High current density aluminium stabilized conductor concepts for space applications

The authors report on a high-current-density aluminium-stabilized conductor concept for large spaceborne energy storage inductors. High-purity-aluminium-stabilized NbTi composite conductors cooled by 1.8-K helium can provide a winding current density up to 15 kA/cm² at fields up to 10 T. The conductors are edge-cooled with enough surface area to provide recovery following a normalizing disturbance. The conductors are designed so that current diffusion time in the high-purity aluminium is smaller than the thermal diffusion time in helium. Conductor design, stability, and current diffusion are considered. The numerical analysis of transient stability shows that aluminium-stabilized conductors with final resistivity ratio greater than 800 can be stable in a 1.8-K pressurized helium II bath up to 50 kA (J=15 kA/cm²) at fields up to 10 T. single-layer toroids are preferred over multilayer ones because of their simplicity of construction, large current requirement, and better magnetoresistance