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

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.