The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch. The first rigid coil loop forms a portion of the first electrical connection. The magnet further comprises a second rigid coil loop (126) operable to actuate the second switch. The second rigid coil loop forms a portion of the second electrical connection.

There is provided a superconducting magnet device including a superconducting coil, a vacuum vessel that accommodates the superconducting coil, a current lead that is connected to the superconducting coil and installed in the vacuum vessel, a power supply cable that is disposed outside the vacuum vessel and connected to the current lead, and a heating unit that is disposed apart from the current lead and heats the current lead via the power supply cable.

A method of energizing or de-energizing a high temperature superconducting, HTS, coil, from an initial transport current to a final transport current. The HTS coil comprises a plurality of turns of HTS material. A transport current is supplied to the HTS coil, the transport current starting at the initial transport current and varying over time to the final transport current. Cooling is applied to the HTS coil. An operating condition of the HTS coil is monitored, wherein the operating condition is indicative of a ratio I/I.sub.c of the transport current, I, to a critical current, I.sub.c, of the HTS material in at least a part of the HTS coil. One or both of the transport current applied to the coil and a net cooling applied to the coil are controlled in a feedback loop responsive to the operating condition, in order to maintain the operating condition in a desired range during energisation or de-energisation, such that the indicated ratio I/I.sub.c is maintained above a threshold ratio (e.g. 0.7).

The invention provides for magnetic resonance imaging system (600) comprising a superconducting magnet (100) with a first current lead (108) and a second current lead (110) for connecting to a current ramping system (624). The magnet further comprises a vacuum vessel (104) penetrated by the first current lead and the second current lead. The magnet further comprises a magnet circuit (106) within the vacuum vessel. The magnet circuit has a first magnet circuit connection (132) and a second magnet circuit connection (134). The magnet further comprises a first switch (120) between the first magnet connection and the first current lead and a second switch (122) between the second magnet connection and the second current lead. The magnet further comprises a first current shunt (128) connected across the first switch and a second current shunt (130) connected across the second switch. The magnet further comprises a first rigid coil loop (124) operable to actuate the first switch. The first rigid coil loop forms a portion of the first electrical connection. The magnet further comprises a second rigid coil loop (126) operable to actuate the second switch. The second rigid coil loop forms a portion of the second electrical connection.

An assembly for generating a superconducting magnetic field with high stability comprises a main power supply unit arranged to provide a main current to generate a superconducting magnetic field, a magnetic field measurement device for measuring the generated magnetic field, and an auxiliary power supply unit arranged to output an auxiliary current based on the measured magnetic field.

Static magnetic field inhomogeneity is reduced by measuring inhomogeneity of a static magnetic field distribution in an imaging space, evaluating a distribution of a correction magnetic field that should be generated by a correction magnetic field generating unit disposed in the vicinity of the imaging space based on the measured static magnetic field distribution, reducing the electric current value of the superconducting coil to a predetermined (greater than zero) low current value smaller than a rated current value, notifying an operator to set a correction magnetic field of the correction magnetic field generating unit to the correction magnetic field evaluated by calculation in a state where an electric current at the low current value is flowing in the superconducting coil and a low static magnetic field B_low is being generated, and repeating the above operations.

In examples, provided are leadless power couplers that include (1) a thermal insulating system having an outer wall and an inner wall, (2) a first electrically conductive winding located outside the thermal insulating system, where the first electrically conductive winding is configured to create a varying magnetic field, (3) a plurality of second electrically conductive windings located inside the thermal insulating system and configured to couple to the varying magnetic field, the plurality of second electrically conductive windings being superconductors, (4) a plurality of cryogenic rectifiers, each cryogenic rectifier being coupled to a respective second electrically conductive winding in the plurality of second electrically conductive windings, and (5) a plurality of cryogenic cables coupled between respective outputs of the plurality of cryogenic rectifiers and respective loads.

A novel cooling system for a superconducting electromagnet (740) that is suitable for use in satellite (700), or at least one or more components of the electromagnet (740) is disclosed. A satellite (700) and electromagnetic control system (705) for position control of such a satellite (700) are also disclosed. The superconducting magnet control system (705) comprises at least one superconducting electromagnet (740) with at least one cooling element and at least one cryocooler (735). The cryocooler (735) is thermally coupled with the cooling element thereby enabling cooling of the superconducting electromagnet (740) or at least one or more components thereof through the cooling element solely by conduction cooling.

In a case where a start current value is higher than a target current value, a control unit performs a control to lower a current value from the start current value to the target current value. In addition, in a case where the start current value is equal to or lower than the target current value, the control unit controls to raise the current value from the start current value to the format current value higher than the target current value, and then lower the current value to the target current value. In this manner, regardless of the value of the predetermined current value before the current value is changed, the current value reaches the target current value in a descending manner. As a result, the coil magnetization magnetic field when the target current value is reached can be kept in the same state.

A regulated current source that provides high DC current and low voltage ripple to a superconducting electromagnet. The current source is a multi-phase synchronous rectifier, wherein the rectifying elements are cryogenically-cooled MOSFETS coupled with a superconducting filter.