GB1135332A - Apparatus for improving the uniformity of magnetic fields - Google Patents

Apparatus for improving the uniformity of magnetic fields

Info

Publication number
GB1135332A
GB1135332A GB993266A GB993266A GB1135332A GB 1135332 A GB1135332 A GB 1135332A GB 993266 A GB993266 A GB 993266A GB 993266 A GB993266 A GB 993266A GB 1135332 A GB1135332 A GB 1135332A
Authority
GB
United Kingdom
Prior art keywords
coils
solenoid
order
diameter
correction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB993266A
Inventor
Robert Edward Gang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Varian Medical Systems Inc
Original Assignee
Varian Associates Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US348442A priority Critical patent/US3287630A/en
Application filed by Varian Associates Inc filed Critical Varian Associates Inc
Priority to GB993266A priority patent/GB1135332A/en
Priority to FR53610A priority patent/FR1476003A/en
Publication of GB1135332A publication Critical patent/GB1135332A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures
    • H01F7/202—Electromagnets for high magnetic field strength
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/381—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets
    • G01R33/3815—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets with superconducting coils, e.g. power supply therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/387—Compensation of inhomogeneities
    • G01R33/3875—Compensation of inhomogeneities using correction coil assemblies, e.g. active shimming

Abstract

1,135,332. Electromagnets. VARIAN ASSOCIATES. 7 March, 1966, No. 9932/66. Heading H1P. [Also in Division G1] In a gyromagnetic resonance spectrometer, a plurality of coils provide first, second and third order connections to the magnetic field to render it uniform. The coils may be supported on a cylindrical former 48 of aluminium or paper which surrounds the sample container. First order correction of linear gradients in the Z direction is provided by a pair of coils 54 connected in opposition and spaced by 0À86 of the diameter of former 48. This spacing is said to eliminate the third order gradients from the coils 54. Second order correction is provided by two pairs of coils 56, 58; coils 56 assist each other and are spaced by 0À25 of said diameter, coils 58 also assist each other but oppose coils 56 and have a spacing greater than 0À5 said diameter. Coils 58 cancel the zero order component of coils 56. If required, four coils 60 may be provided to enhance third order correction. Alternatively, an extra pair of coils having a spacing of 0À5 said diameter may be used. First and second order corrections in the X and Y directions are provided by coil sets 62, 64 and 66, 68 respectively. Each set of coils for each correction has its own separate variable resistance control circuit and, in use, each control would be adjusted to obtain the sharpest resonance line. As described with reference to Fig. 1 (not shown), the coil and sample container assembly (46) is mounted for rotation within a solenoid (10) which produces the magnetic field. The solenoid has superconductive windings of copper-jacketed NbZr wire and end correcting shims (12) and is maintained at 4‹ K in a vessel comprising successive concentric layers of liquid helium (32), vacuum (34), liquid nitrogen (38) and another vacuum (36). A sweep signal is applied either to the windings of the solenoid or to separate sweep coils in which case the windings of the solenoid may be short-circuited to operate in the persistent mode. The r.f. transmitter coils (16) may be positioned with their axes perpendicular or parallel to the solenoid axis. In alternative embodiments, the correcting coils may be external to the solenoid (10) and may themselves be made from superconducting material. The X and Y correcting coils 62, 64, 66, 68 may be circular, elliptical, square or rectangular.
GB993266A 1964-03-02 1966-03-07 Apparatus for improving the uniformity of magnetic fields Expired GB1135332A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US348442A US3287630A (en) 1964-03-02 1964-03-02 Apparatus for improving the uniformity of magnetic fields
GB993266A GB1135332A (en) 1966-03-07 1966-03-07 Apparatus for improving the uniformity of magnetic fields
FR53610A FR1476003A (en) 1966-03-07 1966-03-16 Apparatus for improving the uniformity of magnetic fields

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB993266A GB1135332A (en) 1966-03-07 1966-03-07 Apparatus for improving the uniformity of magnetic fields

Publications (1)

Publication Number Publication Date
GB1135332A true GB1135332A (en) 1968-12-04

Family

ID=9881442

Family Applications (1)

Application Number Title Priority Date Filing Date
GB993266A Expired GB1135332A (en) 1964-03-02 1966-03-07 Apparatus for improving the uniformity of magnetic fields

Country Status (1)

Country Link
GB (1) GB1135332A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2932001A1 (en) * 1978-08-05 1980-05-08 Emi Ltd DEVICE AND METHOD FOR EXAMINING A BODY BY MEANS OF GYROMAGNETIC RESONANCE
US4362993A (en) * 1979-08-10 1982-12-07 Picker International Limited Imaging systems
GB2120391A (en) * 1982-05-06 1983-11-30 Dickey John Corp Method and apparatus for non-destructively determing ingredients of a sample
GB2153083A (en) * 1984-01-20 1985-08-14 Picker Int Ltd Nuclear magnetic resonance apparatus
DE3508332A1 (en) * 1984-03-09 1985-09-12 Mitsubishi Denki K.K., Tokio/Tokyo METHOD AND DEVICE FOR PRODUCING PARTICULARLY HOMOGENEOUS MAGNETIC FIELDS
DE3821258A1 (en) * 1987-06-23 1989-01-05 Mitsubishi Electric Corp MAGNETIC COMPENSATION DEVICE
US5329232A (en) * 1991-09-13 1994-07-12 Picker International, Ltd. Magnetic resonance methods and apparatus
EP1209480A2 (en) * 2000-11-21 2002-05-29 GE Medical Systems Global Technology Company LLC Second-order static magnetic field error correcting method and Mri apparatus
EP1612576A1 (en) 2004-06-28 2006-01-04 Hitachi, Ltd. NMR shim coils

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2932001A1 (en) * 1978-08-05 1980-05-08 Emi Ltd DEVICE AND METHOD FOR EXAMINING A BODY BY MEANS OF GYROMAGNETIC RESONANCE
US4362993A (en) * 1979-08-10 1982-12-07 Picker International Limited Imaging systems
GB2120391A (en) * 1982-05-06 1983-11-30 Dickey John Corp Method and apparatus for non-destructively determing ingredients of a sample
US4496907A (en) * 1982-05-06 1985-01-29 Dickey-John Corporation Method and apparatus for non-destructively determining ingredients of a sample
GB2153083A (en) * 1984-01-20 1985-08-14 Picker Int Ltd Nuclear magnetic resonance apparatus
US4644275A (en) * 1984-01-20 1987-02-17 Picker International Limited Nuclear magnetic resonance apparatus
DE3508332A1 (en) * 1984-03-09 1985-09-12 Mitsubishi Denki K.K., Tokio/Tokyo METHOD AND DEVICE FOR PRODUCING PARTICULARLY HOMOGENEOUS MAGNETIC FIELDS
GB2207762A (en) * 1987-06-23 1989-02-08 Mitsubishi Electric Corp Magnetic field compensating apparatus
DE3821258A1 (en) * 1987-06-23 1989-01-05 Mitsubishi Electric Corp MAGNETIC COMPENSATION DEVICE
US4945446A (en) * 1987-06-23 1990-07-31 Mitsubishi Denki Kabushiki Kaisha Magnetic field compensating apparatus
GB2207762B (en) * 1987-06-23 1992-01-02 Mitsubishi Electric Corp Magnetic field compensating apparatus
US5329232A (en) * 1991-09-13 1994-07-12 Picker International, Ltd. Magnetic resonance methods and apparatus
EP1209480A2 (en) * 2000-11-21 2002-05-29 GE Medical Systems Global Technology Company LLC Second-order static magnetic field error correcting method and Mri apparatus
EP1209480A3 (en) * 2000-11-21 2004-07-21 GE Medical Systems Global Technology Company LLC Second-order static magnetic field error correcting method and Mri apparatus
EP1612576A1 (en) 2004-06-28 2006-01-04 Hitachi, Ltd. NMR shim coils
US7157912B2 (en) 2004-06-28 2007-01-02 Hitachi, Ltd. Apparatus for generating homogeneous magnetic field

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