EAST steady-state long pulse H-mode with core-edge integration for CFETR
Xianzu Gong, A. M. Garofalo, Juan Huang, Jinping Qian, A. Ekedahl, R. Maingi, C. T. Holcomb, Fukun Liu, Yanping Zhao, Bingjia Xiao, Jiansheng Hu, Chundong Hu, Hu Liqun, Mao Wang, Handong Xu, Erzhong Li, Long Zeng, Qing Zang, H.Q. Liu, Bo Lyu, Qiping Yuan, Kedong Li, B. Zhang, J Y Zhang, Tianqi Jia, Muquan Wu, Jiale Chen, X. Zhu, Miaohui Li, Xinjun Zhang, Ling Zhang, Yanmin Duan, L. Wang, Rui Ding, Youwen Sun, Guo Sheng Xu, Y. Liang, Nong Xiang, Baonian Wan, Jiangang Li
Abstract
Abstract A recent EAST experiment has successfully demonstrated long pulse steady-state high plasma performance scenario and core-edge integration since the last IAEA in 2018. A discharge with a duration over 60 s with β P ∼ 2.0, β N ∼ 1.6, H 98y2 ∼ 1.3 and an internal transport barrier on the electron temperature channel is obtained with multi-RF power heating and current drive. A higher β N ( β N ∼ 1.8, β p ∼ 2.0, H 98y2 ∼ 1.3, n e / n GW ∼ 0.75) with a duration of 20 s is achieved by using the modulated neutral beam and multi-RF power, where several normalized parameters are close or even higher than the phase III 1 GW scenario of CFETR steady-state. High-Z impurity accumulation in the plasma core is well controlled in a low level by using the on-axis ECH. Modeling shows that the strong diffusion of TEM turbulence in the central region prevents tungsten impurity from accumulating. More recently, EAST has demonstrated compatible core-edge integration discharges in the high β p scenario: high confinement H 98y2 > 1.2 with high β P ∼ 2.5/ β N ∼ 2.0 and f bs ∼ 50% is sustained with reduced divertor heat flux at high density n e / n GW ∼ 0.7 and moderate q 95 ∼ 6.7. By combining active impurity seeding through radiative divertor feedback control and strike point splitting induced by resonant perturbation coil, the peak heat flux is reduced by 20–30% on the ITER-like tungsten divertor, here a mixture of 50% neon and 50% D 2 is applied.