Abstract— It is recognized that the filaments have a significant effect on the anomalous energy and particle transport in the tokamak periphery. They are actively investigated using various diagnostics in this regard. Recently studies of filaments using the Doppler backscattering method have been performed in the Globus-M and the ASDEX-Upgrade tokamaks. Backscattering from filaments manifests itself

Abstract A brief review is given of the dusty plasma near the surface of the Moon. Electrostatic processes represent an important factor of formation of such plasma. Problems related to theoretical and numerical modeling of the plasma–dust system near the Moon, its experimental investigation, and interpretation of data on near-lunar dusty plasma are formulated.

Abstract— In the region of the surface of the probe introduced into the plasma, there are emission flows that introduce changes in the determination of its parameters. Despite the significant development of the theory of probes, when calculating plasma parameters for experimentally obtained current–voltage characteristics, electron emission is not taken into account, largely due to the serious complication

Abstract In the T-10 tokamak, the results of plasma heating at the first and second electron cyclotron (EC) harmonics differ substantially. However, the problem is multi-parametric, so it is impossible to estimate the heating quality by sight. In this work, the analysis of heating at both harmonics is provided with two transport models, which were constructed separately for simulation in each mode

Abstract The transverse electron current due to the crossed electric and magnetic fields results in the robust instability driven by the electron \({\mathbf{E}} \times {\mathbf{B}}\) drift. In the regime of interest for electric propulsion applications, this instability leads to the excitation of quasicoherent nonlinear wave resulting in the anomalous electron transport. We investigate the nonlinear

Abstract The results of studying the propagation of plasma flows in the surrounding medium performed on the PF-3 plasma focus facility in the laboratory simulation of astrophysical jets from young stellar objects are presented. The modes with the plasma formations which retain their compactness when propagated over significant distances are obtained. The decrement of the flow’s deceleration as a result

Abstract— The kinetics of hydroxyl radical formation in water under the action of a pulsed discharge in vapor-gas bubbles formed near the surface of a graphite electrode immersed into water is studied. The reaction of potassium hexacyanoferrate(II) oxidation is used to determine the concentration and formation rate of OH radicals in the liquid phase. The power dissipated in the discharge is estimated

Abstract The modifications, which arise from ultra-relativistic and degenerate effects of electrons and positrons as well as the chemical potentials in the basic features of three-dimensional isothermal ion acoustic shock waves (IIASWs) propagating in magnetized electron–positron–ion (e–p–i) plasmas are studied. The cold ions are considered to be magnetized and inertial, while the small particles (i

Abstract The present research article presents the investigation of diffraction phenomenon of EM-plane wave by a non-symmetric plate of finite length under the influence of cold plasma. The Wiener–Hopf equation is formulated by boundary value problem related to this model and Fourier transform. The standard way of Wiener–Hopf procedure is used to tackle the resulting equation. Asymptotic expansion

Abstract Pulsed plasma accelerators are widely used for the production of high-temperature pulsed plasma flows for fundamental and practical applications. The basic parameters of pulsed plasma accelerators are the characteristics of the external electric and magnetic circuits, as well as the structural and energy properties of the plasma flow. This work aims to characterize an IPU-30 pulsed plasma

Abstract We suggest a solution of the problem of the description of magnetic and electric fields occurring during large-scale nonradiative processes in the collisionless space plasma. The key idea is that the quasi-neutrality condition and the field-aligned force equilibrium of electrons should be taken into account. Equations describing the plasma are divided into two parts, namely, a system of transport

Abstract— The phenomenon of improved energy confinement during radiative cooling at the plasma edge was studied experimentally in the T-10 tokamak. It was shown that the effect is independent on the kind of radiating gas. No substantial differences were observed using Ne, which radiates at two-thirds of the plasma radius, or He, which radiates at the very edge. This phenomenon is explained in frames

Abstract The stability of a planar plasma crystal in an external confining force field is investigated. Particles are assumed to be located in the plasma with Maxwellian electrons and with a directed flow of cold ions. It is shown that, together with the coupled wave instability, four more types of aperiodic instabilities arise, which lead to the formation of different structures. A region of the crystal

Abstract The process of switching a short vacuum gap using an auxiliary discharge over the surface of a dielectric is studied by the high-speed recording of images of the plasma in the optical spectral range. Based on the analysis of the obtained experimental data, it is suggested that the cathode spot and cathode flame in the ultraviolet spectral range play a significant in the formation of current

Abstract The conditions leading to the development of fast-scale ( f ~ 0.2–1.5 MHz) electromagnetic oscillations in the periphery regions of plasma at an early stage of disruption in the T-10 tokamak are analyzed. Spatial and temporal characteristics of fast-scale oscillations are investigated by moving magnetic and electric probes mounted inside the tokamak vacuum chamber. Analysis reveals that initiation

Abstract The model of the global electric circuit of the Earth (GECE) is considered, which is inseparably linked with the processes in space plasma. The Earth is surrounded by cosmic plasma consisting of electrons, ions, and negatively charged dust particles. Dust particles easily penetrate through the magnetic field and the atmosphere and charge the surface of the Earth negatively. The stationary

Abstract— In this paper, we obtain an expression for the high-frequency quadratic susceptibility of strongly inhomogeneous magnetoactive plasma, which describes the nonlinear coupling of an ordinary wave with longitudinal oscillations.

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

Abstract Resistive oscillations of axial plasma with ionization effects are analyzed in configuration similar to the Hall effect thrusters. From analysis of stationary equations we have identified different types of the steady-state plasma flow profiles and use these solutions as initial conditions in time-dependent initial value simulations. We have identified unstable regimes with intrinsic oscillations

Abstract A model describing the initial phase of the heating of a flare in the solar corona is proposed. The energy equation for a flare plasma in a magnetic tube is reduced to the two-dimensional equation of thermal conductivity with a nonlinear volume source that ensures the heating of the plasma in the blowup mode and nonlinear anisotropic thermal conductivity. Explosive plasma heating is shown

Abstract The results of studying the spectral characteristics of the stochastic motion of charged particles of small chain structures interacting with an arbitrary reciprocal potential in an anisotropic electric field of the trap are presented. The characteristic frequencies of the particles and the method of their analytical calculation are considered. Relations for the spectral density of displacements

Abstract Non-uniformities in the plasma parameters in a magnetized inductively coupled plasma (M-ICP) etcher were investigated. Further in text of this article the silicon dioxide and the photoresist are called as abbreviations the oxide and the PR accordingly. The etch results of an oxide and PR were correlated with the non-uniformity characteristics of the plasma parameters. The plasma density non-uniformities

Abstract A spark discharge is modelled in a long air gap of atmospheric pressure at a positive voltage with a long front duration, excluding the quasi-continuous development of the leader. It is shown that, with a front steepness of less than 30 kV/μs, an ionization wave moves in the gap, whose speed is 2 orders of magnitude slower than the speed of streamers in the streamer zone of the leader. The

Abstract The possibility of the formation of microspherules in plasma-dust processes initiated by meteoroids impacting the lunar surface is discussed. It is demonstrated that spherules are formed from the material of the melt zone created by a high-speed meteoroid impacting the lunar surface. Initially, they rise above the surface of the Moon and then fall back. It is these spherules that were found

Abstract— The stability of a linear chain of dust particles in an external confining force field is studied. It is assumed that the particles are located in a plasma with Maxwellian electrons with a directed flow of cold ions. It is shown that the aperiodic instability of doubling the chain period can develop in a subsonic flow together with the instability of coupled waves. The region of the crystal

Abstract A method for calculating fluctuations in the nonequilibrium plasma-containing random inhomogeneities is developed. Using this method, the fluctuation spectrum in the region of the plasma line is calculated for the case of large-scale inhomogeneities with their characteristic dimensions exceeding the length of plasma waves. The results obtained are valid for both strong and weak inhomogeneities