| The problem of coupling to and driving current with the fast wave in the Lower Hybrid Range of Frequencies is addressed theoretically and experimentally. Previous experimental work on current drive with slow and fast waves in the LHRF is reviewed. A numerical algorithm for solving the problem of coupling electromagnetic energy in the LHRF from a phased array of identical rectangular waveguides to a plane-stratified, magnetized cold plasma is implemented, and a 4 x 3 array designed to launch fast waves is modeled. Surface modes of propagation are found to have a significant effect on coupling to fast waves.;These results are explained by fast-to-slow mode conversion within the plasma, by either a ray-tracing effect or by mode conversion induced by scattering from ambient density fluctuations.;The results of a medium power (P... |
