The world’s largest tokamak has started integrated commissioning, testing in-vessel control coils for the first time on a large superconducting device.
Japan’s JT-60SA began integrated test operations on February 27, 2026, moving the device closer to first plasma heating experiments later this year.
This milestone follows a major upgrade campaign that began in 2024, during which teams installed neutral beam heating, radio-frequency systems, in-vessel control coils, heat-handling components, and new diagnostics. Integrated test operations now verify that all these systems work together.
For the first time on any large tokamak, engineers successfully energized the newly installed in-vessel control coils. These coils will be essential for stabilizing and shaping ultra-hot plasmas during full heating experiments. Testing them represents a “first-of-a-kind experience,” according to QST, building a foundation for ITER and future demonstration reactors.
With commissioning underway, the JT-60SA team aims to begin full plasma heating experiments before the end of 2026, exploring high-temperature plasma control at a scale unmatched by any existing tokamak.
Significance: This proves that a large superconducting tokamak can operate advanced in-vessel magnetic control systems, a crucial capability for regulating burning plasmas in future fusion power plants.
Check the original press release:
https://www.qst.go.jp/site/press/20260313.html