Dust acoustic double layers in a magnetized dusty self-gravitating plasma with superthermal particles

Abstract

Our prime objective of this paper is to examine the parametric regimes for the existence and polarity of dust acoustic double layers (DADLs) and its solitary structures arising from a magnetized self-gravitating opposite polarity dust-plasma (OPDP) model. The constituents of the OPDP model are two species of positively and negatively charged dust grains, Maxwellian electrons and kappa distributed ions. Contributions of gravitational force only on dust grains are taken into account. For weakly nonlinear analysis, the multiple time scale technique has been used to construct the extended Korteweg-de Vries (E-KdV) and modified Korteweg-de Vries (M-KdV) equations. They pinpoint the evolution of DADLs and solitary structures associated with dust acoustic (DA) mode, respectively. The relevant configurational parameters in our study include the superthermality of ions (κ), obliqueness of propagation (θ), ion concentration (δi), static magnetic field B0 (via ωcp,ωcn), and self-gravitational field (via γ), as well as the density (μ0), charge (α), and mass (β) ratio of positive to negative dust species. The proposed OPDP model permits positive and negative double layer polarities, while higher order nonlinear equation dictates us only positive polarity solitary structures. The main modification due to an increase in self-gravitational field (via γ) is an enhancement in the spatial width of double layers, yet leaving their amplitude, phase speed, and polarity practically unaffected. With enhanced superthermality and other intrinsic parameters in OPDP model, there is an opposite trend in both amplitude and width of double layers, while the amplitude and the width of solitary waves (via M-KdV equation) undergo the identical behaviors. In particular, the amplitude of solitary waves manifests monotonic behavior for permissible range of obliqueness θ, whereas this scenario is acceptable to only width of double layers. The results are discussed in the context of laboratory and astrophysical plasma environments (e.g., cometary tails, Earth's mesosphere, etc.).

Dust-acoustic solitary and periodic waves in magnetized self-gravito-electrostatic opposite polarity dusty plasmas

“…These results coincide with those obtained in Refs. [24,30] where α and β have the same effect on the shock wave phase speed, and in the same manner larger β changes the nonlinear term to be negative as is obtained in Fig. 2.…”

“…This Jeans instability was affected by the magnetic field and dust temperature. Later on, Sabetkar and Dorranian [30] found that the increase in the width of the DA double layers resulted due to the considered self-gravitational field enhancement. Sumi et al [32] found also that the amplitude of DA waves was modified by the presence of opposite polarity charged dust and their self-gravitational force.…”

“…The self-gravitational effects have been taken in many OPDP systems [24,[27][28][29][30][31][32][33], such as dust-acoustic (DA) solitary and shock waves investigations [24,27]. The polarization force effect on the small amplitude of gravito-electrostatic excitations was investigated [28].…”

Dust-acoustic wave electrostatic and self-gravitational potentials in an opposite polarity dusty plasma system

“…The works of Mamun and Schlickeiser [40,41] have been further extended to different realistic situations of space and laboratory OPDP systems by a number authors, viz. Sabetkara and Dorranian [42], El-Taibany et al [43], Sumi et al [44], etc. Sabetkara and Dorranian [42] considered the self-gravitating OPDP system containing OPDS, kappa distributed ion species, and Boltzmann electron species to study the DA solitary waves and double layers.…”

“…Sabetkara and Dorranian [42], El-Taibany et al [43], Sumi et al [44], etc. Sabetkara and Dorranian [42] considered the self-gravitating OPDP system containing OPDS, kappa distributed ion species, and Boltzmann electron species to study the DA solitary waves and double layers. El-Taibany et al [43] assumed the self-gravitating OPDP system (containing inertial cold OPDS and q-distributed ion as well as electron species) in presence of external magnetic field and polar-ization force acting on OPDS to study the DA periodic and solitary waves.…”