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In the current paper a numerical study of the forces acting of a one-dimensional chain of three dust particles levitating in the near-electrode layer of a gas discharge plasma is presented. In the described model dust particle motion is calculated in consideration of the action of gravity, external electric field, the Coulomb repulsion and the force induced by plasma space charge. The dependences of the dust particles charges and their position in space on the mean value of external electric field were calculated. The investigation showed the effect of discharging dust particles in the chain due to ion focusing. The spatial distribution of forces acting on the dust particle chain has been studied. It is noted that the Coulomb repulsion force relative to the center of the chain loses its symmetry with an increase in the mean electrostatic field. It is shown that the displacement of a chain of dust particles is determined by the force induced by the plasma space charge.

A low frequency (100 kHz) ferromagnetic enhanced inductively coupled plasma (FMICP) source has been developed to obtain a large volume of dense Cl2/Ar plasma. The influence of chlorine addition on the FMICP parameters was investigated both experimentally and numerically using a global (volume averaged) model of Ar/Cl2 discharge. Radial distributions of the positive ions flux as well as the values of FMICP voltage were measured at a fixed FMICP current of 10 A for molecular chlorine concentrations of 0–4 vol%. Plasma species densities were calculated for various values of chlorine content of 0–4 vol% and absorbed power of 500–2000 W. The calculations showed that chlorine ion density exceeds argon ion density even at low chlorine content of about 0.5 vol%. While experimentally measured discharge voltage and power increased almost linearly up to 3 times with chlorine addition, the experimental and numerical data on plasma density demonstrated only a weak dependence on the discharge power. Thereby, at a fixed FMICP current the discharge power adjusts itself to keep plasma density at the same level even despite a significant change in plasma composition. [ABSTRACT FROM AUTHOR]