Antiprotons are held away from the ship's walls in a magnetic "Penning-style" trap. A small, metered stream is released to meet ordinary matter in a reaction chamber, where every particle-antiparticle pair annihilates completely into energetic pions and gamma rays — no combustion, no leftover ash, the whole rest mass becomes energy.
E = m·c² (100% mass-to-energy conversion)
P = ṁ_total · c² (reactor power from annihilated mass)
F = η · P / c (thrust from the collimated exhaust)
Isp = F / (ṁ_total · g₀)
- Antimatter feed rate — sets how much antimatter meets matter each second; matched matter doubles the annihilated mass, so reactor power and thrust scale with it directly.
- Nozzle field strength — a stronger magnetic nozzle collimates more of the charged pion exhaust into useful directed thrust instead of letting it spray sideways, raising the conversion efficiency η.
- Containment field — keeps the orbiting antiproton cloud clear of the trap walls; too weak and antiprotons would drift into the container and annihilate early, wasting fuel before it ever reaches the chamber.
Real-world relevance: at 100% mass-to-energy conversion, antimatter propulsion has the highest theoretical exhaust energy of any rocket concept — but producing and safely storing even a few micrograms of antimatter remains far beyond current technology, which is why this simulator uses microgram-per-second feed rates rather than the kilograms a real interstellar mission would need.