SHUNT PROTECTION FOR SUPERCONDUCTING MAGLEV MAGNETS
Abstract Closely coupled, short-circuited shunt coils are proposed for quench protection of super-conducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated.
Superconducting Magnetic Levitation and Linear Synchronous Motor Development—The Canadian Program
The Canadian Maglev program has been reviewed previously [1–4]. We are investigating superconducting magnetic levitation, linear synchronous motor (LSM) propulsion, and guidance for 480 km/hr intercity transit along the Toronto-Ottawa-Montreal corridor for the 1990’s. Single 100-passenger vehicles weighing 300 kN are levitated with 15 cm clearance by eight vehicle-borne superconducting magnets (each 1.0 m long × 0.3 m wide, with 3.85 × 105 A turns) interacting with eddy currents induced in 80-cm-wide aluminum strips on an elevated flat-topped guideway. The aluminum strip thickness is graded from 1 cm in high-speed to 3 cm in low-speed sections to maintain total drag (magnetic and aerodynamic) almost speed independent, while minimizing the combined costs of energy requirements and aluminum amortization.
In-House Industrial Production of the Superconducting Conductor for the 43 T Hybrid Magnet of LNCMI-Grenoble
The hybrid magnet being built at LNCMI-Grenoble is based on the combination of resistive inserts, made up of Bitter and polyhelix coils, with a large bore superconducting outsert. It will produce, in the first step, an overall continuous magnetic field of 43 T in a 34 mm warm bore aperture. The superconducting coil will provide a nominal magnetic field of 8.5 T in a 1.1 m cold bore diameter. It relies on the novel development of an Nb-Ti/Cu Rutherford Cable On Conduit Conductor (RCOCC) cooled down to 1.8 K by a bath of superfluid helium pressurized at 1200 mbar. After a brief reminder of the specificity of hybrid magnets, namely the strong electromechanical coupling between resistive and superconducting coils, the main requirements of the RCOCC for efficient and reliable magnet operation are given. The test and validation phases prior to the industrial production of the RCOCC are reported, including the trial production of the ½ hard-drawn (H02 cold-worked) Cu-Ag 0.05% hollow stabilizer in continuous lengths of 325 m. The novelty of the RCOCC development concerns the assembly and the induction soft-soldering of the Rutherford cable on the Cu-Ag hollow stabilizer allowing a strict control of the interstrand contact resistance. Studies, developments, and the integration of the industrial production line at LNCMI-Grenoble are presented together with the result of the production of all RCOCC unit lengths.