I explored the physics behind ion thrusters through my IB extended essay by building my own ion thruster and experimenting with factors that affect thrust; for example, the separation between electrodes. It was quite novel to be able to explore a concept that at first seems to be almost science fiction, but then to discover and learn its real life applications and workings. Despite the limitaitions of being unable to test my thruster in real space-like conditions (as a real thruster would be in), just running it in the normal atmosphere was sufficient. I learned about electrohydrodynamics, how to work with high-voltage circuits (ZVS driver outputting 30-50kV), how to model gases in electrostatic systems and how to design an experiment and measurement setup.
Full Paper
You can read a full (personal info redacted) version of my paper below:
More Images
Below are some additional pictures of the engine in action.
Designing the Engine
Another part of this project was designing the engine itself! It is made of aluminium tubes, clothespins, wood and PLA 3D printed parts. In addition to the physical construction, I also designed a dropper resistor system to be able to measure the current flow to the thruster despite the high voltage.
The use of Fusion 360 made the 3D CAD effortless, producing not only the STL files for 3D printing with Cura on an Anycubic Kossel Mini, but also nice technical drawings like the one below:
Visuallizing Shapes of Electric Fields
As a side project, in order to learn more how the shapes of electric fields are affected by the electrode shapes and separation, I ran experiments using Potassium Permanganate ions on semi-wet coffee filter paper. By applying an electric field, one can trace the movement of the aqueous ions and visualise the field shape.
