SUPERCONDUCTING-MAGNET ADJUSTMENT METHOD

• US 20140329689A1
• Filed: 03/01/2012
• Published: 11/06/2014
• Est. Priority Date: 03/01/2012
• Status: Active Grant

• Current Assignee: Canon Medical Systems Corporation (Canon Inc.)
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Tanabe, Hajime
• Granted Patent: US 9,046,587 B2
• Time in Patent Office: Days
• US Class Current: 505/211
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/3815 with superconducting coils, e.g. power supply therefor
• CPC Class Codes: G01R 33/3873 using ferromagnetic bodies ; Passive shimming

Abstract

There are provided the steps of: measuring a magnetic field in a predetermined space; and performing shimming by arranging a plurality of ferromagnetic shims in a superconducting magnet. The step of shimming includes arranging the plurality of shims at positions that make the magnetic field homogeneous, based on a result of measurement in the step of measuring the magnetic field and that provide a predetermined value of an electromagnetic force caused by the magnetic field to act on the plurality of shims.

Claims

1. A superconducting-magnet adjustment method for adjusting homogeneity of a magnetic field generated in a predetermined space by a superconducting magnet, comprising the steps of:

measuring the magnetic field in said predetermined space; and

performing shimming by arranging a plurality of shims of a ferromagnetic material in the superconducting magnet,

said step of shimming including arranging said plurality of shims at positions that make the magnetic field homogeneous, based on a result of measurement in said step of measuring the magnetic field and that provide a predetermined value of an electromagnetic force caused by the magnetic field to act on said plurality of shims.

2. The superconducting-magnet adjustment method according to claim 1, wherein said step of shimming includes arranging said plurality of shims at positions that provide a predetermined value of an electromagnetic force acting in an axial direction of said superconducting magnet, which is included in said electromagnetic force acting on said plurality of shims.

3. The superconducting-magnet adjustment method according to claim 1, wherein said step of shimming includes arranging said plurality of shims at positions that provide a predetermined value of an electromagnetic force acting in a radial direction of said superconducting magnet, which is included in said electromagnetic force acting on said plurality of shims.

4. The superconducting-magnet adjustment method according to claim 1, wherein said step of shimming uses iron shims as said shims.