1. Investigation of the role of fishbone activity in the formation of internal transport barrier in HL-2A plasma.
- Author
-
Deng, Wei, Liu, Y., Ge, W. L., Jiang, Min, Shi, Z. B., Li, Dong, Ji, X. Q., Dong, Y. B., Wang, Feng, Cao, J. Y., Zhong, W. L., Gao, J. M., Po Zhang, Yi, Li, Yong Gao, Wang, Z. X., Xu, Min, and Duan, X. R.
- Subjects
- *
ELECTRON cyclotron resonance heating , *PLASMA turbulence , *ION temperature , *TOKAMAKS - Abstract
A tokamak scenario with q(0) close to 1 has been achieved on HL-2A tokamak, which is an internal transport barrier (ITB) at low central shear or a steady-state ITB combined with an H-mode edge barrier. In this scenario, the formation of an ITB with a steep ion temperature profile is observed to be closely linked to the q = 1 magnetic surface and magnetohydrodynamic (MHD) activities around it, such as long-lived mode (LLM) or fishbone activities. Experimental evidence and simulation analysis suggest that the fishbone activities can induce a poloidal flow, which is beneficial for the suppression of turbulence in the plasma core region. Furthermore, an application of central electron cyclotron resonance heating (ECRH) to such beam-heated weak shear ITB discharges leads to a substantial effect on central MHD stability, converting the LLM into fishbone activity and hence enhancing the strength of the ITB with a much stronger gradient. Moreover, ITBs in combination with an H-mode barrier were achieved for 10 confinement times with βN = 2.0. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF