Dust Acoustic Waves

In dc glow discharge dusty plasmas, the formation of dust acoustic waves is a commonly observed phenomenon. Experiments in the dusty plasma experiment device produce naturally occurring dust acoustic waves with frequencies f N 5 to 25 Hz and phase velocities of Vph N 0.5 to 10 cm/s. Through the use of particle image velocimetry techniques, particle motion in the vicinity of the wavefronts is identified and measured. Particles are shown to have an oscillatory behavior near the dust acoustic wavefronts with peak speeds w , , , ~ ~ N 4 to 5 c d s . Measurements are performed in argon dc glow discharge plasmas at pressures ranging from 90 to 120 mtorr. This paper discusses the correlation between the dust particle velocities and the density of dust particles in the vicinity of the wavefronts. The experimental measurements are compared against a linearized one-dimensional model for the waves. A brief discussion on the possible impact of nonlinear effects on the dust acoustic waves is also presented. Zndex Terms-Dust acoustic wave, dusty plasma, glow discharge, particle image velocimetry, PIV. TABLE 1 EXPERIMENTAL PARAMETERS FOR THE DUSTY PLASMA EXPERIMEKT