STIMULATED SOUND SCATTERING AT A LIQUID INTERFACE UNDER SURFACE RESONANCE CONDITIONS.

The stimulations scattering of sound is analyzed at an interface between two low-viscosity liquids under surface resonance conditions when the amplitudes of the combination-frequency scattered waves grazing the interface are anomalously large; the perturbation theory based on a small slope of the surface is inapplicable to this case. Correct results are obtained in the solution of the strongly nonlinear self-consistent problem of diffrraction at a periodic surface due to the inception and growth of instability. It is shown that the growth rate decreases as the amplitudes of the amplified surface modes increases. The conditions are deduced for the onset of steady-state stimulated scattering. The dependence of the stimulated scattering threshold on the initial surface-mode amplitude is determined. It is shown that with the occurrence of resonance the value of the threshold decreases significantly by comparison with the nonresonance case.