Resistive ballooning modes driven by anomalous transport effects

Abstract

Using Braginskii’s two fluid equations, the stability of resistive ballooning modes is examined in the presence of parallel thermal conduction, anomalous electron viscosity, and radial thermal conductivity. A generalized set of coupled second-order differential equations in φ and ψ is derived in ballooning space and is solved to obtain analytical solutions in two interesting frequency regimes, SCs/ qR ≪ ‖ω‖ ≪ Cs/ qR and ‖ω‖ ≫ Cs/qR. It is shown that the anomalous thermal transport term excites the new m=1 resistive ballooning mode (‖ω‖ ≫ Cs/qR) with a large growth rate. The excitation of the m=2 type (or Δ′ driven) mode, on the other hand, is found to be strongly influenced by both anomalous electron viscosity and radial thermal conduction. Finally, the additional effect of parallel electron thermal conduction is shown to give new resistive ballooning modes with significantly large growth rates varying as fractional powers of anomalous electron viscosity and classical thermal conductivity.