Magnetic field adjusting device on high-openness superconduction magnetic resonance magnet

Abstract

The invention relates to a magnetic field adjusting device on a high-openness superconduction magnetic resonance magnet. The design difficulty of the high-openness superconduction magnetic resonance magnet is large than that of the common superconduction magnetic resonance magnet, an imaging region has more non-uniform magnetic field and larger leakage magnetic field range due to the limit of the openness of the high-openness superconduction magnetic resonance magnet to sizes of all parts of the magnet, and a superconduction coil and other ferro magnetic materials bear sizable magnetic force. The invention discloses a magnetic field regulating device on the high-openness superconduction magnetic resonance magnet, which comprises a low-temperature dewar fixed on an iron yoke superconduction coil and a superconduction coil arranged in the low-temperature dewar, wherein a magnetic field regulating device corresponding to the superconduction coil is arranged on the iron yoke, and comprises one or more high-permeability components. By using the change of the ferro magnetic material to the magnetic field, the uniformity of the magnetic field of the imaging region is improved, and the size and the range of a leakage magnetic field are reduced.

Description

technical field [0001] The invention relates to a magnetic field adjustment device used on a high-openness superconducting magnetic resonance magnet. Background technique [0002] The magnetic resonance imaging system is a powerful imaging device, and the main magnet is one of its main hardware, which can provide a high-intensity, stable, and highly uniform magnetic field in a designated imaging area. In addition to meeting the above requirements, high-opening magnets can greatly eliminate the claustrophobic feeling of patients in clinical practice due to the low degree of closure in size, and bring convenience to scanning inspections, so they are more popular than ordinary magnets. [0003] However, the design of superconducting magnets with a high degree of openness is more difficult than ordinary superconducting magnets. The limitation of the degree of openness on the size of each part of the magnet leads to a more uneven magnetic field in the imaging area and a larger ra...

AI Technical Summary

Problems solved by technology

[0003] However, the design of superconducting magnets with a high degree of openness is more difficult than ordinary superconducting magnets. The limitation of the degree of openness on the size of each part of the magnet leads to a more uneven magnetic field in the imaging area and a larger range of leakage magnetic fields. Superconducting coils and other ferromagnetic Material parts are subject to considerable magnetic forces

In order to compensate for the inhomogeneity of the magnetic field and reduce the range of the leakage magnetic field, it is often necessary to adjust the radius of the magnet coil or lengthen the superconducting wire, thereby greatly increasing the cost; and in order to support the magnetic force of the order of 100kN, the additional mechanical structure often reduces the degree of opening

On the other hand, the processing and assembly of the main magnet will bring errors, and a positional deviation of 1 mm on the position of the magnetic field source may cause a magnetic force of the order of kN, which requires the design of additional fixing and supporting structures

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