Toroidal drift modes driven by the magnetic drift resonances

Artikel i vetenskaplig tidskrift, 2018

Here, we find that the kinetic and fluid linear drift resonances have several similarities. The reason for our interest in this is that our fluid model has recently been shown to be exact for drift waves and other modes in that frequency range. Thus, transport is driven by the fluid linear growth rate and our drift wave system behaves like a cold beam-plasma system although it has a finite temperature. A main similarity is that neither fluid nor kinetic responses should be expanded in the curvature in the bulk interior of tokamaks. That we can use the fluid response close to the magnetic drift resonance is a consequence of the fact that the closure is exact. A systematic orbit integration technique is introduced for deriving the fluid model and evaluating the effects of nonlinearities.