Influence of fast waves on the collective scattering of microwaves in fusion plasmas

摘要: Microwave scattering by the fluctuations of fusion plasmas is one most promising α-diagnostic techniques. Previous investigations have concentrated on near slow wave branch in lower hybrid range frequencies. The small signal and lack sensitivity to contribution α-particles total cross-section severely limits effectiveness this technique. In paper, we report results frequencies fast branch. Surprisingly, when both branches exist, amplitudes are comparable. More important, α-contribution larger for has a parameter space where it exists. Specifically, exists only above frequency, while can exist at all up electron cyclotron We find numerically that below frequency several orders magnitude than those exist. This may make microwave waves more attractive