Approximate expression for the electric potential around an absorbing particle in isotropic collisionless plasma

Abstract

A new approximate expression for the potential distribution around an absorbing particle in isotropic collisionless plasma is proposed. The approximate expression is given by the sum of the Debye-H€ uckel potential with an effective screening length and the far-field asymptote obtained from the solution of the linearized Poisson equation. In contrast to analogous models, the effective screening length is not fixed but depends on the distance from the particle. This allows us to obtain a more accurate approximation for the potential distribution in the entire range of distances. The dependence of the screening length on the distance is predicted from the analysis of the charge density distribution function. This dependence contains two adjustable parameters, which are calculated by applying the procedure based on charge balance considerations. Using the obtained results, simple expressions for the parameters of the model are proposed. In addition, a simple expression for the characteristic screening length, which can be used to approximate the potential distribution near the particle, is obtained. The developed model potential is shown to be in excellent agreement with the solution of the nonlinear Poisson equation for typical conditions used in experiments with complex plasmas. V C 2015 AIP Publishing LLC.

Thermodynamics of Yukawa systems and sound velocity in dusty plasmas

“…Note that in case of the non-zero parameter ε, this integral is diverging logarithmically. A simple conventional procedure to avoid this divergence is to start integration from Γ = 1 in (11) and add the corresponding value…”

“…This is particularly relevant in complex plasmas, where continuous absorption of plasma electrons and ions on the particle surface (for simplicity we neglect the electron emission processes, which can play a role in certain situations, and then can make the problem even more complicated) results in inverse-power-law asymptotes of interaction at large interparticle separations [2][3][4][5][6][7][8]. At intermediate distances deviations from the simple form (1) can be expected when ion-particle interaction is highly non-linear [9][10][11] or a significant fraction of trapped ions is present [12]. Plasma production and loss processes can produce a double-Yukawa interaction potential characterized by two different screening lengths [13,14].…”

Capacitively coupled rf discharge with a large amount of microparticles: Spatiotemporal emission pattern and microparticle arrangement

“…[38]. The nonlinear screening effects were taken into account by introducing the effective screening length [39][40][41]. Following the results of Ref.…”

Relations between the longitudinal and transverse sound velocities in strongly coupled Yukawa fluids

“…The Yukawa potential is a reasonable starting point to model interactions in complex (dusty) plasmas and colloidal dispersions, 10,11 although in many cases the actual interactions (in particular, their longrange asymptote) are much more complex. [12][13][14][15][16][17][18][19] For a given interaction potential, the QLCA approach requires the equilibrium radial distribution function (RDF), g(r), as an input, characterizing the spatial order in the system. Then, the dispersion relations of the longitudinal and transverse modes can be easily calculated.…”