卷 51, 编号 5 (2025)

Studies of plasma created and confined in quasi-stationary L-2 and L-2M stellarators are presented. In these devices, plasma was created by the induction-free method of electron cyclotron resonance (ECR) microwave heating in the power range P = 0.05 – 1 MW. The radial structure of the region near separatrix (relative radius 0.8–1) and fluctuations of plasma parameters in the mode without changing macroparameters are considered. The fluctuations of peripheral plasma parameters (density, electric potential, and magnetic field) and their evolution during discharges are analyzed. The structure of the electric field and heat flux in the wall plasma measured by Langmuir probes is analyzed. The relationship between changes in fluctuating plasma parameters and possible small-scale instabilities is analyzed. The mechanisms of development of interchange, peeling, and temperature gradient edge instabilities are considered. A comparison is made between the modeling of energy transport in plasma using neoclassical models, taking into account anomalous energy losses and based on canonical pressure profiles. The possibility of using a quasi-stationary stellarator as a source of plasma flows with three-dimensional geometry for materials science is being considered.

The results of numerical modeling of quasi-stationary configurations of a current sheet with a given normal magnetic field component, consisting of a thin ion current sheet and the embedded super-thin electron current layer, are considered. Such sheets are regularly observed during the growth phase of magnetospheric substorms by the MMS satellite mission in the neutral sheet of the near-Earth magnetotail region. New numerical model of a stationary current sheet with kinetic description of the current carrying transient ion and electron populations is proposed, for which the Vlasov equations are solved for the stationary case by method of characteristics, and the distribution functions are calculated on regular grids in velocity space, taking into account the real electron charge-to-mass ratio. Using this model, the symmetrical flat configurations of super-thin electron current sheet are obtained, which are qualitatively and quantitatively consistent with MMS spacecraft observations.

A review of theoretical studies on dusty plasmas in the atmospheres of planets in our Solar System, conducted at the Space Research Institute of the Russian Academy of Sciences, is presented. Particular attention is paid to physical processes associated with such phenomena as noctilucent clouds and polar mesosphere summer echoes, dust acoustic perturbations in the Earth’s atmosphere, clouds in the ionosphere of Mars, and Schumann resonances. It is noted that intensive studies of dusty plasma processes in the atmospheres of planets are currently being conducted in relation to the Earth and Mars. To study the corresponding processes in the atmospheres of other planets of our Solar System, more knowledge is required about the objects being studied, which can only be obtained in future space missions.

An electromagnetic wave amplifier based on the forced Cherenkov effect of a relativistic thin tubular electron beam in a coaxial waveguide with a plasma-dielectric filling is considered. In the linear approximation, a dispersion equation is derived, amplified frequency domains are defined, and wave amplification factors are calculated. Two maximum amplification modes were studied depending on the beam-dielectric gap and frequency. The nonlinear dynamics of the amplification process was investigated. Amplification efficiencies for different beam currents and different frequencies of the amplified signal were determined. The effect of plasma on wave amplification in a coaxial waveguide with a dielectric insert was studied in detail. The interaction of the beam with the potential Langmuir wave in plasma was shown to affect but slightly the amplification of electromagnetic waves.

The nature of lightning plasma evolution at the low-current stage in the interval between a stepped leader and a return stroke or between a return stroke and a dart leader of the next lightning flash is analyzed. It is shown that a typical time to establish the equilibria in the plasma under consideration is small compared to a typical time of slow stages of lightning. Therefore, a local thermodynamic equilibrium is established in the plasma of the conductive channel at a slow stage of its electrons, and the temperature of electrons and atoms is identical. According to the gas dynamic model, a typical time of plasma relaxation after a return stroke of the order of 1 ms is small compared to the duration of the slow stage (about 50 ms), so that an external electric field is required to maintain the plasma at a slow stage, which creates a weak electric current which stabilizes the plasma of the conductive channel. Taking into account the results of numerical models for the relaxation of the plasma of a return stroke, the parameters of heat transfer are determined, which are related to the thermal conductivity of the plasma inside the conductive channel, mainly due to the transfer of dissociative energy and thermal conductivity of electrons. At the boundary of the lightning conducting channel, heat transfer occurs as a result of the convection of surrounding air, which leads to the formation of tongues and vortices, the size of which is about 10 cm. As a result, the total renew of hot air of the conductive channel with cold air proceeds due to convection at the temperature of 7 kK during about 40 ms.

The results of experiments on the use of microwave discharge plasma, supported by microwave radiation of a pulsed (6 ms) gyrotron, for the transfer of matter from a metallic silver nanopowder to the surface of a dielectric ABS (acrylonitrile-butadiene-styrene) plastic target are presented. The experiments were carried out at atmospheric and reduced pressure (up to 50 Torr) of air at microwave radiation power density from 1.25 to 12 kW/cm2. The spatial structures of microwave discharge plasma propagating near a quartz substrate with a layer of silver nanopowder were studied. It was determined that the discharge can have at least 3 types of spatial structure: a) localized microwave discharge at the points of discharge initiation; b) microwave discharge propagating through a quartz substrate; c) microwave discharge propagating along a quartz substrate. The metal layer deposited on the plastic surface was characterized using electron microscopy.

The most interesting new results are discussed that were presented at the LII International Zvenigorod Conference on Plasma Physics and Controlled Fusion, which was held in Zvenigorod, Moscow region, on March 17–21, 2025. The achievements in the main fields of research in plasma physics in Russia are analyzed and compared with those obtained in foreign scientific centers.