Theory of second harmonic electron cyclotron resonance heating of tokamak plasma

A theoretical and numerical study of tokamak plasma heating by the second harmonic of the electron cyclotron resonance is presented. It is found that the extraordinary mode is very efficiently absorbed. In contrast to previous calculations, it is also found that the ordinary mode is well absorbed at oblique incidence to the toroidal magnetic field. This finding indicates the feasibility of heating devices of higher densities than would otherwise be possible.