Self-consistent large theory and simulation of high harmonic gyrotron and peniotron oscillators operating in a magnetron-type cavity

A self-consistent large signal computer simulation code is developed to study the interaction between the RF wave and a large helical-orbit axis-encircling electron beam in a magnetron-type open cavity. In the code, a one-dimensional wave equation for the axial field profile function with the beam current as a source is solved simultaneously with the electron equations of motion which presume the circular motion about the guiding centers of each electron. The study shows unexpectly low efficiency for the gyrotron and high efficiency for the peniotron. The theory and results of simulations are given and discussed in this paper.