January 6, 2026 – The world’s first all-HTS tokamak, HH70, achieved a significant breakthrough. In its 5319th shot, the device successfully realized a 120-second steady-state long-pulse plasma operation. This result marks that HH70 has attained reliable long-pulse operational capability and further validates the engineering reliability and operational stability of the HTS tokamak. This also represents the first instance worldwide of a nuclear fusion device, developed and constructed by a commercial company, successfully completing a plasma current long-pulse operation at the hundred-second level.
Since its commissioning and first plasma achievement in June 2024, the performance and capabilities of the HH70 device have steadily improved:
- December 2024: The cryogenic system was upgraded, lowering the magnet operating temperature to 9 K and enabling the toroidal field to exceed 1 T.
- July 2025: The first wall was manufactured and successfully installed.
- October 2025: The poloidal field magnet power supply was upgraded, passing a 20,000-second continuous operation test.
- November 2025: Two sets of independently developed LHCD current drive systems completed installation and commissioning.
The long-pulse experiment campaign on HH70 officially commenced in November 2025, with plasma discharge duration rapidly surpassing 120 seconds. The Energy Singularity team successfully addressed key physics and engineering challenges associated with long-pulse operation, including plasma-wall interactions, AI-based real-time diagnostics, high-power RF current drive, and plasma shape control. This provides a crucial experimental foundation for the development of subsequent devices like the planned HH170.
In subsequent experiments with HH70, the team will activate the AI-based plasma real-time control system, aiming to achieve even better experimental results.