Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma

TL;DR

This paper develops a nonlinear theory incorporating Landau damping for dust-acoustic waves in unmagnetized dusty negative-ion plasmas, revealing that damping effects can dominate over dispersive effects in certain plasma conditions.

Contribution

It derives a KdV equation with Landau damping for dust-acoustic waves in dusty negative-ion plasmas, highlighting the significance of damping over dispersion in typical plasma environments.

Findings

Landau damping significantly affects dust-acoustic solitary waves.

Dispersive effects are less prominent than damping in certain plasma conditions.

Wave properties depend on ion-to-dust density ratio, temperature ratio, and mass ratio.

Abstract

The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg de-Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids {\bf 12}, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio $(\mu_{pd})$ as well as the ratios of positive to negative ion temperatures $(\sigma)$ and masses $(m)$.