Torque Balance and Rotational Stabilisation of the Resistive Wall Mode
We have investigated a non-linear model of the rotational stabilisation of the Resistive Wall Mode (RWM). Central to the model is a cylindrical plasma that is ideal MHD unstable in the absence of a wall, and possesses an internal resionance. This system is then a qualitative model for the actual toroidal external kink mode that is relevant in Advanced Tokamak scenarios. It has been shown in the past that RWM can possess stability windows for modest rotation frequencies. However, the equilibrium parameter regime in which stabilisation can take place is small. We present a non-linear formulation of the problem, with plasma rotation determined self-consistently by an equation of torque balance. It is found that, within the same small parameter regime, stability windows can be considerably extended at the expense of the growth of a magnetic island. On the other hand, depending on the initial rotation, the system canreduce the plasma rotation rate asymptoticaly to zero while the island continues to grow
Bibliographic Reference: Report: EN (1999) 22pp.
Availability: Available from the Librarian, UKAEA, Culham Laboratory, Abingdon, Oxon (GB)
Record Number: 199910872 / Last updated on: 1999-06-25
Original language: en
Available languages: en