The Interaction and Protection of Superconducting Poloidal Field Coils and Toroidal Field Coils in a Tokamak Experimental Power Reactor

The protection problems of superconducting coils in a large tokamak device are delineated. Effects of the plasma discharge on the first wall, the induced voltage, and the temperature rise during the quench of a superconducting coil, as well as the mechanical load on coils due to their mutual interaction under normal or fault conditions, have been studied. Various design choices and protection schemes are used to ensure the integrity of the coils during quench. For the Oak Ridge Experimental Power Reactor design, a scheme of connecting symmetrically located toroidal field coils in groups isolates and discharges the fault coil only, giving satisfactory results.