Some properties of multiple BWO's

Some of the fundamental properties of multiple BWO's are examined in terms of a simple model. The starting conditions are found for both low and high space-charge conditions and particularly for the case in which there is a small difference between the velocities of the separate beams. The latter results are used to discuss the tolerances which must be met in multiple BWO's. Experiments carried out at X band provide some qualitative confirmation of the theory.