Probing the sheath electric field using thermophoresis in dusty plasma. Part I: Numerical analysis

TL;DR

This study combines fluid and N-body models to analyze dust particle levitation in plasma sheaths, reconstructing electric fields and structures, revealing dust levitation occurs on the plasma side of the Bohm point.

Contribution

It introduces a combined modeling approach and a method to reconstruct electric fields at a sub-millimeter scale in dusty plasma sheaths.

Findings

Dust levitates on the plasma side of the Bohm point.

Electric field is underestimated due to charge overestimation.

Ion drag effects are not fully accounted for.

Abstract

By combining the results from a self-consistent 2D dusty plasma fluid model and a 3D N-body code, the equilibrium position and crystal structure were determined for dust particles levitated in the sheath in a modified Gaseous Electronics Conference (GEC) reference cell, in which the lower electrode was heated or cooled. The Debye length, charge and electric field were reconstructed on a sub-millimeter scale by applying a previously developed, independent method. However, this method seems to overestimate the charge, and hence underestimate the electric field. Even corrected for this fact, the results show that the dust is levitated on the plasma side of the Bohm point. The ion drag, which is not fully taken into.