Effect of ion mean free path length on plasma polarization behind a dust particle in an external electric field

Abstract

In this paper, a self‐consistent numerical model that describes the behavior of plasma around an isolated, highly charged dust particle is presented. Using the developed model, self‐consistent distributions of the space charge density and plasma potential in the presence of an external electric field are obtained. These distributions are thoroughly analysed though Legendre decomposition. For different dust plasma parameters, such as the radius of the dust particle, the amplitude of the external field, and the mean free path of ions, the dipole moment of the ion cloud surrounding the dust particle is calculated. It turns out that the dependencies of the dipole moment on the value of the external electric field obtained for different parameters are reduced to a single curve by simple scaling.

Possible Mechanisms of String Formation in Complex Plasmas at Elevated Pressures

“…For complex plasmas, the main difficulties lie in estimating the multipole moments associated with the trapped ions. Recently, an iterative multipole expansion techniques has been applied for the particle potential in collisional complex plasmas that takes into account the trapped ion effect and slow ion flows [ 18 , 23 ]. It turns out that, in weak electric fields obeying , the long range multipole expansion of the potential converges fast and one can neglect the higher-order terms (see Figure 5 in Ref.…”

“…For estimations of a dipole moment associated with the trapped ions , we use the approximation that follows from expression (10) of Ref. [ 23 ], where we put and . Note that such is based on the self-consistent numerical model describing the polarization of a plasma around an isolated, highly charged particle in collisional limit and may be applicable in the case of low Mach numbers and (see Reference [ 23 ] for details).…”

Plasma anisotropy around non-spherical conductive dust particle

“…In [17][18][19][20], the authors of this article demonstrated the results of calculations of a model in which the distributions of space charges and potentials were determined in a self-consistent manner also around spherical particles. This article presents the dependences of the density distribution and the space charge potential, as well as the dependence of the dipole moment of the "dust particle -ion cloud" system for nonspherical particles: a flattened and elongated ellipsoid.…”

“…Due to the fact that in the most detailed way the model has already been described in the works [17][18][19][20], only its main points will be described later. For convenience, a particle whose geometry is an elongated ellipsoid will be called ellipsoidal, and the geometry of which is a flattened ellipsoid -diskshaped.…”

Plasma Parameters around a Chain-Like Structure of Dust Particles in an External Electric Field

“…What will be the dependence of the charge of dust particles in the chain and the interparticle distance between them on the plasma parameters, and would such a chain will be stable? In references [38,39], a model was presented where the dependence of the spatial distributions of plasma around an isolated dust particle on various parameters of the particle itself, the surrounding plasma, and the external electric field was calculated. It was shown in reference [28] that the approximation of the dipole moment obtained in reference [38] can be used to describe with a good approximation the range of parameters in which dust particles self-organize into a chain.…”