Simulation and experimental investigations on dynamic after cavity interaction (ACI)

In recent years, the so called after cavity interaction (ACI) in high power gyrotrons operating in the 100-200 GHz range gained attention as an influence factor on overall efficiency. While investigations concentrated on ACI as a stationary effect until now, recent simulations show that an undesired interaction in the uptaper region can also result in additional parasitic oscillations. In this paper, such non-stationary, dynamic processes are investigated in first simulations and experiments.