Dust Acoustic Waves With Arbitrary Dust Polarity and Regularized Kappa Distributed Electrons

Abstract

Despite the extensive work on dusty plasma that has been carried out, the interplay between the polarization force and non-Maxwellian distributions is still an interesting topic. The behavior of dust acoustic waves (DAWs) in the proposed plasma model, whose constituents are Maxwellian ions, regularized kappa electrons, and dust grains that may carry either positive or negative charge, is studied. A general expression for the polarization force is derived. Using the reductive perturbation technique (RPT), a Korteweg de Vries (KdV) equation is derived. The effects of both the polarization force and the regularized kappa distributed electrons on the DAW characteristics are numerically examined. It is found that by increasing the superthermal index, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa $</tex-math> </inline-formula>, or the cutoff parameter, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $</tex-math> </inline-formula>, whatever the dust polarity, the amplitude of the produced soliton is reduced. However, for negatively charged dust grains, the amplitude is enhanced with a larger polarization parameter, R, and vice versa for the case of positive dust. Our study gives insight into understanding the characteristics of the nonlinear dust wave structures within dusty plasma, particularly those present in the Earth’s polar mesosphere.