Validation of Petra-M full-wave simulations against LAPD experiments*

Loss of RF heating power to the parasitic slow-wave in the plasma edge is a prominent challenge in ICRF heating for fusion devices. Plasma waves launched from a single strap RF antenna in the Large Plasma Device (LAPD) can be simulated using Petra-M, a C++ based finite element full-wave solver. Petra-M analysis is based on MFEM, an open source C++ FEM library. Experiments performed in the LAPD and Petra-M analysis under fast wave conditions agreed well with each other. Current investigations in Petra-M attempt to simulate slow as well as mixed (slow and fast wave modes) wave conditions with plasma conditions of ne~1018-1019m-3, Te~1-10eV, and B0~0.1-0.18T. Slow waves are difficult to resolve via finite element analysis methods due to a limit on computing power when small mesh sizes are required. Mixed conditions also require small mesh sizes in slow wave propagation regions. The goal of this investigation is to find a means of computing the Petra-M wave model so that a comparison with LAPD data can be made.