Mode-coupling instability in a single-layer complex plasma crystal: Strong damping regime

Abstract

Mode-coupling instability (MCI) in a single-layer complex plasma crystal was studied experimentally in the regime of strong neutral gas damping. To trigger MCI, the discharge power was reduced at constant gas pressure. Surprisingly, at the onset of MCI the mean interparticle spacing became larger and the normalized neutral gas damping rate marginally increased. A steady-state regime where MCI occurred but was suppressed by the neutral gas friction was observed. Suppressed MCI caused heating up of the plasma crystal but did not lead to its melting. A theoretical model is proposed which describes well our experimental observations.