Fast-wave ion-cyclotron and first-harmonic heating of large tokamaks

Supplementary wave heating is examined for two-ion-species plasmas from the fundamental tritium cyclotron resonance (ω = ω CT ) to the first deuteron harmonic (ω = 2ω CD ). At the first harmonic, it is found that a sufficiently large parallel wavelength greatly reduces the region of confluence between the fast wave and ion Bernstein wave. Power absorption considerations neglecting mode conversion processes show that first-harmonic heating efficiency is relatively insensitive to the species concentrations and that a dominant ion heating can be expected. For minority heating at the fundamental deuteron resonance, it is shown that inclusion of the two-ion hybrid resonance absorption considerably lowers the Q from the case where only minority species cyclotron damping is considered.