Multipole Expansions of Aggregate Charge: How Far to Go?

TL;DR

This paper investigates how including quadrupole terms in multipole expansions affects the modeling of aggregate charge interactions in plasmas, comparing results to point charge models to improve understanding of aggregate dynamics.

Contribution

It introduces the effect of quadrupole terms in aggregate charge modeling, extending previous monopole and dipole approaches for better accuracy.

Findings

Quadrupole terms influence aggregate interaction dynamics.

Comparison shows differences between multipole and point charge models.

Results inform more accurate modeling of aggregate behavior.

Abstract

Aggregates immersed in a plasma or radiative environment will have charge distributed over their extended surface. Previous studies have modeled the aggregate charge using the monopole and dipole terms of a multipole expansion, with results indicating that the dipole-dipole interactions play an important role in increasing the aggregation rate and altering the morphology of the resultant aggregates. This study examines the effect that including the quadrupole terms has on the dynamics of aggregates interacting with each other and the confining electric fields in laboratory experiments. Results are compared to modeling aggregates as a collection of point charges located at the center of each spherical monomer comprising the aggregate.