Overview of EXL-50 research progress

作者：Yuejiang Shi, Yumin Wang, Bing Liu, Xianming Song, Shaodong Song, Xuheng Jiang, Dong Guo, Di Luo, Xiang Gu, Tiantian Sun, Xianli Huang, Z Y Li, Lili Dong, Xueyun Wang, Gang Yin, Mingyuan Wang, Wenjun Liu, Hanyue Zhao, Huasheng Xie, Yong Liu, Di Qi, Bo Xing, Jiangbo Ding, Chao Wu, Lei Li, Haijun Zhang, Yuanming Yang, Xin Zhao, Enwu Yang, Wenwu Luo, Peihai Zhou, Lei Han, Qing Zhou, Hanqing Wang, Jiaqi Dong, Baoshan Yuan, Yueng-Kay Martin Peng, Minsheng Liu · 发表于：Nuclear Fusion · 年份：2025 · DOI：10.1088/1741-4326/adf239 · 被引用次数：7 · 研究领域：Engineering Applied Research

Abstract XuanLong-50 (EXL-50) is the first medium-size spherical torus (ST) in China. The engineering design and construction of EXL-50 began in October 2018, and the first plasma discharge was obtained in July 2019. The TF of EXL-50 is around 0.5T at R=50cm. An important characteristic of EXL-50 was that it did not have a central solenoid (CS). Non-inductive current drive via ECRH was the main physics research issue. Discharges with plasma currents of 50kA -180 kA were routinely obtained in EXL-50, with the current flattop sustained beyond 2 s. The current drive effectiveness on EXL-50 was as high as 1 A/W for low-density discharges using 28GHz ECRH alone for heating power less than 200kW. The plasma current reached Ip > 80 kA for high-density (5×10^18m^-2) discharges with 150kW ECRH. Higher performance discharge (Ip ~120 kA and core density 10^19m^-3) was achieved with 150kW 50GHz ECRH. The physics mechanisms for the solenoid-free ECRH current drive and the energetic electrons has also been investigated. A LHCD system and a NBI system were also installed on EXL-50, producing some initial experimental results of LHCD. Several boron injection systems were installed and tested in EXL-50, including B2H6 gas puffing, boron powder injection, boron pellet injection. The last plasma discharge in EXL-50 was completed in June 2023. XuanLong-50U (EXL-50U) which is the upgrade device ST device of EXL-50 will be operated in 2024. The TF coil of EXL-50U is designed to provide high mag...