Effects of Cathode Configuration on Hall Thruster Cluster Plume Properties

Abstract

Clusters of Hall thrusters are being considered for use on a variety of missions requiring electric propulsion systems capable of operating at power levels in excess of the current state of the art. One of the key factors to be considered in determining the optimum cluster architecture is the configuration of the electron-emitting cathode(s). This work presents experimentally determined plume properties and discharge current characteristics obtained with multiple thrusters coupled to a single cathode. Spatially resolved plasma density, electron temperature, and plasma potential data are presented during both single thruster and cluster operation. Measurements taken in this configuration are compared to previously published data obtained with each thruster coupled to its own independent cathode. Significant differences between the two configurations are noted and explained. Additionally, critical plasma parameters in the cluster plume are shown to be strongly influenced by the location of the hollow cathode.

Inertial and anisotropic pressure effects on cross-field electron transport in low-temperature magnetized plasmas

“…A quasineutral boundary condition is used, where electrons are injected from the boundary so that the electron density becomes equal to the ion density at the adjacent cell center. The injected electrons are assumed to be a Maxwellian distribution with an electron temperature of 3 eV [55,56]. Considering that the ion and electron densities are on the cell center and the electric fields are on the cell interface, Gauss's law in 1D results in…”

Plume interference effects of the racetrack-shaped anode-layer Hall thruster system

“…The development of the head is also an important factor in the design of a Hall thruster cluster system, however, it is critical to investigate and evaluate the unique perspective to the cluster system, which is the interference between the plumes from each head. Research on several cluster systems have been ongoing so far (Beal et al, 2005;Lobbia et al, 2007;Walker et al, 2007;Zakharenkov et al, 2005;Tverdokhlebov et al, 2005). Beal et al showed that the plume property was influence in multihead operation (Beal et al, 2005).…”

“…Research on several cluster systems have been ongoing so far (Beal et al, 2005;Lobbia et al, 2007;Walker et al, 2007;Zakharenkov et al, 2005;Tverdokhlebov et al, 2005). Beal et al showed that the plume property was influence in multihead operation (Beal et al, 2005). Lobbia et al showed thrust boost due to clustering (Lobbia et al, 2007).…”

Effect of Cathode Position on Hall-Effect Thruster Performance and Near-Field Plume Properties

“…[3][4][5][6][7][8] Hofer, et al 4 and Jameson, et al, 8 noticed significant performance improvements by placing the cathode in the center of the HET rather than outside, and Beal, Gallimore and Hargus have inferred from probe measurements that cathode placement and number in a cluster of HETs will affect performance. 6 To the best of our knowledge there are two studies available in the literature that specifically address the effect of cathode position on thruster performance across a range of cathode locations. In the first, by Tilley, et al the authors note an increase in cathode coupling voltage as the cathode is moved forward of the exit plane.…”