Spatial Evolution of the Dust-Acoustic Wave

Over the past twenty years, the dust-acoustic wave (DAW) has been a subject of intense study. In this paper, high-speed video imaging is employed to measure the evolution of wavefronts of a propagating DAW as it propagates through a weakly coupled dusty plasma system in an argon dc glow discharge plasma. In particular, measurements of the growth, saturation, and, then, damping of the wave mode as the wave propagates through the cloud are reported. It is observed that the wave amplitude initially exhibits rapid growth while the wavefront compresses. After this initial growth, the width of the wavefront remains relatively constant, while the amplitude of the wavefront evolves like the background dust medium. In some cases, it is also observed that the wave amplitude can decay more quickly than the background dust medium.