Topic/Type: 1.5 Low-temperature, dusty and nano-plasmas, Poster

### Dust particles and gas discharge plasma interaction

For a small Havnes parameter, $\small P_{H}$, the charge of dust particles is determined only by the plasma conditions. With the increase of $\small P_{H}$, the local parameters in the plasma region containing dust particles (the electron density and electron energy distribution function (EEDF)) change, which in turn leads to a change of the average charge of dust particles and, hence, of all properties of dusty plasma. For conditions of RF discharge used for thin films preparation in semiconductor industry, the influence of dust particles on discharge properties was investigated with the help of particle-in-cell Monte Carlo simulations by J.P. Boeuf [Phys. Rev. A, 46, 7910 (1992).]. It was understood that each dust particle acts as an electron and ion sink, and a large concentration of dust particles will have some effect on the plasma properties and on the plasma sustainment conditions. Unfortunately, in late 1990s and 2000s, this important conclusion was almost forgotten in avalanche-like investigations of dusty plasmas in the laboratory conditions (Coulomb structures, waves and so on). Moreover, in almost all papers published in this period in the field of dusty plasma, the electron energy distribution function in dusty plasma was assumed to be Maxwellian one.
The influence of dust particles concentration, $\small N_{d}$, on gas discharge parameters and the charging of dust particles were investigated. It is shown that the increase of $\small N_{d}$ leads to the increase of averaged electric field and ion density, and to the decrease of dust particle charge in the dusty cloud. The strong sink of electrons and ions on the dust particles surface does not lead to the electron energy distribution function depletion due to the self-consistent adjustment of dust particles and discharge parameters.