Electron and ion thermal forces in complex (dusty) plasmas

TL;DR

This paper derives expressions for electron and ion thermal forces on charged grains in weakly ionized plasmas with temperature gradients, highlighting the significance of electron thermal forces in laboratory dusty plasma conditions.

Contribution

It provides new analytical expressions for thermal forces on dust grains, focusing on conditions relevant to laboratory complex plasma experiments.

Findings

Electron thermal forces can be significant in laboratory conditions.

Derived expressions applicable to weakly ionized plasmas with temperature gradients.

Electron temperature gradients of order eV/cm influence dust grain dynamics.

Abstract

Expressions for the ion and electron thermal forces acting on a charged grain, suspended in a weakly ionized plasma subject to temperature gradients, are derived. The main emphasize is on the conditions pertinent to the investigations of complex (dusty) plasmas in gas discharges. Estimates show that for the electron temperature gradients $\sim {\mathcal O}$(eV/cm) typically encountered in laboratory gas discharges, the electron thermal force can become an important player among other forces acting on micron-size grains.