Seriously, who knew this was a thing?
Plasma Cannon (Electrothermal Accelerator)
An experimental weapon that launches a projectile using a plasma discharge instead of chemical propellant.
How It Works
A large capacitor bank charges up, then discharges across electrodes at the breech. This ionizes a non-flammable propellant medium into superheated plasma, and the resulting rapid expansion pushes the projectile out at high speed.
Advantage
Since energy comes from electricity, velocity can be precisely tuned by adjusting power input, potentially exceeding the speed limits of conventional propellant burn rates.
Disadvantage
Weight. Even a small unit with air-gun-level power is roughly 20 kg without its power supply, making it impractical for infantry. It would need to be vehicle- or emplacement-mounted.
Can a Hobbyist Make a Plasma Cannon?
Short answer: not really a practical "cannon," but the underlying phenomenon (electrothermal plasma acceleration) does show up in hobbyist/DIY high-voltage projects in a much tamer form — think coilguns and railguns, which are related but distinct concepts, rather than true plasma-discharge cannons.
A few reasons a genuine plasma-powered cannon is a poor hobbyist project:
- Power requirements are extreme. Even a small unit needs a capacitor bank storing several kilojoules discharged almost instantaneously — that's enough energy to cause severe injury or death if mishandled, arc unpredictably, or ignite nearby materials.
- Electrode erosion and materials science. The electrodes have to survive repeated superheated plasma arcs without rapidly eroding or fusing — this is a nontrivial materials engineering problem that stumps even funded research programs.
- Weight and infrastructure. Even air-gun-power versions weigh around 20 kg before you add the power supply — you're looking at a bench-mounted rig with serious electrical infrastructure, not something built in a garage over a weekend.
- Legal status. Depending on jurisdiction, a device designed to launch projectiles via this kind of energetic discharge could be legally treated the same as a firearm or worse, regardless of "hobbyist" intent.
Coilguns and railguns are the more common DIY high-voltage projectile projects, though they still involve serious high-voltage/high-current hazards and aren't something to approach casually.