Effective interaction potential and ordered structures of dust particles in a gas-discharge plasma

An effective potential is proposed for the interaction between dust particl es in a gas-discharge plasma which takes account of the following physical factors: the spatial dependence of the particle charges on the floating pot ential of the plasma, anisotropy of the interaction, resulting from focusin g of the negatively charged particles of the drift ion current, and aspects of screening of the dust particles by plasma electrons and ions which inte ract strongly with them and recombine faster in their vicinity and on their surface. Monte Carlo calculations explain the formation of threadlike stru ctures of dispersed particles, and also "transverse crystallization'' of th ese "threads'' in a stratified gas-discharge plasma. (C) 1999 American Inst itute of Physics. [S1063-7761(99)00403-5].