Finite density effects near the second harmonic of the electron cyclotron frequency

The analysis of the electromagnetic dispersion relation, with inclusion of the relativistic effects near the second harmonic of the electron cyclotron frequency, points out the possibility of coupling and mode conversion between the extraordinary electromagnetic wave and the quasi electrostatic wave in the region Ω is approx.= 2 Ωsub(C). This result may prove to be important both for plasma R.F. heating purposes, and for emission at Ω approx.= 2Ωsub(C). Numerical calculations are performed for different parameters, typical of Tokamaks. (author)