Physics / mechanism
A Field-Reversed Configuration is a compact toroid plasma confinement geometry where a reversed magnetic field creates a self-contained plasmoid with no toroidal field component. Plasma current generates a poloidal field that reverses the external field inside the separatrix, producing closed field lines without a physical central conductor. Key dimensionless parameter: s (ratio of separatrix radius to ion gyroradius); FRCs typically operate at s = 2–10. TAE Technologies uses beam-driven FRCs targeting p-B11 fusion (aneutronic); Helion uses pulsed, compressing FRCs targeting D-He3 via field-reversed plasmoid collisions. Helion has demonstrated >10 keV plasma temperatures and claims MW-scale recovered flux. Neither has achieved net energy gain.
Competitive landscape
TAE and Helion are the only serious FRC-fusion plays. Adjacent confinement approaches: tokamaks (ITER, Commonwealth Fusion’s SPARC—higher TRL, deuterium-tritium, neutron-heavy), stellarators (Wendelstein 7-X—steady-state but complex engineering), and dense plasma focus / Z-pinch (Zap Energy—simpler hardware, earlier stage). Inertial confinement (NIF, Marvel Fusion) is a separate branch entirely. FRCs compete on compactness and potential aneutronic operation but lag on plasma stability and confinement time. Compact tokamaks currently hold investor momentum.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.