PROTOTYPING AND OPTIMIZATION OF A MINIATURE MICROWAVE-FREQUENCY ION THRUSTER
Open Access
- Author:
- Asif, Mohammed
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 22, 2018
- Committee Members:
- Sven Bilen, Thesis Advisor/Co-Advisor
Michael M. Micci, Thesis Advisor/Co-Advisor
Amy Ruth Pritchett, Committee Member - Keywords:
- space propulsion
plasma propulsion
propulsion
electric propulsion
rocket propulsion
ion engines
microwave thruster
ion thruster
experimental research on electric propulsion
computational research on electric propulsion
miniaturization of electric propulsion
ion thrusters for CubeSats
electric propulsion for CubeSats - Abstract:
- This thesis presents progress on the development of the Miniature Microwave-Frequency Ion Thruster (MMIT), currently being developed at Penn State as a microthruster with high specific impulse that can be used on small satellites for station keeping, attitude adjustments, and modest delta-V maneuvers. The MMIT works by generating a microwave electron cyclotron resonance (ECR) discharge plasma, then accelerating ions through a series of electrostatic grids. Using argon as the propellant, the MMIT can start with as low as 2.6 W of total absorbed power from a 4.98-GHz coaxial input power source. For the current MMIT iteration, our research thrusts have been threefold: demonstrating plasma generation; sustaining and containing the plasma; and extracting the ion beam. We have largely focused on optimizing the geometry of the magnets and antenna used for ECR plasma generation; defining the geometry of the chamber for containment of the plasma; and developing grid geometries for efficient beam extraction. Progress to date toward a functional prototype has leveraged numerical simulations and experimental measurements on the proof-of-concept design, which we are currently further optimizing. A Langmuir probe is used to measure ion density and temperature in the plume as well as beam current, and a Faraday cup is used to measure the current density of the beam. The measurements obtained from these probes are used as the basis for determining a calculated thrust for the MMIT.