Envelope solitary waves in two-negative ions with stationary dust grains

Abstract

Using a multi-fluid model, we look at how modulated electrostatic dust-ion-acoustic wave
packets move nonlinearly through a plasma made up of a three-ion fluid with Maxwellian
electrons and stationary dust grains. A nonlinear Schr¨odinger (NLS) equation describes
the electric potential envelope wave packet. The analysis reveals the existence of different
types of localized modes, namely bright, dark, and grey solitons. We numerically analyse
the coefficients of the NLS equation to identify stable or unstable regions for wave packet
propagation. It is found that higher relative density ratios increase the group velocity of the
wave packets. Stable pulses can become unstable when plasma parameters exceed certain
relative density ratio values. Stable pulses can exist within a crucial window of the relative
dust density ratio. Controlling the dust grain density ratio outside the zone can cause unstable
wave packets or bright envelope solitons to propagate.