Superconducting magnet of 7T clinical magnetic resonance imaging equipment

Abstract

A superconducting magnet of 7T clinical magnetic resonance imaging equipment is disclosed in the invention, and comprises a low-temperature Dewar shell, a cold shield, a main superconducting coil anda portrait imaging channel which are sequentially connected from outside to inside, a double-liquid-helium-cavity structure is arranged between the cold shield and the main superconducting coil, and the double-liquid-helium-cavity structure comprises a first liquid helium cavity and a second liquid helium cavity; the first liquid helium cavity is defined by a first liquid helium cavity inner cylinder, a first liquid helium cavity outer cylinder and an end face flange of the shielding coil, vacuum interlayers are arranged between the first liquid helium cavity and the cold shield and between the first liquid helium cavity and the second liquid helium cavity respectively, and the magnet shielding coil is soaked by filling liquid helium; and the second liquid helium cavity is defined by a second liquid helium cavity inner cylinder, a second liquid helium cavity outer cylinder and an end face flange of the main coil, vacuum is formed between the second liquid helium cavity and the cold shield, and the second liquid helium cavity is filled with liquid helium to soak the magnet main coil. According to the superconducting magnet, it is guaranteed that the superconducting magnet has high space uniformity and time stability in the operation process, the imaging quality of 7T clinical magnetic resonance imaging equipment is guaranteed, and 6000 liters of liquid is saved compared with a single liquid helium cavity structure.

Description

technical field [0001] The invention relates to the technical field of 7T clinical magnetic resonance imaging equipment, in particular to a superconducting magnet of the 7T clinical magnetic resonance imaging equipment. Background technique [0002] The magnetic field is generated by the current in the main superconducting coil. In order to maintain the superconducting state of the coil wire, the coil must be kept at an extremely low temperature, which is generally maintained at a stable low temperature by liquid helium and a cold head of a cryogenic refrigerator. The main superconducting coil is immersed in liquid helium in a cryogenic Dewar's liquid helium vessel. In order to effectively prevent the external heat from conducting, convecting, or radiating to the liquid helium Dewar to cause the evaporation of liquid helium, the main superconducting coil and the cryogenic container of the Dewar must be placed in the vacuum chamber and the radiation-proof cold shield therein...

AI Technical Summary

Problems solved by technology

Even if materials with such excellent properties are used, heat conduction cannot be completely eliminated. If the heat leakage is close to or greater than the cooling power of the cryogenic cold head, it may cause volatilization and consumption of liquid helium, which will hinder the long-term stable operation of the magnet.

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