Physical nature of a hydrodynamic beam-plasma instability

Physical mechanisms, responsible for the development of collective hydrodynamic instability of charged particle beam in anisotropic plasma, were investigated quantitatively. The corresponding increment was calculated on the basis of analyzing dynamics of beam particle motion in the field of their radiation. It is shown that coherence of beam particles provides for sufficient strengthening of collective field, excited by them, which forms coherent bunches according to the mechanism of Veksler-McMillan phasing