Stabilization of TAE instabilities via ion Landau damping

The effect of the ion Landau damping on the Toroidicity induced Alfven Eigenmodes (TAE) is investigated. By treating each species with a newly derived low-(n,m) drift kinetic solution of the linearized Vlasov equation, a general form of the growth rate of energetic particle Alfven modes is derived. In particular, the sideband resonance induced by the toroidal curvature is shown to strongly enhance the ion Landau damping on the TAE instability. Also the parameter ηα = dlnTα/dln nα turns out to be important in the evaluation of the alpha particle driver. For high enough βi the TAE can be completely stabilized. It is also shown that the ion Landau damping has virtually no effect on the Ellipiticity Induced Alfven Eigenmodes (EAE). Both the TAE and EAE need further investigation to determine how detrimental their effects may be on alpha particle confinement in ignited tokamaks