Improving current generation in a tokamak by electron cyclotron waves

Abstract
Current drive by electron cyclotron heating of the far end of a lower-hybrid-sustained electron tail is investigated. The current density profile is determined by means of the kinetic theory and the ray-tracing code for the PLT and the Alcator C parameters. It is shown that the value of the ratio W/I for the combined effects of lower hybrid and electron cyclotron wave absorption can be improved compared to that of the present lower hybrid experiments. Suitable shaping of the current density profiles can be achieved by adjusting the wave-launching parameters.