Primary coil assembly for a superconducting linear induction motor

A primary coil assembly for a superconducting linear induction motor, comprising:

• a plurality of coil units having substantially identical structure and shape and spaced at a predetermined distance from each other, each of the coil units including a nonmagnetic and nonconductive bobbin, an alternating-current superconducting wire wound around the bobbin, and nonmagnetic and nonconductive spacer means interposed between adjacent turns of the superconducting wire being adjacent to each other in an outward direction with respect to an axis of the bobbin or adjacent to each other in a width direction of the bobbin, for providing a clearance therebetween;
• the primary coil assembly being arranged opposite to a secondary conductor for exerting a relative thrust on the secondary conductor when energized;
• and
• wherein the coil units each have a D-shaped end face and a surface opposed to the secondary conductor, said surface being flat in accordance with a shape of the secondary conductor.