(Color online) Schematic diagram of the dc glow discharge dusty plasma device, (a) side view, and (b) top view. The anode glow plasma is formed on a 3.2 cm diameter anode disk and is weakly confined as an elongated “firerod” by a longitudinal magnetic field. Dust is incorporated into the plasma from a floating tray located below the anode. The dust behavior is observed using laser light scattering and fast video cameras.
Single frame video images of (a) quasi-planar dust acoustic waves, and cylindrical dust acoustic waves and shocks produced by inserting a floating slit in front of the anode, (b) and (c). The structure of the dust suspension depends on the location of the slit relative to the anode. Dust acoustic shock waves were observed when the slit was farthest from the anode, as in (c).
(Color online) Dust density profiles obtained from single-frame video images of scattered light intensity. (a) Circles: a typical nonlinear dust acoustic waveform. Solid line: average dust density obtained by averaging the scattered light intensity over a video record containing thousands of wave periods. (b) Solid line: dust acoustic waveform fit using Eq. (5).
(Color online) (a) Experimental profiles of the self-steepening of dust acoustic waves into dust acoustic shocks, over 60 ms. The shocks front steepens but reaches a point at which the shock thickness stabilizes to a minimum value. (b) Calculated dust acoustic shock profiles obtained from numerical computations of Eq. (7) using the theory of Ref. 26. The model equations contain no dissipation mechanisms; hence, the numerical results produce non-stationary solutions.
(Color online) Shock position (x), amplitude (nd/nd0), and thickness (δ) vs. time obtained from the profiles shown in Fig. 4(a). The shock width stabilizes to a minimum value of roughly 0.3 mm, which is very close to the interparticle spacing.
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