Collisionless gyro-kinetics in stellarator geometry

The linear ion gyro-kinetic equation in stellarator geometry is presented. This equation, together with the quasineutrality condition and an adiabatic electron response, is solved as an initial-value problem along the magnetic field line. Numerical results for the toroidal heliac H1-NF (Hamberger S M et al 1990 Fusion Technol. 17 123) are presented. It is shown that the local properties of the confining magnetic field, such as the normal and geodesic curvatures and the integrated residual shear, are important for the mode localization along the field line. (author)