Evaluation of electron cyclotron current drive performance for CFETR

A number of simulations of electron cyclotron current drive (ECCD) have been carried out for the China Fusion Engineering Test Reactor (CFETR) using the C3PO/LUKE code to investigate the performance and optimize schemes of power injection for the design of the launcher. The operation ranges of the toroidal field, cutoff density, and resonance layer location are given at different source frequencies in CFETR phases I and II. A comparison of ECCD performance between the horizontal and top port launch is presented. ECCD efficiency (r_EC) estimated for CFETR phase I is r_EC=0.21 for top port launch and r_EC=0.20 for horizontal port launch. The ECCD efficiency and second-harmonic absorption is calculated at different wave frequencies (from 170 to 230 GHz) in CFETR phase II. It is found that the highest driven efficiency is obtained at 210 GHz with the toroidal field of 6.5 T, and the second-harmonic absorption increases rapidly with the increase of frequency.