Theoretical studies of lower hybrid current drive and ion-cyclotron heating in tokamaks

A computational model for PLT lower hybrid current drive and ramp-up experiments combines a parallel velocity Fokker-Planck treatment of lower hybrid current drive with minor radius flux diffusion and toroidal ray-tracing wave propagation. Computational and experimental results are in good accord. Analytic solutions of the two-dimensional velocity space (v/sub perpendicular/, v/sub parallel/) diffusion problem give values of the current drive parameter J/P/sub d/ which agree with numerical results, both relativistically and nonrelativistically. Turning to ICRF heating, two new all-metal antenna designs will permit power flux up to 10 kW/cm/sup 2/. A full wave solution to the magnetosonic wave equation, based on the parabolic method, yields cylindrical convergence and treats the diffraction limitation on intensity correctly. Mode conversion with energy absorption has been added to the BALDUR ICRF modeling code. A Fokker-Planck treatment of high energy ion tail formation by ICRF finds that enhanced thermonuclear reactivity can occur