Historical research guide · 0787 · 2024
FESAC Decadal Study: Clean, multi-purpose fusion power from small field-reversed configuration (FRC) reactors
Samuel A. Cohen
In one minute
Samuel A. Cohen proposes a research programme for compact field-reversed-configuration fusion reactors, or FRCs. These plasma devices use a magnetic configuration different from a tokamak’s. He argues for fuels that release mainly charged reaction products, making direct electrical conversion worth testing and reducing the neutron burden. His programme targets 0.5–50 megawatts in devices about one metre wide and five metres long. Cohen cites progress on plasma stability and confinement, then sets out the work on heating, kinetic modelling, shielding and energy extraction. Direct conversion methods, thermal efficiencies and reactor output are research targets in this plan. Fuel supply, especially helium-3, also shapes the programme. Early applications include spacecraft and remote power systems.
Connection
FRC geometry connects plasma confinement to energy extraction. Charged reaction products could feed electrical conversion or propulsion; the reactor programme has to measure both plasma performance and the usable output.
From the source
Cohen proposes compact FRC reactors at the 0.5–50 MW scale, approximately one metre across and five metres long. These dimensions and outputs are development targets.Summary; §III
He distinguishes FRC physics from tokamak physics: perpendicular current and magnetic field, magnetic nulls, strong spatial gradients and zero rotational transform. He calls for kinetic modelling.§I, points a–d
He cites Princeton experiments with plasma lifetimes far above an earlier tilt-instability prediction, TAE confinement and instability-control work, and Helion’s direct-conversion design. The conversion example is a design, not measured reactor electricity.§II; §III, energy extraction
His programme calls for testing direct electrical conversion, improving the remaining thermal conversion and determining suitable neutron shielding. Mainly charged reaction products reduce the neutron burden but do not eliminate shielding needs.§III, topics 1–2
Spacecraft power and propulsion are proposed early applications. The Mars/Pluto cost savings and shorter transit times are design estimates, not outcomes of flown fusion missions.§IV
Helium-3 supply constrains expansion. Cohen discusses terrestrial supplies for development, extraterrestrial sources, a helium-3-catalysed D–D cycle, and alternative p–boron-11 or D–D fuels.§III, topic 3; §IV
The way in
https://doi.org/10.2172/2438313How to cite it
Samuel A. Cohen (2024) FESAC Decadal Study: Clean, multi-purpose fusion power from small field-reversed configuration (FRC) reactors doi:10.2172/2438313