Journal Article

A sustained high-temperature fusion plasma regime facilitated by fast ions

Lee, K. D., Lee, J. P., Park, Y. S., Choi, M. J., Yoon, S. W., Choi, G. J., Ko, W. H., Kim, S. K., Kim, W. C., Kim, J. H., Sung, C., Hahm, T. S., Park, S. J., Lee, C. Y., Lee, Y. H., Cha, M. S., Jang, J., Gwak, J., Han, H., Lee, J. K., Kang, J., Lee, K. C., Chung, J., Hahn, S. H., Ko, J., Bak, J. G., Park, J.-K., Na, Y.-S., Seo, J., Yang, S. M., Kim, B., Lee, J. H.

2022

Overview

Nuclear fusion is one of the most attractive alternatives to carbon-dependent energy sources 1 . Harnessing energy from nuclear fusion in a large reactor scale, however, still presents many scientific challenges despite the many years of research and steady advances in magnetic confinement approaches. State-of-the-art magnetic fusion devices cannot yet achieve a sustainable fusion performance, which requires a high temperature above 100 million kelvin and sufficient control of instabilities to ensure steady-state operation on the order of tens of seconds 2 , 3 . Here we report experiments at the Korea Superconducting Tokamak Advanced Research 4 device producing a plasma fusion regime that satisfies most of the above requirements: thanks to abundant fast ions stabilizing the core plasma turbulence, we generate plasmas at a temperature of 100 million kelvin lasting up to 20 seconds without plasma edge instabilities or impurity accumulation. A low plasma density combined with a moderate input power for operation is key to establishing this regime by preserving a high fraction of fast ions. This regime is rarely subject to disruption and can be sustained reliably even without a sophisticated control, and thus represents a promising path towards commercial fusion reactors. A magnetic confinement regime established at the Korea Superconducting Tokamak Advanced Research device enables the generation of plasmas over 10 8  kelvin for 20 seconds with the aid of fast ions without plasma edge instabilities or impurity accumulation.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/4077/4091/4093 / 639/766/1960/1136 / 70 PLASMA PHYSICS AND FUSION TECHNOLOGY / Alternative energy sources / Carbon / Carbon sources / Energy / Fusion reactors / High temperature / Humanities and Social Sciences / Ions / magnetically confined plasmas / multidisciplinary / Nuclear fusion / nuclear fusion and fission / Nuclear reactors / Plasma / Plasma density / Plasma turbulence / Reactors / Science / Science (multidisciplinary) / Temperature requirements