GB1129696A - Superconductor coils - Google Patents

Abstract

1129696 Super-conductor coil SIEMENS AG 28 Sept 1967 [28 Sept 1966] 44308/67 Headings H1A A5 A2E3D2 and A4D A super-conductor coil comprises a plurality of elongate super-conductor members wound in parallel with one another to form a plurality of layers, the respective members of adjacent winding layers being connected together in a normally conductive manner but the adjacent successive turns of each winding layer being insulated from each other. An antimagnetic steel former 3 is lined with an insulating layer 4 and then wound about by a plurality of super-conductor members which are led into the former through an inclined slit 11. Successive super-conductor turns 5 and 7 are separated by a polyethylene terephthalate foil 8 whilst adjacent members 5 and 6 of the winding are connected under normal conductive conditions by a layer 9 of Cu, Al or Ag. The super-conductor members may be coated wires, strips or braids of Nb-Zr, Nb-Sn or Nb-Ta. In one embodiment Fig. 3 (not shown) the super-conductor may be covered with a layer of Sn or In with or without an undercoating of Cu and the coatings on adjacent layers fused together by passing current through the layers. In another embodiment Fig. 2 (not shown), the super-conductor is a braid (21) made from coated wires and the super-conductors of adjacent layers are connected through a copper layer (24) on the sides of the insulating separators (23) together with a copper foil (22) between adjacent layers and a tin filling (25) in the cavity between the foils and the separators. The copper foil and the insulator foil may be undulatory or have slits or grooves to facilitate passage of a coolant. The copper layers and the separators extend beyond the windings to assist washing by the ambient coolant. The various layers of the super-conductor coil are connected in series and Nb 3 Sn may be used for the inner layers whilst NbZr may be used for the outer layers.