Landau damping of dust acoustic waves in a nonthermal plasma

By employing the kinetic theory, the linear dispersion relation and Landau damping rate of dust-acoustic waves (DAWs) in a nonthermal dusty plasma are presented. The real frequency and the Landau damping rate of the mode are calculated by using the Cairns distribution function. It is demonstrated that by changing the spectral index α (index involved in the Cairns distribution), significant changes occur in the damping rate of the DAWs. In the limit α → 0, the non-Maxwellian function approaches to the classic Maxwellian distribution and hence the DAWs reduce to Maxwellian results. A detailed examination of the various relevant plasma parameters on the real frequency and damping rate of DAWs is conducted.