Increase in beta limit in tokamak plasmas

Kamada, Yutaka

This paper reviews recent studies on tokamak MHD stability towards achievement of high beta steady-state, where profile control of current, pressure and rotation, and optimization of the plasma shape play fundamental roles. The key instabilities are the neoclassical tearing mode, the resistive wall mode, the edge localized modes etc. Towards demonstration of an economically attractive tokamak reactor, we need to increase the beta value with sufficiently high integrated plasma performance. Towards this goal, studies on stability control in the self-regulating plasma system are essential.