Minisymposium Presentation

Standard derivations of Gyrokinetic theory are not formally compatible with global MHD theory, even in the collisional and small-Larmor radius limit. On the other hand, simpler kinetic theories, like drift-kinetics, can be straightforwardly shown to be consistent with MHD in appropriate limits. By leveraging the known relationships between these theories, I explain how to formulate and solve such kinetic models in a way that allows system-scale MHD motion to be consistently treated. This provides some insight into which system-scale effects are absent in a conventional global gyro-kinetic approach, and how they might be calculated in a kinetic-MHD type framework. As an illustration, we show how certain equilibrium currents are 'missing' when we attempt to reconstruct them via standard gyrokinetics.