Design of a High Energy-Density SMES Coil With Bi-2212 Cables

This report describes a basic design of an HTS-SMES coil wound with large current capability Bi-2212 cables. The objective of this development is to evaluate fundamental properties of the coil in a high magnetic field. The coil is comprised of an HTS inner coil wound with Bi-2212 Rutherford cables and an LTS outer backup-field coil wound with NbTi conductors. The Bi-2212 coil is designed to generate a maximum field of 8 T at 4.2 K within the backup field at an operating current of 1584 A. In this study, general specifications of the coil were discussed with some important issues; winding dimensions for a peak field, current density limitation, elasticity of the winding, and protection from the thermal runaway. The coil is fabricated in FY 2006, and testing will be performed in FY 2007. In the experiments, superconducting characteristics of the coil in a high magnetic field will be evaluated.