Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

TL;DR

This paper presents an experimental study of large amplitude dust-acoustic shock waves induced by flow in a complex plasma, analyzing their properties and comparing with numerical models.

Contribution

It is the first detailed experimental investigation of flow-induced dust acoustic shock waves in a complex plasma with comparison to theoretical models.

Findings

Shock waves are triggered by flow changes and observed via high-speed imaging.

Shock wave properties depend on flow speed and potential barrier height.

Experimental results align well with modified Korteweg-de-Vries-Burgers model.

Abstract

We report on experimental observations of flow induced large amplitude dust-acoustic shock waves (DASW) in a complex plasma. The experiments have been carried out in a $\Pi$ shaped DC glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change of gas flow rate is used to trigger the onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a modified Korteweg-de-Vries-Burgers type equation.