In the heart of China, a groundbreaking experiment is unfolding, one that could reshape the future of nuclear fusion and, by extension, the global energy landscape. The XuanLong-50 (EXL-50), the country’s first medium-size spherical torus, is making significant strides in achieving non-inductive current drive, a critical step towards practical fusion energy.
Led by Yuejiang Shi of the Hebei Key Laboratory of Compact Fusion at ENN Science and Technology Development Co., Ltd, the EXL-50 team has been pushing the boundaries of what’s possible in fusion research. The device, with its modest 0.5 Tesla magnetic field and 50 cm radius, has achieved plasma currents ranging from 50 kA to an impressive 180 kA, sustained for up to 2 seconds. “The current drive effectiveness we’ve achieved is remarkable,” Shi notes, “reaching up to 1 A per watt for low-density discharges using just 28 GHz electron cyclotron resonance heating (ECRH).”
The implications for the energy sector are profound. Fusion, the same process that powers the sun, promises nearly limitless energy with minimal environmental impact. The EXL-50’s success in achieving high plasma currents without a central solenoid—a device typically used to initiate and sustain the plasma current—is a significant step towards more efficient, compact fusion reactors.
The team has also explored various methods of boron injection, a crucial aspect of achieving proton-boron fusion, a type of fusion reaction that produces fewer neutrons and thus less radioactive waste. “We’ve tested several boron injection systems,” Shi explains, “including gas puffing, powder injection, and pellet injection. Each method has its advantages, and we’re working to optimize them for our upgrade, the EXL-50U.”
The research, published in the English-language journal ‘Nuclear Fusion’, is not just a testament to China’s growing prowess in fusion research but also a beacon of hope for the global energy sector. The findings could accelerate the development of compact, efficient fusion reactors, bringing us one step closer to a future powered by clean, abundant fusion energy.
As the world grapples with climate change and energy security, the EXL-50’s progress serves as a reminder of the power of innovation and the potential of fusion to transform our energy landscape. The journey is far from over, but with each breakthrough, we edge closer to a fusion-powered future.