Instability of dust-acoustic waves in partially ionized collisional dusty gases

A linear dispersion relation for an electrostatic dust-acoustic wave (DAW) has been derived, taking into account dust charging collisions and dust cha rge fluctuations in partially ionized dusty plasmas. It is found that there exist a departure from the Boltzmann ion response when the variation of ch arging collisions owing to dust charge perturbations is self-consistent inc orporated in the ion continuity equation. Consideration of variable chargin g collisions leads to an instability of the dust-acoustic waves. The presen t investigation thus offers a novel mechanism for the excitation of DAW in low-temperature, partially ionized laboratory dusty gas discharges.