  We present a detailed experimental study of gas flow induced motion of dust
particles in a DC glow discharge plasma. The characteristics of the dust
dynamics are investigated as a function of the differential gas flow rate, the
background neutral pressure, the dust particle size as well as the neutral
species of the gas. The experiments have been carried out in the table top
Dusty Plasma Experimental (DPEx) device in which a plasma is created between a
disk shaped anode and a grounded cathode in a $\Pi$-shaped pyrex glass tube.
The asymptotic steady state flow velocity of the injected micron sized dust
particles is found to increase with an increase of neutral flow velocity and
decrease with an increase in the background pressure. Furthermore, this
velocity is seen to be independent of the size of the dust particles but
decreases with an increase in the mass of the background gas. A simple
theoretical model, based on estimates of the various forces acting on the dust
particles, is used to elucidate the role of neutrals in the flow dynamics of
the dust particles. Our experiments thus provide a detailed microscopic
understanding of some of the past phenomenological observations of dust flows
in the DPEx device and can prove useful in future experimental implementations
of dust flow experiments.
