China’s EAST tokamak sustains stable fusion plasma for one minute

Friday 01 May 2026 - 07:42

By: Dakir Madiha

China’s EAST tokamak sustains stable fusion plasma for one minute

Chinese researchers have achieved a stable, high-performance fusion plasma maintained for a full minute inside a metal-walled tokamak, marking a significant step toward practical nuclear fusion energy. The breakthrough addresses several persistent engineering challenges that have long limited the transition from experimental setups to continuous power generation.

The experiment was conducted on the Experimental Advanced Superconducting Tokamak, known as EAST, often described as an artificial sun. The team, led by Xu Guosheng at the Institute of Plasma Physics under the Chinese Academy of Sciences, developed a new operating mode called a detached divertor and turbulence-dominated pedestal regime. This approach relies on precise, real-time control of light impurity gas injection to stabilize plasma behavior.

One of the central challenges in tokamak operation is managing extreme heat loads directed at the divertor, a component designed to handle exhaust heat. Injecting impurity gases can reduce this heat through a process known as detachment, but excessive cooling destabilizes the plasma edge. At the same time, high-confinement mode, which is essential for efficient fusion, often triggers edge-localized modes, sudden bursts of energy that can damage reactor walls.

The newly demonstrated regime addresses both issues simultaneously. By fine-tuning nitrogen gas injection, researchers achieved partial divertor detachment, reducing heat flux while fully suppressing edge-localized modes. The process also increased electron temperature at the plasma edge, improving overall energy confinement. The closed divertor geometry helped trap neutral particles, enhancing temperature gradients and generating microturbulence that naturally regulated pressure buildup and prevented instability.

Sustaining this integrated plasma state for a full minute represents a major advance. Future fusion reactors will need to operate continuously for extended periods, far beyond the short pulses typical of current experiments. The results suggest a viable pathway to balancing thermal control and plasma stability, two critical requirements for commercial fusion systems.

The findings build on a series of recent milestones achieved with EAST. Earlier experiments surpassed the Greenwald density limit and introduced new confinement regimes using three-dimensional magnetic perturbations. Together, these advances indicate steady progress toward making fusion energy a practical and scalable power source, although significant technical hurdles remain.