Dust Particles Selection in Plasma-Forming Gases with Different Ionization Potentials

The sizes of dust particles capable of levitating in dust traps in striations in a glow discharge in all inert gases are quantitatively determined for the same discharge parameters. A more than twofold decrease in the particle size was established upon passing from the gas with the maximum ionization potential (He) to Xe. The dependence found in the experiment is interpreted from the point of view of the conditions of particle levitation. It is shown that in gases with a low ionization potential in the balance of forces, the ion drag force exceeds the force of gravity, while the absolute values of the forces decrease with decreasing particle size. The discovered effect can be used for fine trapping of dust particles in plasma traps.