The Air Force Clustered Hall Thruster Program
Abstract
Preliminary results of the Air Force program investigating clustered Hall thrusters are presented, primarily experimental results on a cluster of four 200 W Busek BHT-200-X3 Hall thrusters. Preliminary measurements of plume current density, start transient interactions, cathode current sharing, and near exit plane magnetic fields are presented. Greatest thruster interaction occurs when cathodes are electrically connected. In a two thruster case, one cathode dominated electron emission, producing 90% of the required current. When the cathodes are electrically independent, the greatest cluster interaction occurs during a Start following exposure of the thruster discharge chambers to water vapor. In this case, the thrusters enter and exit a high anode current mode related to internal plasma oscillations in a non-continuous manner. This is unlike the typical smoothly continuous anode current transient of a single thruster. Individual thrusters appear able to affect the anode current mode, and presumably the plasma oscillations, of neighboring thrusters. Once the thrusters are conditioned and if the cluster is electrically unconnected, no significant interaction is observed. Plume ion current measurements of two thrusters have yielded what appears to he a slight narrowing of the ion current density profile from that e%pected from linear superposition of individual thruster measurements. Near exit plane magnetic field measurements indicate that the magnetic fields between the thrusters are affected by neighboring thruster magnetic fields. As such, the near plume electric fields would also he modified and may be responsible for apparent plume narrowing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 13, 2002
- Accession Number
- ADA406805
Entities
People
- G. Reed
- W. A. Hargus Jr.
Organizations
- Air Force Research Laboratory