Self‐Consistent Simulations of Plasma and Gas Dynamics in Microplasmas with Metallic and Dielectric Electrodes

Abstract

The present paper discusses a self‐consistent model of plasma and gas dynamics for atmospheric microcavities in helium. A self‐consistent and time‐dependant model is described and applied with emphasis on terms involved in the close coupling among charged species, neutral species and the electric field, including space charge. The microplasmas are studied from an initial cloud until the stages of charged particle over‐amplification and breakdown in small‐spaces, where transients are particularly important. Both metallic and dielectric electrodes are compared in terms of spatial and temporal evolution of the plasma and gas dynamics. Gas heating, neutral depletion initiation and electric field reversal are observed, highlighting the close interaction between neutral gas and charged species in governing the evolution of the microplasma.

Multi‐Scale Investigation of a Colloid Micro‐Propulsion System

“…In the simulations shown and described in the paper, the distance between the needle tip and extractor is equal to 1 mm and the needle starting voltage is set to about 1 400 V as depicted in Figure 3. It is important to note that the plasma breakdown effects may become important if the voltages are too high as defined by Paschen's curve—but the conditions currently explored are under this threshold 17, 18. The droplets are assemblies of molecules and range from large droplets to smaller droplets.…”

Two-dimensional particle-in-cell Monte Carlo simulation of a miniature inductively coupled plasma source

“…The boundary conditions of L are zero potential on the metal wall and ‫ץ‬ L / ‫ץ‬r =0 at r = 0. On the dielectric, the potential L satisfies the following equations: 26,27 …”

Characteristics of Nanosecond Pulsed Discharges in Atmospheric Helium Microplasmas

“…For instance, the plasma-induced fluid dynamics, heating and depletion can be captured in microplasmas [17] . The effect of temperature has also been experimentally demonstrated to have some control on transition effects [11] and the present model also includes coupled gas effects.…”

“…1. The self-consistent directly coupled plasma/gas/metastable governing equations have been detailed and validated previously [17] -the key plasma and gas equations are summarized below. Eq.…”

“…The subscript s refers to the particle considered, n s is the density (n e and n i are electron and positive ion densities), v s the mean velocity, S s the source term, D s the diffusion coefficient, µ s the mobility and e the electron charge. The electric field close to the anode is derived by Gauss' law [17] and given by Eq. (3).…”