Fizika plazmy
ISSN(Print): 0367-2921
Media registration certificate: No. 0110354 dated 03/02/1993
Founder: Federal Research Center "Institute of General Physics named after A.M. Prokhorov RAS", National Research Center "Kurchatov Institute", Russian Academy of Sciences
Editor-in-Chief: Smirnov Valentin Panteleimonovich
Number of issues per year: 12
Indexation: White List (level 3), Higher Attestation Commission List, RISC
Ағымдағы шығарылым
Том 51, № 1 (2025)
- Жылы: 2025
- Мақалалар: 10
- URL: https://journals.rcsi.science/0367-2921/issue/view/19609
Бүкіл шығарылым
TOKAMAKS
DESIGN OF VERTICAL THOMSON SCATTERING DIAGNOSTICS FOR THE T-15MD TOKAMAK
Аннотация
For measuring the parameters of the plasma electron component in the T-15MD tokamak, the complex of Thomson scattering diagnostics is being designed, which will make it possible to study different regions of the plasma. In this work, we discuss the design of the Thomson scattering system with vertical probing for T-15MD, which provides for information on the plasma parameters along the vertical diameter of the vacuum vessel. Plasma probing is performed using the Nd:YAG laser with multipass system for inject laser beam into the tokamak. The laser operates at the second harmonic λ = 532 nm. Scattered radiation is collected by one wide-angle lens. Light is transmitted to the registration system by the fiber-optic collector consisting of 159 fiber-optic assemblies with the size 2 × 1 mm. The registration system consists of three units; each unit includes relay optical system and polychromator with detector. The spectrum of scattered radiation is recorded using image intensifier with CMOS camera. For achieving high light transmittance of the diagnostics optical system, the parameters and design of each optical unit were calculated in detail: the collecting lens, the relay optical system, and the polychromator. As compared to the T-10 Thomson scattering diagnostics, the system transmittance was considerably improved due to selecting rigorously the optical materials, as well as applying new design of the relay optical system, consisting mainly of mirrors. Using synthetic diagnostics, the accuracy of measuring the electron temperature and density was estimated. The plasma spectra from the region of T-15MD limiter are used as the plasma background. The Thomson scattering diagnostics system with vertical probing will make it possible to measure the electron temperature of plasma of the T-15MD tokamak with an error of less than 10% in the range from 80 eV to 6 keV at an electron density of more than 6 × 1018 m−3 in the central plasma region. At the plasma edge, the error will be less than 10% for the 𝑇 𝑒 range from 100 eV to 2 keV at densities 𝑛𝑒 > 1 × 1019 m−3. The spatial resolution of the diagnostics will be ∼11 mm at the center of the plasma and ∼22 mm in the edge plasma.
Fizika plazmy. 2025;51(1):5-16
5-16
PLASMA EQUILIBRIUM WITH INNER SEPARATRIX IN TOKAMAKS
Аннотация
Several plasma equilibria with inner (current and magnetic) separatrices in a tokamak have been considered. Calculated and available experimental data for such equilibria have been compared. It is shown that a qualitative change in the equilibrium plasma configuration is possible at a small change in the inner plasma inductance in a tokamak. It is noted that an equilibrium solution is possible for some types of flux functions in the Grad–Shafranov equation, only if the plasma density at its boundary is nonzero. It is established that the formation of a natural poloidal divertor is determined not only by the value but also by the type of flux functions of the Grad–Shafranov equation. The possibility of the existence of equilibrium plasma configurations with magnetic axes located one above the other and the possibility of the existence of equilibrium plasma systems with many magnetic axes are shown.
Fizika plazmy. 2025;51(1):17-24
17-24
PLASMA DYNAMICS
TRENDS AND ACHIEVEMENTS IN THE STUDY OF THE 𝑝–11B FUSION: A REVIEW
Аннотация
The possible use of the aneutronic 𝑝–11B reaction is of interest from the viewpoint of obtaining clean energy. Here, we consider the current studies of the different schemes of implementing this reaction and present the estimates of the limiting energy gain in the plasma at different system parameters. The possibilities of increasing the reaction rate compared to the Maxwellian plasma are discussed. The effect of the accumulation of the alpha particles and the possible means of decreasing it are analyzed.
Fizika plazmy. 2025;51(1):25-41
25-41
PLASMA DIAGNOSTICS
INFLUENCE OF MAGNETIC FIELD ON SPECTRA OF ELECTROSTATIC OSCILLATIONS IN THE PLASMA OF THE E×B DISCHARGE
Аннотация
Simultaneous measurements of the amplitude–frequency characteristics (AFCs) of oscillations of the derivative of the discharge current and the ion current at the frequencies of 20 kHz – 30 MHz in the plasma of a self-sustained 𝐸×𝐵 discharge in an accelerator with an anodic layer under conditions of a strong inhomogeneous magnetic field (the radial component is up to 𝐵𝑟𝐶 = 4200 G at the cathode; up to 𝐵𝑟𝐴 = 1010 G at the anode) have revealed both identical and different properties of oscillations of the derivative of discharge and ion currents. Common features are the discrete spectrum and, mainly, the cluster character of oscillations. The threshold magnetic field values of 𝐵𝑟𝐴 = 660–720 G, at which there is a rapid increase in the frequency of oscillations having a maximum amplitude up to 𝑓max ∼ 4.5 MHz, have been discovered. At the same time, there are jumps of the selected peaks of the amplitude–frequency characteristic from tens of kilohertz to hundreds of kilohertz in the frequency range of not higher than 1 MHz. The differences in the amplitude-frequency characteristics of the discharge current and ion current oscillations are the frequencies of discharge current oscillations with the maximum amplitude, which are ∼ 5 times lower than those of the ion current at 205 ⩽ 𝐵𝑟𝐴 ⩽ 660 G, sharp decay of 𝑓max for AFC of the discharge current, but sharp increase in 𝑓max for AFC of the ion current, when 𝐵𝑟𝐴 becomes larger than 820 G. The results of the measurement of characteristics are analyzed together with the plasma emission spectra in the wavelength range of 200–1100 nm and ion energy distributions in the range of 50–1200 eV measured in the same discharge modes. The possible origin of the generation of discharge and ion current oscillations during excitation of the modified two-stream and electron-cyclotron drift instabilities in the plasma of the 𝐸×𝐵 discharge for frequencies 𝑓 ⩽ 1 MHz are discussed. At higher frequencies, the influence of the axial instability of the flow of non-magnetized ions on the energy ion distribution is analyzed.
Fizika plazmy. 2025;51(1):42-53
42-53
NVESTIGATION OF THE INPUT IONIZATION CHAMBER OF A TWO-STAGE PLASMA ACCELERATOR
Аннотация
Within the framework of the federal project “Development of controlled fusion technologies and innovative plasma technologies”, Troitsk Institute for Innovation and Fusion Research (TRINITI) is working on the creation of a prototype plasma rocket thruster based on a two-stage quasi-stationary high-current plasma accelerator where the processes of propellant preliminary ionization and final high-speed flow formation are separated. The discharge characteristics of the input ionization chamber were determined when using hydrogen and helium as a propellant in the relevant flow range of 1.5–3 mg per pulse, on the basis of which recommended values of specific energy input in the range of 2.2–2.6 kJ/mg for H2 and 1.2–1.6 kJ/mg for He were established. The plasma temperature estimation for hydrogen at 0.8 eV is consistent with the measured plasma flow velocity of 16 ± 3 km/s. The conversion coefficient of the input electrical energy into the plasma flow energy was 65% in the entire studied range. The results obtained make it possible to predict the electrical discharge characteristics, cooling requirements and erosion rate for the first stage of a plasma rocket thruster.
Fizika plazmy. 2025;51(1):54-63
54-63
УСКОРЕНИЕ ЧАСТИЦ В ПЛАЗМЕ
FORMATION OF LASER PRE-PLASMA FOR CONTROLLING THE PARTICLE-ACCELERATION EFFICIENCY
Аннотация
Nanosecond laser ablation is simulated aiming at characterization of the plasma plume at an irradiated target surface and analysis of the possibility of using such a plume for efficient acceleration of charged particles by a high-power short laser pulse. The effect of using different physical models in the hydrodynamic calculations on the results of simulation is demonstrated.
Fizika plazmy. 2025;51(1):64-77
64-77
ЛАЗЕРНАЯ ПЛАЗМА
INCREASING THE EFFICIENCY OF LASER ACCELERATION OF PROTONS USING ULTRA-THIN TARGETS
Аннотация
The results of laser acceleration of protons from aluminum targets 6 μm thick and ultra-thin diamond-like carbon films 100 nm thick when they are irradiated with femtosecond laser pulses with a peak intensity of up to 5 × 1020 W/cm2 are presented. It is shown that decreasing the target thickness from 6 μm to 100 nm does not lead to a significant change in the maximum proton energies, but contributes to an increase in the angular yield and the laser energy conversion coefficient. This effect is due to an increase in the number of protons in the low-energy part of the spectra, which is reflected in a twofold increase in the conversion coefficient.
Fizika plazmy. 2025;51(1):78-84
78-84
NONLINEAR PHENOMENA
ION VELOCITY AND ENERGY DISTRIBUTION FUNCTIONS PERTURBED BY THE ION-ACOUSTIC SOLITONS: ANALYTICAL CALCULATION FOR ARBITRARY AMPLITUDES
Аннотация
Distribution functions of background ions perturbed by the ion-acoustic solitons are calculated using the Sagdeev pseudopotential approach for the case of cold ions. Velocity and kinetic-energy distribution functions are analyzed. Explicit expressions valid for the solitons of arbitrary amplitude are obtained. It is demonstrated that the solitons form a strongly nonequilibrium plasma in their vicinity. The results are compared with previous analytical calculations and results of simulations.
Fizika plazmy. 2025;51(1):85-91
85-91
SPACE PLASMA
NONLINEAR PERIODIC DUST ACOUSTIC WAVES IN THE MAGNETOSPHERE OF SATURN
Аннотация
A characteristic feature of the magnetosphere of Saturn is the presence of two types of electrons, hot and cold ones, which obey kappa distributions. Electrons, magnetospheric ions, and dust particles, which have been discovered within the Cassini mission, form a dusty plasma system in the magnetosphere of Saturn. Nonlinear periodic dust acoustic waves of arbitrary amplitude, which can propagate in the dusty magnetosphere of Saturn, are considered. The obtained results are important for the interpretation of future space observations.
Fizika plazmy. 2025;51(1):92-99
92-99
ION AND PLASMA SOURCES
GENERATION OF A PLASMA BUNCH IN A MULTICHANNEL INJECTOR OF A PULSED PLASMA ACCELERATOR
Аннотация
This work presents experimental studies of the plasma bunch formation in an injector, which is the initial section of a coaxial accelerator. Design solutions, experimental setup, and measurement results are described. The design features of the injector include the controlled supply of the working gas through electrodynamic valves uniformly installed around the circumference of an outer electrode, a profiled inner electrode, and a solenoid located outside the injector. The diagnostic system included measuring currents and voltages in the discharge circuit and the solenoid circuit; high-speed video recording; measuring plasma parameters using spectral methods and a triple Langmuir probe. Video frames of the plasma bunch formation, results of current and voltage measurements, electron temperature and density are presented; the influence of an external magnetic field on processes in the injector is considered.
Fizika plazmy. 2025;51(1):100-110
100-110