Coupling Simulations of RF, Antenna Effects and Scrapeoff-Layer Turbulence*

We discuss progress on coupling tokamak edge/scrapeoff-layer (SOL)-relevant turbulence and ICRF codes and models. A 3D extension of the SOLT model is being developed under the BOUT++ framework [1]. The effects of boundary conditions representing RF launching structures on transport equilibria and turbulence in this model are studied. The simplest such boundary conditions involve regions on the outer flux surface biased at an effective RF sheath potential relative to the parts of the surface not in these regions. We compare solutions between the BOUT++ models and the UEDGE code for cases where these regions are axisymmetric. For cases where they are not, e.g., a rectangle in the toroidal-poloidal plane, the solutions are studied, beginning with steady solutions and proceeding to fluctuating ones. Simulations in which biased structures impinge in an outer layer of the BOUT++ model are also studied and compared with those obtained with biased regions (only) on the outer surface. We also report work on the transfer of data from BOUT++ simulations to the edge-relevant ICRF codes, including development of a generally useful data format and API.

[1] M.V. Umansky et al., this meeting.