Homopolar linear synchronous machines (200) are provided herein that include a mover device (111). The mover device (111) includes a cold plate with ferromagnetic cores extending through slots in the cold plate. Layers of armature coils are located around the ferromagnetic cores on opposite sides of the cold plate. The mover device (111) further includes at least one field coil.

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.

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.

A method of manufacturing includes producing a gradient coil assembly having one or more cooling channels for a magnetic resonance imaging system by a process that includes printing a cooling channel template having a first end, a second end, and a hollow passage extending between the first end and the second end, disposing a dielectric material over at least a portion of the cooling channel template to generate a dielectric layer having the cooling channel template, and removing the cooling channel template from the dielectric layer to thereby produce the one or more cooling channels within the dielectric layer such that the one or more cooling channels have a pattern corresponding to a geometry of the cooling channel template.

The present invention provides a radiation shield (204), in particular for shielding main coils (202) of a magnetic resonance imaging system (110), whereby the radiation shield (204) comprises a cavity (214) for housing at least one main coil (202), whereby the cavity (214) is formed between an inner cylindrical wall (206), an outer cylindrical wall (208), which are arranged essentially concentrically to each other, and two ring-shaped base walls (212), which interconnect the inner cylindrical wall (206) and the outer cylindrical wall (208), wherein at least one out of the inner cylindrical wall (206), the outer cylindrical wall (208), and the two ring-shaped base walls (212) is provided at least partially with an inner layer (216), which faces the cavity (214), and an outer layer (218), wherein the inner layer (216) is a layer comprising carbon fiber reinforced plastic, and the outer layer (218) comprises a metal, which is paramagnetic or diamagnetic. The present invention also provides a shielded main magnet (200) comprising at least one main coil (200) for generating a static main magnetic field in a magnetic resonance imaging system (110), and a radiation shield (204) as specified above, wherein the at least one main coil (202) is housed in a cavity (214) of the radiation shield (204).

A cooling device for sub-MRI units of an embodiment includes a tank in which cooling water for cooling a heat generating unit that an MRI apparatus has is stored, a pump which circulates the cooling water stored in the tank through a circulation path starting from the tank and traveling around the heat generating unit, a heat exchanger which cools the cooling water, and a controller which decides that a water leakage has occurred on the circulation path when a decreasing rate of the cooling water in the tank is greater than a given reference value.

A coil apparatus and methods for magnetic resonance imaging involving a wire winding, the wire winding having at least one of: a hollow cross-section wire and a solid cross-section wire, the solid cross-section wire having at least one of: a solid small cross-section wire and a solid large cross-section wire, the solid large cross-section wire having a thickness greater than that of the solid small cross-section wire, and the solid small cross-section wire disposed in one of adjacent and proximate at least one of the hollow cross-section wire and the solid large cross-section wire, whereby at least one of current density, winding density, and heat extraction are increasable.

According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B.sub.0 coil configured to contribute to a B.sub.0 field suitable for use in low-field magnetic resonance imaging (MRI).

The MRI apparatus includes a main magnet forming a static magnetic field in a bore, and a gradient coil assembly which forms a magnetic field gradient in the static magnetic field and includes a plurality of shim trays arranged therein at a predefined interval and at least one first shim token provided between the shim trays.

A magnet assembly in a magnetic resonance apparatus includes a cryostat and a superconducting main field magnet coil system arranged therein for generating a magnetic field in the direction of a z-axis in a working volume. The magnet assembly includes a shim device arranged inside the cryostat for adjusting the spatial variation or homogeneity of the magnetic field generated in the working volume by the magnet coil system. The shim device comprises at least one closed superconducting shim conductor path having an HTS layer. The HTS layer forms a surface that is geometrically developable such that unwrapping onto a plane changes the geodesic distance between any two points on the surface formed by the HTS layer by no more than 10%. The inner and/or outer contour of the geometrical development of the HTS layer describes a non-convex curve.