Dispersion relations for the dust-acoustic wave under experimental conditions

The dust acoustic wave dispersion relation is tested to quantify its sensitivity to many physical processes that are important in laboratory dusty plasmas. It is found that inverse Landau damping and ion-neutral collisions contribute about equally to the growth rate omega(i), pointing to the advantage of using a kinetic model for the instability. The growth rate omega(i) increases the most with an increase of dust number density, followed by an increase in ion-drift speed. The quantities that cause omega(i) to decrease the most when they are increased are the dust-neutral collision rate followed by the ion-neutral collision rate, ion collection current onto dust particles, and the ion thermal speed. In general, omega(i) is affected more than omega(r) by the choice of processes that are included. Strong Coulomb-coupling effects can be included in a compressibility term. The susceptibilities derived here can be combined in various ways in a dispersion relation to account for different combinations of physical processes. (C) 2014 AIP Publishing LLC.