On the classical theory of charged-particle induced electromagnetic radiation in ondulators

Studies were made to elucidate a possibility of using electron beams with a small period of density modulation which are formed in sources of induced ondulator radiation (OR) for generation of coherent spontaneous OR in a region of high-level far ultraviolet radiation. Particle dynamics is considered in transverse screw field of a spiral ondulator. A high directivity of induced OR is shown in the framework of the classical theory. The efficiency and amplification factor of induced OR sources using a preliminary bunched beam are shown to be able to exceed corresponding characteristics of sources using a homogeneous beam. The realization of a density modulated beam will permit to obtain effective readjustable sources of coherent radiation in a wide spectrum range