Oxford Instruments, Inc.

Oxford Instruments (UK) Ltd.

Peter Hanley

Ian Leitch McDougall

Robert Carter Hawkes

Robert Andrew Slade

David J Hemsley

A magnetic field generating assembly comprising a set (A-A;B-B;C-C) of, typically substantially coaxial, coils substantially symmetrically arranged about a plane orthogonal to the axis. At least some of the coils carry working currents in the opposite sense to the other coils The arrangement of turns and working currents carried by the coils is such that a first working volume () with a substantially homogeneous magnetic field is generated within the envelope defined by the assembly, and two second working volumes () each with a substantially homogeneous magnetic field are generated outside the envelope, the homogeneity of each of the first and second working volumes being sufficient to perform a NMR experiment on a sample in the working volume.

Magnetic field generating assembly and method

Magnetic resonance apparatus is provided comprising a magnet having a plurality of pairs of coils arranged in respective substantially parallel planes. The coils in each pair are operable in a counter-running manner when in use so as to generate a region of magnetic field spaced apart from said planes, having sufficient uniformity to enable magnetic resonance signals to be obtained from a target within the region. The magnetic field has a magnetic field direction Z lying substantially parallel to said planes and each of the coils is elongate in a direction X substantially parallel to said planes.

Single-sided magnetic resonance magnet assembly

A magnet assembly comprising first and second sets of coils () for generating respective magnetic fields, wherein the coils are constructed and arranged such that under working conditions, a first homogeneous region () can be generated within the envelope defined by the magnetassembly and a second homogeneous region () can be generated outside the envelope, the resultant magnetic field in each region being sufficiently homogeneous to enable a NMR process to be performed on an object in the region.

Magnet assembly

An apparatus for magnetic resonance imaging includes a first magnet for generating a first magnetic field and a second magnet for generating a second magnetic field, dissimilar to the first magnetic field, the second magnet being spaced apart from the first magnet. The apparatus is arranged such that the first and second magnets cooperate to generate a substantially homogeneous magnetic field defining a working region wherein the first and second magnetic fields are arranged asymmetrically with respect to the working region, and wherein at least part of the working region is positioned within the first magnet or between the first and second magnets.

Apparatus for magnetic resonance imaging

The present invention relates to an electrical transformer which includes a primary winding coupled to first and second magnetic circuits. A magnetic flux is driven through the magnetic circuits by the primary winding. First and second secondary windings are also provided, each associated with a respective one of the magnetic circuits and being electrically connected together in series opposition. A closed superconducting fault current winding is also provided to link with the magnetic flux in the second magnetic circuit.

Electrical transformer

An electrical current limiting device comprises an electrical superconductor for attachment in an electrical circuit. The superconductor achieves a superconducting condition at relatively high temperatures. A cooling system includes a motor for flowing a cooled gas past the superconductor so that heat can be removed from the superconductor by a heat transfer process with the cooled gas.

Current limiting device

A current limiting device comprises a first superconducting element for connection in an electrical circuit. The superconducting element has a critical current density. A second superconducting element detects the onset of a fault condition. A coil is responsive to the second superconducting element to vary the relationship between the critical current density and the current carried by the first superconducting element so that the element transforms into a resistive state.

Current limiting device utilizing a superconductor

A magnetic field generating assembly for use in NMR apparatus comprises a pair of first magnets arranged coaxially with like poles facing each other and axially spaced apart. At least one second magnet is positioned between the first magnets and with its axis coaxial with the first magnets. The axial positions and strengths of the magnets are arranged such that a working region is defined radially spaced from the magnets and extending substantially parallel with the axis of the magnets. The magnetic field within the working region is suitable for obtaining NMR information from material in the working region and exhibits a radial gradient which is substantially uniform in the axial direction.

Magnetic field generating assembly

Oscillating magnetic field generating assembly

A magnet assembly having a pair of substantially aligned, spaced apart first magnets having like poles facing each other; and one or more auxiliary magnets axially aligned with the first magnets such that all magnets in the assembly are axially aligned. A magnetic field of sufficient homogeneity to perform a nuclear magnetic resonance (NMR) process is generated in a working region laterally offset form the first and second magnets. An oscillating magnetic field generating assembly is provided for performing an NMR experiment and includes a set of electrical coils connected to an oscillating electrical source. The coils are arranged between the first magnets such that the magnetic field generated by the oscillating magnet field generating assembly is also sufficiently uniform within the working region to perform an NMR experiment. A shield of electrically conductive material is positioned adjacent to and laterally offset form the set of electrical coils whereby the magnetic field generated by the oscillating magnetic field generating means is asymmetrically offset from the axis of the first magnets.

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Gloucestershire, United Kingdom

Peter Hanley