Dust ion-acoustic solitary waves in a dusty plasma with arbitrarily charged dust and flat-trapped electrons

The properties of arbitrary amplitude dust ion-acoustic (DIA) solitary waves (SWs) in a dusty plasma containing warm adiabatic ions, electrons following flat-topped velocity distribution, and arbitrarily (positively or negatively) charged immobile dust is studied by the pseudo-potential approach. The effects of ion temperature, resonant electrons, and dust number density are found to significantly modify the basic features of the DIA-SWs as well modify the parametric regime for the existence of compressive DIA-SWs. The pseudo-potential for small but finite amplitude limit is also analytically analyzed.     

Modulational instability of ion-acoustic waves in a plasma with two-temperature kappa-distributed electrons

Existence and characteristics of ion-acoustic (IA) wave modulation are studied in a plasma with two-temperature electron satisfying kappa distribution. Based on the multiple time scales perturbation, a nonlinear Schrödinger equation (NLS) is derived. Similar to the case of double Maxwellian electrons, both polarities of envelope soliton can exist over restricted ranges of the fractional hot electron density ratio and two-temperature superthermal electrons. The transition from stable dark solitons to unstable bright ones shifts to the smaller wavelength regions in the presence of cool and hot superthermal electrons. It is shown that the small values of the hot electron populations leads to shrinking the modulation instability region. It is also found the instability growth rate reduces due to the presence of hot electrons. The result of present investigation contributes to the physics of wave modulation in Saturn’s magnetosphere where two-temperature electrons with kappa distribution exist.     

Obliquely propagating ion-acoustic waves in a magnetized electron-positron-ion plasma with trapped electrons

A theoretical investigation is carried out for understanding the basic features of oblique propagation of linear and nonlinear ion-acoustic waves subjected to an external magnetic field in an electron-positron-ion plasma which consists of a cold magnetized ion fluid, Boltzmann distributed positron, and electrons obeying a trapped distribution. In the linear regime, two dispersion curves are obtained. It is shown that the positron concentration causes the both modes to propagate with smaller phase velocities. Then, owing to the presence of resonant electrons, the modified Korteweg-de Vries equation describing the nonlinear dynamics of small but finite amplitude ion-acoustic waves is derived. It is found that the effects of external magnetic field (obliqueness), trapped electrons, positron concentration and temperature ratio significantly modify the basic features of solitary waves.     

Nonplanar dust ion-acoustic solitary and shock excitations in electronegative plasmas with trapped electrons

It is shown that the three-dimensional cylindrical Kadomtsev-Petviashvili (CKP) and the extended cylindrical Kadomtsev-Petviashvili (ECKP) equations can describe the propagation of nonplanar dust ion-acoustic excitations in a dusty plasma composed of positive ions, negative ions, stationary dust particles, as well as trapped electrons or a small percentage of trapped electrons. It is found that the solution of the CKP equation supports only solitary pulses, while the ECKP equation describes the propagation of both solitary and shock excitations. The effects of physical parameters, namely negative ions density, dust grains density, positive-to-negative mass ratio, direction cosine of the wave propagation on the pulses profile are examined. Furthermore, the existence regions of either localized or shock pulses are investigated. The relevance of nonlinear structures in the Earth’s ionosphere and plasma experiment is discussed.     

Dust-acoustic solitary waves in a magnetized dusty plasmas with nonthermal ions and two-temperature nonextensive electrons

A rigorous theoretical investigation has been made on the obliquely propagating dust-acoustic (DA) waves in a magnetized dusty plasmas consisting of distinct temperature q-distributed electrons with distinct strength of nonextensivities, nonthermal ions and negatively charged mobile dust grains, and analyzed by deriving the Zakharov-Kuznetsov equation. It is found that the characteristics and the properties of the DA solitary waves (DASWs) are significantly modified by the external magnetic field, relative temperature ratio of ions, relative number densities of electrons as well as ions, the nonextensivity of electrons, nonthermality of ions and the obliqueness of the system. The possible implications of the results obtained from this analysis in space and laboratory dusty plasmas are briefly addressed.     

Electron-acoustic solitary waves in a relativistically degenerate quantum plasma with two-temperature electrons

Using the Quantum hydrodynamic (QHD) model Korteweg-de Vries (KdV) type solitary excitations of electron-acoustic waves (EAWs) have been examined in a two-electron-populated relativistically degenerate super dense plasma. It is shown that relativistic degeneracy parameter significantly influences the conditions of formation and properties of solitary structures.     

Nonlinear propagation of dust ion-acoustic waves in dusty multi-ion dense plasma

We have studied the nonlinear propagation of dust ion-acoustic (DIA) waves in a dusty multi-ion dense plasma (with the constituents being degenerate, either non-relativistic or ultra-relativistic) and the propagation of such waves have been investigated by the reductive perturbation method. From the stationary solution of the Korteweg de-Vries (K-dV) equation and Burgers’ equation the nonlinear waves (specially, solitary and shock waves) have been found to be formed in the dusty plasma system under consideration. It has shown that the basic features of these waves are significantly modified by both the positive and negative ions and dust number densities, the degenerate of the constituents. The implications of our results have been briefly discussed.     

Large-amplitude dust-ion acoustic solitary waves in a dusty plasma with nonthermal electrons

Propagation regimes of large-amplitude dust-ion acoustic solitary wave in a dusty plasma with nonthermal electrons are analyzed by employing the Sagdeev potential technique. Two domains of the Mach numbers are defined depending on the nonthermal and plasma parameters. The two types of soliton solution are found to be exited corresponding to certain values of the nonthermal parameter. Numerical solutions are presented that illustrate the dependence of soliton characteristics on practically interesting plasma and nonthermal parameters. The findings of this investigation could be useful in understanding the detected solitary waves in space plasma in the presence of nonthermal electrons such as electrostatic solitary structures observed in Saturn’s E-ring.     

Effects of two-temperature electrons, external oblique magnetic field, and higher-order nonlinearity on dust acoustic solitary waves in a dusty plasma with vortex-like ion distribution

Nonlinear properties of the dust acoustic (DA) solitary waves in a dusty plasma consisting of negatively variable-charged dust particles, vortex-like distributed ions and two-temperature isothermal electrons are reported. A reductive perturbation theory has been used to derive a modified Korteweg-de Vries (mKdV) equation for the first-order perturbed potential and a linear inhomogeneous mKdV-type equation for the second-order perturbed potential. The renormalization method is used to obtain stationary solutions of these coupled equations. The modifications in the amplitude and width of the solitary wave structure due to the inclusion of two different types of isothermal electrons, external oblique magnetic field, higher-order nonlinearity, and vortex-like distributed ions are investigated. Also a method based on energy consideration was used to obtain the stability condition. Moreover, the numerical results are applied to investigate some nonlinear characteristics of the DA solitary waves.     

Influence of arbitrarily charged dust and trapped electrons on propagation of localized dust ion-acoustic waves

A theoretical investigation is developed to study the existence, formation and basic properties of arbitrary amplitude dust ion-acoustic solitary potentials in a dusty plasma consisting of warm ions, trapped electrons and immobile negative (positive) dust particles. It is found a definite interval for the Mach number for which solitary waves exist and depend sensitively on the ion temperature and negative (positive) dust concentration. In addition, the effects of ion temperature, two oppositely charged dust species and resonant electrons on the shape of the solitary waves are also investigated extensively. For both cases of negative and positive dust grains, the effect of ion temperature is found to be destructive for the formation of localized structures. Further, the amplitude of the solitary structures decreases (increases) with the increase in the negative (positive) dust concentration.     

Large amplitude dust ion-acoustic solitary waves in a plasma in the presence of positrons

Properties of propagation of large amplitude dust ion-acoustic solitary waves and double layers are investigated in electron-positron-ion plasma with highly charged negative dust. Sagdeev pseudopotential method has been used to derive the energy balance equation. The expression for the critical Mach number (lower/upper limit) for the existence of solitary structures has also been derived. The Sagdeev pseudopotential is a function of numbers of physical parameters such as ion temperature (σ), positron density (δ _p ), dust density (δ _d ) and electron to positron temperature ratio (β). These parameters significantly influence the properties of the solitary structures and double layers. Further it is found that both polarity (compressive and rarefactive) solitons and negative potential double layers are observed.     

Effects of two-temperature electrons, external oblique magnetic field, concentration of charged dust grains and higher-order nonlinearity on dust ion-acoustic solitary waves in Saturn's E-ring

The purpose of the present work is to investigate some nonlinear properties of the dust ion-acoustic (DIA) solitary waves in a four-component hot-magnetized dusty plasma consisting of charged dust grains, positively charged ions and two-temperature isothermal electrons. Applying a reductive perturbation theory, a nonlinear Korteweg-de Vries (KdV) equation for the first-order perturbed potential and a linear inhomogeneous KdV-type equation for the second-order perturbed potentials are derived. Stationary solutions of these coupled equations are obtained using a renormalization method. A method based on energy consideration is used to obtain a condition for stable solitons. The effects of two different types of isothermal electrons, external oblique magnetic field, concentration of negatively (positively) charged dust grains and higher-order nonlinearity on the nature of the DIA solitary waves are discussed. The numerical results are applied to Saturn's E-ring.     

Evolution of ion-acoustic solitary waves in magnetized plasma contaminated with varying dust charged grains

Propagation of plasma-acoustic wave has been studied in magnetized plasma contaminated with dust charged grains. It has shown that, because of the configuration of magnetized plasma contaminated with dust charge fluctuation, pseudopotential method fails to derive nonlinear wave equation. We thus exercise an alternate approach to yield wave equation in the form of Sagdeev-like potential equation which enables the success to study the nonlinear waves. Again a modified mathematical formalism known as tanh-method has the merit to evaluate the soliton features in relation to its expectation in space. The method has its success in finding the solitary waves along with other exciting formation of shock-like wave, soliton radiation in soliton propagation. The results have more realistic interpretation in showing explicitly the interaction of magnetic field and impurity caused by dust charge variation.     

Dust ion-acoustic shock waves in nonextensive dusty plasma

A parametric survey on the propagation characteristics of the dust ion-acoustic (DIA) shock waves showing the effect of nonextesivity with nonextensive electrons in a dissipative dusty plasma system has been carried out using the reductive perturbation technique. We have considered continuity and momentum equations for inertial ions, q-distributed nonextensive electrons, and stationary charged dust grains, to derive the Burgers equation. It has been found that the basic features of DIA shock waves are significantly modified by the effects of electron nonextensivity and ion kinematic viscosity. Depending on the degree of nonextensivity of electrons, the dust ion-acoustic shock structures exhibit compression and rarefaction. The implications of our results would be useful to understand some astrophysical and cosmological scenarios like stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, dark-matter halos, etc., where effects of nonextensivity can play the significant roles.     

Propagation of ion-acoustic waves in a warm dusty plasma with electron inertia

The KdV equation is derived for weakly nonlinear ion-acoustic waves in an unmagnetized warm dusty plasma with electron inertia. It has been shown that the inclusion of electron inertia and pressure variation of the species not only significantly modifies the basic features (width and amplitude) of dust ion-acoustic solitions, but also introduces a new parametric regime for the existence of positive and negative solitons.     

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized dusty electronegative plasma with trapped negative ions

A theoretical investigation has been made on obliquely propagating dust-ion-acoustic solitary waves (DIASWs) in magnetized dusty electronegative plasma containing Boltzmann electrons, trapped negative ions, cold mobile positive ions, and arbitrarily charged stationary dust. The reductive perturbation method has been employed to derive the modified Zakharov-Kuznetsov (MZK) equation which admits solitary wave solution under certain conditions. The multi-dimensional instability of these solitary waves is also studied by the small-k (long wavelength plane wave) perturbation-expansion technique. The basic properties (speed, amplitude, width, instability, etc.) of small but finite amplitude DIASWs are significantly modified by the effects of external magnetic field, obliqueness, polarity of dust, and trapped negative ions. The implications of our results in space and laboratory plasmas are briefly discussed.     

Effect of dust polarity on dust ion-acoustic localized structures in a superthermal dusty plasma

The effects of dust polarity and superthermal electrons are incorporated in the study of dust ion-acoustic (DIA) solitary waves (SWs) as well double layers (DLs) in a dusty plasma containing warm adiabatic ions, superthermal electrons, and arbitrarily (positively or negatively) charged immobile dust. Based on the energy-like integral equation, a new relationship between the localized electrostatic disturbances and dust polarity is derived. It is shown that there exists rarefactive SWs and DLs with qualitatively different structures in a way that depends on the population of superthermal electrons. As the electrons evolve their thermodynamic equilibrium, the localized structures are found with larger amplitude. It is also found that their amplitude increases (decreases) with the increase in the negative (positive) dust number density.     

Superthermal effect of electrons on nonplanar dust-ion-acoustic solitary waves and double layers in a dusty plasma

The basic features of planar and nonplanar time-dependent dust-ion-acoustic (DIA) solitary waves (SWs) and double layers (DLs) have been studied in an unmagnetized dusty plasma system consisting of positively and negatively charged dust, Boltzmann distributed ions and superthermal electrons (represented by kappa distribution). Using the reductive perturbation technique (RPT) we have derived modified Gardner (MG) equation, which gives information beyond the Korteweg-de Vries (KdV) limits (corresponding to the vanishing of nonlinear coefficient of the KdV equation). It is seen that the properties of nonplanar DIA SWs and DLs are significantly differs as the value of spectral index kappa (κ) changes. The present investigation may have relevance in the study of propagation of DIA waves in space and laboratory plasmas.     

Solitary waves in a dusty plasma with negatively (positively) charged dust grains and non-thermal electrons

For an unmagnetized multicomponent dusty plasma, the effects of non-thermal electron distribution, ion temperature and two oppositely charged dust grains are incorporated in the study of arbitrary amplitude solitary waves. An energy-like integral equation involving Sagdeev potential is derived, and the existence, formation and basic properties of solitons are studied. It is also found a definite interval for the Mach number for which solitary waves exist and depends sensitively upon the population of fast or non-thermal electrons present. Our results should be useful to understand the properties of localized electrostatic disturbances that may occur in space dusty plasma.