The "Football" test coil: A simulated service test of internally-cooled, cabled superconductor

Internally-cooled, cabled superconductor, ICCS, appears from small-scale tests to be a viable alternative to pool-boiling cooled superconductors for large superconducting magnets. Potential advantages may include savings in helium inventory, smaller structure and ease of fabrication. Questions remain, however, about the structural performance of these systems. The "football" test coil has been designed to simulate rather closely the actual "field-current-stress-thermal" operating conditions of a 25 kA ICCS in a commercial scale MHD magnet. The test procedure will permit demonstration of the 20 year cyclic life of such a magnet in less than 20 days. This paper will describe in detail the design and construction and test of that coil which is wound of copper-stabilized niobium-titanium cable in steel conduit.