Researchers have sustained stable fusion plasma for one minute in a metal-wall tokamak, achieving three critical conditions simultaneously for the first time. The plasma maintained partial divertor detachment, an edge-localized-mode-free high-confinement mode, and strong pedestal performance, marking a major advance toward practical fusion energy.
The breakthrough matters because fusion reactors must manage extreme heat loads on their inner walls. Previous approaches forced engineers to choose between different operational modes, each sacrificing something important. This integrated regime solves that tradeoff by combining heat-load reduction with plasma stability and efficiency.
The one-minute duration demonstrates the regime's stability. Earlier attempts lasted only seconds. Sustaining fusion plasma at useful conditions for extended periods moves the technology closer to continuous operation required for power generation.
The team published their results in Physical Review Letters. The work used a metal-wall environment, which better mimics future commercial reactors than carbon walls used in earlier experiments.
Next steps involve extending the duration further and testing the regime at higher power levels. Researchers will also explore scaling the results to larger tokamaks. These advances bring fusion closer to becoming a viable clean energy source.