On a Strong Effect of Nonresonant Three-Wave Interactions on the Saturation of Low-Threshold Parametric Decay Instability

It has been shown that the nonresonant three-wave interaction between daughter waves trapped in the plasma, which excites strongly damped induced oscillations, strongly affects the nonlinear evolution of the low-threshold parametric decay instability, leading to its saturation through a cascade of successive low-threshold decays. As a result, the anomalous absorption of a microwave pump wave in the electron cyclotron heating of the plasma in toroidal magnetic confinement devices can be significantly reduced.