Influences of plasma density perturbations on ion cyclotron resonance heating

Abstract

The scattering of waves in the ion cyclotron range by plasma density perturbations in the edge has been previously studied by Zhang et al with the help of antenna code RAPLICASOL (2020, Nucl. Fusion, 60, 096001). The further interesting question is whether the density perturbations have an effect on ion cyclotron resonance heating (ICRH) in the core. In this paper, finite element method based 2D full wave code integrating the core with the edge is used to study this issue. The analytical density perturbations are applied to study the influence of density perturbations on field distribution, power deposition, wave coupling, power partition among different species in the core, and the fraction of energy dissipation in the scrape-off layer. The influence of density perturbations becomes global and significant when the poloidal size of the density blob is comparable to the perpendicular wavelength. In addition, the strength of wave scattering is directly proportional to the amplitude and the radial size of the density blob. Finally, a typical experiment on the EAST is chosen and the influence of realistic density perturbations on ICRH is evaluated.