Abstract
Dynamic behaviors of fine-particle clouds, negatively charged in RF plasmas, were investigated under microgravity condition using a parabolic flight of an aircraft. We have observed formation processes of spherical fine-particle clouds without a "void" inside, when a spherical grid cage was employed for the plasma production. On the other hand, a flat-spherical structure of fine-particle clouds was formed in the case of a parallel electrode discharge, where we found a formation of an almost spherical "void" inside. Such self-organized spherical structures are created through interactions among charged fine-particles and plasma.
