Stability of kinetic ballooning mode at steep pressure gradient

Abstract

Summary form only given, as follows. A fully kinetic, efficient, integral equation code has recently been developed in the Laboratory to study the ballooning and drift type modes in tokamaks in order to implement ion transit effects and trapped electrons in a satisfactory manner. It has been applied to short wavelength drift type modes driven by ion and electron temperature gradients. In this paper, we report on stability analysis of the kinetic ballooning mode at very steep pressure gradient pertinent to the so called internal transport barrier which develops in weak negative shear regime. It is well known that the ideal MHD ballooning mode is stable when shear is negative. However, the kinetic ballooning mode persists in the parameter regime where the ideal MHD mode is stable.