Abstract: In order to minimize the loss of cryogen during transportation of superconductive magnet systems, or indeed at any time that the refrigerator is turned off, part of the boil-off gas is directed from the cryogen vessel through the refrigerator interface and past the refrigerator to cool the refrigerator. Some of the heat conducted along the refrigerator into the system is intercepted and removed by that part of the boil-off gas. The heat load onto the cryogenic vessel is thereby reduced, which in turn reduces the boil-off of cryogen from the cryogenic vessel. This part of the boil-off gas is then vented from the system along with the remainder of the boil-off gas, for example to leave the cryogenic liquid vessel via the access neck.

Abstract: A turret subassembly for use as part of a cryostat, the turret subassembly comprising a vent tube (32) housing an auxiliary vent (40); a refrigerator sock (34) for housing a refrigerator; a termination box (30) linking the vent tube and the refrigerator sock, and having an opening (52) in one wall (54); and means (38) for attachment of the turret subassembly to a cryogen vessel (12).

Abstract: A cooled current lead for conducting electrical current into a cooled vessel. The current lead comprises an electrical conductor (22) comprising a region (29) which, in use, is heated by electrical current flowing through it; a cooled component (31) situated above a the region (29) and which is provided with a path for removal of heat; and a thermo-siphon comprising a cavity (35) in thermal contact with both the region of the electrical conductor and the cooled component, said cavity containing a fluid (35).

Abstract: The present invention provides a cryostat comprising a cryogen vessel (1), a thermal radiation shield (2), and a sleeve (5) for accommodating a cryogenic refrigerator. Also provided is a first thermal contact for thermally and mechanically connecting a first stage of a cryogenic refrigerator to the radiation shield for cooling thereof. A secondary recondensing chamber is provided (8) for accommodating a second stage of a cryogenic refrigerator, and means (10; 24) are provided for thermally connecting the secondary recondensing chamber to a recondensing surface (11a; 44) exposed to the interior of the cryogen vessel. The cryostat further comprises a pressure control arrangement (100) for controlling the pressure of a gas within the secondary recondensing chamber.

Abstract: A current lead-through for providing an electrically conductive path between an interior of a vessel and the exterior of the vessel. The electrically conductive path is electrically isolated from the material of the vessel. The current lead-through comprises an electrically conductive pin surrounded by an electrically isolating sealing material, and retained within a tubular carrier body by the sealing material, the electrically conductive pin being exposed at each end of the tubular carrier body to enable electrical connection thereto.

Abstract: An imaging magnet has a patient bore for receiving a human or animal patient, including a body coil assembly having a body coil former and a body coil. The body coil assembly is provided with at least one source of light that is incorporated within the body coil assembly, and embedded within the body coil former, that radiates light into the patient bore.

Abstract: A quench line and exit plenum configuration for a mobile MRI system housed in a transportable trailer includes an exit plenum with deflector plates that direct the quench flow of cold gases upward and away from surrounding objects. In addition, the plenum also includes dual vents to facilitate optimum gas flow and water drainage. The deflector plates are configured to utilize the Venturi effect to create an auxiliary flow of the ambient air to help deflect the flow of cold gases away from nearby pedestrians, when the magnet is quenching, and to enable service personnel to fill the magnet safely while in the vicinity of the exit plenum.

Abstract: The present invention provides a thermal radiation shield (1) for a cryostat, formed of a plastic-metal hybrid material, which comprises a plastic component (23) and a conductive filler material (21) comprising a metal. The thermal radiation shield may be formed by injection moulding.

Abstract: A cooled current lead for conducting electrical current into a cooled vessel. The current lead comprises an electrical conductor (22) comprising a region (29) which, in use, is heated by electrical current flowing through it; a cooled component (31) situated above a the region (29) and which is provided with a path for removal of heat; and a thermo-siphon comprising a cavity (35) in thermal contact with both the region of the electrical conductor and the cooled component, said cavity containing a fluid (35).

Abstract: A turret subassembly for use as part of a cryostat, the turret subassembly comprising a vent tube (32) housing an auxiliary vent (40); a refrigerator sock (34) for housing a refrigerator; a termination box (30) linking the vent tube and the refrigerator sock, and having an opening (52) in one wall (54); and means (38) for attachment of the turret subassembly to a cryogen vessel (12).

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: A current lead-through for providing an electrically conductive path between an interior of a vessel and the exterior of the vessel. The electrically conductive path is electrically isolated from the material of the vessel. The current lead-through comprises an electrically conductive pin surrounded by an electrically isolating sealing material, and retained within a tubular carrier body by the sealing material, the electrically conductive pin being exposed at each end of the tubular carrier body to enable electrical connection thereto.

Abstract: A superconductor system cooling apparatus, the apparatus comprising a casing, a solid coolant and a cooling circuit; wherein the cooling circuit comprises a heat exchanger, and a connector to couple the heat exchanger to a pre-cool loop of the superconductor system; wherein the cooling circuit further comprises a heat exchange medium to transfer heat between the solid coolant and the superconducting system.

Abstract: An imaging magnet has a patient bore for receiving a human or animal patient, including a body coil assembly having a body coil former and a body coil. The body coil assembly is provided with at least one source of light that is incorporated within the body coil assembly, and embedded within the body coil former, that radiates light into the patient bore.

Abstract: A processor is provided in a MRI scanner which senses pressure within a cryogen vessel and the ambient environmental pressure outside of the scanner. It controls a pressure controller means in the cryogen to in turn control the pressure to ensure that it is set to provide as large a buffer as possible before a pressure relief valve is opened. This ensures that cryogen is not lost unnecessarily.

Abstract: A cryostat comprises a cryogen vessel housed within an outer vacuum container (OVC), a thermal radiation shield being located between an external surface of the cryogen vessel and an internal surface of the OVC. A decouplable thermal link arrangement is provided between an external surface of the cryogen vessel and an internal surface of the thermal radiation shield, being decoupled by action of an applied magnetic field.

Abstract: The present invention provides a cryostat comprising a cryogen vessel (1), a thermal radiation shield (2), and a sleeve (5) for accommodating a cryogenic refrigerator. Also provided is a first thermal contact for thermally and mechanically connecting a first stage of a cryogenic refrigerator to the radiation shield for cooling thereof. A secondary recondensing chamber is provided (8) for accommodating a second stage of a cryogenic refrigerator, and means (10; 24) are provided for thermally connecting the secondary recondensing chamber to a recondensing surface (11a; 44) exposed to the interior of the cryogen vessel. The cryostat further comprises a pressure control arrangement (100) for controlling the pressure of a gas within the secondary recondensing chamber.

Abstract: A limiter is provided to limit the motion of components in a cryostat during transit. This permits the use of a support structure which minimises the disturbance to an insulating structure and thus reduces ingress of heat to the cryogen. Cryogen loss is reduced leading to lower operating costs.

Abstract: Pumping out of a vacuum vessel and housing of a scanner is facilitated by providing a hole through a radiation shield. To reduce radiation of heat via this hole to an inner coolant containing vessel a closure member is provided. This is held in spaced apart relationship during pump down by clips. The closure member is provided with a ferrous constituent or member which is then attracted inwards during initialization of the superconducting. This draws the closure member into engagement with the shield to close the hole and to prevent radiation thereby. The clips are profiled to maintain the abutment of the closure member over the hole.

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.