EAST steady-state long pulse H-mode with core-edge integration for CFETR. (1st July 2022)

• Record Type: Journal Article
• Authors: Gong, X.Z.; Garofalo, A.M.; Huang, J.; Qian, J.P.; Ekedah, A.; Maingi, R.; holcomb, C.T.; Liu, F.K.; Zhao, Y.P.; Xiao, B.J.; Hu, J.S.; Hu, C.D.; Hu, L.Q.; Wang, M.; Xu, H.D.; Li, E.; Zeng, L.; Zang, Q.; Liu, H.Q.; Lyu, B.; Yuan, Q.P.; Li, K.D.; Zhang, B.; Zhang, J.Y.; Jia, T.Q.; Wu, M.Q.; Chen, J.L.; Zhu, X.; Li, M.H.; Zhang, X.J.; Zhang, L.; Duan, Y.M.; Wang, L.; Ding, R.; Sun, Y.W.; Xu, G.S.; Liang, Y.F.; Xiang, N.; Wan, B.N.; Li, J.G.;
• Is Part Of: Nuclear fusion. Volume 62:Number 7(2022)
• Publication Date: 2022-07-01
• Subjects: steady state -- long pulse -- tokamak; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ac49ad
• Languages: English
• ISSNs: 0029-5515

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, H98y2 ∼ 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, H98y2 ∼ 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 H98y2 > 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% D2 is applied.