Abstract EN:

In this thesis we present a study of the effects of cyclotron resonance heating in Tokamak plasmas, both theoretical and experimental. The effect of the cyclotron and the two ion hybrid resonances is reviewed. In the frame of the WKB approximation, we present an algorithm which allows deriving the connection formulas that connect the set of waves on each side of the conversion layer. Furthermore using a variational principle, we analyze the effect of the resonance on the amplitude of the perturbed field generated by the antenna set. In this last approach, we only consider perturbed fields of compressional type. Such a principle allows to derive the amplitude of the perturbed fields in the Tokamak geometry. Moreover, it permits to compute the power damped by the thermal motion of the particles or transferred onto the converted field of torsional type that is outgoing form the conversion layer. In the remaining part, the experimental results obtained on the TFR Tokamak are reported. The role of the conversion process in the damping of the ICRF power is clearly evidenced, while the question on the impurity production during ICRH is addressed.