Instabilities and turbulence in the plasma of Wendelstein 7-X

Stellarators are characterised by a complex three-dimensional structure, distinguishing them from other toroidal magnetic confinement concepts. The investigation of instabilities, especially micro instabilities, and their development into turbulence is not well understood for stellarators. It is particularly interesting if turbulence in stellarators is different from those in other confinement configurations and if a manipulation by optimisation of the magnetic structure is possible. In the following, numerical simulations of the ion-temperature driven instability in the plasma core and of turbulence in the plasma edge for Wendelstein 7-X will be presented.