An overview of the theory of lower hybrid and ion cyclotron heating of tokamak plasmas

Some effort is devoted to discuss the linear dispersion relation and the mechanisms of wave-particle interactions. In particular it is tried to show how the guidelines for heating experiments are dictated by the properties of linear plasma waves. LH waves have very attractive features as far as generation and coupling is concerned, and have proved to be the best candidate for h.f. current drive. ICRH has proved very successful, and there is every reason so believe that it will remain so in reatorgrade plasmas. The status of ICRH theory can be considered satisfactory: the basic mechanisms of coupling, propagation and absorption are well understood, and modeling has recently improved to the point of including also fine effects such as the influence of toroidicity on mode conversion. (GG)