Technologies that convert the kinetic energy of charged fusion products directly into electricity without a thermal cycle — potentially doubling the efficiency of aneutronic and mirror fusion reactors.
In a conventional power plant (fission or fusion), thermal energy heats a working fluid to drive a turbine and generator. Direct energy conversion (DEC) skips this thermal cycle by decelerating charged particles (ions or electrons) through electric or magnetic fields, converting their kinetic energy directly into electrical current.[1]
Mirror machines: Particles escaping through the ends of a magnetic mirror can be decelerated by electrostatic fields in an expander tank. This was demonstrated at LLNL in the 1970s–80s. Realta Fusion demonstrated DEC on the WHAM experiment in June 2026.[2]
Helion Energy: Uses a pulsed approach where the expanding FRC plasmoid compresses a magnetic field, inducing current in external coils — a form of magnetic direct conversion.
Aneutronic fusion: For p-11B or D-3He reactions that produce mostly charged particles, DEC is essential because there are few neutrons to capture thermally.
DEC has only been demonstrated at low power levels. Scaling to hundreds of megawatts while maintaining high efficiency and managing space charge effects, electrode erosion, and secondary electron emission are unsolved engineering problems.[3]