Dust charging in dynamic ion wakes

Abstract

Micron-sized dust grains have been successfully employed as non-perturbative probes to measure variations in plasma conditions on small spatial scales, such as those found in plasma sheaths. The dynamics of the grains can be used to map the forces due to electric fields present in the sheath, but the particle charge and electric field are difficult to measure independently. The problem is further complicated by the ion wake field which develops downstream of the dust grains in a flowing plasma. Within a sheath, ions are accelerated towards the charged boundary, and this ion flow creates a positively-charged spatial region downstream of the dust grain, called the ion wake. The ion wake in turn modifies the interaction potential between the charged grains. Here we use a molecular dynamics simulation of ion flow past dust grains to investigate the interaction between the charged dust particles and ions. The charging and dynamics of the grains are coupled self-consistently and derived from the ion-dust interactions, allowing for detailed analysis of the wakefield-mediated interaction as the structural configuration of the dust grains changes. The decharging of a dust grain as it moves through the wake of an upstream particle and the attractive ion wakefield force are mapped for a range of ion flow speeds.

23 pages

References in corpus (13)

• On the Wake Structure in Streaming Complex Plasmas
• Crystallization dynamics of a single layer complex plasma
• Vertical pairing of identical particles suspended in the plasma sheath
• Intergrain forces in low Mach-number plasma wakes
• One-dimensional vertical dust strings in a glass box
• Helical Structures in Vertically Aligned Dust Particle Chains in a Complex Plasma
• Determination of the levitation limits of dust particles within the sheath in complex plasma experiments
• Mode coupling and resonance instabilities in quasi-two-dimensional dust clusters in complex plasmas
• Dust as probe for horizontal field distribution in low pressure gas discharges
• Mode couplings and resonance instabilities in dust clusters
• Ion-wake Field inside a Glass Box
• Discrete stochastic charging of aggregate grains
• Plasma flow around and charge distribution of a dust cluster in a rf discharge

Cited by in corpus (9)

• Dust as probes: determining confinement and interaction forces
• Stability of two-dimensional complex plasma monolayers in asymmetric capacitively-coupled radio-frequency discharges
• Influence of Temporal Variations in Plasma Conditions on the Electric Potential Near Self-Organized Dust Chains
• Effect of ionization waves on dust chain formation in a DC discharge
• Fractional Laplacian Spectral Approach to Turbulence in a Dusty Plasma Monolayer
• OpenDust: A fast GPU-accelerated code for calculation forces, acting on microparticles in a plasma flow
• Evolution of Ion Wake Characteristics with Experimental Conditions
• Experiments and modeling of dust particle heating resulting from changes in polarity switching in the PK-4 microgravity laboratory
• Sparse identification of effective microparticle interaction potential in dusty plasma from simulation data