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 50A, 34keV electr
on beam, the corrugated cavity thus designed operates at 10.5GHz in the 2 p
i -mode with two radial variations. The monotron operation is examined thro
ugh 2.5D particle-in-cell simulation giving 260kW average power output. Thi
s corresponds to 15.3 percent overall efficiency at the theoretical limit o
f 20.0% percent electronic efficiency as predicted by one-dimensional analy
sis.