Theory and modeling of high power backward wave oscillators

Summary form only given, as follows. Microwave sources driven by high current relativistic electron beams are capable of producing high power coherent radiation in the centimeter and millimeter wavelength regions. In particular, Backward Wave Oscillators (BWO´s) are very promising sources of high power microwaves. Over recent years we have employed a general model to analyze these devices. This model describes the interaction of the radiation and beam electrons self consistently in time and space. In addition, the model has been extended to include the effects of non-synchronous spatial harmonics and the effects of the AC space charge field. The theory is used to describe the operation of BWO´s in a number of regimes: with current close to and much above the starting current, with beam voltage corresponding to operation far and close to the /spl pi/ point, with a guided magnetic field far and close to the cyclotron resonance value. The results of the modeling compared both with PIC simulations using MAGIC and with the data obtained from BWO experiments.