Combining Effects between LHW and IBW Injections on EAST

The quasilinear combining effects between lower hybrid wave (LHW) and ion Bernstein wave (IBW) injections on current drive profiles are systematically studied based on the MHD equilibrium profiles of the Experimental Advanced Superconducting Tokamak (EAST). The simulation results indicate that the modifications of the distribution function due to IBW injection are nonlocalized in space and can affect the current drive profiles. The lower hybrid current drive efficiency can be either enhanced or reduced depending on the spectrum of the IBW injected into the plasma. In order to achieve stronger driven current, an appropriate IBW spectrum should be chosen for the combination of the LHW and IBW injections.