POSSIBLE EXCITATION OF NONLINEAR PLASMA-WAVES BY A RELATIVISTIC ELECTRON-BEAM

The problem of the generation of plasma waves with a phase velocity close to the velocity of light by a relativistic electron bunch of finite length is analyzed in the ID approximation. For a given bunch density, there exist optimum values of the bunch length and of the plasma density, which maximize the amplitude of the wakefield oscillations of the electron density. Even at comparatively low current densities (approximately 10 kA/cm2), huge accelerating electric fields, approximately 1 GV/m, can be excited.