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论文类型：期刊论文

发表时间：2013-08-01

发表刊物：NUCLEAR FUSION

收录刊物：SCIE、EI、Scopus

卷号：53

期号：8

ISSN号：0029-5515

摘要：The radial structures of multiple sheared flow populations and fluctuations are simultaneously measured using combinations of Langmuir probe arrays in the edge plasmas of the HL-2A tokamak with ohmic and electron cyclotron resonance heating (ECRH). The maximum of geodesic acoustic mode (GAM) amplitude locates at similar to 2-3 cm inside the last close flux surface (LCFS). The low-frequency zonal flow (LFZF) and GAM tend to coexist in the inner region. The dependences of the amplitudes of the multiple sheared flows and turbulence on ECRH heating power are also investigated. The measured turbulent Reynolds stresses are shown to be strongly correlated with the sheared flows, as predicted by theory. The turbulence is modulated at the each frequency of the multiple sheared flows simultaneously, and the particle fluxes induced by the turbulence are significantly reduced near the LCFS and in the GAM peaking region. The analyses also show that the spatial structures of the turbulent envelopes at the LFZF and GAM frequencies are similar to those observed in LFZF and GAM.