Effects of divertor geometry on detachment and core plasma performance with impurity seeding in EAST

作者：L.Y. Meng, Liang Wang, Jianbin Liu, Kedong Li, Xin Lin, Xiaoju Liu, Guozhang Jia, Jin Guo, Tao He, Lin Yu, Panjun Tang, J.C. Xu, Wenmin Zhang, Ling Zhang, Jinju Yang, Yanmin Duan, Fubin Zhong, Tao Zhang, Minrui Wang, Zichao Lin, Tianqi Jia, Bin Zhang, Qing Zang, Yaowei Yu, Zhaoxi Chen, Guo Sheng Xu, Baonian Wan · 发表于：Nuclear Fusion · 年份：2024 · DOI：10.1088/1741-4326/ad80aa · 被引用次数：3 · 研究领域：Magnetic confinement fusion research、Fusion materials and technologies、Nuclear reactor physics and engineering

Abstract Divertor detachment operation compatible with the core plasma is an effective method to alleviate the steady-state heat flux approaching the divertor target; this scheme will be adopted by high-performance tokamaks in the future, such as International Thermonuclear Experimental Reactor (ITER). Currently, two ITER-like tungsten divertors with different geometries have been installed at the top and bottom of Experimental Advanced Superconducting Tokamak (EAST), providing conditions for the present study to investigate the effect of divertor geometry on the compatibility between detachment and core plasma. Recent H-mode experiments show that the electron temperature and heat flux of the outer target of the lower divertor decrease lower than those of the upper divertor after similar amounts of impurity are truly injected into the plasma. SOLPS simulations further prove that the closed lower divertor with a ‘corner slot’ structure is beneficial for trapping impurity and deuterium particles, thereby increasing momentum and energy losses. For the upper single-null discharges, the divertor electron temperature can be relatively reduced by increasing impurity seeding, but it is also easy to decrease the plasma stored energy and even lead to an H-L back transition. In addition, statistical data on discharges with impurity seeding show that the proportion of detachment discharges achieved by using the closed divertor is higher than that achieved by using the open divertor. The ...