Status review of research on millimeter-wave tubes

Devices employing electron beam-electromagnetic wave interaction are classified in accordance with the phase velocity of the wave. Some general principles are stated governing the beam size and position applicable to all types of slow-wave interaction and for various types of fast-wave devices such as the gyrotron, the free-electron laser, and their derivatives. The quality of the electron beam, its energy, and the magnetic field strength required are indicated for each type of interaction. The characteristics of the various devices are compared in the context of achieving high-power operation at millimeter wavelengths. Some recent experimental research achievements in the U.S. and the U.S.S.R. are listed to indicate the current state of the art. Finally, areas that appear fruitful for further work are recommended.