Design of a CW 1 THz gyrotron (Gyrotron Fu Cw III) using a 20 T superconducting magnet

Design of a CW 1 THz gyrotron at second harmonic operation using a 20 T superconducting magnet has been described. The mode competition analysis is employed to investigate operation conditions of second harmonic mode, which is being excited at the frequency ranging from 920 GHz to 1014 GHz. The output power up to 250 watt corresponding to the efficiency of 4.16 percent could be achieved by using an electron beam with accelerating voltage 30 kV and current 200 mA. The important advantage of this gyrotron is that the single mode excitation at second harmonic, and extremely high frequency of the radiation, could be maintained even at high currents. It opens possibility to realize a high power radiation source at 1 THz. Such gyrotron is under construction at FIR Center, University of Fukui.