ABSTRACT
These lectures are an introduction to the theory of ion cyclotron heating of tokamak plasmas. In the first part we will derive the kinetic equation which describes the evolution of the ion distribution function under the effect of resonant interactions with the waves, and briefly discuss its solution. The second, somewhat longer, part will be devoted to a discussion of launching, propagation and absorption of h.f. waves in this frequency range, largely based on the examination of the local dispersion relation. Only very briefly will we also mention the derivation and solution of differential wave equations adequate to describe wave propagation in non-uniform plasmas. It should be clear that the kinetic and wave-propagation aspects of the theory are not really independent of each other, since the distribution functions influence the coefficients of the wave equations (particularly those which describe absorption) and, conversely, the distribution of h.f. field in the plasma is an essential ingredient of the kinetic equations describing particle-wave interactions. The coupling between wave propagation and kinetic equations is nevertheless sufficiently loose that in practice it is possible, and advantageous, to keep the two subjects separate, provided one remains aware that mutual influences always exist.
Because of the tutorial nature of the lectures and the limited time available, we will discuss mainly the physical foundations of the theory, omitting almost completely its more technical aspects. In particular, we do not include any detail on the extensive numerical simulations which play a most important role in the practical applications. We have, however, mentioned some of the more subtle problems which arise because of the complicated geometry of tokamak plasmas, giving sufficient references for the interested reader to be able to deepen her or his understanding with the help of the original literature.
