On April 16, ENN’s Xuanlong-50U (EXL-50U) spherical torus (ST) achieved a major milestone by generating a plasma current of one million amperes (1 MA) using hydrogen-boron fuel, the first time in the world. The result advances ENN’s research into high-performance parameters and positions the EXL-50U among the leading international ST experiments, a significant milestone in advancing hydrogen-boron fusion toward a commercial power source.

The EXL-50U is an upgrade of the earlier EXL-50, completing its overhaul in late 2023 within just two and a half months. After initiating its first plasma discharge in January 2024, the device exceeded its performance targets by August 15, 2024. Plans for 2025 will focus on MA experiments of higher-performance hydrogen-boron plasmas.

In this experiment, researchers utilized pure hydrogen-boron fuel combined with microwave heating systems delivering megawatt power. The team resolved the technical challenge of generating large plasma currents efficiently in a ST configuration and demonstrated the feasibility of sustaining hydrogen-boron plasmas of fusion-relevant parameters. These findings advanced the development of hydrogen-boron plasma operation techniques and introduced an important tool for the broader magnetic confinement fusion research.

Looking ahead, the ENN team will address even higher plasma parameters and conduct hydrogen-boron fusion reaction measurements on EXL-50U. Success in these efforts is expected to inform the design and construction of the next-generation Helong-2 (EHL-2) experimental facility, to advance hydrogen-boron fusion research toward power producing conditions.