A remarkable feat has just been achieved in China in the quest for clean and inexhaustible energy. An experimental nuclear fusion machine has succeeded in maintaining plasma confinement for a record-breaking duration, far surpassing previous performances. This breakthrough could bring humanity closer to mastering nuclear fusion, often hailed as the energy of the future.
The EAST tokamak has set a new record for plasma confinement duration.
Credit: HFIPS
The EAST tokamak, nicknamed the "Chinese artificial sun," maintained stable plasma for 1,066 seconds. This unprecedented duration was achieved by researchers at the Hefei Institutes of Physical Science, affiliated with the Chinese Academy of Sciences. For comparison, the previous record, set by the same facility in 2023, was 403 seconds.
For decades, scientists have been trying to replicate on Earth the fusion reactions that naturally power the Sun. By fusing hydrogen nuclei, this process releases an immense amount of energy without greenhouse gas emissions or highly radioactive waste. However, for this reaction to be industrially viable, plasma must be maintained at over 100 million degrees Celsius for an extended period.
The director of the Hefei Institutes of Physical Science, SONG Yuntao, emphasized that the stable operation of plasma over such a long period is a key step toward designing operational reactors. He noted that plasma stability is essential to ensure the viability of a continuous fusion power plant.
Significant technical improvements enabled this achievement. According to Gong Xianzu, head of experimental operations at EAST, several systems were upgraded, including the heating device, which now delivers double the power compared to previous tests. The injected energy is equivalent to that produced by tens of thousands of domestic microwave ovens.
Prolonged plasma stability represents a major breakthrough for nuclear fusion.
Credit: HFIPS
Since its launch in 2006, EAST has served as a testing ground for researchers worldwide. China also plays a central role in the ITER project, under construction in France, where it contributes 9% of the technical input. ITER is set to become the largest experimental magnetic confinement fusion reactor ever built.
The progress made on EAST provides crucial data for ITER and future Chinese reactors, such as the CFETR. These facilities will explore the conditions necessary for continuous energy production through fusion. The stated ambition is to turn these experiments into concrete solutions for global energy supply.
In parallel, China is investing in new nuclear fusion research infrastructure. In Anhui Province, where EAST is located, additional laboratories are under construction to accelerate the development of this technology. The ultimate goal remains unchanged: to make fusion an accessible and sustainable energy source for future generations.
Why is nuclear fusion a promising energy source?
Nuclear fusion is the process that powers the Sun and stars. It involves fusing two light nuclei to form a heavier nucleus, releasing a large amount of energy. Unlike nuclear fission, used in current power plants, it does not produce long-lived radioactive waste or risks of uncontrolled chain reactions.
One of its main advantages in the current experimental context is its fuel: deuterium, extracted from seawater, and tritium, produced from lithium. These elements are abundant, ensuring a nearly inexhaustible energy source. Moreover, fusion does not generate greenhouse gas emissions, making it an ideal alternative to fossil fuels.
What is a tokamak?
A tokamak is an experimental device designed to confine hot plasma using a powerful magnetic field. Its goal is to replicate the nuclear fusion reactions that occur naturally in stars, in order to produce energy on Earth.
Its structure relies on a torus-shaped chamber, where atomic nuclei are heated to temperatures exceeding 100 million degrees Celsius. At these extreme temperatures, nuclei collide and fuse, releasing an even greater amount of energy in the form of heat.
The magnetic field, generated by superconducting coils, prevents the plasma from touching the reactor walls. Without this confinement, the temperatures would destroy the tokamak's materials. One of the major challenges remains maintaining this plasma stable and confined for a sufficiently long duration to produce usable energy.
Projects like ITER in France and EAST in China aim to demonstrate that tokamak fusion can become a viable energy source. If these experimental reactors succeed, they will pave the way for fusion power plants capable of providing clean and nearly limitless energy.