A Four Cavity High Harmonic Gyroklystron Amplifier

[[abstract]]This device is one of a family of gyrotubes in which a relativistic, rotating shell of electrons interacts synchronously with high-order azimuthal, cylindrical TE modes. Harmonic operation together with RF gyroresonant acceleration of the electron beam constitutes a compact, lightweight, moderate-power millimetre wave amplifier. Recent changes in our fifth harmonic, four cavity device include the doubling of the drift region lengths and the improvement of the electron gun, electron optics, and accelerator drive quality. The maximum observed gain was 45 dB and the peak output power was 600 W. Data from an improved diagnostic for axial velocity is presented along with results from the experiment, analytic theory and simulation.[[fileno]]2010137010056[[department]]物理