Comments On Icrh Current Drive In Jet

To study current drive via the mode-converted slow wave during ICRH the authors assess for which plasma compositions and wave numbers mode conversion from the magnetosonic wave to the slow wave can dominate. They have used a simple slab model to investigate the competition between mode conversion and minority cyclotron absorption for a deuterium plasma with H+ and 3He2+ minority species in JET. A 3He2+ minority should be more appropriate for mode conversion current drive than H+ because the 3He2+ concentration can be chosen near its optimum for the 'Budden absorption' without bringing the ion hybrid resonance and the cyclotron resonance so close that the minority absorption dominates. 3He2+ minority also allows operation at toroidal numbers which are characteristic of present JET antennae.