Superconducting magnets with thermal radiation shields

A cylindrical superconducting magnet structure, comprising:

• a plurality of resin-impregnated, axially aligned annular coils of superconducting wire, each coil having an axis around which the coil is wound, and a radially outer surface and a radially inner surface;
• a tubular support structure at least partially surrounding the respective radially outer surfaces of said annular coils and having a larger diameter than said radially outer surfaces, each of said annular coils exhibiting a thermal resistance between the respective annular coil and the tubular support structure;
• a cooling arrangement in thermal communication with said tubular support structure that cools at least said tubular support structure to a cryogenic temperature;
• and
• a cryogenic radiation shield between the respective radially inner surfaces of the annular coil and the respective axes of the annular coils, said cryogenic radiation shield comprising a conformal layer of metal foil applied over the radially inner surface of each of said annular coils, and an electrically and thermally insulating layer interposed between each of said annular coils and said metal foil layer, and wherein said conformal layer of metal foil is also applied over axially facing surfaces of each of said annular coils, with said electrically and thermally insulating layer also interposed between each annular facing surface of each coil and said metal foil layer, with a thermal resistance between each metal foil layer and said tubular support structure being less than the thermal resistance between the respective annular coils and the tubular support structure.