Broadband Frequency Tuning in a Powerful Gyrotron for Fusion

The paper presents the possibility of broadband stepwise frequency tuning in the powerful gyrotron created at the IAP RAS, operating at the frequency of 250 GHz. The main approach used for the stepwise tuning in gyrotrons is the consecutive excitation of modes of the cylindrical cavity. The use of correcting cathode coil for increasing of frequency fill factor is considered. The theoretical estimates are verified by the experiment.