Sustained edge-localized-modes suppression and radiative divertor with an impurity-driven instability in tokamak plasmas. (5th October 2021)

• Record Type: Journal Article
• Authors: Ye, Y.; Xu, G.S.; Tao, Y.Q.; Chen, R.; Wang, L.; Guo, H.Y.; Wang, H.Q.; Li, K.D.; Meng, L.Y.; Yang, Q.Q.; Wang, Y.F.; Lin, X.; Sun, Z.; Wu, K.; Yuan, Q.P.; Xu, J.C.; Duan, Y.M.; Zhang, L.; Liu, H.Q.; Wan, B.N.
• Is Part Of: Nuclear fusion. Volume 61:Number 11(2021)
• Publication Date: 2021-10-05
• Subjects: ELM-control -- radiative divertor -- impurity radiative condensation instability -- EAST; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ac26eb
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Simultaneous control of the large edge localized modes (ELMs) and divertor heat fluxes in a metal wall environment is a critical issue for steady-state operation of a tokamak fusion reactors. Here we report a sustained ELM suppression scenario achieved in the EAST tokamak compatible with radiative divertor using different seeding impurity species over a wide range of conditions. A low- n mode appears, as manifested by the oscillations of a radiation front near the X-point. This mode appears to drive strong particle transport and tungsten exhaust, which is essential to the maintenance of the ELM-stable state. We have developed a model to explain the mode excitation, by coupling the impurity radiative condensation instability to drift waves, which could explain some characteristics of the low- n mode well. The low- n mode may offer a new ELM-stable scenario compatible with radiative divertor for future fusion reactors.