Properties of Density Fluctuations Induced by Geodesic Acoustic Mode in the Edge of HT-7 Tokamak
Properties of the geodesic acoustic mode (GAM)density fluctuations are studied using two toroidally separated Langmuir triple-probe arrays on the top of HT-7 tokamak. The GAM scenario is identified in the potential fluctuations with the toroidally symmetric structure (n=0) and satisfying the temperature scaling of GAM mode frequency. Some theoretical predictions about the mode features of GAM density fluctuations are verified in our experiments: the toroidal mode number of GAM density fluctuations is n=0; its amplitude is consistent with the theoretical prediction in a factor of 2; the density and potential fluctuations of GAM is in anti-phase at the top of plasma cross-section. Strong nonlinear interactions are found between GAM density fluctuations and ambient turbulence (AT). The results support the conclusions that the envelope modulation of potential fluctuations is dominantly caused by the direct regulation of GAM in the generation processing, and the envelope modulation of density fluctuation is due to the GAM shear effect.
zonal flows geodesic acoustic mode (GAM) density fluctuations
ZHAO Hailin WAN Baonian LI Jiangang LAN Tao LIU Adi KONG Defeng XIE Jinlin LIU Wandong YU Changxuan ZHANG Wei CHANG Jiafeng
CAS Key Laboratory of Basic Plasma Physics, and Department of Modern Physics, University of Science Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
国际会议
西安
英文
262-267
2009-10-26（万方平台首次上网日期，不代表论文的发表时间）