Stabilization and modulation of the output power of submillimeter wave gyrotron

High frequency, medium power gyrotrons (Gyrotron FU series) have been developed at the Fukui University as radiation sources convering a broad frequency band from millimeter to submillimeter wave region. We have performed cw operation of the Gyrotron FU IV. However, the output power was not stable (approximately several tens %) due to the fluctuation of the cathode potential (similar to 40 V). The output power was stabilized within several percent by controlling the anode potential. Such a technique was also used for amplitude modulation of the gyrotron output. Improved stabilization of output power and effective modulation will be achieved by stabilizing the cathode potential. (C) 2001 Elsevier Science B.V. All rights reserved.