Dynamic analysis of Eddy currents and forces in the TFTR vacuum vessel due to plasma disruptions

The sudden disappearance of electrical current during a plasma disruption in the Tokamak Fusion Test Reactor (TFTR) induces large transient eddy currents in the surrounding vacuum vessel. These eddy currents interact with the background magnetic fields to produce significant mechanical loads. In this study a detailed model of a representative 36 degree segment of the vessel was chosen for analysis and assumed to have a ten-fold rotational symmetry. The eddy currents and Lorentz forces were calculated using an extended version of the eddy current code SPARK with plasma drivers corresponding to several different stationary and moving plasma disruption scenarios. The forces were then used as input to the structural analysis code NASTRAN to calculate the dynamic mechanical response of the vacuum vessel.