2D3V kinetic simulation of Hall effect thruster, including azimuthal waves and diamagnetic effect

Abstract

Axial-azimuthal (2D3V) full-kinetic PiC+MCC-model was built to simulate dynamics of Hall effect thruster discharge plasma taking into account azimuthal waves and diamagnetic effect. The transition from ignition to the steady-state regime was simulated. Calculation of discharge ignition shows a significant distortion in the shape of the magnetic field caused by high azimuthal-drift current. This effect and intensive ionization lead to the fact that full potential drop localizes in a thin non-magnetized cathode layer. In the steady-state regime, the distortion of the magnetic field is small. Plasma divides into three regions: dense anode plasma where ionization occurs; magnetic layer where ions accelerate and quasineutral cathodeside plasma (plume). The steady-state regime is subject to auto-oscillations at a gas-transit frequency (20 kHz 'breathing modes'). Also, two types of azimuthal instabilities have been observed: gradient drift instability and electron cyclotron instability. All these instabilities lead to collisionless 'anomalous' electron transport across the magnetic field. Kinetic effects also were considered. It was found that the electron distribution function evolves from initial isotropic (Maxwellian) to essentially anisotropic due to electric field heating. Isotropy is partially restored inside anode plasma due to collisions.

The comparison of two-term Boltzmann approximation and Monte-Carlo solutions for e+Ar0 plasma

“…The TTB code described in the article is based on the idea of a weak anisotropy of the eEDF in the electric field, which makes it possible to take into account only the first two terms of the eEDF decomposition in the energy space, i.e., to perform linearization of eEDF, and implements the solution of the non-stationary BKE. The MCC code takes its origin from the ΘHall PiC+MCC code described before in [36,37]. The Monte-Carlo module was heavily modified and rewritten to support an arbitrary set of reactions and active/background components.…”

The influence of the inclination of strong magnetic field lines on the performance and plume divergence of a magnetically shielded Hall thruster

“…Therefore, the change in the discharge current is mainly concerned with the electron cross-field transport. However, the electron dynamics in Hall thrusters is sensitive to a lot of factors, such as the magnitude and shape of the magnetic field [34,35], the electron-wall interaction [36], and the discharge oscillation [37]. Plenty of works have been performed so far to investigateelectron cross-field transport in the strong magnetic field region of unshielded Hall thrusters; unfortunately, the involved mechanism is far from being understood [38].…”

Utilizing the L-curve criterion for the inverse magnetostatic problem of Hall drift current estimation

“…For the sake of establishing a coordinate system, we utilize a straight line where the outer magnetic pole intersects with the outer wall surface of the channel, denoting them as the r-axis and z-axis, respectively. The center points of the 16 magnetic sensors are cataloged as: (20,10), (30,10), (40, 10), (50, 10), (30,20), (40, 20), (50, 20), and (45, 30). At each of these positions, a pair of magnetic sensors are strategically placed perpendicular to one another, designed to measure both axially and radially.…”