  Although lower hybrid waves are effective at driving currents in present-day
tokamaks, they are expected to interact strongly with high-energy particles in
extrapolating to reactors. In the presence of a radial alpha particle birth
gradient, this interaction can take the form of wave amplification rather than
damping. While it is known that this amplification more easily occurs when
launching from the tokamak high-field side, the extent of this amplification
has not been made quantitative. Here, by tracing rays launched from the high-
field-side of a tokamak, the required radial gradients to achieve amplification
are calculated for a temperature and density regime consistent with a
hot-ion-mode fusion reactor. These simulations, while valid only in the linear
regime of wave amplification, nonetheless illustrate the possibilities for wave
amplification using high-field launch of the lower hybrid wave.
