Coherent structures and transport properties in magnetized plasmas
Coherent structures and transport properties in magnetized plasmas
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DOI：
10.1088/0741-3335/49/12b/s25
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发表时间：
2007-11
影响因子：
2.2
通讯作者：
G. Serianni;M. Agostini;V. Antoni;R. Cavazzana;E. Martines;F. Sattin;P. Scarin;E. Spada;M. Spolaore;N. Vianello;M. Zuin
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文献类型：
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作者：
G. Serianni;M. Agostini;V. Antoni;R. Cavazzana;E. Martines;F. Sattin;P. Scarin;E. Spada;M. Spolaore;N. Vianello;M. Zuin
磁化等离子体的一个共同特征是存在波动，这可能导致充分发展的湍流。通常，大事件（称为爆发）是从剩余的低层湍流中出现的，赋予波动间歇性特征；也就是说，波动的统计特性取决于进行调查的时间尺度。在磁化等离子体中，爆发通常被认为是由于磁场对齐结构的存在造成的。此外，实验表明，信号中检测到的间歇事件与等离子体中粒子损失的相关贡献相关。所有这些观察结果对于跨越较宽温度和密度范围并且在线性和环形装置中均受到磁约束的等离子体来说是常见的。特别是，在用于热核聚变的高温等离子体中，研究旨在设计合适的方法来通过作用于等离子体结构来控制传输，例如通过使用电极偏置等离子体边缘。本文描述了磁化等离子体中的结构及其对粒子输运的贡献；此外，还讨论了速度剪切对结构的影响。重点将放在最先进的诊断上，允许通过光学和静电技术重建湍流结构。
A common feature of magnetized plasmas is the presence of fluctuations, which can lead to fully developed turbulence. Often large events—called bursts—emerge from the remaining low-level turbulence, giving an intermittent character to fluctuations; namely the statistical properties of fluctuations are found to depend on the temporal scale over which the investigation is conducted. In magnetized plasmas, the bursts are generally believed to be due to the presence of magnetic-field-aligned structures. Moreover, it has been experimentally shown that the intermittent events detected in the signals are associated with a relevant contribution to the loss of particles from the plasma. All these observations are common to plasmas spanning a wide range of temperature and density and magnetically confined both in linear and toroidal devices. In particular, in high-temperature plasmas for thermonuclear fusion, research aims at devising suitable ways to control transport by acting on the plasma structures, for instance by biasing the plasma edge using electrodes. This paper gives a characterization of the structures found in magnetized plasmas and of their contribution to the particle transport; moreover, the effect of the velocity shear on structures is addressed. Emphasis will be laid on to the most advanced diagnostics allowing the reconstruction of turbulent structures by optical and electrostatic techniques.