China has marked another milestone in its pursuit of next-generation fusion technology, with the successful completion of a key system for its "artificial sun" project. This system, which passed an expert review and acceptance on Mar. 9, meets international standards in both development and operational capability.

The system, known as one-eighth vacuum chamber and overall installation system, was developed by the Institute of Plasma Physics at the Hefei Institutes of Physical Science, part of the Chinese Academy of Sciences. It is one of the 19 key subsystems for Comprehensive Research Facility for Fusion Technology (CRAFT), China's next-generation "artificial sun." Designed as a testing platform for critical fusion reactor components, CRAFT is expected to be completed in 2025.

Resembling a gigantic orange slice, the newly approved vacuum chamber features a D-shaped cross-section with a double-layer shell that stands 20 meters tall. Constructed from ultra-low-carbon stainless steel, the chamber weighs an impressive 295 tons. Once operational, eight of these "orange slices" will combine to form a complete structure capable of containing plasma at temperatures exceeding 100 million degrees Celsius.

LIU Zhihong, the lead scientist for this project, emphasized the importance of the vacuum chamber's role as a nuclear safety barrier surrounding the reactor core. He highlighted the need for extreme precision in welding, as well as ensuring structural integrity and magnetic permeability.

The research team dedicated the past decade to overcoming various technical challenges, securing more than 40 invention patents along the way.

"With the completion of the one-eighth vacuum chamber, we have acquired critical technologies necessary for the complete toroidal vacuum chamber in future fusion reactors," LIU said. He further noted that the innovations developed for this system have also found applications in particle accelerators, precision machinery, and electronics.

The ultimate vision behind the artificial sun is to replicate the nuclear fusion process that powers the sun, thus providing humanity with a virtually limitless and clean energy source, while also enabling future space exploration beyond our solar system.

Comprehensive Research Facility for Fusion Technology reaches internationally advanced level. (Image by HFIPS)

Researchers and experts take photos in front of the one-eighth vacuum chamber and overall installation system. (Image by HFIPS)