  Lower-hybrid current drive (LHCD) actuators are important components of
modern day fusion experiments as well as proposed fusion reactors. However,
simulations of LHCD often differ substantially from experimental results, and
from each other, especially in the inferred power deposition profile shape.
Here we investigate some possible causes of this discrepancy; "full-wave"
effects such as interference and diffraction, which are omitted from standard
raytracing simulations and the breakdown of the raytracing near reflections and
caustics. We compare raytracing simulations to state-of-the-art full-wave
simulations using matched hot-plasma dielectric tensors in realistic tokamak
scenarios for the first time. We show that differences between full-wave
simulations and raytracing in previous work were primarily due to numerical and
physical inconsistencies in the simulations, and we demonstrate that good
agreement between raytracing and converged full-wave simulations can be
obtained in reactor relevant-scenarios with large ray caustics and in
situations with weak damping.
