Effect of Glow Discharge Parameters on the Mean Interparticle Distance in Dusty Plasma Structures in the Cryogenic–Room Temperature Range

The molecular dynamics method is used for studying the effect of forces acting in a dusty plasma and discharge parameters on the mean interparticle distance in structures in a dc glow discharge in the temperature range 50–300 K. We report on the results of the dependence of the mean interparticle distance on the neutral gas temperature in simplified and modified models of the dusty plasma. The simplified model includes the screened Coulomb potential and the ambipolar trap; in the modified model, the thermophoretic force, the ion shading force, and the neutral shading force are accounted for additionally. All these forces are calculated from the experimental values of the discharge parameters (current, pressure, temperature, and type of gas). The modified model of the dusty plasma system makes it possible to explain the experimental form of the dependence of the mean interparticle distance in dusty structures on the discharge gas temperature. We propose a method for estimating the ion concentration in the discharge gas from the mean interparticle distance in dusty plasma structures.