Integrated modelling of ICRH in a quasi-axisymmetric stellarator
We apply the code package SCENIC to a two field-period quasi-axisymmetric stellarator. Ion cyclotron resonance heating (ICRH) is applied both on the high-and low-field side to a 1% He-3 minority in a deuterium plasma. It is shown that due to toroidal variations, the results are considerably different from similar tokamak studies. In particular, toroidal variations in power deposition and pressure are created and accentuated during radio frequency heating, such that modifications to the magnetic equilibrium depend on toroidal angle. We demonstrate that due to enhanced particle loss, low-field side heating is significantly less efficient than high-field side heating, and that toroidally trapped particles impose upper power limits for efficient radio frequency injection.