Electron Scale Physics in Plasma Expansion: Grid-based Vlasov Simulations

• Published in: 2023 IEEE International Conference on Plasma Science (ICOPS) p. 1
• Main Authors: Cui, C., Wang, J.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 21.05.2023
• Subjects: Fluids; Ions; Perturbation methods; Plasmas; Propulsion; Slabs; Space vehicles
• ISSN: 2576-7208
• DOI: 10.1109/ICOPS45740.2023.10481338

Plasma expansion is a fundamental plasma dynamics problem and has various applications such as spacecraft plasma wake formation and electric propulsion plume expansion. Previous studies of plasma expansion have mostly focused on the ion time scale whereas the electrons were commonly treated as an equilibrium charge-neutralizing fluid. However, recent studies have shown that the electrons during plasma expansion are non-equilibrium and highly anisotropic and that the massless fluid assumption for electrons breaks down in the outer expansion region. Recently, Cui and Wang also showed that the electron Langmuir wave is excited during one-dimensional plasma expansion which propagates ahead of the ion rarefaction wave into the unperturbed plasma. In this work, a parallel multi-dimensional grid-based Vlasov-Poisson system solver recently developed at USC, Vlasolver, is used to study the plasma slab expansion in a 2D planar domain with various different initial conditions. This work extends our recent one-dimensional study to investigate the excitation and propagation of electron-scale perturbations and the mechanisms accounting for the formation of electron temperature anisotropy during the multi-dimensional plasma expansion process.