Emittance effects on linear beams for millimeter-wave tubes with thermionic cathode

摘要

Emittance effects become more prominent as the decrease of electron beam radius in millimeter wave (MMW) tube. In this paper, emittance effects on linear beams for an MMW tube with thermionic cathode were performed by utilizing a model derived from emittance effects on Brillouin flow. The results showed that emittance should be treated as dominative quantities for practical design of 150GHz or higher frequency linear-beams with thermionic cathode, when the voltage and current of these beams are 20kV and 100mA, respectively.