Effects of dust correlations on the marginal stability of ion stream driven dust acoustic waves

The effect of dust–dust correlations on the marginal stability of dust acoustic waves excited by ion drift is studied. The ion drift is driven by the electric field $E_0$ which is generally present in the discharge. Correlation effects on marginal stability are studied using augmented Debye–Hückel approximation. The marginal stability boundary is calculated in $E_0-P_0$ (P ₀ is the pressure of the neutral gas) space with correlated dust grains. We show that due to dust-dust correlation the stability boundary moves into the unstable region thereby stabilizing the DAW. The effects are significant for smaller values of $\kappa$ ($=a/{\lambda }_d)$ below unity ($a$ is the mean particle distance and ${\lambda }_d$ is Debye length). (paper)