A three-dimensional electronegative plasma model is studied. Modulated ion-acoustic waves are investigated via the activation of modulational instability in the Davey-Stewartson equations, with three space variables. The contributions of the modulation angle (θ) and electronegative plasma parameters are discussed to that effect, including some particular cases such as the parallel and transverse modulations. The parametric linear stability analysis that is proposed shows that the growth rate of instability displays opposite regions of instability for parallel and transverse modulations when the negative ion concentration ratio (α) and the electron-to-negative ion temperature ratio (σn) change.
Tabi, C. B., Panguetna, C. S., & Kofané, T. C. (2018). Electronegative (3+1)-dimensional modulated excitations in plasmas. Physica B: Condensed Matter, 545, 370-376. https://doi.org/10.1016/j.physb.2018.06.032