Liu A D, Lan T, Yu C X, Zhao H L, Yan L W, Hong W Y, Dong J Q, Zhao K J, Qian J, Cheng J, Duan X R, Liu Y
CAS Key Laboratory of Basic Plasma Physics, and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Rev Lett. 2009 Aug 28;103(9):095002. doi: 10.1103/PhysRevLett.103.095002. Epub 2009 Aug 27.
A low-frequency (<4 kHz), poloidally and toroidally symmetrical potential structure that peaks near zero frequency is observed in the edge plasma of the HL-2A tokamak. The axisymmetry structure exhibits a radial coherence length less than 1 cm. These characteristics are consistent with the theoretically predicted low-frequency zonal flows (LFZF). The radial wave-number frequency spectra of the LFZF show that the LFZF packets propagate both outwards and inwards. The geodesic acoustic mode (GAM) is found to coexist with the LFZF, and the LFZF is found to modulate the GAM and ambient turbulence with in-phase and antiphase relations, respectively, through an envelope analysis.
在HL-2A托卡马克装置的边缘等离子体中，观测到一种低频（<4千赫兹）、具有极向和环向对称性的电势结构，其峰值出现在接近零频率处。这种轴对称结构的径向相干长度小于1厘米。这些特征与理论预测的低频带状流（LFZF）相符。LFZF的径向波数频率谱表明，LFZF包既向外传播也向内传播。发现 geodesic 声学模（GAM）与LFZF共存，并且通过包络分析发现，LFZF分别以同相和反相关系调制GAM和环境湍流。
