System studies of copper- and superconducting-coil pilot plants

The TETRA systems code is used to examine devices with both normal copper and superconducting coils as vehicles for steady-state production of fusion power in a Pilot Plant. If the constraints of plasma ignition and net electrical power production are dropped, such devices are much smaller and less expensive than ITER-like devices. For wall loads near 0.5 MW/m² with nominal ITER physics guidelines, devices with copper coils have major radii R near 2 m and direct costs near 1×10⁹ $, while devices with superconducting coils have R = 4.1 m and costs of 2.4×10⁹ $. However, the copper-coil devices have the burden of hundreds of megawatts of resistive power losses. All cases tend towards high aspect ratio (A>4), high fields, and low current. The situation improves for the superconducting-coil cases if higher beta limits are permissible, whereas the copper-coil cases see less benefit from higher beta limits.