EP0251342A2
Expired / Lapsed
EP
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Magnet assembly
Assignee: Oxford Medical Ltd
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Filing: 1984-11-09
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Granted: —
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Expires: 2004-11-09
Abstract
Abstract A magnet assembly (1) comprises a first superconducting coil assembly (A,Aʹ-C,Cʹ) for generating a first magnetic field; and a second superconducting coil assembly (D-F) for generating a second magnetic field. The second superconducting coil assembly (D-F) is concentric and electrically connected in series with the first superconducting coil assembly, wherein the first and second super conducting coil assemblies each generate, in use, magnetic fields whose corresponding components are of substantially the same order of magnitude. The assemblies are arranged such that a resultant uniform magnetic field is generated in a working volume (3), and the second magnetic field opposes the first magnetic field outwardly of the magnet assembly (1). The first and second coil assemblies are also arranged such that they only generate a uniform magnetic field within the working volume (3) when operated together.
Inventors
- 👤 Ian Jesse Brown
- 👤 John Maurice Bird
- 👤 David Black
- 👤 Ian Leitch Mcdougall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 03:42
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/42; G01R33/421; G01R33/38; G01R33/381; G01R33/3815; G01R33/387; G01R33/3875; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/879
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
131 words
A magnet assembly (1) comprising a first superconducting coil assembly (A,Aʹ-C,Cʹ) for generating a first magnetic field; and a second superconducting coil assembly (D-F) for generating a second magnetic field, the second superconducting coil assembly being concentric with and electrically connected in series with the first superconducting coil assembly, wherein the first and second superconducting coil assemblies each generate, in use, magnetic fields whose corresponding components are of substantially the same order of magnitude, the assemblies being arranged such that a resultant, uniform magnetic field is generated in a working volume (3), and the second magnetic field opposes the first magnetic field outwardly of the magnet assembly (1), and such that the first and second coil assemblies only generate a uniform magnetic field within the working volume (3) when operated together.
Claim 2
Dependent Claim
131 words
A magnet assembly (1) comprising a first superconducting coil assembly (A,Aʹ-C,Cʹ) for generating a first magnetic field; and a second superconducting coil assembly (D-F) for generating a second magnetic field, the second superconducting coil assembly being concentric with and electrically connected in series with the first superconducting coil assembly, wherein the first and second superconducting coil assemblies each generate, in use, magnetic fields whose corresponding components are of substantially the same order of magnitude, the assemblies being arranged such that a resultant, uniform magnetic field is generated in a working volume (3), and the second magnetic field opposes the first magnetic field outwardly of the magnet assembly (1), and such that the first and second coil assemblies only generate a uniform magnetic field within the working volume (3) when operated together.
Claim 3
Dependent Claim
40 words
An assembly according to claim 1, wherein the first superconducting coil assembly comprises a plurality of coaxial coils (A,Aʹ - C,Cʹ) arranged symmetrically about a mid-plane (6) of the magnet assembly (1) normal to the axis (4) of the coils.
Claim 4
Dependent Claim
41 words
An assembly according to claim 1 or claim 2, wherein the second superconducting coil assembly comprises a plurality of coaxial coils (D-F) arranged symmetrically about a mid-plane (6) of the magnet assembly (1) normal to the axis (4) of the coils.
Claim 5
Dependent Claim
27 words
An assembly according to claim 3, when dependent on claim 2, wherein the axes of the coils of the first and second superconducting coil assemblies are coincident.
Claim 6
Dependent Claim
26 words
An assembly according to any of the preceding claims, further comprising a shield (38) of magnetic material arranged around at least the first superconducting coil assembly.
Claim 7
Dependent Claim
21 words
An assembly according to claim 5, wherein the shield is constituted by a former (7) supporting the second superconducting coil assembly.
Claim 8
Dependent Claim
17 words
An assembly according to claim 5 or claim 6, wherein the shield (38,7) is made of iron.
Claim 9
Dependent Claim
46 words
An assembly according to any of the preceding claims, further comprising a pair of additional coils (39) positioned adjacent to each end of the working volume (3) and arranged to oppose the resultant magnet field generated by the first and second coil assemblies at these positions.
Claim 10
Dependent Claim
26 words
An assembly according to any of the preceding claims, wherein the first and second superconducting coil assemblies are connected in parallel to a protection circuit (28-30).
Claim 11
Dependent Claim
37 words
An assembly according to any of the preceding claims, wherein the first and second superconducting coil assemblies are arranged such that the second magnetic field opposes the first magnetic field radially outwardly of the magnet assembly (1)
Claim 12
Dependent Claim
35 words
NMR imaging apparatus incorporating a magnet assembly according to any of the preceding claims; a power supply for activating the first and second superconducting coil assemblies; and control means for controlling operation of the apparatus.
References Cited (Backward Citations)
No citation records indexed.
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