Design and installation of a field ionization test chamber for ion thrusters

Abstract

The utilization of carbon nanotube arrays for field ionization in ion thrusters allows for a substantial reduction in thruster size and weight. The availability of miniature ion thrusters may enable the development of a suitable propulsion system for nano- and picosatellites, and can realize substantial weight, volume, and cost savings in existing satellite platforms. This research focuses on the design of a field ionization test chamber that can be used to determine a comprehensive performance metric for the carbon nanotube field ionization micro-ion thruster (CNTFIMIT). Using the knowledge gathered from two previously employed test chamber designs, a third generation apparatus with higher precision and improved capabilities is constructed. This new design incorporates a mass flow controller for propellant flow rate measurements, a high-voltage source-measure unit for ionization current measurements, and a linear shift with position feedback for adjusting the distance between the carbon nanotubes and the counter electrode during field-ionization. The design emphasizes user-friendly operation by simplifying the sample exchange and by reducing the chamber volume under vacuum for a faster turn-around time between experiments. The proposed design is highly modular, allowing for easy installation of additional analytic capabilities and other future upgrades.