Three-dimensional simulation of the vertical displacement event in tokamaks

Tokamak plasmas with highly elongated cross sections are subject to a vertical displacement event (VDE). The nonlinear magnetohydrodynamic (MHD) evolutions of tokamak plasmas during VDE are visualized by a three-dimensional MHD simulation. The nonlinear evolution during VDE is strongly affected by the relative amplitude of the nonaxisymmetric to the axisymmetric mode.