Optimum Toroidal Phasing for Stable Loading of an ICRF Wave in JT-60

Abstract
The propagation and absorption of the ion cyclotron range of frequencies (ICRF) waves, which are launched by toroidal-phased antennas, were studied in a JT-60 plasma. The second ion cyclotron resonance in a one-dimensional pure hydrogen plasma was considered by solving the kinetic wave equation. The dependence of the loading resistance on the antenna phasing as well as on the plasma parameters was obtained by numerical calculation. A model of a transmission line was introduced in our analysis. The optimum phasing and the plasma parameter region were obtained for a stable loading. Furthermore, it is shown that a combined heating with the neutral beam injection (NBI) makes the stable loading region wider.