Current-driven dust-acoustic instability in a collisional plasma

The excitation of the dust-acoustic instability in a collisional dusty plasma is investigated. For conditions similar to those of recent laboratory experiments with neutral gas pressures of ∼ 100mTorr, it is found that zero-order electric fields E0 ≳ 10 Vm−1 are sufficient for the growth of perturbations with centimeter wavelengths. Much larger wavelengths generally require larger values of E0. Free electrons in the dusty plasma have a stabilizing effect, which can be very pronounced at the longest wavelengths.