Boundary Conditions for Continuum Simulations of Wall-bounded Kinetic Plasmas

Abstract: Continuum kinetic simulations of plasmas, where the distribution function of the species is directly discretized in phase-space, permits fully kinetic simulations without the statistical noise of particle-in-cell methods. Recent advances in numerical algorithms have made continuum kinetic simulations computationally competitive. This work presents the first continuum kinetic description of high-fidelity wall boundary conditions that utilize the readily available particle distribution function. The boundary condition is realized through a reflection function that can capture a wide range of cases from simple specular reflection to more involved first principles models. Examples with detailed discontinuous Galerkin implementation are provided for secondary electron emission using phenomenological and first-principles quantum-mechanical models. Results presented in this work demonstrate the effect of secondary electron emission on a classical plasma sheath.