STUDY OF GAIN IN C-BAND DEFLECTION CAVITIES FOR A FREQUENCY-DOUBLING MAGNICON AMPLIFIER

We report an experimental study of the gain between two half-wavelength, 5.7 GHz TM110 pillbox cavities, separated by a quarter-wavelength drift space, and powered by a 170A, 500 keV electron beam immersed in an 8.1 kG magnetic field. 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 (alpha = upsilon(perpendicular-to)/upsilon(z) greater than or similar to 1) for injection into the output cavity of a frequency-doubling magnicon amplifier. We have observed a gain of approximately 15 dB 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.