关键词: 耙子型探针, 梳状型探针, 径向传播, 三维空间结构

Abstract: The toroidal and poloidal symmetries(m~0, n~0) of the measured low frequency zonal flows (f=0~5kHz) and geodesic acoustic mode zonal flow(f=16kHz) electric potential and radial promulgate features were unambiguously identified with displaced Langmuir probe arrays in the edge plasma of the HL-2A tokamak for the first time. The finite radial wave vector (K_r-LF=0.6cm^-1, K_r-GAM=2cm^-1)of the flows was simultaneously estimated. The formation mechanism of the flows is identified to be nonlinear three wave coupling between high frequency turbulent fluctuations and the flows. Changes of zonal flow amplitude bring by ECRH power and the boundary safety factors were simply studied. Moreover, change of zonal flow amplitude in radial direction was too observed.

Key words: Rake probe array, Pectinate probe array, Radial promulgate, Three dimensional spatial structure