Propagation characteristics of nonlinear dust acoustic waves in inhomogeneous complex plasmas

An experimental investigation of the propagation characteristics of nonlinear Dust Acoustic Waves (DAWs) in inhomogeneouscomplex plasmasis presented. The experiments have been carried out in a $\Pi $-shaped dusty plasma experimental (DPEx) device with micron sized Kaolin particles embedded in a DC glow dischargeArgon plasma. The dust density inhomogeneity along the axial direction of the device is created by a slight imbalance of the pumping rate and the gas flow rate. NonlinearDAWsare excited by compressing the dust fluid during the generation of dust flow and are observed to propagate away from the anode. The effect of the dust density inhomogeneity is investigated on the propagation characteristics of nonlinear Dust Acoustic Waves by analyzing the successiveimages, which are recorded using a high speed camera.It is found that the wave amplitudes and phase velocities increases with the decreaseof dust density along the length of the dust cloud. Our experimental observations for these high amplitude DAWs are found to be consistent with existing fluid theories for the propagation of nonlinear DAWs in inhomogeneous complex plasmas . The details of the experimental procedure and the results will be presented at the conference.