Abstract: A cylindrical superconducting magnet has a number of axially-aligned annular coils of superconducting wire, arranged for cooling by thermal conduction through a cooled surface in mechanical contact with the coils. The coils are provided with a cryogenic radiation shield located between respective radially inner surfaces of the coils and respective axes of the coils. The cryogenic radiation shield is formed of a metal layer in thermal contact with the cooled surface.

Abstract: A cylindrical superconducting magnet system for use in magnetic resonance imaging has axially aligned primary superconducting coils surrounded by a thermal radiation shield within a vacuum vessel. A gradient coil assembly is axially aligned with and located radially within the primary superconducting coils. An assembly support is, radially positioned outside of the primary superconducting coils and is mechanically attached to the gradient coil assembly at a number of locations around the circumference of the gradient coil assembly, and at a number of axial locations along the gradient coil assembly, by radially-directed mechanical attachments that pass though through-holes through the vacuum vessel and the thermal radiation shield, and mechanically isolated from the vacuum vessel. At least some of the mechanical attachments each comprise an active force transducer arranged to provide impulses of force onto a surface of the gradient coil assembly to oppose vibrations of the gradient coil assembly.

Abstract: In a method or joint for joining first and second semiconductor wires, each comprising a number of filaments which each comprise a superconductive core within a respective sheath, the filaments being embedded within a matrix and wherein the superconductive cores comprise magnesium diboride and the sheaths comprise niobium, over a certain length a matrix is removed to expose the filaments. The exposed filaments are immersed in molten tin such that the nobium of the sheaths is converted to niobium-tin throughout a thickness of the sheaths. A superconductive path is provided between the superconductive cores of filaments of the first wire through the niobium-tin sheaths of the filaments to the superconductive cores of the second wire.

Abstract: A cylindrical superconducting magnet system for use in magnetic resonance imaging has axially aligned primary superconducting coils that are situated within an outer vacuum chamber (OVC). A thermal radiation shield surrounds the primary superconducting coils within the OVC. A primary gradient coil assembly is axially aligned with the primary superconducting coils and is situated radially within the primary superconducting coils. The cylindrical superconducting magnetic system also includes a secondary gradient coil assembly, that is radially situated outside of the primary superconducting coils and that is mechanically attached to the primary gradient coil assembly.

Abstract: In a method or joint for joining first and second semiconductor wires, each comprising a number of filaments which each comprise a superconductive core within a respective sheath, the filaments being embedded within a matrix and wherein the superconductive cores comprise magnesium diboride and the sheaths comprise niobium, over a certain length a matrix is removed to expose the filaments. The exposed filaments are immersed in molten tin such that the nobium of the sheaths is converted to niobium-tin throughout a thickness of the sheaths. A superconductive path is provided between the superconductive cores of filaments of the first wire through the niobium-tin sheaths of the filaments to the superconductive cores of the second wire.

Abstract: In a combined MRI and radiation therapy system, a magnet structure and radiation therapy equipment are provided. The magnet structure comprises a single substantially cylindrical field coil structure comprising a number of superconducting coils joined by a support structure and extending axially of a central region. An outer vacuum chamber encloses the field coil structure in an evacuated volume. A cooling arrangement comprising cooling tubes is in thermal contact with the superconducting coils and receives a cryogen flowing through the cooling tubes. The radiation therapy equipment comprises a gamma radiation source rotatable about an axis of the field coil structure to direct a radiation beam substantially radially through the field coil structure.

Abstract: In a method or joint for joining first and second semiconductor wires, each comprising a number of filaments which each comprise a superconductive core within a respective sheath, the filaments being embedded within a matrix and wherein the superconductive cores comprise magnesium diboride and the sheaths comprise niobium, over a certain length a matrix is removed to expose the filaments. The exposed filaments are immersed in molten tin such that the nobium of the sheaths is converted to niobium-tin throughout a thickness of the sheaths. A superconductive path is provided between the superconductive cores of filaments of the first wire through the niobium-tin sheaths of the filaments to the superconductive cores of the second wire.

Abstract: A magnet assembly has a number of axially-aligned coils, the radial mid-point of each coil being axially-aligned with a portion of a radial extent of an adjacent coil in the assembly. Compression blocks are provided between adjacent coils at circumferential intervals, to retain the coils in fixed relative positions.

Abstract: A hollow cylindrical thermal shield for a tubular cryogenically cooled superconducting magnet, has a first axis, an inner cylindrical tube having an axis aligned with the first axis, an outer cylindrical tube of greater diameter than the diameter of the inner cylindrical tube, having an axis aligned with the first axis, and annular end pieces, joining the inner cylindrical tube and the outer cylindrical tube to form an enclosure. The hollow cylindrical thermal shield further has a cylindrical stiffener, extending axially at least part of the axial length of the inner cylindrical tube, the stiffener being joined at intervals to the inner cylindrical tube, thereby to improve the mechanical rigidity of the inner cylindrical tube.

Abstract: A method for centralising and retaining a molded end coil (20) in a magnet former (12) which includes an oversleeve (24) for retaining the end coil in position, the radially outer (A2) surface of the end coil being of lesser diameter than the radially inner surface of the oversleeve.

Abstract: In a method and apparatus for joining a number of superconductive cables to establish electrical connection therebetween, a cup-like member having a base, a sidewall, and an opening to receive electrically conductive ends of said cables is provided. The base of the cup-like member is attached to a holder device. The holder device is attached to a cryogenically cooled surface. The ends of the superconductive cables are connected together within the cup-like member.

Abstract: In a cylindrical superconducting magnet system for magnetic resonance imaging, primary superconducting coils are positioned within an outer vacuum chamber. A thermal radiation shield surrounds the primary superconducting coils. A gradient coil assembly is axially aligned with the primary superconducting coils. A mechanical support assembly is radially positioned outside of the primary superconducting coils and is mechanically attached to the gradient coil assembly by mechanical attachments which pass through through-holes through the outer vacuum chamber and the thermal radiation shield.

Abstract: A hollow cylindrical thermal shield for a tubular cryogenically cooled superconducting magnet, has a first axis, an inner cylindrical tube having an axis aligned with the first axis, an outer cylindrical tube of greater diameter than the diameter of the inner cylindrical tube, having an axis aligned with the first axis, and annular end pieces, joining the inner cylindrical tube and the outer cylindrical tube to form an enclosure. The hollow cylindrical thermal shield further has a cylindrical stiffener, extending axially at least part of the axial length of the inner cylindrical tube, the stiffener being joined at intervals to the inner cylindrical tube, thereby to improve the mechanical rigidity of the inner cylindrical tube.

Abstract: In a solenoidal electromagnet arrangement for a magnetic resonance imaging system, annular inner coils and annular end coils are provided, all concentrically aligned about an axis, the end coils being placed at axial extremities, axially outside of the inner coils. A pair of annular outer coils are provided concentrically aligned about the axis. An arrangement is provided retaining the pair of outer coils against an axial force urging the outer coils away from one another. The arrangement comprises strap elements which extend around a radially inner surface, a radially outer surface and an axially outer surface of each outer coil in certain circumferential locations. Each strap element on one of the outer coils is linked to a corresponding strap element on the other outer coil of the pair by a tensile member.

Abstract: In a solenoidal electromagnet arrangement for a magnetic resonance imaging system, annular inner coils and annular end coils are provided, all concentrically aligned about an axis, the end coils being placed at axial extremities, axially outside of the inner coils. A pair of annular outer coils are provided concentrically aligned about the axis. An arrangement is provided retaining the pair of outer coils against an axial force urging the outer coils away from one another. The arrangement comprises strap elements which extend around a radially inner surface, a radially outer surface and an axially outer surface of each outer coil in certain circumferential locations. Each strap element on one of the outer coils is linked to a corresponding strap element on the other outer coil of the pair by a tensile member.

Abstract: A method of manufacturing a solenoidal magnet structure, includes the step of providing a collapsible accurate mold in which to wind the coils winding wire into defined positions in the mold, placing a mechanical support structure over the coils so wound, impregnating the coils and the mechanical support structure with a thermosetting resin, allowing the thermosetting resin to harden, and collapsing the mold and removing the resultant solenoidal magnet structure formed by the resin impregnated coils and the mechanical support structure from the mold as a single solid piece.

Abstract: A method for manufacturing a solenoidal magnet having one or more coils wound onto a cylindrical former, and an annular end coil (20), mounted onto an end of the former such that no part of the former is present on the radially inner (A1) or axially outer (B2) sides of the end coil.

Abstract: A method of manufacturing a solenoidal magnet structure, includes the step of providing a collapsible accurate mold in which to wind the coils winding wire into defined positions in the mold, placing a mechanical support structure over the coils so wound, impregnating the coils and the mechanical support structure with a thermosetting resin, allowing the thermosetting resin to harden, and collapsing the mold and removing the resultant solenoidal magnet structure formed by the resin impregnated coils and the mechanical support structure from the mold as a single solid piece.

Abstract: A method of manufacturing a solenoidal magnet structure, includes the step of providing a collapsible accurate mold in which to wind the coils winding wire into defined positions in the mold, placing a mechanical support structure over the coils so wound, impregnating the coils and the mechanical support structure with a thermosetting resin, allowing the thermosetting resin to harden, and collapsing the mold and removing the resultant solenoidal magnet structure formed by the resin impregnated coils and the mechanical support structure from the mold as a single solid piece.

Abstract: In a method and apparatus for joining a number of superconductive cables to establish electrical connection therebetween, a cup-like member having a base, a sidewall, and an opening to receive electrically conductive ends of said cables is provided. The base of the cup-like member is attached to a holder device. The holder device is attached to a cryogenically cooled surface. The ends of the superconductive cables are connected together within the cup-like member.