Dynamics of tokamak plasma surface current in 3D ideal MHD model

Interest in the surface current which can arise on perturbed sharp plasma vacuum interface in tokamaks was recently generated by a few papers (see [1-4] and references therein). In dangerous disruption events with plasma-touching-wall scenarios, the surface current can be shared with the wall leading to the strong, damaging forces acting on the wall [2] A relatively simple analytic definition of $\delta $-function surface current proportional to a jump of tangential component of magnetic field nevertheless leads to a complex computational problem on the moving plasma-vacuum interface, requiring the incorporation of non-linear 3D plasma dynamics even in one-fluid ideal MHD. The Disruption Simulation Code (DSC), which had recently been developed in a fully 3D toroidal geometry with adaptation to the moving plasma boundary, is an appropriate tool for accurate self-consistent $\delta $function surface current calculation. Progress on the DSC-3D development will be presented. Self-consistent surface current calculation under non-linear dynamics of low m kink mode and VDE will be discussed.\\[4pt] [1] L.E. Zakharov, Phys. Plasmas, \textbf{15}, 062507 (2008)\\[0pt] [2] A.J. Webster, Phys. Plasmas \textbf{17}, 110708 (2010)\\[0pt] [3] A.J. Webster, Phys. Plasmas \textbf{18}, 112507 (2011)\\[0pt] [4] L.E. Zakharov, S.A. Galkin, S.N. Gerasimov, Phys. Plasmas \textbf{19}, 055703 (2012)