Speaker
Dmitry Moseev
(IPP Greifswald)
Description
Due to the 3D geometry, the toroidal canonical momentum is not an adiabatic invariant in stellarators. Typically, this leads to higher losses of fast ions in comparison with tokamaks. Wendelstein 7-X, an optimized stellarator, is predicted to have improved confinement of isotropically distributed fast ions in equilibria with high beta. Whether this property of the optimized equilibrium can be demonstrated by NBI-generated fast ions, and which parts of the phase space distribution function are actually affected by the optimization – these are the topics of our contribution.