Abstract: A 2-D Fokker-Planck equation is discretized and solved by an implicit 5-point scheme and the NAG library routine D03UAF. With a my-tracing code combined with a Fokker-Planck equation, the effect of the local synergistic interaction between LHW and IBW and current fully driven by waves with or without IBW in the HT-7 Tokamak are studied. Numerical simulations show that the LHW power deposition profile and the driven current distribution are modified due to the interaction between IBW and LHW and the efficiency of LHCD is improved. The current distribution driven completely by LHW expands obviously than the one driven fully by LHW+IBW. The current distribution driven by waves changes with frequencies and n_// spectrum of IBW during the synergy of LHW+IBW.

Key words: lower hybrid wave, ion Bernstein wave, synergy, numerical simulation, electron Landau damping, current fully driven by waves