Beta-Value Limits and MHD 2.Increase in Beta Limit in Tokamak Plasmas

Abstract

This paper reviews recent studies of tokamak MHD stability towards the achievement of a high beta steady state, where the profile control of current, pressure, and rotation, and the optimization of the plasma shape play fundamental roles. The key instabilities include the neoclassical tearing mode, the resistive wall mode, the edge localized mode, etc. In order to demonstrate an economically attractive tokamak reactor, it is neccesary to increase the beta value simultaneously with a sufficiently high integrated plasma performance. Towards this goal, studies of stability control in self-regulating plasma systems are essential.