Intermittent turbulence and turbulent structures in a linear magnetized plasma
Intermittent turbulence and turbulent structures in a linear magnetized plasma
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DOI：
10.1063/1.2158929
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发表时间：
2005-04
影响因子：
2.2
通讯作者：
T. Carter
中科院分区：
文献类型：
--
作者：
T. Carter
在美国加州大学洛杉矶分校的大型等离子体装置中，在限制器的阴影中观察到了强间歇性湍流[W。Gekelman等人，Rev. Sci.仪器。62，2875（1991）]。湍流的振幅概率分布函数是强烈偏斜的，其中密度耗尽事件（或“空穴”）在高密度区域中占主导，而密度增强事件（或“斑点”）在低密度区域中占主导。二维交叉条件平均表明，斑点是分离的，向外传播的对流结构具有明确的偶极电位，而孔似乎是一个更广泛的湍流结构的一部分。对这些斑点的统计研究显示，它们的典型尺寸是离子声音回旋半径的十倍，典型速度是声速的十分之一。
Strongly intermittent turbulence is observed in the shadow of a limiter in the large plasma device at UCLA [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)]. The amplitude probability distribution function of the turbulence is strongly skewed, with density depletion events (or “holes”) dominant in the high-density region and density-enhancement events (or “blobs”) dominant in the low-density region. Two-dimensional cross-conditional averaging shows that the blobs are detached, outward-propagating filamentary structures with a clear dipolar potential, while the holes appear to be part of a more extended turbulent structure. A statistical study of the blobs reveals a typical size of ten times the ion sound gyroradius and a typical velocity of one-tenth the sound speed.