Modeling Agglomeration of Dust Particles in Plasma

TL;DR

This paper reviews numerical and experimental methods for studying dust particle agglomeration in plasma environments, emphasizing how charge distribution, grain shape, and plasma properties influence aggregate morphology and growth.

Contribution

It provides a comprehensive overview of recent techniques and findings related to dust agglomeration in plasma, including effects of charge distribution and grain properties.

Findings

Porous aggregates have reduced collisional velocities.

Grain shape influences aggregate morphology.

Plasma properties affect dust growth rates.

Abstract

The charge on an aggregate immersed in a plasma environment distributes itself over the aggregate's surface; this can be approximated theoretically by assuming a multipole distribution. The dipole-dipole (or higher order) charge interactions between fractal aggregates lead to rotations of the grains as they interact. Other properties of the dust grains also influence the agglomeration process, such as the monomer shape (spherical or ellipsoidal) or the presence of magnetic material. Finally, the plasma and grain properties also determine the morphology of the resultant aggregates. Porous and fluffy aggregates are more strongly coupled to the gas, leading to reduced collisional velocities, and greater collisional cross sections. These factors in turn can determine the growth rate of the aggregates and evolution of the dust cloud. This paper gives an overview of the numerical and experimental methods used to study dust agglomeration at CASPER and highlights some recent results.