人工太陽実験で核融合プラズマ密度限界を突破する方法を発見（China’s “artificial sun” Experiment Finds Way to Break Fusion Plasma Density Limit）

2026-01-04 中国科学院（CAS）

＜関連情報＞

• https://english.cas.cn/newsroom/cas_media/202601/t20260104_1145019.shtml
• https://www.science.org/doi/10.1126/sciadv.adz3040

EASTにおけるECRH支援オーミック起動による密度ゼロ領域へのアクセス Accessing the density-free regime with ECRH-assisted ohmic start-up on EAST

Jiaxing Liu, Ping Zhu, Dominique Franck Escande, Wenbin Liu, […] , and the EAST team
Science Advances  Published:1 Jan 2026
DOI:https://doi.org/10.1126/sciadv.adz3040

Abstract

High plasma density operation is crucial for a tokamak to achieve energy breakeven and burning plasma. However, there is often an empirical upper limit of electron density in tokamak operation, namely, the Greenwald density limit n_G, above which tokamaks generally disrupt. Achieving high-density operation above the density limit has been a long-standing challenge in magnetic confinement fusion research. Here, we report experimental results on the Experimental Advanced Superconducting Tokamak (EAST) achieving line-averaged electron density in the range of (1.3 to 1.65)n_G , significantly above the typical EAST operational range of (0.8 to 1.0)n_G . This is performed with electron cyclotron resonance heating (ECRH)–assisted ohmic start-up and sufficiently high initial neutral density. These experiments are shown to operate in the density-free regime first predicted by a recent plasma-wall self-organization theory. These results suggest a promising scheme for substantially increasing the density limit in tokamaks, a critical advancement toward achieving burning plasma.