热电子等离子体低频不稳定性的非线性理论

NONLINEAR THEORY OF LOW FREQUENCY INSTABILITIES IN A HOT ELECTRON PLASMA

本文分析了热电子等离子体中低频漂移不稳定性和交换不稳定性的非线性性质,导出了扰动幅度随时间变化的非线性耦合方程,得到了等离子体密度扰动的饱和幅度,讨论了热电子成分对饱和幅度的影响。漂移波引起的等离子体密度扰动相对幅度约20％,交换模引起的等离子体密度相对扰动幅度约5％。当热电子成分达到线性稳定条件所要求的阈值时,漂移波和交换模的饱和幅度降为零。

Nonlinear behaviors of low frequency drift instability and interchange instability in a hot electron plasma are analyzed. Nonlinear coupled equations describing evolution of perturbed densities are derived. Saturated amplitudes of plasma perturbations are found. Effects of the hot electron component on the saturated amplitudes are discussed. The amplitude of perturbed density of the drift wave is about 20%, and that of the interchange mode is about 5%. The amplitudes of plasma perturbations vanish if the hot electron component satisfies the linear stability criteria of the instabilities.