Electron Landau damping of lower hybrid waves
Electron Landau damping of lower hybrid waves
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DOI：
10.1088/0029-5515/18/4/005
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发表时间：
1978-04
期刊：
影响因子：
3.3
通讯作者：
M. Brambilla
中科院分区：
文献类型：
--
作者：
M. Brambilla
回顾了电子朗道阻尼（ELD）在较低混合谐振区域中的作用。首先，结果表明，只有当天线面对脆弱的等离子体时，才可能实现与有限长度天线的有效 ELD 足够大的平行指数 n|| 的波的良好匹配，使得 。这种情况在最近使用相控波导阵列作为发射结构的实验中似乎很普遍。此外，研究表明，在遭受明显的 ELD 之前，频谱的相关部分将被线性波变换耗尽，除非频率至少比等离子体核心的谐振频率高 1.5 倍。因此，在设计用于在谐振区域中高效离子加热的相控波导阵列的情况下，几乎不超过百分之几的功率将被通过ELD的电子吸收。另一方面，只要天线设计合适，ELD 本身就可以被视为一种将大型等离子体加热到热核温度的简单而有效的方法。
The role of electron Landau damping (ELD) in the lower hybrid resonance region is reviewed. First, it is shown that good matching of waves with parallel index n∥ large enough for efficient ELD from a finite-length antenna is possible only if the antenna is facing a tenuous plasma such that . This situation appears to prevail in recent experiments using phased waveguide arrays as launching structures. Moreover, it is shown that the relevant portion of the spectrum will be depleted by linear wave transformation before suffering appreciable ELD, unless the frequency is at least 1.5 times higher than the resonant frequency in the core of the plasma. Thus, in the case of a phased waveguide array designed for efficient ion heating in the resonance region, hardly more than a few per cent of the power will be absorbed by the electrons through ELD. On the other hand, provided that the antenna design is appropriate, ELD itself can be regarded as a simple and efficient method of heating large plasmas up to thermonuclear temperatures.