Observation of Simultaneous Oscillation of Multiple Modes in a CW 300 GHz Gyrotron

抄録

Multi-mode oscillation was observed in a 300 GHz fully CW gyrotron. It has been developed and installed in the Research Center for Development of Far-Infrared Region, University of Fukui as a power source of a submillimeter-wave material processing system. This gyrotron delivers 1.75 kW/CW at maximum. The radiation pattern is a Gaussian beam when the magnetic field strength B_c at the cavity is properly adjusted. However, within a range of B_c values, simultaneous oscillation of competing modes is observed, manifesting in radiation of the output power in multiple directions.