Improvement of Hybrid-Type High-Power Gyrotron Launcher

A numerical synthesis method for hybrid-type high-power gyrotron launchers has been tested to transform the $TE_{32,9}$ mode of the ITER EU 1-MW gyrotron operating at 170GHz with a specific set of TE modes to generate a Gaussian-like field distribution as the target function. However, we cannot perfectly transform the operating mode into the specific set of TE modes of target function due to the diffraction effect of the launcher cut. In this case, we proposed a method to generate an optimized target function to improve the process of transforming the operating mode into the target set of TE modes. Simulation results show that the higher fundamental Gaussian mode content (FGMC) of 99.1% of the RF wave beam can be achieved at the aperture of launcher using the optimized target function.