Resonant Wave-Particle Interaction in an Explosively Unstable Beam-Plasma System II. Investigation of the Relaxation Behaviour of the Electron Beam

Three typical saturation mechanisms of the explosive instability (EI) in a beam-plasma system are investigated. It is shown that the maximum values of the electric field strengths of the explosively unstable plasma waves can be of the same order as the maximum wave amplitude of the linearly unstable waves. Some conclusions with regard to the role played by the EI in the evolution of a real beam-plasma system are presented. The relaxation of a strongly modulated electron beam by the explosive wave coupling mechanism is examined in an appendix. A qualitative interpretation of the diversity of the EI saturation mechanisms found in this investigation is given.