NONLINEAR-INTERACTION OF COPROPAGATING AND COUNTERPROPAGATING WAVES RADIATED BY AN ELECTRON REAM AN ONDULATOR ELECTRODYNAMIC SYSTEM

An electron beam moving in a spatially periodic field can be a source of a type of shortwave radiation called ondulator radiation [1]. The s timulated ondulator radiation is a key physical mechanism for electrom agnetic radiation sources such as a free electron lasers [2, 3]. In th e presence of a periodic field, the electron beam excites two electrom agnetic waves: a copropagating and a counterpropagating one. Usually, the theory treats the excitation of these ondulator waves separately. But this is not always justified because of a possible nonlinear wave interaction due to which the co- and counterwaves may effect each othe r, resulting in energy redistribution between the ondulator systems. T his work considers these phenomena.