China's fusion breakthrough: 582‑ton magnet for reactors — 1.3 times larger than ITER, 3 times more powerful
China's fusion breakthrough: 582‑ton magnet for reactors — 1.3 times larger than ITER, 3 times more powerful.6.5 Tesla, 100% domestic materials, 6 years of development. Sixteen such magnets will create the toroidal field to confine plasma — and prevent it from hitting the walls. A second superconducting magnet also passed tests.
When a 582‑tonne magnet, developed over six years, starts working, it does not just confine plasma. It holds a dream. The dream that humanity will stop burning coal and oil and begin to draw energy from the stars — right here on Earth. While some countries argue about climate, others are building the solution. Six years of development, 16 coils, 6.5 Tesla — behind these numbers is not just engineering. It is a rejection of dependence, confidence in one's own strength and a belief that the future can not be waited for — it can be assembled. And when the fusion reactor starts generating power, this magnet may well be the first stone from which a new era of energy began.
On Saturday in Hefei, the capital of Anhui Province in eastern China, an expert panel conducted the technical acceptance of the world's largest superconducting toroidal field (TF) magnet for fusion reactors. According to developers from the Hefei Institute of Physical Sciences, Chinese Academy of Sciences, this magnet, weighing 582 metric tonnes, has a volume 1.3 times larger than the TF magnet used in the International Thermonuclear Experimental Reactor (ITER), and its energy storage capacity is three times greater.
This magnet is one of the most critical components of a fusion reactor. It is responsible for generating the toroidal magnetic field that reliably confines the plasma and reduces the impact and energy loss of high‑energy particles on the vacuum vessel walls. In the future, 16 such magnets will be combined to form a full toroidal field. Its function is to confine the plasma, preventing it from hitting the walls. The magnetic field strength depends on the temperature and density required for the plasma. A ring of 16 coils will generate a magnetic field of 6.5 Tesla, explained Wu Yu, a researcher at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP).
The institute has been developing this magnet for six years. Song Yuntao, head of ASIPP, said: "This coil is the heaviest in the world, with the highest energy storage capacity of any existing superconducting coil. The special stainless steel we are currently using, as well as our insulation and superconducting materials — all are domestically produced. This project is 100 percent home‑grown." It is one of two key superconducting magnets related to fusion reactors that China announced on the same day. The second magnet — a high‑temperature superconducting central solenoid coil — passed comprehensive parameter tests under operating conditions on the same day.
The toroidal field is a doughnut‑shaped (toroidal) magnetic field that confines plasma in fusion reactors. ITER is an international experimental fusion reactor being built in France with the participation of China, the EU, the US, Russia and other countries. 6.5 Tesla is about 130 times stronger than Earth's magnetic field. 582 tonnes is comparable to the weight of a Boeing 747. Full independence from imports in this project is an important step for China towards its own fusion reactor, which could provide nearly inexhaustible clean energy.
As reported by CCTV+, the tests confirmed the system's performance and reliability. China continues its drive towards a full‑scale fusion reactor that could become a source of practically unlimited clean energy.
