Fully self-consistent ion-drag force calculations for dust in collisional plasmas with external electric field

TL;DR

This paper presents self-consistent calculations of the ion-drag force on dust particles in collisional plasmas with external electric fields, extending previous analytic models across all collisional regimes.

Contribution

It introduces a comprehensive numerical approach using Particle In Cell simulations to accurately compute ion-drag forces without relying on simplifying assumptions.

Findings

Force direction is generally aligned with plasma flow.

Opposite force direction occurs only in the continuum limit.

Results extend the validity of prior analytic models.

Abstract

The ion-drag force on a spherical dust particle immersed in a flowing plasma with external electric field is self-consistently calculated using the Particle In Cell code SCEPTIC in the entire range of charge-exchange collisionality. Our results, not based on questionable approximations, extend prior analytic calculations valid only in a few limiting regimes. Particular attention is given to the force direction, shown never to be directed opposite to the flow except in the continuum limit, where other forces are of much stronger magnitude.