Physics design of current drive and strategy of heating system for EHL-2 spherical torus

作者：xinchen Jiang, Yuejiang Shi, Shaodong Song, Wenjun Liu, Guang 光 YANG 杨, Xianming Song, Xueyun Wang, Xiang Gu, Gang Yin, Danke Yang, Hanyue Zhao, Yumin Wang, Huasheng Xie, Pengmin Li, Hanqing Wang, K. Zhang, Lei Han, Xiaohe Wu, Chengyue Liu, Bin Wu, Chenyi Song, Xin Li, Jiakang Chen, Pingwei Zheng, D. Banerjee, Quanhe Yang, Jiaqi Dong, Y. Liang, Baoshan Yuan, Yuankai Peng, Xianmei Zhang, the EHL-2 Team · 发表于：Plasma Science and Technology · 年份：2025 · DOI：10.1088/2058-6272/adae71 · 被引用次数：7 · 研究领域：Power Systems and Renewable Energy、Iterative Learning Control Systems、Silicon and Solar Cell Technologies

Abstract ENN He Long-2 (EHL-2) is the next-generation large mega-Ampere (MA) spherical torus (ST) proposed and funded by the ENN company. The design parameters are: T i0 > 30 keV, , I p ~ 3 MA, B t ~ 3 T. One of the biggest challenges of EHL-2 is how to achieve several MA current flat-tops with limited voltage-seconds (Vs) of the center solenoid (CS) coils. In order to minimize the consumption of Vs, a fully non-inductive start-up by electron cyclotron resonance heating (ECRH) will be applied in EHL-2. The ramp-up phase will be accomplished with the synergetic mode between the CS and non-inductive methods. The strategy of non-inductive start-up and ramp-up with synergetic mode has been verified on EXL-50U’s experiments. Based on this strategy, numerical simulations indicate the feasibility of EHL-2 achieving 3 MA plasma current. A high-performance steady-state scenario with I p ~ 1.5 MA is also designed. In this scenario, the bootstrap current fraction f BS > 70%, the safety factor q at the magnetic axis q 0 > 2, the minimum safety factor q min > 1, the poloidal beta β p > 3 and normalized beta β N > 2.3. Each design iteration integrates the validation of physical models with the constraints of engineering implementation, gradually optimizing the performance of the heating and current drive (H&CD) systems. Numerical simulation results for general auxiliary H&CD systems such as neutral beam injection (NBI), electron cyclotron (EC) wave, ion cyclotron ...