Resolving multi-dimensional plasma phenomena in Hall thrusters using the reduced-order particle-in-cell scheme

Abstract

Plasma in Hall thrusters exhibits a complex behavior, characterized by the interplay between various dominant processes in each of the thruster’s coordinates. The emergence of high-power Hall thrusters in the recent years and the design modifications intended to extend the lifetime of these devices have further amplified the three-dimensional nature of the plasma behavior. In this regard, the novel reduced-order particle-in-cell (PIC) scheme provides the possibility to resolve the multi-dimensional interactions in a Hall thruster at a significantly reduced computational cost compared to current multi-dimensional PIC simulations. To demonstrate this point, we present in this article the results from a series of pseudo-two-dimensional simulations we performed in three configurations: axial-azimuthal, azimuthal-radial, and axial-radial. We show that, in each configuration, the pseudo-2D PIC scheme provides a significantly improved picture of the involved physics compared to a one-dimensional PIC simulation and captures self-consistently the coupling between the plasma processes in different directions, notably similar to the observations from full-2D kinetic simulations.

Generalized Reduced-Order Particle-in-Cell Scheme for Hall Thruster Modeling: Concept and In-Depth Verification in the Axial-Azimuthal Configuration

“…In our previous works [10] [11], we presented a preliminary formulation to split the 2D Poisson's equation into a set of decoupled 1D Ordinary Differential Equations (ODE), which yielded the "pseudo-2D" PIC scheme. We studied the feasibility of the concept of reduced-order PIC scheme through performing several pseudo-2D kinetic simulations along various coordinates of a Hall thruster, i.e., axial-azimuthal, azimuthal-radial and axial-radial, comparing the results against the observations in full-2D reference cases.…”