The theory of the kink mode during the vertical plasma disruption events in tokamaks

This paper explains the existence of the m/n=1/1 kink mode during the vertical disruption event when the plasma has an electrical contact with the plasma facing conducting surfaces. It is shown that the kink perturbation can be in an equilibrium state even with a stable safety factor q>1, if the surface currents, excited by the kink mode, can flow through the conducting structure. The present theory suggests an explanation of the so-called sideway forces on the tokamak in-vessel components during the disruption event. For the general case of such wall touching kink modes, the energy principle is derived, which includes the current sharing effect