Mine countermeasures HTS magnet

American Superconductor has designed, manufactured, and tested a model high-temperature superconducting (HTS) magnet system for airborne mine countermeasures (MCM) for the Office of Naval Research. The magnet has a magnetic moment of 80 kA-m/sup 2/, or about one-fourth that of the full-scale magnet. The magnet is a solenoid consisting of 16 layers of laminated Bi-2223 HTS wire. The coil was manufactured at Everson Electric and tested at American Superconductor. The coil has an inside diameter of 455 mm, an outside diameter of 476 mm, and is 914 mm in length. The magnet was successfully ramped to its operating current of 193 A at 30 K. It was also successfully modulated with /spl plusmn/26 A current at 0.5 Hz. The magnet is conduction-cooled with a single-stage GM cryocooler. The design, manufacture, and test results of the magnet will be presented.