Equilibrium and Stability Aspects of a Screw-Pinch Based on the Sharp-Boundary Model of a High-beta Tokamak.

摘要

The sharp-boundary model of a high-beta tokamak surrounded by force-free currents (FFC) should yield a good description of the magnetohydroynamic stability of a screw-pinch: a tokamak with uniform q-profile. To arrive at the relationship between the equilibrium parameters giving rise to such a q-profile in the FFC region the poloidal field outside the plasma (with a prescribed cross-section) must be determined. An analytical solution has been derived for this field from which the desired relationship can be obtained by numerical means. From the results of a number of cross-sections it is evident that an approximation can be made that leads to this relationship more readily. Based on the latter the stability of a screw-pinch with a number of different cross-sections has been analyzed. (Atomindex citation 12:636419)