Generation of Field-Reversed Configurations via Neutral Beam Injection

A breakthrough in Magnetic Fusion Energy (MFE) has been achieved at TAE Technologies. The generation of a Field-Reversed Configuration (FRC) by Neutral Beam Injection (NBI), which has long been attempted without success [1], is now a reality [2]. The advanced beam-driven FRC device "Norman" [3] has been converted into a more compact version called "Norm" that no longer includes theta-pinch formation coils or outer divertors. In Norm, energetic beam neutrals are trapped by an initial seed plasma, leading to a direct source of toroidally directed energetic ion current and resulting current drive. Current builds up gradually, and fully formed FRCs are generated in ∼10 ms. This breakthrough, enabled by technological improvements in NBI, results in FRCs that exhibit macroscopic stability in quiescent equilibrium for the duration of beam injection (up to 40 ms in Norm). Our results demonstrate a new method of forming closed magnetic field topologies, which offer technological simplifications that will significantly decrease the cost of future power plants. This talk will describe this revolutionary FRC generation technique and provide evidence for its efficacy via a variety of independent measurements and calculations.

[1] W.C. Turner et al 1979 Nucl. Fusion 19 1011

[2] T. Roche et al. Generation of field-reversed configurations via neutral beam injection. Nat. Commun. 16, 3487 (2025).

[3] H. Gota et al. Overview of C-2W: high temperature, steady-state beam-driven field-reversed configuration plasmas. Nucl. Fusion 61, 106039 (2021).