Numerical study of the instability in a Maxwellian beam-plasma system. 2

The relaxation of the beam-plasma system with several preliminarily excited unstable waves in its spectrum is investigated on the basis of computer simulations. The nature of the waves and particles interaction during the instability development is analysed. It is shown that the destroying of the amplitude oscillations of the single wave after saturation in the presence of additional waves is caused by the well known effect of resonance overlapping. A chaotization of the motion of the beam particles occurs even in the case when the amplitudes of the neighbouring waves are small. (author)