Plasma heating by a relativistic electron beam with secondary instabilities

Relativistic electron beam heating of a dense plasma through the two-stream instability is studied. A large amplitude beam-plasma wave excited by the instability induces waves of wide wavenumber spectrum at low phase velocities through secondary parametric instability processes. In some cases such a complicated mode coupling of the beam-plasma wave into low phase velocity waves and their saturation may be described in terms of soliton formation. A beam stopping length associated with this process is obtained.