|
Recent advances
in the study of collective effects and particle motions in plasma-dust crystals,
ordered structures that form in the cathode sheath region
of
low
temperature gaseous discharges, are presented. Plasma collective processes
influence the arrangements and vibrations
of
dust particles in
these Coulomb lattice structures. One important effect is the wake potential
formation due to ion flow, leading to the vertical alignment
of
dust grains in
experiments. The oscillations
of
dust particles in
the lattices are strongly affected by collective processes in the ambient
plasma, in particular by the wake. Modes associated with vertical vibrations of
dust grains are identified, and their dispersion characteristics are discussed.
The modes can provide a useful tool for diagnostics in the sheath
region of the
discharge. |