Core-edge coupling in Tokamak RF simulation via the multidomain pseudospectral method

The primary uncertainty in heating Tokamak plasmas with RF power in the ICRF regime are the various linear and non-linear interactions of RF waves with the plasma edge. This will be of particular importance in ITER. The linear problem can be addressed by extending spectral full-wave core plasma calculations to the vessel wall. However, a uniform mesh of sufficient resolution to resolve the fine scale antenna features is not tractable for the core hot plasma calculation, even on todays peta-scale supercomputers. To retain all relevant physics the core plasma calculation requires a pseudospectral (or collocation) method (PSM). As such, here we investigate the implementation of the multi-domain (MD) PSM to achieve a variable mesh, device geometry matching and tractable runtime. While the MD-PSM has been successfully employed for simple dielectrics and interfaces[1], its application to a hot plasma is complicated by the non-local plasma current. This prevents implementation of the standard MD patching boundary conditions. Here we discuss these complications and present progress towards a MD all-orders core/antenna coupled simulation. [1] Q.H. Liu, IEEE Antenn. Wireless Popag. Lett., 1, 131-134, 2002