  The plasma is generated in a low frequency glow discharge within an elongated
glass tube oriented vertically. The dust particles added to the plasma are
confined above the heater and form counter-rotating clouds close to the tube
centre. The shape of the clouds and the velocity field of the conveying dust
particles are determined. The forces acting on the particles are calculated. It
is shown that convection of the dust is affected by the convective gas motion
which is triggered, in turn, by thermal creep of the gas along the
inhomogeneously heated walls of the tube.
