Recent Results from the SciDAC Partnership for Simulation of Fusion Relevant RF Actuators

We present an overview of research related to predicting the behavior of the plasma boundary region in the response to applied radio frequency (RF) power in the ion-cyclotron and lower-hybrid range of frequencies. We focus on the production of impurities via RF sheath enhancement and the non-linear, multi-timescale response of the scrape-off-layer plasma to RF power. Particular results include: (i) a successful multi-implementation benchmarking of the non-linear fluid RF sheath boundary condition, additional verification of that fluid condition with fully-kinetic calculations of the same, and estimates of impurity sputtering as a result for simple geometries; (ii) calculations of the RF ponderomotive force driving terms in full high fidelity 3D geometry in front of an ICRF antenna and initial estimates which show that force as a significant source on density transport; (iii) benchmarking of the combined use of high-order finite-elements with field-aligned meshes towards a new far-scrape-off-layer fluid transport simulation capability; and (iv) demonstrated progress on the effective preconditioning of iterative solvers for the frequency-domain Maxwell equations for larger degree-of-freedom, high geometric-fidelity simulations.