Wake formation behind a finite-size dust grain in a plasma

Summary form only given. The theory of the wake potential was proposed as a possible candidate for the formation of vertical arrangement and alignment of dust grains in plasma crystals. The theory was based on a point test dust grain placed in a supersonic ion flow. Some recent experiments on plasma crystals involve rather large (more than 10 /spl mu/m) size grains. Finite size grains in a plasma will necessarily have dipole moments in the distributed charge. We consider the dipole effects on the formation of wake potential associated with plasma crystals.