학술논문
An overview of recent HL-2A experiments
Document Type
article
Author
Duan, XR; Ding, XT; Dong, JQ; Yan, LW; Liu, Yi; Huang, Y; Song, XM; Zou, XL; Xu, M; Yang, QW; Liu, DQ; Rao, J; Xuan, WM; Chen, LY; Mao, WC; Wang, QM; Cao, Z; Li, B; Cao, JY; Lei, GJ; Zhang, JH; Li, XD; Chen, W; Zhao, KJ; Xiao, WW; Chen, CY; Kong, DF; Isobe, M; Morita, S; Cheng, J; Chen, SY; Cui, CH; Cui, ZY; Deng, W; Dong, YB; Feng, BB; Hong, WY; Huang, M; Ji, XQ; Li, GS; Li, HJ; Li, Qing; Liu, CH; Peng, JF; Shi, BZ; Wang, YQ; Yao, LH; Yao, LY; Yu, DL; Yu, LM; Yuan, BS; Zhou, J; Zhou, Y; Zhong, WL; Tynan, G; Diamond, P; Yu, CX; Liu, Yong
Source
Nuclear Fusion. 53(10)
Subject
Language
Abstract
For the first time supersonic molecular beam injection (SMBI) and cluster jet injection (CJI) were applied to mitigate edge-localized modes (ELMs) in HL-2A successfully. The ELM frequency increased by a factor of 2-3 and the heat flux on the divertor target plates decreased by 50% on average after SMBI or CJI. Energetic particle induced modes were observed in different frequency ranges with high-power electron cyclotron resonance heating (ECRH). The high frequency (200-350 kHz) of the modes with a relatively small amplitude was close to the gap frequency of the toroidicity-induced Alfvén eigenmode. The coexistent multi-mode magnetic structures in the high-temperature and low-collision plasma could affect the plasma transport dramatically. Long-lived saturated ideal magnetohydrodynamic instabilities during strong neutral beam injection heating could be suppressed by high-power ECRH. The absolute rate of nonlinear energy transfer between turbulence and zonal flows was measured and the secondary mode competition between low-frequency (LF) zonal flows (ZFs) and geodesic acoustic modes (GAMs) was identified, which demonstrated that ZFs played an important role in the L-H transition. The spontaneously generated E × B shear flow was identified to be responsible for the generation of a large-scale coherent structure (LSCS), which provided unambiguous experimental evidence for the LSCS generation mechanism. New meso-scale electric potential fluctuations (MSEFs) at frequency f ∼ 10.5 kHz with two components of n = 0 and m/n = 6/2 were also identified in the edge plasmas for the first time. The MSEFs coexisted and interacted with magnetic islands of m/n = 6/2, turbulence and LF ZFs. © 2013 IAEA, Vienna.