等离子体交换不稳定性的模耦合理论

本文研究部分电离等离子体中交换不稳定性的爆炸型模耦合。从磁流体动力学方程出发,导出交换模相干三波相互作用的模耦合方程,分析产生爆炸不稳定的可能的耦合类型,具体讨论产生爆炸不稳定的条件。结果表明,非线性效应能使交换模达到饱和状态表现为小幅度的正弦型扰动,也能通过模耦合而导致大幅度扰动的爆发。本文的分析,适用于磁镜位形的等离子体和电离层等离子体。 关键词：

MODE COUPLING OF INTERCHANGE INSTABILITY IN PLASMAS

Explosive mode coupling of low frequency interchange instability in partially ionized plasmas is studied. The coupled equations describing coherent wave-wave interactions of the interchange mode are derived. The possibilities of explosive instabilities for the interchange mode are found. It is shown that there exist the explosive coupling of positive energy wave and negative energy wave, positive energy wave and negative dissipation, and negative energy wave and positive dissipation, in the partially ionized plasmas. The theoretical results obtained can be applied to the ionospheric plasma and the mirror-confined plasma.