Experimentally Characterizing the Plume of a Divergent Cusped-Field Thruster
Abstract
Divergent cusped-field thrusters are electric propulsion devices characterized by a divergent, dielectric wall channel and a magnetic topology dominated by two magnetic cusps and a magnetic bottle near the anode. Initial testing results suggest that this technology may lend itself to miniaturization while providing improved lifetime performance over miniature Hall thruster designs. This paper presents results of detailed probing of the divergent cusped-field thruster plume using a faraday cup and a retarding potential analyzer to measure the ion current density and energy distributions at varied operating conditions. These results provide a more complete experimental characterization of the plume than was previously available by measuring plume attributes at wider angles with increased spatial resolution. Plume data analyses show regions with the greatest current density contain the most energetically uniform ion populations. However, the retarding potential analyzer results indicate that highly energetic ions are expelled at large angles relative to the thruster axis of symmetry, though the current densities at these angles are much lower. Plume measurements made while varying the cathode operating condition are also presented. The operating conditions of the divergent cusped-field thruster and cathode are found to be strongly coupled, motivating a future study that systematically examines the effect of cathode location and operating condition on the performance of the thruster. The mode transitions that occur while operating the divergent cusped-field thruster are also examined, providing a quantitative comparison between the two.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 24, 2009
- Accession Number
- ADA506747
Entities
People
- Manuel Martinez-sanchez
- Michael R. Nakles
- Stephen R. Gildea
- William A. Hargus
Organizations
- Air Force Research Laboratory