Initial operation of the CubeSat Ambipolar Thruster

Summary form only given. Operation and characterization of the CubeSat Ambipolar Thruster (CAT), a miniature helicon electric propulsion device, is presented. Its small plasma volume (~10 cm3) and low power requirements (<;100 W) make it ideal for propelling nanosatellites (<;10 kg). Permanent magnets generated a magnetic nozzle with a maximum field strength of 600 G. This field decreased to 0.5 G, the strength of earth´s magnetic field, within 50 cm allowing the entire exhaust plume to develop in the vacuum chamber without being affected by the chamber walls. Low gas flow rates (~10 sccm) and high pumping speeds (~10,000 l/s) were used to more closely approximate the conditions of space. A parametric study of the thruster operational parameters was performed to determine its capabilities as both a thruster and as a plasma source for magnetic nozzle experiments. The plasma density, electron temperature, and plasma potential in the plume were measured with Langmuir probes, double probes, and emissive probes. These measurements characterized the ion acceleration mechanism which produced thrust.