A superconducting magnet for producing part of a substantially toroidal field in a device is described. The magnet comprises: a set of conductors comprising one or more first conductors (31f) and one or more second conductors (32f), and a set of joints (33). Each of the joints (33) connects a region of a first conductor (31f) with a region of a second conductor (32f) to form a series of alternating first and second conductors corresponding to at least part of a winding of the magnet. Each of the joints (33) is positioned away from a midplane of the toroidal field. The joints (33) are positioned on alternating sides of the midplane. Each first conductor (3 If) passes through the midplane at a smaller distance from an axis of rotation of the toroidal field than does each second conductor (32f). Each of the regions is elongate and extends in a direction at least partly away from the midplane.