An axial monotron with rippled wall resonator

With application to centimeter-wave monotron oscillators, the present work proposes a rippled wall cylindrical cavity that provides efficient coupling to a coaxial output circuit. Driven by a centered, solid 50 A, 34 keV electron beam, the corrugated cavity thus designed operates at 10.5 GHz in the 2/spl pi/-mode with two radial variations. The monotron operation is examined through 2.5 D particle-in-cell simulation giving 260 kW average power output. This corresponds to 15.5 percent overall efficiency at the theoretical limit of 20.0 percent electron efficiency as predicted by one-dimensional analysis.