Multiwave relativistic electron devices: Progress and prospects

During the last decade, attempts to use the properties of coherent eigen radiation of bunches of high-power relativistic electron streams have led to the multiwave conception of the beam-field interaction. In the multiwave electron devices an electron beam interacts simultaneously at a definite frequency with a number of modes, or waves, of electrodynamic structure within the syncronism band. The electron efficiency is shown to be higher in the multiwave regimes in comparison with the onewave ones. All types of multiwave devices are possible.