Solitary Waves In Dusty Plasma Research Articles

Contribution of higher order dispersion to nonlinear dust-acoustic solitary waves in dusty plasma with different sized dust grains and nonthermal ions

The propagation of nonlinear dust-acoustic waves (DAWs) in an unmagnetized, collisionless dusty plasma consisting of dust grains obeying the power-law dust size distribution and nonthermal ions are investigated. For nonlinear DAWs, a reductive perturbation method was employed to obtain a Korteweg–de Vries (KdV) equation for the first-order potential. As the wave amplitude increases, the width and the velocity of the soliton deviate from the prediction of the KdV equation, i.e. the breakdown of the KdV approximation occurs. To overcome this weakness, we extended our analysis to obtain the KdV equation with the fifth-order dispersion term. After that, the higher order solution for the resulting equation has been achieved via what is called the perturbation technique. The effects of dust size distribution, dust radius and nonthermal distribution of ions on the higher order soliton amplitude, width and energy of electrostatic solitary structures are presented.

Solitons of the Kadomstev-Petviashvili (KP) and the modified KP (mKP) equations for dust acoustic solitary waves in dusty plasmas with variable dust charge and nonthermal ions

By using the reductive perturbation theory, the Kadomstev-Petviashvili (KP) equation in unmagnetized dusty plasmas with variable dust charge, electrons with Boltzmann distribution and nonthermal ions, is derived and the propagation of nonlinear waves is analyzed. It is found that compressive and rarefactive solitons can be appeared. Amplitude of solitonic solutions of KPequation becomes diverges at the critical densities.

Salient features of solitary waves in dusty plasma under the influence of Coriolis force

The main interest is to study the nonlinear acoustic wave in rotating dusty plasma augmented through the derivation of a modified Sagdeev potential equation. Small rotation causes the interaction of Coriolis force in the dynamical system, and leads to the complexity in the derivation of the nonlinear wave equation. As a result, the finding of solitary wave propagation in dusty plasma ought to be of merit. However, the nonlinear wave equation has been successfully solved by the use of the hyperbolic method. Main emphasis has been given to the changes on the evolution and propagation of soliton, and the variation caused by the dusty plasma constituents as well as by the Coriolis force have been highlighted. Some interesting nonlinear wave behavior has been found which can be elaborately studied for the interest of laboratory and space plasmas. Further, to support the theoretical investigations, numeric plasma parameters have been taken for finding the inherent features of solitons.

Effects of obliqueness and external magnetic field on the large amplitude solitary waves in a dusty plasma

The nonlinear excitation of large amplitude dust-acoustic (DA) solitary waves in a magnetized hot dusty plasma consisting of fast ions and charged dust grains is revisited to take into account the effects of embedding external magnetic field. The DA solitary wave is assumed to propagate obliquely to the magnetic field. Sagdeev's approach, which is valid for arbitrary amplitude solitary waves, is used. Both compressive and rarefactive solitary structures are shown to coexist by the effects of obliqueness and nonthermal or fast ions. It is found that as the percentage of fast particles ( β ) increases, the critical Mach number ( M c ) increases and the increase is more effective at the higher value of the direction cosine ( L z ). The solitary wave solutions for small amplitude DA waves exhibit distinct behaviors for different values of dust fluid temperature, β and L z .

The dust acoustic solitary waves in dusty plasmas: Effects of ultraviolet irradiation

The effects of ultraviolet irradiation on small but finite amplitude dust-acoustic solitons, are studied by the reductive perturbation method. The self-consistent dust charge variation is taken into account. It is shown that the ultraviolet irradiation can significantly lower the magnitude of the dust negative charge, and even make the dust grains charged positively. With the growth of the dust charge, the phase velocity and the width of the solitary wave increase, whereas its amplitude decreases. The related physical mechanism is discussed.

Effect of ionization on ion acoustic solitary waves in a collisional dusty plasma

The nonlinear wave propagation characteristics of ion acoustic (IA) solitary waves in a dusty plasma, i.e. dust ion acoustic (DIA) solitary waves in the presence of ionization, collisions of ions with dust grains and with the background neutral gas, have been investigated by employing a reductive perturbation technique. It has been found that the nonlinear DIA wave is governed by Korteweg–de Vries (KdV) equation with a positive or negative linear damping term. It has also been found that the ionization instability leads to the exponential growth of the DIA solitary wave amplitude with time, whereas ion–dust and ion–neutral collisions reduce the growth rate.

Sagdeev’s approach to study the effect of the kinematic viscosity on the dust ion-acoustic solitary waves in dusty plasma

Sagdeev’s technique is used to study the dust ion-acoustic solitary waves (DIASWs) in a dusty plasma comprising ions, electrons, and charged dust grains taking into account the ion kinematic viscosity. Exact analytical results for the solitary wave solutions were obtained for small amplitude DIASW. The effects of the ion kinematic viscosity and the ion temperature on the feature of DIASW have been investigated.

Ion acoustic solitary waves in a dusty plasma obliquely propagating to an external magnetic field

The nonlinear ion acoustic solitary wave in a magnetized dusty plasma, obliquely propagating to the embedding external magnetic field, is revisited. It is found that when the charge density of dust particles is high, the Sagdeev potential needs to be expanded up to δn4 near n=1. In this case, it is shown that there could exist rarefactive ion acoustic solitary waves as well as the kink-type double layer solutions, in addition to the conventional hump-type ones found in the δn3 expansion. The amplitude variations of ion acoustic solitary waves in a magnetized dusty plasma are also examined with respect to the change of the dust charge density and the wave directional angle.

Dust-acoustic solitary waves in a finite temperature dusty plasma with variable dust charge and two temperature ions

In this paper, the characteristics of dust-acoustic solitary waves in dusty plasma are studied. Dust charge and temperature are treated as variables. The authors have used the pseudopotential method to investigate the possibility of compressive as well as rarefactive solitons. An expression for the pseudopotential has been derived. The pseudopotential is a function of the Mach number, the relative temperature of low and high ion components, the relative ion concentration of dust charge and the temperature. Numerical computation shows that for the chosen set of parameters, only compressive solitons exist and their amplitudes increase with increasing Mach number. An increase in the dust temperature results in the disappearance of the compressive soliton. It is the only small parameter regime where compressive as well rarefactive solitons coexist. The effect of the relative ion temperature on solitons is also investigated. In the small amplitude limit, an increase in the dust temperature leads to a transition from compressive to rarefactive solitons.

Observation of ion-acoustic solitary waves in a dusty plasma

An experiment on ion-acoustic solitary waves in dusty plasma is performed in a dusty double-plasma device. The leading part of a sinusoidal pulse develops to an oscillation. The troughs of the oscillation become shallow when dust particles are mixed into the plasma. The Mach velocity of the first peak in the oscillation decreases due to the presence of negatively charged dust grains for a fixed height of the peak. The width of the peak normalized with Debye length increases when the dust particles are introduced into the plasma. The experimental results are compared with the numerical integrations of a modified Korteweg–de Vries–Burgers equation which contains the terms of kinematic viscosity and of collisions of ions with the dust particles.

Bäcklund transformations, a simple transformation and exact solutions for dust-acoustic solitary waves in dusty plasma consisting of cold dust particles and two-temperature isothermal ions

Dusty plasma with inertial dust fluid and two-temperature ions admits both compressive and rarefactive solitary waves. The Korteweg-de Vries equations (KdV-type equations) with cubic nonlinearity at the critical density of low-temperature isothermal ions are considered to discuss properties of dust-acoustic solitary waves. In the vicinity of the critical density of low-temperature ions, a KdV-type equation with mixed nonlinearity is discussed. The method of characteristics is used and the Bäcklund transformations (BTs) are employed to generate new solutions from the old ones. Another new solution of the KdV–mKdV equation is obtained using a simple transformation between the sine-Gordon equation and a linear equation combined with an extension of the tanh method of Malfliet.

Response to “Comment on ‘A new mathematical approach for finding the solitary waves in dusty plasma’ ” [Phys. Plasmas 6, 4392 (1999)

Response to “Comment on ‘A new mathematical approach for finding the solitary waves in dusty plasma’ ” [Phys. Plasmas <b>6</b>, 4392 (1999)

A new mathematical approach for finding the solitary waves in dusty plasma

In a sequel to a recent work [Das, Sarma, and Talukdar, Phys. Plasmas 5, 63 (1998)], the different nonlinear plasma-acoustic waves, based on the fluid approximation, have been derived showing the coexistences of dust-acoustic waves in plasmas contaminated by dust-charged grains. The features of the nonlinear waves, depending on the plasma composition, describe various natures of solitary waves. A new formalism, known as the tanh method and stemming from the modified simple wave solution technique, has been developed for finding the soliton propagation in the nonlinear plasma wave dynamics. The method is straightforward, with minimal mathematical manipulation, finding the heuristic formation and propagation of ion-acoustic solitary waves in the dusty plasma. The main aim is, based on the tanh method, to revisit the results in a simpler case and extending them to explain the behavior of higher-order nonlinear waves derived in generalized multicomponent plasmas. The theoretical observations highlight the salient features of nonlinear waves coexisting with the dust-acoustic wave. The new findings might expect the effect, because of the dust-charged grains, to be the common feature of nonlinear waves in the dusty plasmas, and could be of interest for future experiments in laboratory as well as in space plasmas.

Large-amplitude solitary waves in finite temperature dusty plasma

Large-amplitude solitary waves in dusty plasma are investigated, taking into account the dusty particle temperature. It is shown that finite dusty temperature restricts the region for the existence of solitary waves.