Amplitude Dust-acoustic Solitary Waves Research Articles

Large amplitude dust-acoustic solitary waves and double layers in nonthermal warm complex plasmas

Using a Sagdeev pseudo-potential approach, where the nonlinear structures are stationary in a comoving frame, the arbitrary or large amplitude dust-acoustic solitary waves and double layers have been studied in dusty plasmas containing warm positively charged dust and nonthermal distributed electrons and ions. Depending on the values of the critical Mach number, which varies with the plasma parameter, both supersonic and subsonic dust-acoustic solitary waves are found. It is found that our plasma system under consideration supports both positive and negative supersonic solitary waves and only positive subsonic solitary waves and negative double layers. The parametric regimes for the existence of subsonic and supersonic dust-acoustic waves and how the polarity of solitary waves changes with plasma parameters are shown. It is observed that the solitary wave and double layer solutions exist at the values of Mach number around its critical Mach number. The basic properties (amplitude, width, speed, etc.) of the solitary pulses and double layers are significantly modified by the plasma parameters (viz., ion to positive dust number density ratio, ion to electron temperature ratio, nonthermal parameter, and positive dust temperature to ion temperature ratio). The applications of our present work in space environments (viz., cometary tails, Earth’s mesosphere, and Jupiter’s magnetosphere) and laboratory devices, where nonthermal ion and electron species along with positively charged dust species have been observed, are briefly discussed.

Small amplitude dust acoustic solitary waves in a magnetized dusty plasma with nonthermal distribution for both electrons and ions

The propagation of dust acoustic solitary waves (DASWs) has been investigated in a magnetized dusty plasma consisting of negatively charged dust particles, nonthermal ions and nonthermal electrons. Using reductive perturbation method, the Korteweg-de-Vries (K-dV) equation is derived. It is found that the basic structures (such as polarity, amplitude, width) of DASWs are influenced by nonthermal ions and nonthermal electrons. The results show that both compressive and rarefactive DASWs exist in such dusty plasma. It is observed that by increasing the nonthermality parameter of ions and electrons, the nonlinear wave phase velocity increases. Furthermore, nonthermal distributed ions have more effect on the nonlinear wave phase velocity of the DASWs than nonthermal distributed electrons. The dependence of the angle that the external magnetic field makes with the propagation direction of wave on the amplitude and width of DASWs has been also investigated. It was concluded that this angle strongly affects the DASWs. Finally, the effect of the magnetic field appears only in the width and not in the amplitude of the DASWs. The findings of this study can be helpful in understanding the structures of DASWs in the dusty plasma in which both nonthermal ions and nonthermal electrons exist. Such structures can be found in different regions of space and astrophysics mediums such as the upper ionosphere and Saturn’s E-ring.

Large Amplitude Dust Acoustic Solitary Waves with Non-Thermal Distribution for Both Electrons and Ions

Large Amplitude Dust Acoustic Solitary Waves with Non-Thermal Distribution for Both Electrons and Ions

Arbitrary amplitude dust-acoustic waves in Jupiter atmosphere

Arbitrary amplitude dust-acoustic solitary waves in a dusty plasma in Jupiter atmosphere are expected to occur for distance greater than 15RJ, where RJ is the distance from the center of the Jupiter (RJ = 71398 km). We used the generalized hydrodynamic model for positive dust grains, Maxwellian electrons and ions those interact with solar wind protons and electrons. The energy-balance-like equation containing Sagdeev potential is derived and its numerical analysis is presented. The existence region of the arbitrary amplitude dust-acoustic solitary waves is defined. It is found that subsonic (Mach number <1) and supersonic (Mach number >1) acoustic waves can exist, but the dominant pulses are supersonic modes and the pulses have positive potential. The main effects to change the soliton existence region are the dust number density and the streaming solar wind protons parameters, via solar wind proton number density, temperature, and streaming speed. Increasing the dust grains number density leads to reduce the width and enhances the amplitude. For higher temperature solar wind proton, the solitary waves dwarfed and broader, while enhancement the solar wind proton number density and streaming speed leads to transfer more energy into the plasma that makes the pulses towering.

Small amplitude dust acoustic solitary wave in magnetized two ion temperature plasma

The characteristics of obliquely propagating dust acoustic solitary wave in magnetized dusty plasma are analysed by considering the plasma to have electrons, two-temperature ions and massive dust grains with heavy charge. The reductive perturbation technique is used to derive relevant Korteweg-deVries (KdV) equation. The effect of density and temperature of hot and cold ions, angle of wave propagation, and mass, charge and temperature of the dust grains on the soliton characteristic is investigated in greater detail. The situation of electron-depleted plasma is also uncovered.

Effects of axial magnetic field and nonextensivity on small amplitude dust acoustic solitary waves in dusty plasma

The nonlinear propagation of small amplitude dust‐acoustic (DA) solitary waves in magnetized dusty plasma consisting of negatively charged mobile dust fluid, and Boltzmann‐distributed electrons and ions with two distinct temperatures following a q‐nonextensive distribution are investigated. In this article, a number of nonlinear equations, namely, the Korteweg–de‐Vries (K‐dV) equations, have been derived by employing the reductive perturbation technique that is valid for a small but finite amplitude limit. The effects of nonextensivity of ions with two distinct temperatures and dust concentration on the amplitude and width of DA solitary waves are investigated theoretically. It is observed that both the nonextensive and low‐temperatures ions significantly modify the basic properties and polarities of DA solitary waves. It is shown that both positive and negative potential DA solitons occur in this case. The implications of these results to some astrophysical environments and space plasmas (e.g., stellar polytropes, peculiar velocity distributions of galaxies, and collisionless thermal plasma), and laboratory dusty plasma systems are briefly mentioned.

The Maximum Amplitude of Dust-Acoustic Waves in Dusty Plasma with Vortex-Like Ions

Theoretical investigations are carried out for the properties of small amplitude dust-acoustic solitary waves in plasmas consisting of extremely massive, high negatively charged inertial dust grains, Boltzmann distributed electrons and trapped ions, for one-dimensional case and three-dimensional case. An energy integral equation involving the Sagdeev potential is derived. The dependence of the critical Mach number corresponding to maximum amplitude on other parameters is obtained. It is observed that the magnitude of the external magnetic field has no effect on the amplitude of the solitary waves.

Multidimensional Instability of Dust‐Acoustic Solitary Waves in a Magnetized Hot Dusty Plasma with Superthermal Electrons and Ions

AbstractMultidimensional instability of dust‐acoustic solitary wave (DASW) in magnetized dusty plasma with superthermal electrons and ions and micron size hot dust particles is investigated. The Zakharov‐Kuznetsov (ZK) equation, describing the small but finite amplitude DASW, was derived using the reductive perturbation method and its solitary answers was introduced. Effects of electrons and ions superthermality as well as the external magnetic field on the nature of DASW are discussed in detail. Dispersion relation, threshold condition, and growth rate of multidimensional instability of DASW were derived using small‐k (long wavelength plane wave) perturbation expansion method. We found that the direction and strength of external magnetic field extremely affect the growth rate and instability criterion. Results show that growth rate of instability decreases with increasing the number of superthermal electrons and increases with increasing the number of superthermal ions. (© 2015 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Effects of strong electrostatic interaction on multi-dimensional instability of dust-acoustic solitary waves in a magnetized strongly coupled dusty plasma

The effects of strong electrostatic interaction among highly charged dust on multi-dimensional instability of dust-acoustic (DA) solitary waves in a magnetized strongly coupled dusty plasma by small-k perturbation expansion method have been investigated. We found that a Zakharov-Kuznetsov equation governs the evolution of obliquely propagating small amplitude DA solitary waves in such a strongly coupled dusty plasma. The parametric regimes for which the obliquely propagating DA solitary waves become unstable are identified. The basic properties, viz., amplitude, width, instability criterion, and growth rate, of these obliquely propagating DA solitary structures are found to be significantly modified by the effects of different physical strongly coupled dusty plasma parameters. The implications of our results in some space/astrophysical plasmas and some future laboratory experiments are briefly discussed.

Dust-acoustic solitary waves and double layers with two temperature ions in a nonextensive dusty plasma

Small amplitude dust-acoustic solitary waves in an unmagnetized dusty plasma consisting of electrons and two temperature ions obeying the q-nonextensive distribution are investigated. Employing reductive perturbation method, the Korteweg-de Vries (KdV) equation is derived. From the solitonic solutions of KdV equation, the influence of nonextensivity of electrons as well as ions and dust concentration on the amplitude and width of dust-acoustic solitary waves has been studied. It is observed that both positive and negative potential dust acoustic solitary waves occur in this case. The modified KdV (mKdV) equation is derived in order to examine the solitonic solutions for the critical plasma parameters for which KdV theory fails. The parametric regimes for the existence of mKdV solitons and double layers (DLs) have also been determined. Positive potential double layers are found to occur in the present study.

Dust-acoustic solitons in quantum plasma with kappa-distributed ions

Arbitrary amplitude dust-acoustic (DA) solitary waves in an unmagnetized and collisionless quantum dusty plasma comprising cold dust particles, kappa (κ)-distributed ions and degenerate electrons are investigated. The influence of suprathermality and quantum effects on the linear dispersion relation of DA waves is investigated. Then, the effect of κ-distributed ions and degenerate electrons on the existence domain of solitons is discussed in the space of (M, f). The comparison of the existence domain for higher and lower values of κ shows that suprathermality results in propagation of solitons with lower Mach number, and the quantum effects, lead to a higher values of Mach number. The existence domain of solitons for nondegenerate κ-distributed electrons is considered for comparison with effect of degenerate electrons. Also, we found that the Sagdeev potential well becomes deeper and wider as e F − i decreases, as for lower κ values, the influence of quantum effects on the Sagdeev pseudopotential profile is smaller.

Large amplitude dust-acoustic solitary waves in electron-positron-ion plasma with dust grains

Propagation of large amplitude dust-acoustic (DA) solitary waves is investigated in electron–positron–ion plasmas in the presence of dust grains using Sagdeev potential method. It is shown that acceptable values of Mach number for propagation of the large amplitude DA solitary waves depend strongly on plasma parameters. It is also observed that the amplitude of DA solitary waves increases as both the Mach number M and dust charge Zd are increased. Furthermore, it is found that a dusty plasma with inertial dust fluid and Boltzmann distributed electrons, positrons, and ions admits only negative solitary potentials associated with nonlinear dust-acoustic waves. In addition, it is remarked that the formation of double layers is not possible in this plasma system.

Arbitrary amplitude dust acoustic solitary waves in a dusty plasma with an ion beam

Propagation regimes of an arbitrary amplitude dust acoustic solitary wave in a dusty plasma with an ion beam are analyzed by employing the Sagdeev potential technique. Two domains of the Mach numbers are defined depending on the ion beam and plasma parameters. Only a rarefactive soliton solution is found in a low velocity regime. Numerical solutions are presented that illustrate the dependence of soliton characteristics on practically interesting plasma and ion beam parameters. The findings of this investigation could be useful in understanding the nonlinear interaction of external ion beam and dusty plasma observed in laboratory plasma experiments.

Arbitrary amplitude dust acoustic solitary waves in an electron-depleted dusty plasma with two high energy-tail ion distributions

Arbitrary amplitude dust acoustic waves (DAW’s) in two high energy-tail ion distributions are investigated. The electron number density has been assumed sufficiently depleted during the charging of the dust grains, on account of the attachment of the background plasma electrons on the surface of the dust grains. Our results reveal that under certain conditions, DA solitary waves with either negative or positive potential may be admitted. The high degree of suprathermalization of the relatively low temperature ion component favors the development of compressive localized structures. This behavior is preserved to a large extent in the small but finite amplitude regime. This means that the presence of additional relatively low temperature suprathermal ions does not only significantly modify the basic properties of DA structures, but also causes the existence of positive solitary potentials. This feature is completely new in a dusty plasma with two suprathermal ion components with widely disparate temperatures. Our results may be relevant to a number of space dusty plasma systems, particularly, the Saturn’s F-ring where electron depletion and suprathermality are thought to come into play.

Arbitrary amplitude dust-acoustic solitary waves in a dusty plasma with flat-topped ion distribution

The properties of arbitrary amplitude dust-acoustic (DA) solitary waves (SWs) in a dusty plasma containing warm adiabatic dust fluid, isothermal electrons and ions following flat-topped velocity distribution is studied by the pseudo-potential approach. The effects of dust temperature and flat-trapped ions are found to significantly modify the basic features of DA-SWs as well modify the parametric regime for the existence of rarefactive solitary waves. The pseudo-potential for small amplitude limit is also analytically analyzed, and the numerical results are found to agree with analytical results.

Effects of flat-topped ion distribution and dust temperature on small amplitude dust-acoustic solitary waves and double layers in dusty plasma

The combined effects of the flat-topped ion distribution and dust temperature are incorporated in the study of small but finite amplitude dust-acoustic (DA) solitary waves (SWs) as well double layers (DLs) in an unmagnetized dusty plasma. Due to the flat-trapped ions, our plasma model admits only rarefactive localized structures. It is found that the effects of dust temperature and resonant particles significantly modify the criteria for the existence of DA SWs and DLs, as well as significantly modify their basic properties.

Solitary solution and energy for the Kadomstev–Petviashvili equation in two temperatures charged dusty grains

The nonlinear properties of small amplitude dust-acoustic solitary waves (DAWs) in a homogeneous unmagnetized plasma having electrons, singly charged ions, hot and cold dust species with Boltzmann distributions for electrons and ions have been investigated. A reductive perturbation method was employed to obtain the Kadomstev-Petviashvili (KP) equation. The effects of the presence of charged hot and cold dust grains on the nature of DAWs were discussed. Moreover, the energy of two temperatures charged dusty grains were computed. The present investigation can be of relevance to the electrostatic solitary structures observed in various space plasma environments.

Finite amplitude solitary excitations in rotating magnetized nonthermal complex (dusty) plasmas

The nonlinear dynamics of finite amplitude dust acoustic solitary waves in rotating magnetized nonthermal plasma are investigated. For this purpose, the hydrodynamic equations for the dust grains, nonthermal ion density, and Boltzmann electron distributions together with the Poisson equation are used to derive the energy integral equation with a new Sagdeev potential. It is found that the solitary excitations strongly depend on the nonthermal ion parameters, rotational frequency, as well as dust gyrofrequency. The present investigations may be applicable to the dusty plasma situation near to the moon.

Large amplitude dust acoustic solitary waves and double layers in positively charged warm dusty plasma with nonthermal electrons

Large amplitude dust acoustic solitary waves and double layers in a nonthermal plasma consisting of positively charged dust grains, nonthermal electrons, and isothermal ions including the effect of dust temperature have been studied using the Sagdeev potential technique by a computational scheme. The effect of different parameters on the nature of existence of solitary waves and double layers has been investigated to delimit their compositional parameter space. The physics corresponding to the computational result has been pointed out.

Alternative dust acoustic solitary waves in a plasma consisting of superthermal electrons and nonthermal ions having kappa-vortex-like velocity distribution function

The existence of arbitrary amplitude dust acoustic solitary waves is investigated in an unmagnetized dusty plasma comprising a negatively charged dust fluid, superthermal electrons, and nonthermal ions having a κ-vortex-like velocity distribution function. It is shown that due to electron and ion superthermality, the present dusty plasma model may support subsonic as well as supersonic electrostatic solitary waves involving cusped potential humps. The interplay between different concepts of nonisothermality is highlighted. Our results should help to understand the role that phase-space holes may play in reconnection by scattering and energizing particles and to provide an explanation of the intense solitary structures observed by the FAST mission.