Abstract: There is described an MRI system in which the detection of the NMR signal is performed by a resonant input at a median field range above 100 gauss and where the main field is cycled to a low field of below 50% of the resonant frequency after the excitation of the NMR signal for a period sufficient to develop differences in magnetisation (T1). The advantage of this system is that images can be generated at much lower field intensities than prior art systems and is able to detect abnormalities in tissue such as cancerous tissues in a patient.

Abstract: There is described an MRI system in which the detection of the NMR signal is performed by a resonant input at a median field range above 100 gauss and where the main field is cycled to a low field of below 50% of the resonant frequency after the excitation of the NMR signal for a period sufficient to develop differences in magnetisation (T1). The advantage of this system is that images can be generated at much lower field intensities than prior art systems and is able to detect abnormalities in tissue such as cancerous tissues in a patient.

Abstract: A superconductive magnet assembly is disclosed. The superconductive magnet assembly includes a primary magnet formed of a coil of superconductive material, a magnet former supporting the primary coil, a plurality of gradient coils of superconductive material operative to produce field gradients during operation of the magnet, and a radiation shield within which the primary coil and the gradient coils are housed. The gradient coils are supported by the magnet former.

Abstract: A super-conducting magnet, particularly suitable for use with an MRI system is provided. The super-conducting magnet includes a closed loop former, a coil winding around the former of a material which is super-conducting at low temperatures, a vacuum vessel containing the former and also of closed loop shape to define a passage through the magnet for receipt of objects to be investigated by nuclear magnetic resonance, electrical connection for the coil winding, a thermal shield within the vacuum vessel and around the former, characterized in that the former is non-electrically conductive and in that refrigeration is provided, operatively connected to the coil winding and the thermal shield, the refrigeration being such that no liquid reservoir for liquid helium or liquid nitrogen is required.

Abstract: Apparatus for maintaining a superconducting magnet which is refrigerated within a cryostat at or near its operating temperature in the event of the cryostatic refrigerator ceasing to operate comprising a heat sink within the cryostat and in thermal communication with the magnet and means automatically to transfer heat from the heat sink out of the cryostat.

Abstract: Separation apparatus and method for separating relatively magnetic particles from a stream of particulate material made up of relatively magnetic and relatively non-magnetic particles. A mixture of the magnetic and non-magnetic particles flows in a three-dimensional stream in a common path closely adjacent to the wall of a channel. A magnet producing a strong magnetic field force is located adjacent the wall of the chamber to produce a strong horizontal magnetic force and a vertical force which is less than that of gravity. The free fall of the particles adjacent the channel wall is interrupted in the vicinity of the magnet to cause the particles to move away from the wall. Thereafter, the magnetic particles move back towards the magnet whereas the non-magnetic particles are not drawn away from their diverted path.

Abstract: A superconducting magnetic separator wherein the magnet coil or coils are in the shape of a vertically oriented oval. The coils are mounted in an evacuated cryostat housing which provides a flat vertical magnetic separating zone on one or both vertical faces.

Abstract: The invention relates to separators for separating relatively magnetic particles from relatively non-magnetic particles in the dry state. The method of the invention involves allowing a mixture of the particles to flow past a magnet, preferably a high strength magnet, which is so arranged as to produce a strong magnetic field in a radial direction, the radial component greatly exceeding the axial component and the axial component exerting a force which is preferably substantially less than that of gravity. In this way, the magnetic particles are diverted towards the magnet but not retained by it while the non-magnetic particles continue in their original path.