Cold plasma finite element methods for RF waves with synthetic turbulence*

New 2-D and 3-D cold plasma finite element simulations of lower hybrid (LH) waves with synthetic turbulence will be shown that can modify the polarization, penetration and scrape-off-layer (SOL) absorption of the LH wave. The key parameters required to observe these modifications are that the turbulence amplitude needs to be large and that the turbulence scale length is close to the LH wavelength.  This may have implications for the coupling of LH waves through the SOL into the core plasma given that these parameters are necessary to reproduce LH electric field polarization measurements on Alcator C-Mod. Because these finite element simulations are computationally expensive, different solvers are being developed and tested to increase the maximum solvable problem size. This problem is typically solved using a direct solver, but it will be shown that an iterative domain decomposition with a multiplicative Schwarz method can possibly reduce the memory footprint for cold plasma finite element problems. Scaling studies for direct and iterative solvers on both shared and distributed memory system will be shown.