REVIEW ARTICLE Electron cyclotron resonance heating and current drive in toroidal fusion plasmas

Abstract. A review of experiments and theory of electron cyclotron resonance heating (ECRH) and current drive (ECCD) is presented. An outline ofthe basic linear theory of wave propagation and absnrption in the electron cyclotron range of frequencies and their harmonics is &en and compared with experimentd results from many devices. The experimental data base on quasi-linem and nonlinear physics as well as on parametric wave decay is reviewed and compared to theory. Experiments and theory on doppler shifted absorption either by bulk or tail electrons (which can be created by other means) are discussed. ECRH provides means for controlled plasma breakdown and current ramp up in tokamaks and plays a key role in net current-free stellarator research. Start-up was investigated in many tokamaks and stelhalors and the results are discussed in the light of the present day theoretical understanding. The role of ECRH to improve the understanding of both parlicle and energy confinement is described and special heating correlated features, such as 'density pump out ' during ECRH are discussed. The application of modulated ECRH for pertdative heat wave studies and the comparison with both sawtooth heat pulse propagation and the steady state power balance analysis is presented. Electron cyclotron eurrent drive is a possible method for current profile and MHD control i