An electrically conductive structure includes: a holding member that is an annular member with electrical conductivity around an axis x; and an electrically conductive member that is an annular member around the axis. The electrically conductive member has at least one gap formed to extend in a radial direction and includes at least one electrical conductor with electrical conductivity extending around the axis x. The electrically conductive member is held by the holding member. The electrical conductor has a pair of ends in a direction around the axis x. The gap is continuous with the ends of the electrical conductor.

An improved system for handling delicate linear media and in particular to a method and apparatus for winding delicate linear media such as superconducting wire or tape or optical fibers onto a spool or former, and electric machines produced thereby. A combination of direct closed loop control and media routing design facilitates the handling of the delicate media without causing damage. The axial tension in the linear media may be closely controlled during winding by means of feedback control loop using tension measurements to control the rotation speeds of the wind-from and wind-to spools. Further, during winding, the delicate linear media is only exposed to large radius bends with no reverse bending. Finally, output devices and features, commercial or otherwise, made possible by delicate linear media handling are revealed. This includes advanced SC devices and features.

A method of magnetising or demagnetising an annular component for a rotary machine, a flux arrangement for performing a magnetising or demagnetising method, and a flux assembly for such a flux arrangement; wherein, the annular component includes an alternating arrangement of radial elements and angular elements for forming a Halbach array. A magnetizer is caused to induce magnetic flux in a primary set of elements of the annular component including a primary radial element and an adjacent primary angular element. A shield element shields a secondary angular element of the annular component from magnetic flux from the magnetizer.