Two-Nozzle FRC Mirror Architecture
Symmetric open-field geometry — both ends produce thrust in the same direction
FRC Fusion Core
p + ¹¹B → 3α + 8.7 MeV
Isotropic emission into 4π
Primary Nozzle
Collimated exhaust → thrust
Secondary Nozzle
Captures "lost" alphas → more thrust
Spacecraft structure (radially outboard, magnetically shielded)
Spacecraft structure
← Net thrust
Trapped alphas bounce between mirrors,
transferring momentum each bounce, until scattering into a loss cone
Capture fraction → ~100% (minus thermalization losses). Both nozzles push the same direction.