Wave-Wave Coupling in Ion Wave Propagation

Abstract

Wave-wave coupling among ion waves is investigated, experimentally and theoretically. When two ion waves of different frequencies of f₁ and f₂ are excited by one grid, the signals of the harmonic (2f₁) and f₁−f₂ are detected by another grid. They are found to grow spatially in some region, on the contrary to those of f₁ and f₂ which decrease monotonously in the region. The growing regions of the harmonic and f₁−f₂ are in accord with those obtained from the theory of the wave-wave coupling among ion waves. The propagation of small-amplitude wave under the large-amplitude wave and the propagation of ion wave with large-amplitude are also investigated.