Fundamental limits in a magnetically confined thermonuclear fusion reactor

A theory is presented for quantitative calculations of confinement time limits for plasma thermal energies in magnetically confined thermonuclear fusion reactors [1]. The theory is based on radiation reaction associated with spontaneous electron cyclotron radiation as described by the Larmor formula. Good agreement is found between the theory and the measurements of energy confinement times from the early TFTR D-T fusion experiment [2] and the recent Wendelstein 7-X hydrogen plasma experiment [3]. A new, advanced Lawson criterion for D-T ignition is derived. A fundamental limit of fusion energy gain is predicted, which is consistent with the latest magnetically confined D-T fusion energy record achieved experimentally at JET [4].

1. Chen, C., et al. New criterion for ignition in a magnetically confined thermonuclear fusion reactor, submitted for publication in IEEE Trans. Plasma Sci., May 23, 2022.

2. Meade, D.M. TFTR Twenty Year Perspective, 17th IEEE/NPSS Symposium Fusion Engineering, vol. 1, 10, 1997. https://doi.org/10.1109/FUSION.1997.685658

3. Klinger, T., et al. Overview of first Wendelstein 7-X high performance operation, Nucl. Fusion 59, 112004 (2019).

4. Gibney, E. Nuclear fusion reactor smashed new record, Nature 602, 371 (2022).