Fluid Modelling of DC Argon Microplasmas: Effects of the Electron Transport Description

The paper gives an overview of the influence of the description of the electron transport properties on the characteristics of a DC microplasma in argon at atmospheric pressure. A spatially one-dimensional model is presented which solves the equations for continuity and conservation of energy of electrons and heavy particles in the entire inter-electrode region, the Poisson equation for the self-consistent electric field coupled with the heat transfer in the cathode and an external electrical circuit for the regulation of the current density. The model is applied to a single setup with an inter-electrode gap of 400 µm for three cases that differ in particular in the drift–diffusion formulation of the transport of electron particles and energy. The results obtained cover discharge regimes from normal glow through abnormal glow to arc discharge. They show that even at similar discharge voltage the plasma properties (particle densities, temperatures of electrons and heavy particles) can differ in the plasma depending on the description of the electron transport.