REB relaxation in an inhomogeneous collisional plasma

Relaxation of monoenergetic REB in a longitudinal inhomogeneous plasma when developing dissipative beam-plasma instability with regard of nonresonance oscillations is investigated. Requirements to the value of the plasma density gradient are obtained. When meeting these requirement, relaxation of REB in the systems of a limited length is absent. Numerical simulation of the nonlinear stage of beam instability in the plasma is carried out