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: In a superconducting magnet apparatus, at least one superconducting winding and an outer vacuum chamber are provided. A thermal radiation shield is located between the superconducting winding and the outer vacuum chamber. A cryogen vessel is positioned within the thermal radiation shield and within the outer vacuum chamber. The superconducting winding is positioned outside of the cryogen vessel. A refrigerator is operable to cool the cryogen vessel to a liquid cryogen temperature and to cool the at least one thermal radiation shield to an intermediate temperature between the liquid cryogen temperature and a temperature of the outer vacuum chamber. A substantial portion of an outer surface of the cryogen vessel has a thermal emissivity at the liquid cryogen temperature which is greater than an average surface emissivity of the superconducting winding by at least 0.1.

Abstract: A cylindrical magnet assembly has at least one coil mounted on a former, assembled to a bore tube by a number of inserts within holes formed in a material of the former. Each insert can bear on a dished radially outer extremity of a radially-outwardly directed protrusion or each insert can bear on a radially outer concave surface of a radially-inwardly directed protrusion.

Abstract: In a superconducting magnet apparatus, at least one superconducting winding and an outer vacuum chamber are provided. A thermal radiation shield is located between the superconducting winding and the outer vacuum chamber. A cryogen vessel is positioned within the thermal radiation shield and within the outer vacuum chamber. The superconducting winding is positioned outside of the cryogen vessel. A refrigerator is operable to cool the cryogen vessel to a liquid cryogen temperature and to cool the at least one thermal radiation shield to an intermediate temperature between the liquid cryogen temperature and a temperature of the outer vacuum chamber. A substantial portion of an outer surface of the cryogen vessel has a thermal emissivity at the liquid cryogen temperature which is greater than an average surface emissivity of the superconducting winding by at least 0.1.

Abstract: A hollow cylindrical vessel comprising a cylindrical outer shell (12) and a cylindrical inner shell (14) joined by annular end caps (16), wherein at least one of: an end cap, or the cylindrical outer shell (12), or the cylindrical inner shell (14), is provided with an arrangement of recesses or protrusions (18). Preferably, the arrangement of recesses or protrusions is asymmetrical in all axes.

Abstract: A cylindrical magnet assembly has at least one coil mounted on a former, assembled to a bore tube by a number of inserts within holes formed in a material of the former. Each insert can bear on a dished radially outer extremity of a radially-outwardly directed protrusion or each insert can bear on a radially outer concave surface of a radially-inwardly directed protrusion.

Abstract: An assembly includes a cylindrical magnet assembly, which includes comprises at least one coil mounted on a former. The assembly also includes a bore tube with a number of radially-directed retaining protrusions formed in a material of the bore tube, each of the number of radially-directed retaining protrusions configured to bear against a periphery of a corresponding cavity in the former.

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 tool for assembling a cylindrical magnet assembly to a bore tube and a resulting assembly. The cylindrical magnet assembly includes at least one coil mounted on a former. A cavity is provided in the former at selected locations. At each of the selected locations, the material of the bore tube is deformed to form a radially-directed protrusion. Each protrusion is brought to bear against a periphery of each corresponding cavity.

Abstract: A method for progressively introducing current into, or removing current from, a superconducting coil mounted on a former, in which the coil vibrates relative to the former.

Abstract: A method for assembling a cylindrical magnet assembly, which includes at least one coil mounted on a former, to a bore tube is provided. The method involves providing a cavity in the former at selected locations. At each of the selected locations, the material of the bore tube is deformed to form a radially-directed protrusion. Each protrusion is brought to bear against a periphery of each corresponding cavity.

Abstract: A method for progressively introducing current into, or removing current from, a superconducting coil mounted on a former, in which the coil vibrates relative to the former.

Abstract: A method for assembling a cylindrical magnet assembly to a bore tube, wherein the cylindrical magnet assembly comprises at least one coil mounted on a former, comprising the steps of providing a cavity in the former at selected locations; at each of the selected locations, deforming the material of the bore tube to form a radially-directed protrusion (26; 29; 40; 60); and bringing each protrusion to bear against a periphery of each corresponding cavity.

Abstract: A cryostat has a cryogen vessel retained within an outer vacuum container, a thermally insulating jacket surrounding the outer vacuum container and insulating it from ambient temperature.

Abstract: In a method and apparatus for mounting and retention of ancillary equipment to cover panels of a magnetic field generator of a magnetic resonance imaging system having a cryogenic refrigerator and/or liquid cryogen housed within at least an outer vacuum container, ancillary equipment, cables and conduits are attached to the magnetic field generator, by integrating the electronic assemblies, cables and conduits into a set of modular covers which are connected to each other on installation. The covers may be mechanically mounted directly to the OVC, enabling them to be quickly fitted either in the factory or on the user's site.

Abstract: A magnetic resonance imaging system has a superconducting magnet housed within a cryostat, a cryogenic refrigerator that cools within the cryostat, a helium compressor that supplies compressed helium to the cryogenic refrigerator and to receive a return flow of compressed helium from the refrigerator, and a magnet supervisory system controlling operation of the magnet resonance imaging system. An apparatus is provided for controlling the speed and/or timing of operation of the helium compressor in accordance with predefined algorithms in response to system state data.

Abstract: A magnetic resonance imaging system has a superconducting magnet contained within a cryostat, the cryostat being cooled by a cooling system that includes a healing and compressor, a refrigeration device and a local supervisory system. The helium compressor provides compressed helium to the refrigeration device, and the local supervisory system controls operation of the refrigeration device. The helium compressor is in communication with the local supervisory system, and also is able to communicate, independently of the local supervisory system, with a remote service provider.

Abstract: A superconducting annular electromagnet for MRI purposes includes an annular winding within which a generally cylindrical space is provided. The winding includes at least one pair of annular coils, each having an outer cylindrical surface which is suitably formed to define a feature which facilitates fixing.

Abstract: A superconducting annular electro-magnet for MRI purposes includes an annular winding within which a generally cylindrical space is provided. The winding adjacent each end of the space is formed with a chamfer to provide flaring at each end of the space.

Abstract: An electromagnet for use in an MRI apparatus includes an annular vessel inside of which annular windings, energizable to produce a magnetic field, are contained together with cold iron components. The iron components are mechanically anchored with respect to the windings. A pair of iron rings is positioned so that one ring is provided at each end of the magnet in close proximity to the annular windings. The rings are formed so as to define a flared opening at each end of a cylindrical space within the magnet which, in use of the magnet for MRI purposes, is occupied by a patient.