Modifications of turbulence and turbulent transport associated with a bias-induced confinement transition in the Large Plasma Device
Modifications of turbulence and turbulent transport associated with a bias-induced confinement transition in the Large Plasma Device
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DOI：
10.1063/1.3059410
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发表时间：
2008-07
影响因子：
2.2
通讯作者：
Troy Carter;James Maggs
中科院分区：
文献类型：
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作者：
Troy Carter;James Maggs
方位流在大型等离子体装置 (LAPD) 的边缘被驱动 [W. Gekelman 等人，Rev. Sci。仪器。 62, 2875 (1991)]通过相对于等离子体源阴极偏置真空容器的一部分。当施加的偏压超过阈值时，观察到径向粒子限制的转变，密度分布急剧陡化证明了这一点，类似于环形限制装置中的 L 模式到 H 模式的转变。径向传输的阈值行为和动态行为与流动渗透以及流动剪切和密度梯度剖面之间的空间重叠程度有关。对与约束转变相关的湍流和湍流粒子输运的变化进行了研究。二维互相关测量表明，LAPD 边缘湍流的空间相干性随偏置发生显着变化。湍流中的方位角相关性急剧增加，而径向相关性长度却几乎没有......
Azimuthal flow is driven in the edge of the Large Plasma Device (LAPD) [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] through biasing a section of the vacuum vessel relative to the plasma source cathode. As the applied bias exceeds a threshold, a transition in radial particle confinement is observed, evidenced by a dramatic steepening in the density profile, similar to the L- to H-mode transition in toroidal confinement devices. The threshold behavior and dynamic behavior of radial transport is related to flow penetration and the degree of spatial overlap between the flow shear and density gradient profiles. An investigation of the changes in turbulence and turbulent particle transport associated with the confinement transition is presented. Two-dimensional cross-correlation measurements show that the spatial coherence of edge turbulence in LAPD changes significantly with biasing. The azimuthal correlation in the turbulence increases dramatically, while the radial correlation length is little al...