Particle-in-cell simulation on power coupling of grill for KSTAR 5.0-GHz LHCD launcher

Summary form only given, as follows. The 5.0-GHz, 2.0-MW KSTAR Lower-Hybrid Current Drive (LHCD) system is under design for the steady-state operations of the KSTAR tokamak. The launcher structure is designed as a grill-type which provides asymmetric power spectra. The KSTAR tokamak plasma is high-density and high-temperature plasma. The power coupling to the KSTAR plasma edge depends on the impedance matching between the grill assembly and the LH wave in the edge plasma. And it depends on the edge density and the phase difference between guidelets. For the coupling calculation, the Brambilla coupling code uses equations derived from wave equations in the waveguide and the plasma with a linear density gradient. The power coupling efficiencies are also investigated using the Particle-in-Cell code called XOOPIC-2D. This paper describes the preliminary result of the LH power coupling calculation using the Brambilla coupling code and XOOPIC-2D code simulation.