Studies on Parametric Instabilities in High-Frequency Wave Heating of Fusion Plasmas

摘要

The effect of secondary wave coupling mechanism on parametric instabilities in plasmas for fusion applications was investigated. Harmonic generation of the low-frequency wave is found to reduce well the reflectivity of Brillouin scattering and to suppress the convective growth of the lower hybrid decay instability. Saturation of Raman scattering by ion wave coupling of the low-frequency mode is also obtained. A very complicated (apparently chaotic) time behavior for weakly damped waves is observed, illustrating the strong nonlinearity inherent in the wave equation systems. The linear threshold for the parametric scattering of the heating wave in electron-cyclotron resonance heating of tokamak plasma was studied.