Fragmentation of electron stream propagation through plasma

Summary form only given, as follows. The propagation of an electron stream is considered in the limit of weak turbulence when the quasilinear time is much smaller than the time of electron stream flying-off. It is found out that the initial electron distribution function of the electron stream propagating in plasma is unstable to decay into separate beams. Langmuir waves excited by the fast beams accelerate electrons of slow beams that leads to interaction between them: the number of particles in the fast beams increases and their phases change. The electron distribution function and spectral energy density of plasma oscillation are found by gas-dynamic approximation.