Beta limits in long-pulse tokamak discharges
The maximum normalized beta achieved in long pulse tokamak discharges at low collisionality falls significantly below both that observed in short pulse discharges and that predicted by the ideal magnetohydrodynamic (MHD) theory. Recent long-pulse experiments are often limited by low m/n non-ideal MHD modes. The paper focusses on a quantitative comparison between conventional resistive and neoclassical theories, and the experimental results of several machines, which have all observed low m/n non-ideal models. This enables us to single out the key issues in projecting the long-pulse beta limits of ITER-size tokamaks and also to discuss possible plasma control methods which can increase the soft beta limit, decrease the seed perturbations and/or diminish the effects on confinement.
Bibliographic Reference: Article: Physics of Plasmas (1996)
Record Number: 199710181 / Last updated on: 1997-04-01
Original language: en
Available languages: en