Toroidal kinetic ηi-mode study in high-temperature plasmas

A new kinetic integral equation for the study of the ion-temperature-gradient-driven mode in toroidal geometry is developed that includes the ion toroidal (curvature and magnetic gradient) drift motion ωD, the mode coupling from finite k∥ due to the toroidal feature of the sheared magnetic configuration. The integral equation allows the stability study for arbitrary k∥vi/(ω − ωD) and k⊥ ρi. A systematic parameter study is carried out for the low β circular flux surface equilibrium. Possible correlations between the unstable mode characteristics and some experimental results such as the fluctuation spectrum and the anomalous ion thermal transport measurements are discussed.