- China has unveiled its first blueprints for the HL-4 fusion reactor, with a presentation planned for 2026.
- The HL-4 facility's primary goal is to achieve steady-state burning plasma operation without overheating.
- The facility will become the world's first experimental platform for high-temperature superconducting, high-field, steady-state burning plasmas.
- HL-4 will serve as an engineering validation device, paving the way for a future demonstration reactor.
China has for the first time revealed blueprints and concept art for its next-generation fusion reactor, presenting them at the 2026 Shanghai Fusion Energy Conference. The device, called HL-4, is a tokamak designed to harness the same nuclear fusion process that powers the Sun. To reproduce that process on Earth, tokamaks use toroidal magnetic fields to confine and twist superheated plasma. This motion gives the reactor its name, derived from "tokamak," meaning "circular" or "toroidal flow." China has been exploring this technology for more than fifty years. Since the 1980s, the Southwestern Institute of Physics (SWIP) in Chengdu has led the design of the HL series, progressing from HL-1 through HL-4.
While HL-3 reproduced the core physics of a real burning reactor, it relies on conventional copper coils. Because copper magnets are prone to overheating, the machine cannot operate continuously, according to Nuclear Engineering International.
Key Features of the HL-4 Facility
The new HL-4 facility, currently under construction in Shanghai, aims to address this operational bottleneck. Its primary mission is to achieve steady-state burning plasma operation, meaning the device can run continuously without overheating. It will become the world's first experimental platform for high-temperature superconducting, high-field, steady-state burning plasmas. Engineers at China Fusion Energy have highlighted three major advantages driving the project. First, its fully high-temperature superconducting magnets can generate a magnetic field of 25 Tesla. This powerful field keeps the plasma stable while significantly reducing the reactor's overall footprint, thereby accelerating the technology's iteration cycle.
Second, the facility incorporates AI-driven intelligent operations to manage the reactor's performance. Third, the powerful magnetic field allows physicists to study plasma behavior under conditions previously out of reach.
Building such a powerful magnet system poses formidable engineering challenges, and the team is currently carrying out initial process development on site to keep construction on schedule. Researchers plan to relocate next year to a purpose-built facility in Shanghai. According to Chinese state media outlet CGTN, "By next June, the R&D team will move into a new 500-meter-long super factory, where full-scale magnet manufacturing and testing will begin," noting that the project's goal is to validate the reliability of HTS magnets under complex fusion conditions.
The Project's Future Development Path
Scientists view the project as a key building block rather than an end product. The current goal is to demonstrate that HTS magnets can operate reliably under complex fusion conditions. In essence, HL-4 serves as a scaled-down engineering validation device. Domestic teams in China are exploring multiple technical routes to achieve fusion, but the overall development path follows a clear, phased sequence. Once engineers have validated these core scientific and engineering challenges with HL-4, the plan is to build a demonstration reactor that proves out the technology commercially. "The next stage is the demonstration reactor—commercially showcasing what has already been validated.
Only after that will we enter the commercial reactor stage," said Chen Zhe, deputy director of the design department at China Fusion Energy.
HL-4's Significance for China's Fusion Research
The development of HL-4 marks a major advance for China in fusion technology, particularly in the application of high-temperature superconducting magnets. This not only improves plasma stability but also accelerates rapid technological iteration. Through this project, China hopes to secure a place in the global fusion research landscape and lay the groundwork for future commercial reactors. As the technology matures, China's fusion program could have a profound impact on the global energy landscape.