Design of a Quasi-Optical Launcher for a 135/170GHz, Dual-Frequency Gyrotron

In this paper, the design of a quasi-optical launcher (QOL) for a 1351170GHz 1-MW double-frequency gyrotron is presented. The gyrotron operating at both 170GHz and 140GHz is being designed, then this investigation is on the design of a launcher toward 170GHz and 140GHz dual-frequency gyrotron. The accurately chosen modes and operating frequencies are TE
25,10
for 170GHz and TE
20,8
for 135GHz. Gyrotrons at these two frequencies can be used for plasma heating applications in Controlled Nuclear Fusion. A numerical calculation code has been written for calculating the related data of the launcher, and LOT was used to simulate the electric field distribution on the launcher's wall. The results show that the energy conversion efficiency of the launcher is more than 99%, Gaussian content factor is more than 85% at the frequencies of both 135GHz and 170GHz. This will be used for the design of a dual-frequency quasi-optic mode converter from operation modes to Gaussian mode.