TSC PLASMA HALO SIMULATION OF A DIII-D VERTICAL DISPLACEMENT EPISODE

A benchmark of the Tokamak Simulation Code (TSC) plasma halo model has been achieved by calibration against a DIII-D vertical displacement e pisode (VDE) consisting of vertical drift, thermal quench and current quench. With a suitable halo surrounding the main plasma, the TSC pred ictions are in good agreement with experimental results for the plasma current decay, plasma trajectory, toroidal and poloidal vessel curren ts, and for the magnetic probe and flux loop values for the entire VDE . Simulations with no plasma halo yield much faster vertical motion an d significantly worse agreement with the magnetics and flux loop data than do halo simulations.