A polycrystalline bulk body of this invention has uniformity in superconducting properties, in comparison to a polycrystalline bulk body including crystal grains each constituted by (Ba.sub.1-xK.sub.x)Fe.sub.2As.sub.2. A polycrystalline bulk body (1) of this invention includes crystal grains each constituted by an iron-based compound (10) expressed by chemical formula AA′Fe.sub.4As.sub.4, where A is Ca and A′ is K, the iron-based compound (10) having a crystal structure in which AFe.sub.2As.sub.2 layers (16) and A′Fe.sub.2As.sub.2 layers (17) are alternately stacked.

A polycrystalline bulk body of this invention has uniformity in superconducting properties, in comparison to a polycrystalline bulk body including crystal grains each constituted by (Ba.sub.1-xK.sub.x)Fe.sub.2As.sub.2. A polycrystalline bulk body (1) of this invention includes crystal grains each constituted by an iron-based compound (10) expressed by chemical formula AA′Fe.sub.4As.sub.4, where A is Ca and A′ is K, the iron-based compound (10) having a crystal structure in which AFe.sub.2As.sub.2 layers (16) and A′Fe.sub.2As.sub.2 layers (17) are alternately stacked.

A system for energizing a main coil of superconducting magnet in a magnetic resonance imaging (MRI) system includes a cryostat comprising a housing. A first coil is positioned within the housing of the cryostat. Alternatively, the first coil may be positioned external to the housing of the cryostat. A second coil is coupled to the first coil and positioned external to the housing of the cryostat. The second coil is configured to inductively couple to the main coil. A controller is coupled to the first coil and the second coil and is configured to control the first coil and the second coil to induce current in the main coil.

The present disclosure provides a support device and a display apparatus. The support device includes: a support platform; a base disposed opposite to the support platform; and a plurality of superconducting magnetic levitation structures, each of the superconducting magnetic levitation structures including a superconductor and a magnet disposed oppositely; in each of the superconducting magnetic levitation structures, one of the superconductor and the magnet is disposed on the support platform, and the other is disposed on the base. The plurality of superconducting magnetic levitation structures are arranged to operate independently of each other without interference, and a repulsive force between the superconductor and the magnet of each of the superconducting magnetic levitation structures is set to be adjustable.

There is described a magnet assembly comprising a superconducting coil, a cryogenic system, a DC voltage source, an SMPS, current leads, and a controller. The cryogenic system comprises a cryostat and is configured to maintain the superconducting coil at an operating temperature below the critical temperature of the superconductor. The DC voltage is source located outside the cryostat. The SMPS is located inside the cryostat and configured to supply power from the DC voltage source to the superconducting coil. The SMPS comprises a voltage step-down transformer having a primary and a secondary winding. The current leads connect the DC voltage source to the SMPS. The controller is configured to cause the SMPS to supply a first amount of power to the magnet in order to ramp up the magnet to operating current, and a second amount of power to the magnet during steady state operation of the magnet, wherein the first amount of power is greater than the second amount of power.

A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.

A high temperature superconducting, HTS, magnet system. The HTS magnet system comprises an HTS field coil, a temperature control system, a power supply, and a controller. The HTS field coil comprises a plurality of turns comprising HTS material; and a resistive material electrically connecting the turns, such that current can be shared radially between turns via the resistive material. The temperature control system is configured to control the temperature of the coil, the temperature control system comprising at least a cryogenic cool system configured to keep the coil below a self-field critical temperature of the HTS material. The power supply is configured to supply current to the HTS field coil. The controller is configured to cause the power supply to provide a current greater than a critical current of all of the HTS material.

A high-temperature superconducting (HTS) magnetic levitation (maglev) Dewar capable of increasing damping and levitation force and a width calculation method thereof. The HTS maglev Dewar includes an outer container and an inner container. The outer container is fixedly connected to the inner container through a connecting column. The inner container has a cavity configured to accommodate liquid nitrogen. A bottom of the inner container is provided with a bulk superconductor. The inner container is communicated with outside through a liquid nitrogen feeding pipe. The outer container is made of an electrically conductive material.

Systems and methods for rapidly ramping the magnetic field of a superconducting magnet, such as a superconducting magnet adapted for use in a magnetic resonance imaging system, are provided. The magnetic field can be rapidly ramped up or down by changing the current density in the superconducting magnet while monitoring and controlling the superconducting magnet's temperature to remain below a transition temperature. A superconducting switch is used to connect the superconducting magnet and a power supply in a connected circuit. The current generated by the power supply is then adjusted to increase or decrease the current density in the superconducting magnet to respectively ramp up or ramp down the magnetic field strength in a controlled manner. The ramp rate at which the magnetic field strength is changed is determined and optimized based on the operating parameters of the superconducting magnet and the current being generated by the power supply.

An electromagnet assembly has an inner magnet, an outer magnet, arranged around the inner magnet with an annular region extending between the inner magnet and the outer magnet, and a number of support elements extending through the annular region and dividing the annular region into a number of annular segments. The support elements are distributed in the annular region so as to form a small annular segment and a large annular segment.