Plasma Vertical Control with Internal and External Coils in Next Step Tokamaks
Authors: C.E. Kessel, P. Heitzenroeder, and C. Jun
Date of PPPL Report: November 2000
Published in: Nucl. Fusion 41 (July 2001) 953-961.
Vertical stability and control are examined for a tokamak configuration intended to be a generic representation of next step devices. Vertical stability calculations show that a critical resistive wall location can be determined for realistic structures, and that the introduction of small amounts of low resistivity material to an all steel structure can significantly reduce the vertical instability growth rate. Vertical control simulations show that internal control coils require significantly less feedback power than external coils, and that low resistivity materials can allow very low feedback powers or coils to be located externally with reasonable feedback powers.