Oscillation Amplitudes in 3-D Dust Density Waves in Dusty Plasmas Under Microgravity Conditions

Large dust clouds in dusty plasmas exhibiting self-excited dust density waves (DDWs) have been investigated in a microgravity environment. With the help of the tracer particle technique [1], 3-D trajectories of single dust particles within the dust cloud have been measured using a stereoscopic camera setup. With the availability of the full phase-space information, 3-D wave properties can be accessed. In this paper, the spatial variation of the oscillation amplitude of single particles participating in a DDW is presented. We find that the amplitude increases in the direction of wave propagation and is nearly homogenous in the plane perpendicular to that direction.