HIS-TORIC: Extending core ICRF wave simulation to include realistic SOL plasmas

This paper presents a novel approach to incorporating an arbitrarily shaped edge scrape-off-layer (SOL) plasma and an ion cyclotron range of frequency (ICRF) antenna structure into existing core ICRF wave simulation models. We partition the entire computation domain into two sub-domains: a core and an edge region. Simulations in each domain are performed separately with appropriate numerical solvers. For the core, the TORIC ICRF solver [M. Brambilla, Plasma Phys. Contrl. Fusion 41, 1 (1999)] was modified to impose an essential (Dirichlet) boundary condition at its interface with the edge domain. In the edge, a finite element method (FEM) is used to solve a cold collisional plasma model. The domains are then joined together using the continuity boundary condition for the tangential electric and magnetic fields at their interfaces (Hybrid Integration of SOL to TORIC: HIS-TORIC). The model developed here was tested using an ICRH H minority heating scenario on the Alcator C-Mod tokamak [I. Hutchinson et. al., Phys. Plasmas 1, 1511 (1994)]. The simulated pattern of core wave propagation agrees well with a standard TORIC simulation. This approach opens the possibility of using a realistic diverted SOL plasma and a complicated 3D RF antenna together with a rigorous hot core plasma model, while requiring only minimal modification to existing RF codes.