Advanced RF heating schemes in preparation for ICRF heating and fast ion experiments in the W7-X stellarator

ion experiments in the W7-X stellarator M. Machielsen1, H. Patten1, J. Graves1 1 Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland Motivation Fast ion confinement is crucial for the demonstrating the viability of the stellarator approach as a nuclear fusion reactor. There are three main ways of generating these fast ions: fusion born fast alphas, NBI, ICRF heating. For the stellarator W7X option two and three are the most feasible short term. The device is currently being upgraded, going from two neutral beams to four. Also ICRF heating should be available in operational phase 2 (OP2.0). The code package SCENIC is in a unique position to model ICRF heating schemes in 3D geometries, such as W7X, right now. This will be in preparation for OP2.0. Secondly, a recent extension to the wave model for hot plasma is used to investigate higher harmonic heating in JET. This is important for instance when investigating higher harmonic heating on tritium in the upcoming DT experiments (He-3 minority heating).