Trapping of waves in a flowing dusty plasma

We report on experimental observations of trapping of waves in a flowing dusty plasma. The experiments are performed in an inverted p-shaped dusty plasma experimental device in which the dusty plasma is created in a DC glow discharge argon plasma using micrometer-sized kaolin particles. Two copper wires are installed radially on the cathode, which serve to generate the flow in the dust fluid as well as to confine the waves. The dust fluid is initially made to flow over both the wires by altering the sheath potential of one of these wires, and as a result, the wave gets excited and propagates in the downstream direction. The wave gets trapped in between the wires when their separation is below a critical value of & SIM;2 cm. For a long time (of the order of a few seconds), the trapped-wave structure retains its identity. The amplitude of the wave crests and the distance between them remain constant with the dust fluid flow velocities. A numerical solution of the forced Korteweg-de Vries equation with two source terms as well as molecular dynamic simulations reproduce our experimental findings in a qualitative manner.

Automated summary

We report experimental observations of trapping waves in a flowing dusty plasma. By installing copper wires on the cathode, the flow in the dust fluid and wave propagation can be generated and confined. When the separation between the wires is below a critical value, the wave gets trapped between the wires for a few seconds, with constant amplitude of wave crests and distance between them. Numerical solutions and molecular dynamic simulations qualitatively reproduce the experimental findings.