Monotron Oscillation in Double-Gap Coupling Output Cavities of Multiple-Beam Klystrons

This paper presents a method to calculate the admittance of electron beam and of circuits in a multiple-beam klystron output circuit of double-gap coupling cavity. With the conditions of monotron oscillation, the possibility of forming monotron oscillations in a double-gap coupling output cavity is studied based on analytical calculations, and a method for calculating the initial oscillation current of monotron oscillation is derived. To further verify whether monotron oscillations form in the coupling double-gap output cavity and to analyze the characteristics of monotron oscillation, a particle simulation is performed to a particular coupling double-gap output cavity loaded by a cutoff waveguide filter, and the results show that monotron oscillations form in the particular coupling double-gap output cavity with an initial current of about 22 A under the condition of 18 kV accelerating voltage of the beam.