Cross-Field Anomalous Electron Transport Due to Multidimensional Plasma Instabilities

Abstract

Electron transport plays an important role in cross-field plasma discharges such as Hall thrusters and planar magnetrons. Several studies in recent years have indicated that plasma waves initiated by instabilities in such discharges interact with magnetized electrons and significantly enhance their diffusion across the magnetic field lines, in comparison to classical diffusion due to intermolecular collisions. In this work, we employ a two-dimensional particle-in-cell simulation in which doubly and singly charged ions are generated and accelerated in a magnetized DC discharge with applied magnetic fields. The nonlinear coupling of instabilities excited within this framework (the electron cyclotron drift instability and ion-ion two-stream instability) generates a multidimensional plasma wave, which enhances the cross-field electron transport. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> These numerical results agree with experimental findings on instabilities from coherent Thomson scattering experiments and provide previously-inaccessible insights into the role of instability coupling in electron transport.