Magnet Operation Strategies for Achieving Mega-Ampere Plasma in the HL-2M Tokamak

作者：Qinghua Ren, Xiaolong Liu, Yin Qiu, Long Zhang, Xu Jie, Tao Lin, Hui Zou, Yanfeng Xie, Ruibao Jia, Jianpeng Meng, Ming Li, Jiaqi Wang, Hongbin Xu, Yingqiao Wang, X.Q. Ji · 发表于：IEEE Transactions on Applied Superconductivity · 年份：2024 · DOI：10.1109/tasc.2024.3351957 · 被引用次数：2 · 研究领域：Magnetic confinement fusion research、Superconducting Materials and Applications、Particle accelerators and beam dynamics

HL-2M, a medium-sized tokamak equipped with copper conductors, features a magnetic system comprising a toroidal field (TF) magnet and a poloidal field (PF) magnet. The TF magnet, composed of 20 D-shaped coils, is designed to generate a magnetic field of 3 T at the plasma's center. The PF magnet system includes a central solenoid (CS) coil and eight pairs of independent PF coils, capable of sustaining the plasma with a flux swing in excess of 14 Vs. Prior to entering the mega-ampere plasma operation phase, both TF and PF magnets underwent routine pre-operation inspections. Notably, the TF magnet was pre-stressed using a synchronous hydraulic system to counterbalance the electromagnetic forces from the PF coils, the plasma, and the TF coils themselves. During operational phases, the magnet system was closely monitored by a dedicated machine safety system that measured electrical parameters such as terminal voltages, coil currents, and grounding currents. To prevent mechanical overloading, the interplay between the TF coils' thermal dynamic loads and the preload force applied by the hydraulic system was meticulously controlled. Three-axis accelerometers were installed on the TF coils to measure local forces directly. Through composite detection methods, the TF coil magnetic field achieved 1.5 T, the CS coil current reached 100 kA, and a plasma current of 1.15 MA was successfully sustained. The preparation and implementation of a safety system for magnet operation, with particula...