卷 49, 编号 8 (2023)

The evolution of fluctuating signals from electrostatic and magnetic probes and reflectometry on the L-2M stellarator is presented. The L-2M facility is a quasi-stationary toroidal magnetic trap in which plasma is generated and heated by high-power pulsed microwave radiation. Pulses with transitions to improved confinement modes accompanied by an increase in energy, increase in plasma density, and restructuring of the peripheral electric field, were analyzed. Spectral analysis of signals is carried out using Fourier analysis and various wavelets. The possible influence of magnetohydrodynamic and kinetic instabilities on the development of transient processes is considered.

Исследованы последствия эффекта локализации ионных бернштейновских (ИБ) волн, которые возбуждаются при вторичных распадах, сопровождающих низкопороговую параметрическую распадную неустойчивость необыкновенной волны накачки, приводящую к генерации необыкновенной волны и локализованной в плазме верхнегибридной (ВГ) волны. Показано, что обнаруженный эффект приводит к уменьшению как уровня насыщения первичной неустойчивости, так и уровня аномального поглощения волны накачки в экспериментах по электронному циклотронному нагреву плазмы на второй гармонике резонанса.

A detailed interpretation of the effect of anomalous radiation is given, which was first observed at the TEXTOR tokamak in experiments on electron cyclotron resonance heating by the extraordinary wave at the second resonance harmonic in a wide range of plasma densities.

The electron energy distribution function (EEDF) and the spatial profile of the electron density in the cathode–anode gap in a helium discharge are calculated within a one-dimensional model by the Monte Carlo method. Numerical studies are performed for experimental conditions known from the literature in a discharge with a hollow cathode: the cathode–anode distance of 3 cm, the helium pressure of 0.75 Torr, and the electric field strength in the discharge gap of 1.3 V/cm. The calculations are performed without and with allowance for the anode potential drop and the effect of electron reflection from the anode. The dependence of the form of EEDF on the energy spectrum of the electron source used in the calculations is also studied. In all variants of calculations, the main feature of the EEDF is retained, that is, a significant depletion of the low-energy part of the distribution function due to the effect of electron absorption by the anode. The calculated EEDF and the spatial profile of the electron density are compared with the available experimental data.

The structure of a low-pressure microwave discharge sustained by a standing surface electromagnetic wave (SEW) in a quartz tube filled with argon was studied. The standing wave was formed using a set of two flat metal mirrors, which formed an open SEW resonator. The plasma density profile and structure of the electromagnetic field of the SEW were studied in the pressure range from 0.25 to 10 Torr. The excitation of the standing wave allowed us to independently study the longitudinal Ez and transverse Er components of the SEW electric field vector. It was confirmed experimentally that the oscillation phases of the components of the SEW are shifted by π. The excitation of the standing wave in the plasma column leads to the formation of local minimums and maximums of plasma density, whose period equals half the wavelength of the surface wave. At the same time, the spatial period of density modulation is close to the distribution of the Ez component of the standing SEW. It was shown that the formation time of the modulated structure of plasma density is close to the characteristic time of diffusion, while the degree of modulation increases with increasing pressure. It was shown experimentally that it is possible to produce a plasma column with plasma density modulation nemax/nemin ≈ 5 and a length of about 10 wavelengths.

Впервые изучено поведение линии единичного фактора сжимаемости в области низкотемпературной плотной плазмы металлов. Ее форма является универсальной на плоскости плотность–температура для многих однокомпонентных газов и жидкостей при низких температурах, а также для жидких металлов. С помощью вириальных разложений и расчетов в рамках химической модели показано, что это подобие нарушается при переходе в область низкотемпературной плазмы металлов. Тем не менее, в этой области при сравнительно низких плотностях для этой линии возможно более слабое подобие, выражаемое степенным законом.

The paper presents a numerical simulation of the dynamics of high-velocity aluminum plasma jets with multiple injection in the Earth’s ionosphere. Scenarios of single injection, counter injection, and collimation of plasma jets at a given convergence angle are considered. The gas-dynamic parameters of plasma formations and their optical characteristics are determined.

We present a brief review of research on dusty plasma in the solar system. Special attention is paid to theoretical studies related to the solar-system bodies without atmosphere that are conducted at the Space Research Institute of the Russian Academy of Sciences.

The electron energy distribution function (EEDF) and the spatial profile of the electron density in the cathode–anode gap in a helium discharge are calculated within a one-dimensional model by the Monte Carlo method. Numerical studies are performed for experimental conditions known from the literature in a discharge with a hollow cathode: the cathode–anode distance of 3 cm, the helium pressure of 0.75 Torr, and the electric field strength in the discharge gap of 1.3 V/cm. The calculations are performed without and with allowance for the anode potential drop and the effect of electron reflection from the anode. The dependence of the form of EEDF on the energy spectrum of the electron source used in the calculations is also studied. In all variants of calculations, the main feature of the EEDF is retained, that is, a significant depletion of the low-energy part of the distribution function due to the effect of electron absorption by the anode. The calculated EEDF and the spatial profile of the electron density are compared with the available experimental data.