Superconducting magnets with thermal radiation shields

摘要

A superconducting magnet comprises a plurality of axially-aligned annular coils 10 of superconducting wire which are in mechanical contact with a cooled surface 15 of a cooling system transferring thermal energy by conduction. There is a thermal radiation shield 24 located between the inner radial surface of the said coils and their axis. The thermal radiation shield 24 is a metal layer in thermal contact with a cooled surface 15 of the said cooling system. The radiation shield 24 may provide a route of lower thermal resistance to the cooled surface 15 than any passing through a superconductive coil 10. The radiation shield 24 may be provided as at least one metal cylinder which is mechanically and thermally joined to the cooled surface 15 at axial and circumferential intervals. The radiation shield 24 may include metal layers with cladding and/or foil layers allowing a structural support to be provided with high thermal conductive layers. Also disclosed is a method of manufacturing a superconducting magnet comprising providing conductive channel pieces with a layer of electrically insulating material over the inner surfaces of the channel and where a superconducting coil is located within the said channel such that the channel covers the axial and the radial inner surfaces of at least one coil 10.