The uniform-field magnicon: an architecture more suitable for high-perveance beams

This paper provides the details and modeling results of a 700-MHz, 2.5-MW, continuous wave, non-conventional magnicon architecture. It then compares the new architecture to the conventional design. The new magnicon architecture proves less sensitive to beam size yet provides the very high dc-to-RF conversion efficiency demonstrated in the initial magnicon development. The magnicon developments to date have utilized longitudinal, dc magnetic fields with different field strengths in the deflection system and output cavity. While this transition between field strengths was used in the initial magnicon to assist in the conversion of the initial longitudinal beam energy into the transverse direction, it also spreads the beam bunch (for finite beam size), reducing conversion efficiency. The new magnicon architecture presented in this paper utilizes a constant focusing field over the entire device. Conventional and new magnicon designs are presented for the 700-MHz, 2.5-MW requirements. Large-signal modeling techniques are used to compare magnicon performance of these designs for large-diameter beams. The modeling techniques used to generate the self-consistent solutions for the beam-driven magnicon cavities are discussed, and the relationship between the magnicon efficiency and electron-beam diameter is presented