Quasi-optical design of EC H&CD launcher for CFETR

Abstract The China Fusion Engineering Test Reactor (CFETR) is the next-generation device for China magnetic controlled fusion program. A high power (36 MW) and continuous millimeter-wave injected by two Upper Launchers (ULs) are planned for Electron Cyclotron Heating and Current Drive (EC H&CD) in CFETR. A 3D visual quasi-optical design tool for the UL has been developed based on MATLAB that is capable of accurate visualization of beam propagations and the evaluations of quasi-optical system layout in the UL. One UL has two identical sets of quasi-optical modules, each one is mainly composed of nine fixed focusing mirrors and one flat steering mirror. By using the design tool to optimize the quasi-optical system for the UL, the minimum concentration radius (∼ 110 mm) of the nine mm-wave beams is obtained at the resonance layer. The evaluation results of the peak heat load on the FMs and SM obtained were 0.71 MW/m2 and 1.46 MW/m2, respectively.