The world’s biggest superconducting magnet for a nuclear fusion reactor has passed final tests as part of China’s CRAFT “artificial sun” project, eclipsing international performance benchmarks. The assembly comprises two coils: a toroidal-field magnet that acts as a magnetic cage, and a central solenoid that serves as the igniter. The results, achieved by researchers with the Institute of Plasma Physics, Chinese Academy of Sciences, clear a major engineering hurdle on the path to confining a...