A direct fusion drive for rocket propulsion

The Direct Fusion Drive (DFD), a compact, anuetronic fusion engine, will enable more challenging exploration missions in the solar system. The engine proposed here uses a deuterium-helium-3 reaction to produce fusion energy by employing a novel field-reversed configuration (FRC) for magnetic confinement. The FRC has a simple linear solenoid coil geometry yet generates higher plasma pressure, hence higher fusion power density, for a given magnetic field strength than other magnetic-confinement plasma devices. Waste heat generated from the plasma's Bremsstrahlung and synchrotron radiation is recycled to maintain the fusion temperature. The charged reaction products, augmented by additional propellant, are exhausted through a magnetic nozzle. A 1MW DFD is presented in the context of a mission to deploy the James Webb Space Telescope (6200kg) from GPS orbit to a Sun-Earth L2 halo orbit in 37 days using just 353kg of propellant and about half a kilogram of 3He. The engine is designed to produce 40N of thrust with an exhaust velocity of 56.5km/s and has a specific power of 0.18kW/kg.