Linear stability studies for a quasi-axisymmetric equilibrium including plasma flow, drift and viscosity effects

Linear stability studies are presented for a quasi-axisymmetric stellarator equilibrium which is unstable with respect to external kink and peeling-ballooning modes. Using the three-dimensional linear stability CASTOR3D code, the effects of parallel viscosity, gyro-viscosity, ion diamagnetic drift velocity, E x B velocity and an externally driven flow in direction of the quasi-symmetry are investigated with respect to their influence on growth rate, oscillation frequency and mode structure.