Study of electron transport in a Hall thruster by axial–radial fully kinetic particle simulation

Abstract

Electron transport across a magnetic field in a magnetic-layer-type Hall thruster was numerically investigated for the future predictive modeling of Hall thrusters. The discharge of a 1-kW-class magnetic-layer-type Hall thruster designed for high-specific-impulse operation was modeled using an r-z two-dimensional fully kinetic particle code with and without artificial electron-diffusion models. The thruster performance results showed that both electron transport models captured the experimental result within discrepancies less than 20% in thrust and discharge current for all the simulated operation conditions. The electron cross-field transport mechanism of the so-called anomalous diffusion was self-consistently observed in the simulation without artificial diffusion models; the effective electron mobility was two orders of magnitude higher than the value obtained using the classical diffusion theory. To account for the self-consistently observed anomalous transport, the oscillation of plasma properties was speculated. It was suggested that the enhanced random-walk diffusion due to the velocity oscillation of low-frequency electron flow could explain the observed anomalous diffusion within an order of magnitude. The dominant oscillation mode of the electron flow velocity was found to be 20 kHz, which was coupled to electrostatic oscillation excited by global ionization instability.

Kinetic analysis of the ionization ratio effects on a three‐species plasma

“…Partially, even Weakly Ionized Plasmas (WIP) are ubiquitous in nature and in laboratory, where they are of huge importance for actual practical applications, as for instance, plasma thrusters for space propulsion and, at the same time, they constitute the basis of theoretically important analyses such as wall‐plasma interactions and plasma‐diagnosis procedures . In these systems, the large density of neutral particles can influence the whole collective dynamics because charge‐neutral collision processes become effective enough to produce momentum and energy transfers among all species .…”

Particle-in-Cell Simulation of a 5 Kw Hall Thruster

“…The collisions with other particles and the Bohm diffusion are two main factors affecting the electron diffusion. In many of the PIC models [9][10][11], the same Bohm diffusion coefficient is used in the whole region. However, experiments [8] have shown that the effect of Bohm diffusion is different in various regions.…”

Propagator integral method for plasma physics kinetic equations with practical applications

“…Among the multiple methods, some of them highlight due to its applicability, as the Navier-Stokes solvers for magnetohydrodynamics (MHD) [9,10], Euler-Vlasov (EV) solvers [11], and particle-in-cell (PIC) codes [12][13][14][15][16][17]. Specially, PIC codes have gained a large popularity over the years and have proven an outstanding tool to analyse the dynamics of a large variety of plasmas.…”

“…Particle-in-cell (PIC) codes are widely employed for the simulation of plasma dynamics [12][13][14][15]163]. In these numerical approaches, the kinematic equations of a large number of macro-particles, which may represent a huge amount of real particles, are solved to obtain the transient position of each particle, based on the electromagnetic force action and the possible boundary conditions involved in the problem.…”

“…The resolution of two and three-dimensional problems in the velocity space is of huge importance in the transport coefficient calculation for plasmas and gases [13,18,43,[69][70][71][72][73][74]. Unlike in the 1D1V case, here the diffusive matrix is usually non-singular.…”