Propagation of electron beam in inhomogeneous plasma

Summary form only given. The propagation of electron beam generating solar type III bursts is considered at the distances much larger than the length of quasilinear relaxation. As it takes place in homogeneous plasma the electron beam being initially monoenergetic propagates as a beam-plasma structure that consists of electrons and Langmuir waves. Beam-plasma structure propagating in uniform plasma loses a part of the fastest and the slowest electrons that leads to its decay. The maximum of electron density and energy density of plasma waves propagates with constant velocity. The numerical simulations fulfilled show that the inhomogeneity with decreasing density at the scales larger than the relaxation length can increase the time of this structure existence in corona.