Dense supercritical-helium cooled superconductors for large high field stabilized magnets

We have developed an analytical model of a dense, supercritical helium-cooled superconductor, stabilized to withstand short-term instabilities. The model allows for the absorption of energy from transient instabilities and Joule heating during current sharing. Coolant heat transfer parameters are optimized with respect to geometry and superconductor critical temperatures. Data is presented to demonstrate the advantages of a novel extended surface conductor bundle. This work has been directed at large, high-field magnets in the 5 to 9 Tesla range. Conceptual designs of a toroidal "Tokamak" coil of 6 meter minor diameter and a 10 m. long × 2.5 m. diameter saddle-wound "MHD" magnet are presented.