Rodlike particles in gas discharge plasmas: theoretical model.

Recently, complex plasmas with strongly asymmetric (rodlike) particles were investigated experimentally in rf and dc discharges [V. I. Molotkov et al., JETP Lett. 71, 102 (2000); B. M. Annaratone et al., Phys. Rev. E 63, 036406 (2001)]. In this paper, a theoretical model is proposed which describes the behavior of such systems. Major results of the proposed model are the following: Equilibrium charge is calculated for particles orientated perpendicular and parallel to the ion flux (electric field); equilibrium states of particles (orientation angle and levitation height) are obtained; energy of electrostatic interaction between rods is derived, depending on the mutual orientation. Comparison of experimental and theoretical results shows quite good agreement. In conclusion, some important theoretical issues as well as possible new experiments are discussed.