An analysis of acoustic oscillations in dust plasma structures

Low-frequency oscillations in the density of dust particles, which are spon taneously excited in the standing plasma column of a dc glow discharge in n eon, were experimentally studied. The longitudinal waves were monitored by a special visualization technique, and the dust sound oscillation character istics were determined and analyzed using specially developed algorithm and data processing software. It was established that the longitudinal waves p ropagate from anode to cathode, the frequency and wavevector of the dust so und oscillations being dependent on the discharge current, gas pressure, pa rticle density in the dust cloud, and spatial coordinates. Two-dimensional (2D) fields of the main wave characteristics were studied using an original algorithm. The possible mechanisms of excitation of the dust sound oscilla tions is discussed. The experimental spatial distributions of the wave para meters are compared to the patterns obtained within the framework of variou s theoretical models. (C) 2001 MAIK "Nauka/Interperiodica".