Conceptual Design of a Toroidal Field Coil for a Fusion Power Plant Using High Temperature Superconductors

Taking a step further from the International Thermonuclear Experimental Reactor (ITER), the next step will be a demonstration fusion power plant, DEMO, i.e., a fusion power plant (FPP) prototype. As a part of European Union (EU) DEMO studies, the result of the so-called PROCESS system code has been taken as the basis to design a toroidal field coil (TFC) winding pack with high temperature superconductor (HTS) REBCO, which is a promising HTS candidate. From this, the cable space area, the winding pack current density, and the total current in one TFC has been obtained. In this paper, a conceptual design of a HTS TFC is presented, and related parameters, such as peak magnetic field at the conductor, conductor current, and coil inductance, are calculated. The results have been used to evaluate the temperature margin and the hot spot temperature in case of a quench. With the calculated results, it is shown that at 4.5 K, the actual available HTS conductor can be used to design a TFC for DEMO within the available space given by PROCESS code.