Development of a Miniature Microwave-Frequency Ion Thruster
Open Access
- Author:
- Lubey, Daniel Patrick
- Area of Honors:
- Aerospace Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Michael Matthew Micci, Thesis Supervisor
Dr. Sven G Bilén, Thesis Supervisor
Michael Matthew Micci, Thesis Supervisor
Robert Graham Melton, Thesis Honors Advisor
Dr. George A Lesieutre, Faculty Reader - Keywords:
- Ion Thruster
Electric Propulsion
Microwave - Abstract:
- Miniature ion thrusters offer low-thrust, high specific impulse capabilities to small spacecraft for use in attitude and orbit control systems. This thesis presents the design of a miniature ion thruster called the Miniature Microwave-frequency Ion Thruster (MMIT). This thruster uses coaxially inputted microwave power at 4.2 GHz with argon or xenon propellant injected via a gas plenum at 0.15 sccm during nominal operating conditions. The optics use a two-grid system with the screen grid kept at a nominal voltage of 1500 V and the accelerator grid kept at −500 V. In this operational mode, the MMIT is predicted to produce a thrust of approximately 258 μN with a total efficiency of 32%, mass utilization efficiency of 32%, and an electrical efficiency of approximately 50%. This configuration will also produce exit velocities of approximately 54 km/s, which translates into a specific impulse of approximately 5500 s, assuming complete single ionization of the propellant, no exiting plume angle, and a constant electric field across the grids. These predictions will be tested with experiments in a vacuum chamber at 10e−6 Torr with a Langmuir probe and Faraday cup used to provide measurements of exiting beam properties.