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-mode with two radial variations. The monotron operation is examined through 2.5D particle-in-cell simulation giving 260 kW average power output. This corresponds to 15.3 percent overall efficiency at the theoretical limit of 20.0% percent electronic effciency as predicted by one-dimensional analysis.