Multi-field characteristics and eigenmode spatial structure of geodesic acoustic modes in DIII-D L-mode plasmas
Multi-field characteristics and eigenmode spatial structure of geodesic acoustic modes in DIII-D L-mode plasmas
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DOI：
10.1063/1.4819501
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发表时间：
2013-09
影响因子：
2.2
通讯作者：
Gang Wang;W. Peebles;T. Rhodes;M. Austin;Zheng Yan;G. McKee;R. L. Haye;K. Burrell;E. Doyle;J. Hillesheim;M. Lanctot;R. Nazikian;C. Petty;L. Schmitz;Sterling P. Smith;E. Strait;M. A. Zeeland;L. Zeng
中科院分区：
文献类型：
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作者：
Gang Wang;W. Peebles;T. Rhodes;M. Austin;Zheng Yan;G. McKee;R. L. Haye;K. Burrell;E. Doyle;J. Hillesheim;M. Lanctot;R. Nazikian;C. Petty;L. Schmitz;Sterling P. Smith;E. Strait;M. A. Zeeland;L. Zeng
测地线声学模（GAM）是纬向流的一种相干形式，在湍流调节和横向磁场输运中起着关键作用。在DIII-D托卡马克装置上，测量了本征模高斯姆的多场特性和径向结构的独特信息。两个同时且不同的、径向重叠的本征模GAM（即，在L模等离子体中的极向E×B流中观察到了一种频率与半径的关系为常数的现象。当等离子体从L模式过渡到欧姆状态时，这些本征模GAM中的一个成为连续GAM（频率响应于局部参数），而第二个衰减到低于噪声水平。本征模的GAM分别占据ρ = 0.6-0.8和0.75-0.95的径向范围。此外，在GAM频率的振荡是第一次观察到多个等离子体参数，包括ne，Te，和Bθ。在GAM频率下Te/Te的大小（与ne/ne的大小相似）和测量的ne-Te交叉相位（在GAM频率下为140°）的结果一致。
The geodesic acoustic mode (GAM), a coherent form of the zonal flow, plays a critical role in turbulence regulation and cross-magnetic-field transport. In the DIII-D tokamak, unique information on multi-field characteristics and radial structure of eigenmode GAMs has been measured. Two simultaneous and distinct, radially overlapping eigenmode GAMs (i.e., constant frequency vs. radius) have been observed in the poloidal E×B flow in L-mode plasmas. As the plasma transitions from an L-mode to an Ohmic regime, one of these eigenmode GAMs becomes a continuum GAM (frequency responds to local parameters), while the second decays below the noise level. The eigenmode GAMs occupy a radial range of ρ = 0.6–0.8 and 0.75–0.95, respectively. In addition, oscillations at the GAM frequency are observed for the first time in multiple plasma parameters, including ne, Te, and Bθ. The magnitude of Te/Te at the GAM frequency (the magnitude is similar to that of ne/ne) and measured ne–Te cross-phase (∼140° at the GAM frequen...