Effects of the neutral point of dust charge in plasma sheath

TL;DR

This study numerically examines dust charging dynamics in plasma sheaths, revealing how initial conditions influence the neutral point of dust charge and its impact on dust density distribution.

Contribution

It introduces a self-consistent dynamic model of dust charge variation in plasma sheaths, extending the fluid approximation to include dust charge as a variable.

Findings

Dust grains charge negatively at sheath edge and then positively in the sheath.

Initial dust velocity and ion-electron density ratio affect the neutral point of dust charge.

Neutral point of dust charge influences dust density distribution.

Abstract

We numerically investigate the dust charging in the sheath, by using the usual fluid approximation, it is extended to include self consistently the dust charge variation. The grain charge becomes a new self consistent dynamic variable, it is found that dust grains are first charged negatively at the sheath edge and then begin to be charged positively in the sheath. The numerical results show that the initial velocity of dust charged grains, sized grains and the density ratio of ion to electron at the sheath edge have affected the neutral point of dust charge. Moreover, the neutral point of dust charge affects the spatial distribution of dust density.