The sequential snap shots showing the side views of the evolution of the laser induced dusty plasma bubble. The laser pulse is turned on at 0 ms.
(a) The dust trajectories in the right half of the viewing plane in different time intervals after the laser pulse. The open circle corresponds to the starting position of each trajectory. Only half of the trajectories of dusts are plotted. The positions of the rest dusts at the starting time of each panel are indicated by the gray dots. [(b)–(e)] The magnified dust trajectories from 2 to 200 ms of a few typical dusts initially sitting along the axis at and , 1.5, 3.3, and 5.3 mm, respectively. [(f) and (g)] The temporal evolutions of the vertical and the horizontal displacements of the dusts shown in (b)–(e), respectively. The vertical bars correspond to 1 mm. (h) The vertical and the horizontal excursion ranges ( and ) of the first oscillating cycle vs dust initial horizontal coordinates for dusts initially located at . (i) The temporal evolution of the dust image taking from a narrow horizontal strip 0.6 mm in width and centered at .
(a) The vertical position evolutions of dusts in the center vertical strip. [(b)–(d)] The top view and the few typical curves of evolution measured from a vertical strip along the center vertical axis of the initial bubble. The tilted lines indicate the leading rarefaction front, the first compressional crest, and the subsequent trailing crests in the wake, respectively. indicates the time (10 ms) when all the dusts above the upper bubble boundary start to rebound downward. indicates the rebounding upper bubble edge. In (c) and (d), the gray horizontal lines indicate the reference levels where and the vertical bar at the upper right corner corresponds to the scale of .
[(b) and (c)] The plots of the dust vertical speed vs dust vertical position in the frame with origin moving with the front , obtained from the few dust trajectories in the upper and lower zone marked by the dotted boxes in the spatiotemporal dust density evolution plot shown in (a). The gray lines in (b) and (c) are dust density distributions directly obtained from the inverse of .
The crest speed with the corresponding Mach number (a), and the crest width (b), vs the normalized crest amplitude measured from the crests at different . The first to the third crests correspond to the crests indicated by , respectively, in Fig. 3.
The 60 ms snap shot and the temporal evolutions of the overdamped vertical displacements of the dusts in the central vertical strip at high pressure (440 mTorr). Dusts only return to their original height with negligible overshooting. The new white lines in the center region after 75 ms are from the horizontally inward moving particles that fill up the center.
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