ITER Relevant Simulations of Lower Hybrid and Ion Cyclotron Waves with Self-Consistent Non-Maxwellian Species

The next step toward fusion as a practical energy source is the design and construction of ITER. ITER relies in part on ion-cyclotron radio frequency (ICRF) power to heat the deuterium-tritium plasma to fusion temperatures as well as to provide a portion of the current during flat-top operations. Lower hybrid (LH) RF power is under consideration as an upgrade to the baseline heating and current drive system in order to provide control over the current profile and additional current during start up. We have applied a suite of mature radio frequency (rf) full wave codes using self-consistent particle distributions from a Fokker-Planck code to ITER ICRF scenarios and ITER relevant LH experiments on Alcator C-Mod. We will present three dimensional fullwave simulations showing that the ICRF waves propagate radially inward in ITER with strong central focusing and little toroidal spreading. Fokker-Planck coupled rf simulations show that because of the high plasma density, energetic ion tail formation in ITER is typically weak, with the exception of the minority deuterium heating scheme where strong tails can develop on the minority ion distribution. Absorption by the fast alpha particles can approach five to ten percent of the injected power. Massively parallel full wave simulations in the lower hybrid range of frequencies using 2000 poloidal modes and 1000 radial elements have shown that proper reconstruction of wave fronts in the full wave treatment at caustics and cut-offs, where WKB methods fail, can lead to significant spectral broadening. We demonstrate that this linear mechanism is sufficient to bridge the spectral gap (the difference between the high injected phase velocities and the slower phase velocity at which damping on electrons occurs) and explains the efficient damping of lower hybrid waves. This is seen to affect the amount of broadening in the phase velocity and the current drive location.