Low-frequency wave excitation by weak nonlinear interaction of two high-frequency pump waves: part II-experiments
This paper presents an experimental study of the characteristics of the LF wave excited in a hot magnetized plasma column by weak nonlinear interaction of two HF pump waves. These experimental features are systematically compared with theoretical ones which have been established in a previous theoretical paper.
Plasma Resonances of Positive Column in a Magnetic Field
By applying a weak magnetic field along the axis of positive column of discharge the resonance absorption was observed. The resonance due to surface wave of dipole mode showed splitting. However, the resonance due to dipole oscillation and the resonance due to longitudinal plasma wave did not change remarkably. An explanation for those phenomena was given.
Bounded, Resonantly Sustained High‐Frequency Plasmas in a Magnetic Field and Densities High above Critical Density
It is shown that the wave properties of a magnetized plasma column, i.e., of a bounded magnetized plasma, at low incident high‐frequency power determine the behavior of the column at high hf power. At high hf power, the energy absorbed is sufficient to sustain the plasma in one of its linear (i.e., low‐power) resonant states. The plasma can either be sustained in one of its cold plasma resonant states or in its hot plasma resonant states. A partially quantitative theoretical picture can be drawn and maxima of the density as a function of B0 (static magnetic induction) exactly predicted. In this manner densities high above critical density (ωe > ω; ω is the angular frequency of hf field; ωe is the electron plasma frequency) can be obtained in the neighborhood of the lower cyclotron harmonics and along the upper branch of the cold plasma resonances. Ejection of plasma outside the interaction region between plasma and wave is observed. This ejection gives rise to plasma “tongues” with density maxima not corr...