Dynamics of three-wave processes in plasmas

Travelling waves with a frequency of the order of 109 c/s were excited in a plasma column and their non-linear interaction with the ionic sound waves (f = 104 c/s) was observed. At various distances from the input the authors recorded combination spectra showing the dynamics of the processes involved: the travelling wave amplitude decreases and, at a distance of 29 cm from the input, falls to zero, its energy being redistributed to numerous satellites. The energy redistribution process is not periodic. The characteristic wave interaction time is found to be short (τ ∼ 10−8 s), which indicates the efficiency of the process and enables conclusions to be drawn regarding the determinacy of the interacting wave phases (δω⋅τ ≪ 1).