Shielding and Interaction of Dust Particles in Non‐Equilibrium Plasma

Abstract

This paper investigates the interaction of two dust particles in non-equilibrium plasma at elevated pressures. On the basis of asymptotic shielding theory resulting in two-exponential shielding the electrostatic energy of two charged fine particles is determined. The electrostatic energy dependence on interparticle distance proves to have a minimum as in an equilibrium plasma. The electrostatic interaction force of the particles is calculated. This force is proved to be non-symmetric: for different charges the force acting on one dust particle was not equal to the force acting on the other dust particle. This is due to non-symmetric charge separation in the vicinity of different charged dust particles. It is stated that likely charged particles repel each other and at the closest approach the attraction is only possible. Relationships to determine the modified nonideality parameter for the interaction potential, which consisted of two exponents with different shielding lengths, were obtained.

Microparticle Charge Screening in Non‐Equilibrium Plasmas with Two Types of Positive Ions

“…Eq. (45) coincides with the equation obtained in [4][5][6] for the screening constants in a two component electron-ion plasma.…”

“…Note, that introduced charge and sinks are not equal to the real ones and are some effective quantities, whose values cannot be found within the framework of the asymptotic theory [4][5][6]. They can be found by comparision of theoretical results with numerical calculation.…”

“…Study of screening of a charged macroscopic particle immersed in a plasma is of special interest as for the probe theory so for dusty or complex plasma theory. It was shown in [4][5][6] that dust particle charge screening in non-equilibrium conditions differs from the Debye one and that the potential distribution is described by two exponentials with two screening radii. In this paper three-component plasma with two types of argon ions (Ar + and Ar + 2 ) is considered.…”

“…In this paper three-component plasma with two types of argon ions (Ar + and Ar + 2 ) is considered. The model of point sink, taking into account the electron and ion absorption by particle or probe, was taken for analytical estimations as it had been done in [4][5][6] …”

New Model of Dusty Plasma Particles Interaction

“…It was argued, however, in [6,7] that the attraction is impossible in the Poisson-Boltzmann model considered above. In this context it has to be mentioned here that the buffer plasma was treated in [6,7]as a liquid dielectric medium [4] and, then, the stress tensor was applied to calculate the force between the dust grains.…”