Two-component Plasma Research Articles

The effect of dust on the propagation of a hydromagnetic solitary wave along the magnetic field in a cold collision-free plasma

The effect of dust is studied on the parallel propagation of a solitary hydromagnetic wave in a magnetized, cold, collision-free plasma. The fully nonlinear analysis is based on the Adlam–Allen method. The system of nonlinear differential equations was derived using the assumption of massive dust, namely, that the dust velocity is constant and parallel to the background magnetic field. Self-consistent solutions obtained from the model for the lighter particles dynamics and for the resulting electric and magnetic fields are presented, together with the validity range of Mach numbers as a function of dust parameters. In particular, supersonic solutions are possible in scenarios tending to two-component plasmas (positively charged ions and negatively charged dust). The stationary solitary pulse in terms of particle densities, magnitude of transverse magnetic field, transverse electron–ion velocities, and bipolar electric field is presented. The magnitude of these amplitudes is maximum at the center of wave and minimum at the boundary. Furthermore, it is shown that all the solitary wave amplitudes are decreases with dust parameter.

Effects of specular reflectance in laser-induced breakdown of metals

We investigate the effects of specular reflection on the laser-induced breakdown (LIB) of copper, iron, and tungsten using fast photography and optical emission spectroscopy. The laser parameters include spot diameter ranging from 30.89 to 1589.33 μm, irradiance from 467.10 to 0.17 GW/cm2, with a single pulse of 6 ns duration and 21 mJ energy. As the laser spot defocuses, the plasma morphology changes from a single plasma near the target surface to a separated, independently evolving two-component plasma, and then to a single plasma suspended above. The defocusing distance for this transition is significantly influenced by specular reflectance. The separate plasma, comprising of a metallic component and an air component, occurs only under high specular reflectance conditions: ≥66.7% for copper, ≥51.4% for iron, and ≥44.9% for tungsten. The spectral emission of the metallic component initially increases and then decreases with reducing specular reflectance, due to a trade-off between enhanced surface absorption and reduced irradiance caused by surface roughening. LIB threshold irradiance increases with specular reflectance, rising from 0.31 to 1.22 GW/cm2 for copper, 0.24 to 0.70 GW/cm2 for iron, and 0.38 to 0.87 GW/cm2 for tungsten. These findings show the impact of sample pretreatment on LIB ignition and subsequent plasma evolution, offering insights into potential sources of inaccuracy in LIB applications.

Impacts of neutral collisions and finite electron inertia on longitudinal thermal instability of two-component radiative plasma for star formation in interstellar medium (ISM)

The impact of neutral friction, finite electron inertia and radiative heat-loss function on the thermal instability of viscous two-component plasma has been explored, integrating the impacts of thermal conductivity. A general dispersion relation is gained by means of the normal mode analysis scheme with the assist of appropriate linearized perturbation equations of the problem, and an amended circumstance of thermal instability is acquired. For the case of longitudinal propagation, it is obvious that the circumstance of thermal instability is independent of the finite electron inertia, magnetic field strength and viscosity of two components but relies on the radiative heat-loss function, thermal conductivity and neutral particle. From the curves, it is clear that the temperature-dependent heat-loss function, thermal conductivity and viscosity of two components represent stabilizing impact, while finite electron inertia and neutral collision depict destabilizing impact. Results discussed in this problem are helpful for star formation in ISM.

On the Existence of Global Compactly Supported Weak Solutions of the Vlasov–Poisson System with an External Magnetic Field

We consider the first mixed problem for the Vlasov–Poisson system with an external magnetic field in a domain with piecewise smooth boundary. This problem describes the kinetics of a two-component high-temperature plasma under the influence of a self-consistent electric field and an external magnetic field. The existence of global weak solutions is proved. In the case of a cylindrical domain, sufficient conditions are obtained for the existence of global weak solutions with supports in a strictly internal cylinder; this corresponds to the confinement of high-temperature plasma in a mirror trap.

Kinetic Theory of Expansion of Two-Component Plasma in a Plane Vacuum Diode

Kinetic Theory of Expansion of Two-Component Plasma in a Plane Vacuum Diode

Kinetic Model of Vacuum Plasma Expansion in a Cylindrical Gap

Results of a theoretical description of collisionless kinetics of radial expansion of two-component (electron–ion) plasma in the one-dimensional cylindrical formulation of the problem are presented. The electric-field mechanism of supersonic expansion of the plasma flame due to the motion of the electron–ion ensemble and self-consistent electric field in the diode with the potential difference applied to it is demonstrated. The spatiotemporal evolution of the ion energy distribution function, electric potential, and rate of expansion of the emission boundary of the plasma flame is shown. The calculated rates of flame expansion at the copper cathode (~1.5 × 106 cm/s) well agree with the experimental data.

Kinetic Model of Vacuum Plasma Expansion in a Cylindrical Gap

Results of a theoretical description of collisionless kinetics of radial expansion of two-component (electron–ion) plasma in the one-dimensional cylindrical formulation of the problem are presented. The electric-field mechanism of supersonic expansion of the plasma flame due to the motion of the electron–ion ensemble and self-consistent electric field in the diode with the potential difference applied to it is demonstrated. The spatiotemporal evolution of the ion energy distribution function, electric potential, and rate of expansion of the emission boundary of the plasma flame is shown. The calculated rates of flame expansion at the copper cathode (~1.5 × 106 cm/s) well agree with the experimental data.

Kinetic Theory of Expansion of Two-Component Plasma in a Plane Vacuum Diode

The results of study of the initial stage of expansion of a collisionless plasma with the electric current into a plane vacuum gap on the basis of kinetic equations for electrons and ions and the Poisson equation for the electric field are given. Self-consistent dynamics of a two-component plasma and electric field are theoretically modeled and the fundamental mechanism for establishing superthermal velocities of charged particles is described in detail. The parameters of anode-directed flows of positive ions in the cathode plume plasma are calculated. The expansion velocities of the cathode plume plasma observed in vacuum arcs at the level of (1−5) × 106 cm/s can be explained within the framework of the proposed collisionless mechanism.

A global spectral-Galerkin investigation of a Rayleigh–Taylor instability in plasma using an MHD–Boussinesq model

This paper presents a new efficient algorithm based on the spectral-Galerkin numerical approximations complemented by a magnetohydrodynamics–Boussinesq model and a new solver for studying the development of a Rayleigh–Taylor (RT) instability. We use the Shenfun computational framework in the Cartesian coordinates, which gives the spectral order and accuracy for the considered model based on the magnetohydrodynamics equations and the Boussinesq conjecture. The numerical simulations were conducted for each two- and three-dimensional case, both with and without an external static magnetic field. The validity of the numerical results was examined by comparing the calculated squared L2-norm of the density parameter with the linear stability analysis. We also examined the effects of a uniform tangential magnetic field on the onset and growth of an RT instability at different magnetic field strengths. The analysis of the effectiveness of the presented method suggests that it can be modified for further research on two-component plasma.

Acoustic stability of a self-gravitating cylinder leading to astrostructure formation

We employ a quantum hydrodynamic model to investigate the cylindrical acoustic waves excitable in a gyromagnetoactive self-gravitating viscous cylinder comprised of two-component (electron–ion) plasma. The electronic equation of state incorporates the effect of temperature degeneracy. It reveals an expression for the generalized pressure capable of reproducing a completely degenerate (CD) quantum (Fermi) pressure and a completely non-degenerate (CND) classical (thermal) pressure. A standard cylindrical wave analysis, moderated by the Hankel function, yields a generalized linear (sextic) dispersion relation. The low-frequency analysis is carried out procedurally in four distinct parametric special cases of astronomical importance. It includes the quantum (CD) non-planar (cylindrical), quantum (CD) planar, classical (CND) non-planar (cylindrical), and classical (CND) planar. We examine the multi-parametric influences on the instability dynamics, such as the plasma equilibrium concentration, kinematic viscosity, and so forth. It is found that, in the quantum regime, the concentration plays a major role in the system destabilization. In the classical regime, the plasma temperature plays an important role in both the stabilization and destabilization. It is further seen that the embedded magnetic field influences the instability growth dynamics in different multiparametric regimes extensively, and so forth. The presented analysis can hopefully be applicable to understand the cylindrical acoustic wave dynamics leading actively to the formation of astrophysical gyromagnetic (filamentary) structures in diverse astronomical circumstances in both the classical and quantum regimes of astronomical relevance.

The Influence of Oxygen Ions on the Formation of a Thin Current Sheet in the Magnetotail

A thin current sheet in the Earth’s magnetotail with characteristic thickness of one to several proton gyroradii is often observed during magnetospheric disturbances named substorms, when a relatively thick current configuration in the magnetotail is narrowed to an extremely small thickness and then can spontaneously be destroyed. The current-sheet destruction is usually accompanied by such active processes as plasma acceleration and heating, as well as generation of an induced electric field and magnetohydrodynamic waves. In this paper, we developed and investigated a model of formation of a thin current sheet in which, along with protons, we have taken into account single-charged oxygen ions coming from the ionosphere into the magnetotail current sheet during magnetically active periods. The aim of this simulation is to study the peculiarities of thin current-sheet formation in two-component plasma and investigate its structure. It is shown that equilibrium configuration can have some characteristic properties. In particular, if the system consists only of protons or heavy ions, single-scale current equilibrium supported by quasi-adiabatic particles is formed. When a current sheet is formed in plasma that consists of a mixture of protons and oxygen ions in comparable concentrations, a current sheet can be formed with heavy ions as current carriers and chaotic proton trajectories that make a negative contribution to the current, due to which the current-density profile becomes bifurcated with the minimum at the center and maxima at the periphery of the sheet. The results may be useful for the interpretation of observational data in the Earth’s magnetotail.

ELECTROMAGNETIC WAVE MODEL OF HYDROGEN AND HELIUM DISTRIBUTION AT THE FORMATION OF THE SOLAR SYSTEM

This paper considers the formation process of the protosolar hydrogen-helium cloud in chronological order. From the list of hypotheses about the solar system formation, the electromagnetic hypothesis of Alfvén was selected since it is based on the plasma state of the protosolar hydrogen-helium cloud. It presumably describes a supernova explosion and its contribution to the solar system formation. The spatial-temporal dynamics of changes in the density and velocity of ions in a cylindrical two-component hydrogen-helium plasma is described. It is shown that the motion velocities of two-type particles represent Benard cells oscillating with different periods. The proposed electromagnetic wave model was used to calculate the distribution of hydrogen and helium ions in the solar system at the beginning of its formation and after a supernova explosion.

New hyperbolic statistics for the equilibrium distribution function of interacting electrons

New statistics of a low-parameter distribution of the sech (ε, µ) type are presented, which reproduce the results of plasma simulation by the method of dynamics of many particles (DMP) with high accuracy. The distribution is based on a conceptual model of a two-component plasma — virtual quasiparticles of negative energy (exciton phase ε<0); the scattering region of positive energy (gas phase ε>0). Optimization and elementary estimates of the applicability of the sech (ε, µ) distribution statistics were made after the results of DMP experiments. The sech (ε,µ) distribution reduces the number of parameters of the three-piece DMP distribution from 4 energy diffusion coefficients (D1, D2, D3, D4) to two — the chemical potential µ and the asymmetry coefficient α. The functional relationship D1, D2, D3, D4 with the chemical potential of the system µ in the sech (ε, µ) distribution is introduced in a similar way to the Einstein relation between mobility and energy diffusion constants. The functional variety of the differential equation belongs to the family of elliptic functions. It is much wider than the hyperbolic solution given, which has significant physical application for complex values of the energy ε. The proposed simplified scheme grounded in the physical interpretation of negative energies can be written for the electrometric electrons of the atmosphere, which previously presented significant methodological difficulties. The chemical potentials of the fluid (metastable states) and gas phases are presented as functions of the plasma imperfection parameter. The problem is posed as an application to the problem of electrometric electrons in the atmosphere. The proposed distribution is not represented in mathematical statistics and statistical physics; it is new and extremely relevant.

Diagnostic Techniques for Electrical Discharge Plasma Used in PVD Coating Processes

This article discusses the possibilities of two methods for monitoring Physical Vapor Deposition (PVD) process parameters: multi-grid probe, which makes it possible, in particular, to determine the energy distribution of ions of one- or two-component plasma and spectrum analyzer of the glow discharge plasma electromagnetic radiation signal based on the Prony–Fourier multichannel inductive spectral analysis sensor. The energy distribution curves of argon ions in the low-voltage operation mode of ion sources with closed electron current have been analyzed. With a decline in the discharge current, the average ion energy decreases, and the source efficiency (the ratio of the average ion energy W to the discharge voltage U) remains approximately at the same level of W/U ≈ 0.68, …, 0.71 in the operating voltage range of the source. The spectrum analyzer system can obtain not only the spectra at the output of the sensor, but also the deconvolution of the spectrum of the electromagnetic radiation signal of the glow discharge plasma. The scheme of a spectrum analyzer is considered, which can be used both for monitoring and for controlling the processing process, including in automated PVD installations.

Quantum and Relativistic Effects on the KdV and Envelope Solitons in Ion-Plasma Waves

In this article, we investigate the linear and nonlinear behavior of ion-plasma waves in a two-component plasma containing ions and dust particles. We have studied the linear dispersion characteristics, nonlinear KdV solitons, and amplitude modulated electrostatic waves. Such ion-plasma wave modes in dust-ion plasma have been theoretically investigated by incorporating quantum diffraction and relativistic effects. Numerical analysis of the linear dispersion relation with variations of different parameters has been carried out. By employing the reductive perturbation technique the KdV equation describing the small amplitude solitary profile has been studied. Using the standard multiple scale perturbation method, a nonlinear Schrödinger (NLS) equation has been derived by including quantum and relativistic effects, which describes the nonlinear evolution of the ion-plasma waves in dust-ion plasma. The wave is found to become modulationally unstable beyond certain critical wavenumber. The critical wavenumber and the growth rate of modulational instability are shown to depend significantly on the relativistic motion of plasma particles and the quantum diffraction effect. The results presented in the article are expected to be helpful for understanding the propagation of finite amplitude ion-plasma waves in some laboratory and astrophysical plasma systems. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PACS</i> —52.59.Hq, 67.10.Jn, 52.20 −j, 52.25 −b, 52.30 −d, 52.35 Mw, 52.65 Vv

Supernonlinear wave, associated analytical solitons, and sensitivity analysis in a two-component Maxwellian plasma

This analysis investigates the occurrence of super nonlinear waves (SNWs) in a two-component electron-ion plasma containing Maxwell distributed electrons. The effect of Mach number (M) on the presence of SNWs is also discussed. Analytical findings for all conceivable dark-pitch solitons, singular solitons, associated hyperbolically, trigonometrically, and rational solitons, and super nonlinear periodic wave solutions are discussed in this study. A graphical representation of the research findings is also presented. This study successfully shows 2D- graphs to offer further insight into the physical properties of the solutions described for the various ranges of M that is, for M<1 the velocity of the wave profile will be treated as subsonic, for M>1 the velocity of the wave profile will be treated as supersonic and for M=1 the velocity of the wave profile will be treated as sonic for super nonlinear waves in two-component Maxwellian plasma. We have further demonstrated the sensitivity assessments for the altered dynamical structural system’s supersonic, subsonic, and sonic wave profiles, utilizing six unique initial conditions. That whole research justifies the appearance of SNWs in such a two-component Maxwellian plasma, which used to be formerly unidentified until about the study’s start in 2011. The new analytical findings of the different categories and sensitivity analysis for the dynamical system with supersonic, subsonic, and sonic wave profiles are new things here.

Relativistic Wave Propagation in Anisotropic Two-Component Magnetohydrodynamics Plasmas

This paper investigates the instabilities and characteristics of relativistic linear waves of two-component plasma by assuming the plasma to be in-viscid, homogeneous, collision-less, and magnetized. To do this, by taking moments of the relativistic Vlasov equation, the basic equations of the two-component relativistic an-isotropic plasma are derived. The linearized equations are analyzed for small perturbation under the assumption of the plasma which is initially at rest. After we derived the dispersion relations, different wave modes and instabilities are discussed analytically and numerically presented as well.

Two-component plasma and electron trapping’s influence on the potential of a solitary electrostatic wave with the dust-ion-acoustic speed

In this paper, the ion-acoustic waves’ dynamic behavior in plasma and dusty plasma is investigated to explain the electron trapping’s effect on the potential of a solitary electrostatic wave with the dust-ion-acoustic speed in two-components plasma. This study investigates the soliton wave solutions of the Schamel–Korteweg–de Vries (S–KdV) equation that Hans Schamel derived in 1973. In a nonlinear dispersive medium, the S–KdV equation is used to describe a coherent localized wave structure propagates are demonstrated. One-dimensional, unmagnetized plasma with positive ions, negative ions, trapped electrons, and stationary dust grains with both positive and negative charges is studied for the nonlinear propagation of dust-ion-acoustic (DIA) waves. The Bernoulli sub-equation function (BSEF) method is applied to the S–KdV equation for constructing some novel soliton wave solutions that explain the effect of the plasma parameters on the DIA solitary waves. The obtained solitary wave solutions are represented through some different graphs by Mathematica 12 software. Additionally, the axisymmetric pulse propagation is demonstrated in some stream plots. All the obtained solutions are checked by putting them back into the original model.

Dissipative Ion-Acoustic Solitary Waves in Magnetized κ-Distributed Non-Maxwellian Plasmas

The propagation of dissipative electrostatic (ion-acoustic) solitary waves in a magnetized plasma with trapped electrons is considered via the Schamel formalism. The direction of propagation is assumed to be arbitrary, i.e., oblique with respect to the magnetic field, for generality. A non-Maxwellian (nonthermal) two-component plasma is considered, consisting of an inertial ion fluid, assumed to be cold for simplicity, and electrons. A (kappa) κ-type distribution is adopted for the electron population, in addition to particle trapping taken into account in phase space. A damped version of the Schamel-type equation is derived for the electrostatic potential, and its analytical solution, representing a damped solitary wave, is used to examine the nonlinear features of dissipative ion-acoustic solitary waves in the presence of trapped electrons. The influence of relevant plasma configuration parameters, namely the percentage of trapped electrons, the electron superthermality (spectral) index, and the direction of propagation on the solitary wave characteristics is investigated.

Exact Solution for Equilibrium Configurations of Two-Component Plasma Confined between Parallel Plates

It is the fifth part of the study published under the common umbrella of “The Gibbs Variational Method in Thermodynamics of Equilibrium Plasma”. In Parts 1 - 4, we formulated a novel approach to thermodynamics of one- and two-component heterogeneous systems completely or partially filled with a liquid substance in the plasma state. The approach is based on the use of Gibbs variational principles, and it enables efforts to address a variety of problems relating to the equilibrium and stability of such systems. In this fifth part, the results of Parts 1 - 4 are applied to the analysis of equilibrium configurations of a two-component charged plasma trapped between two parallel plates (the geometry often used in various applications).