Abstract: An MRI system is housed within a housing that is provided with a set of deployable barriers that are attachable to the housing. The magnet in the MRI system may be operated at a first magnetic field intensity, such that the magnetic field outside of the housing remains below a safety limit when the barriers are not deployed. The magnet in the MRI system may be operated at a second magnetic field intensity, higher than the first, when the barriers are deployed, such that the magnetic field outside of the barriers remains below the safety limit.

Abstract: The present invention provides a material for the construction of external coverings accessible by humans or animals. It aims to increase the breakdown voltage between a high voltage VRF, high frequency source of energy and the human or animal, by adaptation of materials and structures. According to an embodiment of the invention, a structure is provided for the cover 18 used in MRI or NMR systems, which carries a greater proportion Vs of the voltage VRF across itself, thereby reducing the voltage Vg across the gap 22 and reducing the likelihood of breakdown.

Abstract: The present provides a cryogenic thermal battery arrangement for maintaining a superconducting magnet coil or similar apparatus at cryogenic temperature for a required shipping period, such as thirty days, without consuming a significant amount of costly cryogen. According to another aspect, the invention allows extended shipping periods without incurring excessive costs.

Abstract: A patient table for use in equipment such as Magnetic Resonance Imaging (MRI) scanners that are susceptible to electrical or magnetic interference, is moved by hydraulic means, thus avoiding the need for electric motors that give rise to such interference.

Abstract: A quench protection circuit for a superconducting magnet, comprises at least one heater associated with a corresponding coil of the superconducting magnet. The at least one heater is arranged to be driven by an inductor which is connected in series with it and is arranged to derive a voltage from variation in a magnetic field of the superconducting magnet. The at least one heater and the inductor are arranged in a series circuit which further comprises a non-linear positive temperature coefficient resistors.

Abstract: An electromagnet comprising a plurality of coils of superconductive material, monolithically embedded in an embedding material, which is solid at the temperature of operation of the superconductive electromagnet, and a method for producing an electromagnet comprising a plurality of coils of superconductive material, comprising the steps of winding coils of superconductive material, retaining the coils at predetermined relative positions, and monolithically embedding the plurality of superconducting coils in an embedding material, which is solid at the temperature of operation of the superconductive electromagnet.

Abstract: A method of producing a former for winding a magnet coil, said former (14) comprising a pattern of recess-defining ridges (16) which define at least one recess (18) into which wire may be wound to form a magnet coil, comprising the steps of: (a) producing an accurately machined tool (10) bearing a pattern of protrusions (12) conforming to an inverse of said pattern of recess-defining ridges; (b) producing said former by moulding material against said accurately machined tool; and (c) separating the former from the accurately machined tool. The invention also provides a method of producing a magnet coil employing the former so produced.

Abstract: A superconducting magnet system comprising a superconducting magnet, itself comprising a plurality of magnet coils, arranged to protect quench heaters yet provide effective quench protection.

Abstract: The present invention provides a recondensing service neck for a cryostat. A service neck tube (22) provides access to the interior (10) of the cryostat. A recondensing surface is provided (44) for recondensing liquid cryogen boiled off from a liquid cryogen (12) within a cryostat; and a recondensing refrigerator (30) is provided for cooling the recondensing surface to below the boiling point of the cryogen.

Abstract: A cryogenic magnet control system has a number of magnet coils each formed by superconductive material wound on a former and a supply for energizing the magnet coils to generate an operational magnetic field of predetermined strength and homogeneity, wherein each former also supports control wineings of a non-superconductive material provided as over-bindings upon the magnet.

Abstract: A substantially cylindrical cryostat defining an axial imaging region, the cryostat housing a magnet which, in use, provides a substantially homogeneous magnetic field in the imaging region, further comprising a refrigerator arranged to cool certain elements of the cryostat, said refrigerator comprising a magnetic material which, in use, oscillates along an axis of the refrigerator. The cryostat is arranged such that the axis of the refrigerator is substantially tangential to a circle centred on the axis of the cylindrical cryostat.

Abstract: An arrangement for producing an imaging region of increased maximum radial diameter in a magnetic resonance imaging (MRI) system, comprising a solenoidal magnet arrangement (30) comprising primary magnet coils (32) arranged symmetrically about an axis (A-A) and a shim coil set.

Abstract: A cryogenic magnet system, comprising a cryogenic vessel (1) housing a magnet winding, a vacuum jacket (3) enclosing the cryogenic vessel and a refrigerator (4) at least partially housed within the vacuum jacket and thermally linked (6) to the cryogenic vessel. In particular, the system further comprises an electromagnetic shield.

Abstract: A burst disc arrangement for a cryostat comprising a replaceable burst disc (52) held in compression between a high-pressure flange formed at an end of a high-pressure conduit (12), and a low-pressure flange (60) formed at an end of a low-pressure conduit (14). In particular, the burst disc arrangement further comprises: a housing (50) enclosing the high- and low-pressure flanges; and compression means (56), distributed around the housing (50) and being arranged to bear upon the one of the flanges (60), so as to urge it towards the other flange, thereby retaining the burst disc (52) in compression between the flanges. The housing (50) includes a first opening (20) large enough to allow the replaceable burst disc (52) to pass therethrough.

Abstract: An assembly comprising a number of superconductive coils, at least one quench heater arranged to heat the superconductive coil(s) in the event that at least part of at least one of the coils enters a quenched state; means for transferring energy from the coil(s) to the heater(s) in the event that at least part of at least one of the coils enters a quenched state; wherein the means for transferring energy from the coil(s) to the heater(s) includes a series capacitance, through which the energy transferred must pass.

Abstract: A thermal interface between a removable cryogenic refrigerator (4) and an article (10) to be cooled by the cryogenic refrigerator. The thermal interface consists of a recondensing chamber filled with a gas (12), the recondensing chamber being in thermal contact with a cooling surface (9) of the refrigerator and the article (10) to be cooled.

Abstract: The invention provides tools and methods for shimming magnets such as MRI and NMR magnets, while at field. The invention provides safe methods for shimming at field. The invention particularly provides a tool (40) for withdrawing and inserting a shim tray (7) into slots (34) in a magnet (30), in the presence of a magnetic field. The tool comprises a channel (11, 12) for guiding a shim tray, alignment means (64, 74, 76, 6) for aligning the channel with a selected slot, a drive means (9) arranged to propel a shim tray along the channel; and a connector (96) arranged to detachably link the drive means to a shim tray.

Abstract: A method for centralising and retaining a moulded 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 an emergency run down unit for a superconductive magnet assembly, a quench in the magnet is induced by the release of stored mechanical energy or by direct manual actuation.

Abstract: A cryostat for transporting cooled equipment at an upper cryogenic temperature, the cryostat being arranged to cool the cooled equipment by a working cryogen which boils at a lower cryogenic temperature, comprising a vacuum container surrounding the cooled equipment and defining a nominally evacuated layer between the vacuum container and the cooled equipment. Means are provided to reduce contamination of the nominally evacuated layer by a vacuum contaminant which is present in gaseous form within the evacuated layer at the upper cryogenic temperature, but which is retained in liquid or solid form at the lower cryogenic temperature.