Plasma-wave interaction in present-day magnetic fusion research

The plasma physics community is involved since long in the research to achieve the conditions for commercial fusion power, thus giving a contribution to the sustainable energy problem. This is an international effort, which takes place in a highly coordinated way in Europe within the magnetic confinement approach, aiming at the success of the ITER project in the near term and at the design of DEMO in the longer term. In addition, there is an active scientific accompanying programme on other tokamaks, to investigate the scientific and technological challenges still to be addressed. We focus here on the crucial role played by waves in present-day and future experiments. Injection of electromagnetic waves can assist the plasma discharge in its various stages for plasma start-up and burn-through, core heating, control of MHD instabilities, etc. Linear and nonlinear processes take place on various time scales and lengths, and advanced theory and modelling are required for propagation and absorption investigation. As an example, the physical analysis done at ISTP-CNR for the design of the EC system of ITER is presented.