Stationary Dust Particles Research Articles

Dynamical generation of macroscale magnetic fields and fast flows in a four-component astrophysical plasma

We explore the possibility of the generation or amplification of macroscale magnetic fields and flows in a four-component astrophysical dusty plasma composed of mobile massless electrons and positrons, inertial positive ions and negatively charged static dust particles. The investigation demonstrates that when microscopic turbulent ambient plasma energy is predominantly kinetic, a straight dynamo (DY) mechanism is feasible. Conversely, a unified reverse-dynamo/dynamo (RDY/DY) mechanism is possible when the microscopic turbulent ambient plasma energy is primarily magnetic. Additionally, the evolution of Alfvén Mach numbers at the macro- and microscale are significantly affected by plasma species densities and invariant helicities. The potential implications of the present study for astrophysical settings are also highlighted.

(3+1)-dimensional cylindrical dust ion-acoustic solitary waves in dusty plasma

The basic properties of (3+1)-dimensional cylindrical dust ion-acoustic (DIA) solitary waves have been studied in a multi-component plasma medium consisting of inertial ions, Maxwellian electrons, and stationary negative dust particles. The reductive perturbation method has been used to derive a cylindrical (3+1)-dimensional Kadomtsev–Petviashvili equation for small but finite amplitude of dust ion-acoustic waves. The impacts of nonplanar geometry and presence of static negative dust particles on the dust ion-acoustic solitary structures have been investigated. DIA solitary waves with both positive and negative polarity is observed to generate for this existing multi-component and complex plasma medium. The changes in the DIA wave structure in radial, azimuthal, and axial coordinates over time have been presented analytically. The results of this present investigation may contribute to a better understanding of laboratory plasma events as well as nonlinear electrostatic excitations in astrophysical environments.

Dust ion acoustic waves with Cairns–Tsallis electrons in the framework of KP-type equation

The features of dust ion acoustic waves (DIAWs) composed of cold ions, nonthermal nonextensive electrons as well as stationary dust particles are presented by KP-type equations. The effect of system parameters and higher order contributions on the phase velocity, amplitude and width of DIAWs is discussed. The parametric range for the existence of negative and positive solitons described by KP equation is presented. It is found that nonthermal and nonextensivity parameters and higher order contribution play a very crucial role in the formation of DIAWs. The results obtained would be valuable in interpreting certain nonlinear physical phenomena presented in the Earth's magnetosphere.

Nonlinear ion‐acoustic waves in magnetized plasmas in presence of energetic electrons and positively charged dust

AbstractA theoretical investigation has been carried out for exploring different features of ion‐acoustic solitary and shock waves in a three‐component magnetized plasma containing a mixture of thermal and nonthermal (energetic) inertialess electrons, warm inertial ions, and positively charged stationary dust particles. The standard Korteweg‐de Vries (Burgers) equation has been derived by employing the reductive perturbation method, and its solitary (shock) wave solution has been derived and examined analytically as well as numerically. The latter exhibits characteristic properties (amplitude, width, speed, and polarity) of the ion‐acoustic solitary and shock waves. It has been shown that the ion‐acoustic solitary and shock waves are significantly modified by different plasma parameters (viz. parameter measuring the ratio of dust charge density to ion charge density, parameter measuring the fraction of energetic electrons, parameter measuring ion or electron temperature, and the external magnetic field). The present investigation may help in understanding the physics of various nonlinear phenomena formed in many space plasma systems, (viz. earth's mesosphere, solar wind, and cometary tails) and laboratory devices (laboratory experiments of Samarian et al., Phys. rev. E. 64, 056407 [2001] and of Fortov et al., New J. Physics 5, 102 [2003]).

Bifurcation analysis for dust ion acoustic waves in magnetized four-component plasmas with superthermal electrons

In collisionless, dissipative, and magnetized dusty plasma, the propagation of nonlinear dust-ion-acoustic (DIA) solitary and shock waves has been studied, whose constituents are cold positive ions, negative ions obeying the Boltzmann distribution, superthermally distributed electrons and positively charged stationary dust particles. The Korteweg-de Vries–Burgers (KdVB) equation is derived using the reductive perturbation method. This equation is solved using the tangent hyperbolic method, yielding a shock wave solution. Also, other interesting physical solutions and the corresponding electric field are determined. By applying the bifurcation theory to the planar dynamical system of the derived KdVB equation under two conditions and , the presence of solitary wave solutions and periodic traveling wave solutions has been established. According to both numerical and analytical investigations, The basic properties of dust ion acoustic waves are significantly modified by the influence of superthermal electrons, viscosity coefficients, and the existence of an external magnetic field. The current results could help in a full understanding and studying of plasma waves in both space and astrophysical environments (such as the magnetospheres of Saturn and pulsars) and also in the laboratory.

Higher-order nonlinear and dispersive effects on dust-ion-acoustic solitary waves in magnetized dusty plasmas

We deal with the theoretical investigation of the higher-order nonlinear and dispersive effects on the basic features of dust-ion-acoustic (DIA) solitary waves in a magnetized dusty plasma. Also, we examine the impacts of the external magnetic field and adiabaticity, obliquity, etc. in changing solitary wave structures. The waves of small but finite amplitude propagate obliquely through the dusty plasma where the system comprises adiabatic positively charged ions (mobile), negatively charged trapped light ions, Maxwellian distributed electrons and stationary dust particles with arbitrary charges. The reductive perturbation method is extensively used for incorporating the higher-order terms into the modified Korteweg-de Vries (mKdV) equation, and the procedure yields an inhomogeneous mKdV-type equation. It is observed that the inclusion of higher-order nonlinear and dispersion effects increases the wave’s amplitude and width. Furthermore, in the presence of higher-order effects, the magnetic field and adiabaticity have decreasing and increasing effects respectively on the wave features. It is expected that the results will be useful to describe higher-order effects on DIA solitary waves.

Dust-ion acoustic solitons in superthermal dusty plasmas

In this research, the properties of dust- ion-acoustic (DIA) solitons in an unmagnetized dusty plasma, whose constituents are inertial ions, superthermal electrons, and stationary dust particles, are studied by using the Pseudopotential method. As an important result it is shown that DIA solitons are accepted beyond a certain critical value of the electron-to-ion density ratio (μ) as well as the superthermal parameter of electrons. We show that Mach permissible numbers shift to lower values in supethermal dusty plasmas. The results of this study help to gain a better understanding of the dust-ion wave behavior propagated in various spaces such as the Earth's atmosphere, Venus ionosphere and solar winds.

The magnetorotating and parametric effects on the dust-ion-acoustic solitary waves in a dusty plasma with trapped negative ions

The effects of the magnetic field, plasma rotation and different parameters on the nonlinear natures of dust-ion-acoustic solitary waves have been investigated theoretically. The contemplated dusty plasma system is three-dimensional and homogeneously magnetized through which solitary waves of small amplitude propagate obliquely. The plasma consists of trapped negatively charged lighter ions, stationary dust particles with arbitrary charges, Maxwellian distributed electrons and mobile positively charged heavier ions. In this article, at the outset, we have derived the nonlinear modified Zakharov-Kuznetsov (mZK) equation by the reductive perturbation method, and then the equation is examined by a suggested mathematical technique. Therefore, advanced and typical wave solutions have been computed to analyze the dust-ion-acoustic solitary waves which propagate in the magnetorotating plasma. The effects of the magnetic field, the Coriolis force, and different plasma constituents on wave characteristics have been thoroughly investigated and it is found that they have a significant role in changing the amplitude and width of the dust-ion-acoustic solitary waves. Furthermore, the electric field and the soliton energy have also been calculated. These results might be significant to illustrate astrophysical and fusion devices, cosmic phenomena, pulsar radiations, rotating plasma waves, etc.

Dust-ion-acoustic shock waves in the presence of dust charge fluctuation in non-Maxwellian plasmas with Kappa-distributed electrons

A three-component plasma composed of nonthermal Kappa-distributed electrons, mobile ions, stationary and dust-fluctuating (spherical) dust particles is considered. By employing reductive perturbation method in a weakly nonlinear limit, the Burger’s equation has been derived and the basic properties of dust ion acoustic shock waves are analyzed. It is observed that for increasing ion–electron temperature ratio, the shock’s amplitude decreases, and vice versa. Moreover, shock steepens for increasing electron–ion equilibrium density ratio. Furthermore, it is observed that the shock potential distribution is directly proportional to the spectral index κ, whereas the shock’s width is inversely proportional to the latter. Thus, the non-Maxwellian nature of the electronic velocity distribution significantly modifies the perturbed potential profile. In the limiting case κ→∞, the corresponding Maxwellian results are retrieved. Present work will be useful in understanding the nonlinear propagation of dust-ion-acoustic shock waves (DIASHW) in space plasmas where nonthermal population of electrons exist due to various physical phenomena, and in laboratory (e.g., in a double plasma (DP) device, or in tokamak where runaway electrons may result in a non-Maxwellian plasma).

Nonlinear dust ion acoustic shock wave structures in solar F corona region

Shock wave formation in dusty plasma consisting of mobile positive and negative ions, nonthermal electrons, and negatively charged static dust particles is theoretically studied in the presence of a magnetic field. Using the reductive perturbation technique, the basic set of fluid equations is reduced to the three-dimensional Zakarov–Kuznetsov Burgers nonlinear wave equation. The dissipation generated by ion kinematic viscosity in the system is taken into consideration. Distinct features of the dispersive (oscillatory) shock-like structures are discussed for different plasma parameters such as ion kinematic viscosities, ion density ratio, dust density ratio, nonthermal electrons, and magnetic field effect. It is observed that at large value of ion viscosities, nonthermal electrons, and ion density ratio, the formation of compressive shock strength increases. However, at certain critical values of nonthermal electrons, ion density ratio, the transition in the polarity of shock wave occurs within this range of plasma parameters. The considered parameters are reliable in the Solar F Corona (Dust corona) region. The findings of this work may be helpful in understanding shock formation in the Solar F Corona (Dust corona) region and astrophysical related plasma environments.

Modulational instability of bright envelope soliton and rogue waves in ultra-relativistic degenerate dense electron-ion-positron plasma

Modulational instability and bright envelope solitons of ion acoustic waves in dense plasma consisting of ultra-relativistic degenerate electrons and positrons, cold and mobile inertial ions, and negatively charged static dust particles have been investigated using Fried and Ichikawa method. Nonlinear Schrodinger equation has been derived and the growth rate of modulationally unstable ion acoustic wave in such plasma is discussed. It has been found that ion acoustic wave will be always modulationally unstable for all possible values of density of positrons, electrons and charged dust particle but there is no instability of the wave for any value of plasma parameters in such plasma. The solutions of ion acoustic envelope- solitons and rogue waves are obtained from the Nonlinear Schrodinger equation. The theoretical results have been analyzed numerically for different values of plasma parameters and the results are presented graphically. It is found that only bright envelope soliton would be excited in the ultra-relativistic plasma. Our results are new and may be applicable for the study of nonlinear wave processes in relativistic degenerate dense plasmas of astrophysical objects, namely, in white dwarfs and neutron stars.

Dust ion acoustic solitons in a complex dusty plasma system with an adiabatic state

In this theoretical work nonlinear behavior of dust ion acoustic solitary waves (SWs) has been investigated, and then the effect of the adiabatic change on them has been observed. The complex plasma system consists of inertial positive and negative ions, Maxwell's electrons, and positively and negatively charged stationary dust particles. The effects of dust polarity on the dust ion acoustic SWs have also been observed. Using the reductive perturbation method, we first derive K-dV equation which lets to analyze both the positive (bright) and negative (dark) solitons in a very limited region. After that mK-dV equation has been derived, and this let to analyze positive soliton for a large region, but cannot show the negative soliton. Finally, the Gardner equation has been derived employing the same method, through which we were able to analyze both the positive and negative solitons for a large region. It has been found that both the positive and negative solitons significantly depend on the mass number density, ion number density, and dust polarity in the adiabatic and isothermal system.

Modulation Instability of Bright Envelope Soliton and Rogue Waves in Ultra-relativistic Degenerate Dense Electron–Ion–Positron Plasma

Modulation instability, bright envelope soliton, and rogue waves of ion acoustic waves in dense plasma consisting of ultra-relativistic degenerate electrons and positrons, cold and mobile inertial ions, and negatively charged static dust particles have been investigated using Fried and Ichikawa method. Nonlinear Schrodinger equation has been derived and the growth rate of modulationally unstable ion acoustic wave in such plasma are discussed. It has been found that ion acoustic wave will be always modulationally unstable for all possible values of density of positrons, electrons, and charged dust particle. The solutions of envelope solitons and rogue waves are obtained from the nonlinear Schrodinger equation. The theoretical results have been analyzed numerically and graphically for different values of plasma parameters. It is found that only bright envelope soliton would be excited in the ultra-relativistic degenerate plasma. Our results are new and may be applicable for the study of nonlinear wave processes in relativistic degenerate dense plasmas of astrophysical objects, namely, in white dwarfs and neutron stars.

Analytical solutions of cylindrical and spherical dust ion-acoustic solitary waves

Abstract In the present work, employing the conventional reductive perturbation method to the field equations of an unmagnetized dusty plasma consisting of inertial ions, Boltzmann electrons and stationary dust particles in the nonplanar geometry we derived cylindrical(spherical) KdV and mKdV equations. Being aware of the fact that there exists no exact analytical solution for the progressive waves for such evolution equations we presented the exact analytical solution of a generalized form of such evolution equations in the planar geometry and used this solution to obtain an analytical approximate progressive wave solution to the generalized evolution equation. Then the progressive wave solutions for the cylindrical(spherical) KdV and m-KdV equations is obtained as some special cases. The analytical approximate solutions so obtained are compared with the numerical solutions of these equations. The results reveal that both solutions are in a good agreement. One advantage of present analytical approximate solution is that it allows readers to gain information, share understandings, or carry out a physical parametric study on the evolution solution behavior as well as the solution calculation has no CPU time-consuming or round off error.

Modulational instability of electrostatic waves in a magnetized dusty plasma with kappa distributed electrons

The modulational instability of dust-ion acoustic wave (DIAW) and dust-ion cyclotron wave (DICW) is investigated in a magnetized plasma containing static dust particles. The static dust particles can be positively or negatively charged, while ions are taken to be dynamic and inertialess electrons follow the kappa distribution in a magnetized dusty plasma. The nonlinear Schrödinger equation is derived to study the amplitude modulation of obliquely propagating electrostatic waves in a magnetized dusty plasma using the Krylov-Bogoliubov-Mitropolsky method. The dispersive and nonlinear coefficients, i.e., P and Q of nonlinear Schrödinger equation, are obtained which depend on the dust charge concentration, the magnetic field intensity, dust charge polarity, angle of wave propagation, and spectral index kappa for the nonthermal electrons. The modulationally stable and unstable regions of DIAW and DICW are investigated numerically, and the illustration of contour plots of product PQ with wave propagation angle θ and critical wave number kc is also presented. It is found that DIAW and DICW become modulationally unstable at low values of wave number k for negatively charged dust particles in comparison with positively charged dust particles or without dust particles case in a magnetized plasma. The stable region for DIAW, whose wave frequency now depends also on wave propagation angle in a magnetized plasma, is found to be increased in comparison with the unmagnetized plasma case. The observations and existence of positively and negatively charged dust particles in different regions of space plasmas and in laboratory experiments are also pointed out.

Dust Charge Polarity Effect on Dust-Ion Acoustic Modulational Instability in a Nonthermal Dusty Plasma With Adiabatic Ions

The effects of dust charge polarity, ion temperature, and nonthermal electrons on dust-ion acoustic modulational instability and on the region (i.e., modulated wave number) for the formation of bright and dark envelope soliton structures are investigated. The dust particles are considered to be stationary and have positive and negative charges, while ions are taken dynamic and warm, and hot nonthermal electrons are assumed to be inertialess and kappa distributed in a dusty plasma. The Krylov–Bogoliubov–Mitropolsky method is used to derive the nonlinear Schrodinger equation (NLSE) for nonlinear amplitude modulation of dust-ion acoustic wave (DIAW) in plasmas. The dispersive and nonlinear coefficients of NLSE are obtained for DIAW, which depends on ion temperature, spectral indices of the nonthermal distributed electrons, dust density, and charge polarity of stationary dust particles. The modulationally stable and unstable regions of DIAW and its growth rate are investigated numerically. It is found that finite ion temperature, dust density, dust charge polarity, and spectral index of kappa for nonthermal electrons play a significant role to unstable the modulated DIAW modulated wave. The existence of positively and negatively charged dust particles and their observation in different regions of space plasma and in laboratory experiments is also pointed out.

Effect of hall currents on thermal instability of dusty couple stress fluid

Abstract In this paper, effect of Hall currents on the thermal instability of couple-stress fluid permeated with dust particles has been considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For the case of stationary convection, dust particles and Hall currents are found to have destabilizing effect while couple stresses have stabilizing effect on the system. Magnetic field induced by Hall currents has stabilizing/destabilizing effect under certain conditions. It is found that due to the presence of Hall currents (hence magnetic field), oscillatory modes are produced which were non-existent in their absence.

Variational principle, conservation laws and exact solutions for dust ion acoustic shock waves modeling modified Burger equation

The nonlinear dust ion acoustic (DIA) shock waves have been investigated in one-dimensional, collisionless and unmagnetized dusty plasma consisting of mobile ion, vortex-like electron and charge fluctuating static dust particles. The basic set of fluid equations is reduced to the modified Burger equation by using the reductive perturbation method. The effects of dust grain charge fluctuation and vortex-like (trapped) electron are found to modify the properties of the DIA shock waves significantly. By the semi-inverse method, a variational principle, and conservation laws for the modified Burger equation are obtained. It is shown that the modified Burger equation is non-integrable using Painlevé analysis. A set of new exact solutions are obtained by the auto-Bäcklund transformations. Finally, we will study the physical meanings of solutions.

Time evolution of nonplanar dust ion-acoustic solitary waves in a charge varying dusty plasma with superthermal electrons

A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equation is derived. It is shown that the propagation characteristics of the cylindrical and spherical DIA solitary waves significantly differ from those of their one-dimensional counterpart.

Dust-ion acoustic waves modulation in dusty plasmas with nonextensive electrons

The nonlinear amplitude modulation of dust-ion acoustic wave (DIAW) is studied in the presence of nonextensive distributed electrons in dusty plasmas with stationary dust particles. Using the reductive perturbation method (RPM), the nonlinear Schrodinger equation (NLSE) which governs the modulational instability (MI) of the DIAWs is obtained. Modulational instability regions and the growth rate of nonlinear waves are discussed. It is shown that the wave characters are affected by the value of nonextensive parameter and also relative density of plasma constituents.