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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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Fusion Science and Technology
November 2025
Latest News
What’s the most difficult question you’ve been asked as a maintenance instructor?
Blye Widmar
"Where are the prints?!"
This was the final question in an onslaught of verbal feedback, comments, and critiques I received from my students back in 2019. I had two years of instructor experience and was teaching a class that had been meticulously rehearsed in preparation for an accreditation visit. I knew the training material well and transferred that knowledge effectively enough for all the students to pass the class. As we wrapped up, I asked the students how they felt about my first big system-level class, and they did not hold back.
“Why was the exam from memory when we don’t work from memory in the plant?” “Why didn’t we refer to the vendor documents?” “Why didn’t we practice more on the mock-up?” And so on.
Panle Liu, Bo Li, Xue Zheng, Xiang Chen, Qiang Li, Junzhao Zhang, Yihang Chen, Jian Zhou, Rui Ma, Zhongmin Huang
Fusion Science and Technology | Volume 81 | Number 5 | July 2025 | Pages 413-424
Research Article | doi.org/10.1080/15361055.2024.2437331
Articles are hosted by Taylor and Francis Online.
Achieving advanced divertor configurations and high-confinement operating regimes is crucial for mitigating divertor heat loads and exploring enhanced confinement physics in the HL-2M tokamak. However, these scenarios with highly elongated plasmas face severe vertical displacement events that can lead to rapid plasma termination and potential device damage. Robust active control of vertical instability is therefore essential. As HL-2M lacks internal control coils, we developed two sets of vertical stabilization (VS) control systems, each employing a pair of external poloidal field (PF) coils, PF main power supplies, and VS power supplies. This paper details the first vertical stabilization (VS1) control system’s circuit diagram, hardware architecture, and software implementation and discusses issues encountered during commissioning and their solutions. By improving the internal hardware of the VS power supply, the voltage rise time was reduced to approximately 30 μs, resolving branch current imbalances. The transmission delay of the control signals is approximately 38 μs. Preliminary plasma experiments demonstrated effective vertical displacement control with the VS1 control system, achieving a maximum plasma elongation of 1.73 and typical control accuracy of ~20 mm. This work lays the foundation for robust control under high-parameter operational scenarios and the design and implementation of the higher-power second vertical stabilization (VS2) control system.