7t superconducting magnet for clinical magnetic resonance imaging equipment

Abstract

The invention discloses a superconducting magnet of a 7T clinical magnetic resonance imaging device, comprising a low-temperature Dewar shell, a cold screen, a main superconducting coil and a portrait imaging channel sequentially connected from the outside to the inside, and the cold screen and the main superconducting coil are arranged between the There is a double liquid helium cavity structure, the double liquid helium cavity structure includes a first liquid helium cavity and a second liquid helium cavity; the first liquid helium cavity is composed of the inner cylinder of the first liquid helium cavity, the outer cylinder of the first liquid helium cavity and the shielding coil. The end face flange is surrounded by a vacuum spacer between the cold screen and the second liquid helium cylinder, respectively, and is filled with liquid helium to soak the magnet shielding coil; the second liquid helium cavity is composed of the second liquid helium cavity inner cylinder, The outer cylinder of the second liquid helium chamber is surrounded by the end face flange of the main coil, and there is a vacuum between it and the cold shield, which is filled with liquid helium to soak the main coil of the magnet. The superconducting magnet of the present invention ensures that it has strong spatial uniformity and time stability during operation, ensures the imaging quality of 7T clinical magnetic resonance imaging equipment, and saves 6,000 liters of liquid 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 the 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 evaporation of liquid helium caused by conduction, convection, or radiation from the outside world to the liquid helium Dewar, the main superconducting coil and the cryogenic container of the Dewar must be placed in a vacuum chamber and a 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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