Finite elements method based ICRF waves heating simulation integrating with SOL plasma for EAST tokamak

Abstract

Abstract Ion cyclotron range of frequency (ICRF) waves heating simulation is often carried out in the core plasma region. However, the inclusion of scrape-off layer (SOL) plasma in the simulation model may lead to new physical phenomenon and needs to be studied. In this paper, we apply finite elements method (FEM) based on the approach of [Vallejos 2019], to simulate ICRF waves heating in account of the realistic SOL plasma for EAST tokamak. In the presence of density pedestal near last closed flux surface (LCFS), a kind of cavity mode is observed for the case of low parallel wave number. Near ion-ion hybrid resonance (IIR) layer in SOL region, mode conversion from fast waves to slow waves takes place. ICRF waves coupling characteristics are roughly consistent with the prediction of the dispersion relation except for some small deviations, which may be caused by fast waves reflection in the high field side. Approximate on axis heating of minority H is observed and power deposition zone broadens with parallel wave number increasing. Waves energy dissipation in SOL plasma is less than 7% and localized near IIR region. Furthermore, the comparison between D(H) and D(He-3) minority heating scenarios is also carried out. The results and conclusions in this paper can provide theoretical reference to ICRF heating experiments and may supply a new insight in ICRF waves form in the plasma edge.