Distributions of Polydisperse Dust Grains in Noble Gas Mixtures

The size of levitating dust grains depends on the discharge conditions. By varying the plasma parameters, one can control the characteristics of dust structures. The method is presented for controlling the parameters of the dust trap in a standing stratum by creating the plasma-forming gas as mixture of noble gases with different ionization potentials (xenon and helium). The experimental technique consists in using polydisperse grains, from which in the trap, the grains are selected with sizes corresponding to the conditions in the plasma. Based on accounting for approximately 1000 grains, histograms of grain distributions over average size were obtained. It is shown that, under the chosen experimental conditions, when adding of up to 10% xenon to helium, the grain sizes change maximally from 8.9 to 3.3 mu m. The balance of forces was numerically estimated.

Automated summary

The size of levitating dust grains depends on the discharge conditions, and the characteristics of dust structures can be controlled by varying the plasma parameters. Experimental results show that the addition of up to 10% xenon to helium can change the grain sizes.