In some aspects, a magnetic system for use in a low-field MRI system. The magnetic system comprises at least one electromagnet configured to, when operated, generate a magnetic field to contribute to a B.sub.0 field for the low-field MRI system, and at least one permanent magnet to produce a magnetic field to contribute to the B.sub.0 field.

A magnetic resonance imaging (MRI) system includes a set of magnet coils for generating a magnetic field. The set of magnet coils are composed of a superconducting material. The system further includes a mechanical cryocooler in thermal contact with the set of magnet coils and operable to reduce and maintain a temperature of the set of magnet coils below a transition temperature of the superconducting material, and an energy storage device coupled to the set of magnet coils. The energy storage device may be capable of receiving and storing energy dissipated from the set of magnet coils during rapid shutdown of the set of magnet coils. The system may also include a controller coupled to the energy storage device. The controller may be programmed to recharge the set of magnet coils using the energy stored in the energy storage device during the rapid shutdown of the set of magnet coils.

A superconducting magnet includes a superconducting coil, a refrigerant container, a radiation shield, a vacuum container, a refrigerating machine cooling an interior of the refrigerant container, a tubular current lead passing from outside of the vacuum container to inside of the refrigerant container electrically connected to the superconducting coil, a power source electrically connected to the current lead, a manometer measuring a pressure inside of the refrigerant container, a thermometer to measure a temperature of the current lead, and a control unit connected to each of the power source, the manometer, and the thermometer. The control unit raises an output of the power source to vary a value of a current flowing into superconducting coil only when a measurement value of the manometer is higher than or equal to a set value and a measurement value of the thermometer is lower than or equal to a set value.

A cooling device (1) has a cryostat (2) and a cold head (3) of a cooling system (52), and additionally includes a pivot bearing (35), with which the cold head (3) is mounted on the cryostat (2) so as to be rotatable about a rotation axis (A). A connecting line (15) for a working gas of the cooling system (52) is connected to the cold head so that forces caused by the cooling system (52) act on the cold head via the connecting line (15) at a force application point (EP) in a force application direction (ER). The force application direction (ER) is inclined by no more than 40° with respect to the normal (N) of a lever plane (HE) which contains the rotation axis (A) and the force application point (EP).

According to one embodiment, a magnetic resonance imaging apparatus includes an imaging unit and a shield. The imaging unit is configured to perform magnetic resonance imaging of an object by transmitting a radio frequency signal from a radio frequency coil while magnetic fields are formed by a gradient coil and a superconducting magnet respectively. The shield is configured to form a gradient magnetic field for the magnetic resonance imaging with the gradient coil and to prevent ingress of heat into the superconducting magnet.

An arrangement for cryogenic cooling comprising a cryogen tank (14), a cryogenic recondensing refrigerator (12) arranged to cool a heat exchanger which is exposed to the interior of the cryogen tank (14) and an arrangement (16; 26) for conducting heat from a cooled article (10) to the cryogen tank. A further cryogen tank (20) is provided below the heat exchanger and arranged to receive cryogen liquid recondensed on the heat exchanger.

An arrangement for shimming a background magnetic field of a magnetic resonance imaging apparatus having an outer vacuum chamber (OVC) bore tube (1). Rails (8, 9) are provided on the OVC bore tube and shim trays (4) are mounted between respective rails.

A cryostat for subcooled (<2.5 K) liquid helium includes two separate helium tanks. A Joule-Thomson cooling unit includes a heat exchanger in the lower part of the first helium tank and uses liquid stored in the second helium tank in order to cool the subcooled liquid helium stored in the lower part of the first helium tank. The Joule-Thomson cooling unit draws in liquid helium either directly from the second helium tank or from the first helium tank, which is replenished via the gas phase from the second helium tank. In this way, the subcooled liquid helium of the first helium tank can be cooled for a long time from a combined stock of liquid helium in the first helium tank and the second helium tank. The second helium tank may be arranged adjacent or surrounding the first helium tank to maintain a lower overall height of the cryostat.

A measurement mechanism having a body and a vacuum chamber that is located on the body and in which a measurement process is performed is disclosed. A first sample and a second sample between which a heat transfer occurs are placed in the vacuum chamber and contact each other. A piston that provides the first sample and the second sample to continuously contact each other and a cooler that is located below the first sample and the second sample is also disclosed.

A metal assembly (1) suitable for being wound into a coil and used in DC magnet applications. The metal assembly comprises an insulated superconductive wire (2) extending in a longitudinal direction. The insulated superconductive wire comprises a superconductive wire (4), comprising a material (5) that exhibits superconducting properties within a defined temperature range embedded in a metal matrix (6), and an electrically insulating layer (7) arranged as a coating on the superconductive wire. The metal assembly further comprises a thermal conduction element (3) comprising a thermally conductive material arranged as a layer at least partly surrounding the insulated superconductive wire, such that the metal assembly, when wound into a coil, exhibits isotropic or essentially isotropic thermal conduction properties.