Discrete stochastic charging of aggregate grains

Area of Science:

• Plasma Physics
• Materials Science
• Computational Modeling

Background:

• Dust particles in plasma acquire charge through random electron and ion collection, leading to fluctuations around an equilibrium value.
• Small dust grains or those in tenuous plasmas are highly sensitive to individual charge additions.

Purpose of the Study:

• To numerically model discrete stochastic charge fluctuations on aggregate dust grains.
• To determine the impact of these charge fluctuations on the dynamics of dust grain aggregation.

Main Methods:

• Development of a numerical model to simulate charge fluctuations on aggregate grains.
• Coupling of dust dynamics and charging models to analyze aggregation processes.

Main Results:

• Mean and standard deviation of charge on aggregate grains show trends similar to spheres but with greater variation.
• Charge fluctuations occur on timescales relevant to aggregate growth in certain plasma environments.
• Simulations reveal that charge fluctuations promote the formation of more linear or filamentary aggregates.

Conclusions:

• Stochastic charge fluctuations significantly impact dust aggregate morphology in plasma.
• Aggregate structures formed under fluctuating charge conditions are distinctly different from those in stationary charge environments.