  An experimental investigation of the propagation characteristics of shock
waves in an inhomogeneous dusty plasma is carried out in the Dusty Plasma
Experimental (DPEx) device. A homogeneous dusty plasma, made up of
poly-dispersive kaolin particles, is initially formed in a DC glow discharge
Argon plasma by maintaining a dynamic equilibrium of the pumping speed and the
gas feeding rate. Later, an equilibrium density inhomogeneity in the dust fluid
is created by introducing an imbalance in the original dynamic equilibrium.
Non-linear wave structures are then excited in this inhomogeneous dusty plasma
by a sudden compression in the dust fluid. These structures are identified as
shock waves and their amplitude and width profiles are measured spatially. The
amplitude of a shock structure is seen to increase whereas the width broadens
as it propagates down a decreasing dust density profile. A modified-KdV-Burger
equation is derived and used to provide a theoretical explanation of the
results including the power law scaling of the changes in the amplitude and
width as a function of the background density.

Plasma Physics