Study of gain in C-band deflection cavities for a frequency-doubling magnicon amplifier

An experimental study of the gain between two half-wavelength, 5.7-GHz TM₁₁₀ mode pillbox cavities, separated by a quarter-wavelength drift space, and powered by a 170-A, 500-keV electron beam immersed in an 8.1-kG magnetic field is reported. These cavities constitute the first section of a planned multicavity deflection system, whose purpose is to spin up an electron beam to high transverse momentum (α≡υ⊥/υ_z⩾1) for injection into the output cavity of a frequency-doubling magnicon amplifier. A gain of ~15 dB was observed in the preferred circular polarization, at a frequency shift of approximately -0.18%, in the opposite circular polarization, at a frequency shift of approximately +0.06%. These results are in good agreement with theory