Effect of a dust component on the rates of elementary processes in low-temperature plasmas

Elementary processes in dusty, beam-driven plasma discharges are studied ex perimentally and theoretically for the first time. A theoretical model is c onstructed for a beam-driven plasma containing macroscopic particles. The e ffect of macroscopic particles on the electron energy distribution function is estimated assuming a Coulomb field for the particles. The resulting rat e of electron-ion recombination on the macroscopic particles is compared wi th the electron loss constant calculated from the electron energy distribut ion function with an electron absorption constant in the orbital-motion app roximation. This approximation, which is valid in the collisionless case, i s found to work satisfactorily beyond its range of applicability. The distr ibutions of the charged particles and electric fields created by macroscopi c particles in a helium plasma are determined. The experimental data demons trate the importance of secondary emission by high-energy electrons. (C) 19 99 American Institute of Physics. [S1063-7761(99)00906-3].