Motion of Charged Nonspherical Dust Grains in the Plasma Sheath and Influence of their Rotation on Wave Instability

The motion of nonspherical (elongated) dust grains in a plasma sheath are analytically investigated. It is found that charged dust grains execute quivering (vibrating) and bouncing motions due to coupling of the dust dipole moment with the plasma sheath electric field and action on the gravity force. Dust rotational motion can be set up by circularly polarized electromagnetic fields. The results are in accord with the laboratory observation of dust cloud motion. The dispersion properties of dusty plasmas are examined. A kinetic equation for the dust grains is derived. The dispersion relations are analyzed to demonstrate that the dust grain rotation introduces new classes of instabilities involving low-frequency waves