On the Consequences of Electrical Failures of PF Magnet Systems for Fusion Reactors

Several fault scenarios for electrical failures in the Poloidal Field (PF) magnet system are investigated involving shorts and faults with constant applied voltage at the coil terminals. A simplified model of the Compact Ignition Tokamak (CIT) is used to examine the load conditions for the PF and the Toroidal Field (TF) coils resulting from these fault scenarios. It is concluded that shorts do not pose large risks for the PF coils. Also, the type of plasma disruption has little impact on the net forces on the PF and the TF coils. However, the out-of-plane loads at the inner corner of the TF coils can increase substantially for a wide range of scenarios, and this effect can even be stronger depending on the terminal constraints on the internal PF coils.