Multistage passive uniform-field permanent magnet for nuclear magnetic resonance detection

Abstract

The invention relates to a multistage passive uniform-field permanent magnet for nuclear magnetic resonance detection. The multistage passive uniform-field permanent magnet is characterized in that the permanent magnet comprises a main magnet, a magnet-conductive steel yoke rack and a multistage uniform field device, wherein the main magnet is composed of a pair of permanent magnet poles; the magnet-conductive steel yoke rack comprises an upper magnet-conductive cover (1) and a lower magnet-conductive cover (7) which are arranged in a manner of facing each other, a left magnet-conductive supporting rack (5) and a right magnet-conductive supporting rack (12) which are arranged in a manner of facing each other; the main magnet comprises an upper permanent magnet pole (2) and a lower permanent magnet pole (8) which are arranged in a manner of facing each other; and the multistage uniform field device comprises a first auxiliary uniform field magnetic block (4), a second auxiliary uniform field magnetic block (6), a third auxiliary uniform field magnetic block (11), a fourth auxiliary uniform field magnetic block (13), a first gradient uniform field ring (9) and a second gradient uniform field ring (10). The multistage passive uniform-field permanent magnet has advantages of high magnetic field uniformity, simple structure, high openness, easy production, easy assembling, etc. Furthermore the multistage passive uniform-field permanent magnet has good application prospect in a portable miniature nuclear magnetic resonance detection system.

Description

technical field [0001] The invention relates to a structure design of a permanent magnet, which can generate a high-intensity and high-uniformity static magnetic field applied to NMR detection in a large air gap area. Background technique [0002] NMR (nuclearmagnetic resonance) detection is nuclear magnetic resonance detection. It uses electromagnetic waves of a certain frequency to excite the sample in the detection magnetic field. The nucleus of the sample undergoes nuclear magnetic resonance under the action of electromagnetic waves, so as to collect nuclear magnetic resonance signals to analyze the structural components and density distribution of substances, etc. information. NMR detection technology is widely used in life sciences, agricultural food safety, energy exploration and other fields due to its rapidity, non-destructiveness, accuracy and high sensitivity. [0003] The main magnet is an indispensable part of the NMR detection system, which generates the stati...

AI Technical Summary

Problems solved by technology

Active shimming is performed by adding shim coils in the magnetic field area. Not only does it need to be equipped with a current control part, but the heat generated by the coil is easy to affect the permanent magnet.

Passive shimming can avoid problems caused by energized coils. CN2404130 discloses a magnet device for magnetic resonance imaging systems, using shimming rings for shimming, but the processing error of oblique or arc shimming rings is large, Affects shimming effect; CN203299363U discloses a passive shimming structure of permanent magnet magnetic resonance equipment, but the processing and assembly of this structure is difficult and the adjustment method is complicated

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