Electron Bernstein wave heating and diagnostic

This paper gives a review on the experiments with electron Bernstein waves (EBWs) in fusion devices. The different methods of EBW generation are described and compared with experimental results. The influence of density fluctuation and parametric instability on the conversion efficiency is discussed. The related experiments are reported. The EBW propagation is calculated by ray-tracing codes. The results are used to analyse EBW emission, heating and current drive experiments in stellarators and tokamaks. With high power microwave sources EBWs have been excited over a wide range of frequencies for plasma heating and current drive. The experimental results demonstrated that EBW can efficiently heat over-dense plasmas. The local power deposition allows the generation of heat waves for transport studies. Due to their electrostatic character, EBWs can achieve parallel refractive indices (N||) larger than 1, which is favourable for efficient current drive. This could be confirmed by a first current drive experiment. The EBWs also express a strong cyclotron damping, which enabled efficient heating at higher harmonics in several experiments.