Verifying raytracing/Fokker–Planck lower-hybrid current drive predictions with self-consistent full-wave/Fokker–Planck simulations

Raytracing/Fokker–Planck (FP) simulations used to model lower-hybrid current drive (LHCD) often fail reproduce experimental results, particularly when LHCD is weakly damped. A proposed reason for this discrepancy the lack of ‘full-wave’ effects, such as diffraction and interference, in raytracing breakdown approximation. Previous studies using non-Maxwellian full-wave/FP have been performed, but these were not self-consistent enforced power conservation between FP full-wave code a numerical rescaling factor. Here, we created fully that automatically conserving. This was accomplished by coupling an overhauled version TORLH solver CQL3D Integrated Plasma Simulator. We performed converged Alcator C-Mod discharges compared them with raytracing. found excellent agreement deposition profiles from could be obtained, however, had somewhat lower efficiency broader some cases. appears result limitations present small amount diffractional broadening wave spectrum. Our results suggest simulation likely necessary interference represented only correction account differences experiment.