Retractable magnetizing current lead device and method of same

Abstract

The invention discloses a retractable magnetizing current lead device and method of the same. The retractable magnetizing current lead device comprises three parts: a retractable normal conducting lead section (1) deposed inside a liquid nitrogen chamber, a high temperature superconducting transition lead section (2) thermally connected with a cold head (71) and a low temperature superconducting coil lead section (3), wherein the retractable normal conducting lead section (1) is connected with a high-temperature part; the high temperature superconducting transition lead section (2) is connected with a low temperature part; the low temperature superconducting coil lead section (3) is connected with a superconducting coil (8); a lower end of the retractable normal conducting lead section (1) is connected with an upper end of the high temperature superconducting transition lead section (2) by way of plugging and a retractable electrical contact (20) is disposed at the junction; a lower end of the high temperature superconducting transition lead section (2) is connected with the low temperature superconducting coil lead section (3) by welding; and a high current conductive rod (10) and a high temperature superconducting lead (24) together form a current path for the whole magnetizing lead. The retractable magnetizing current lead device has the characteristics of low conduction heat loss, high sealing performance and convenient excitation operation.

Description

technical field [0001] The invention relates to a magnetizing current lead device for a superconducting magnet system, in particular to a retractable magnetizing current lead device and a use method thereof. Background technique [0002] The superconducting magnets of most magnetic resonance imaging (MRI) systems currently in clinical use are filled with expensive liquid helium (LHe) to maintain the critical temperature required for low-temperature superconducting wires. However, the rising price of liquid helium and the possible shortage of liquid helium resources have greatly increased the demand for liquid helium-free magnets. Compared with liquid helium magnets, liquid helium-free magnets do not require liquid helium as a refrigerant, and only the refrigerator controls the working environment temperature. However, the cooling power of current refrigerators is limited, such as pulse tube refrigerators, when the cooling power of the first-stage cold head is 50K It is 35W,...

AI Technical Summary

Problems solved by technology

[0004] The current lead method of copper and high-temperature superconducting lead wire has greatly reduced the heat leakage, but for the liquid-free superconducting magnet whose working environment temperature is only controlled by the refrigerator, when the magnetizing current of about 600 amperes When the copper rod of the current lead is passed through, the heat leakage from the copper current lead to the first-stage cold head is still very large, so that the temperature of the cold shield cannot be lowered very low. The higher the temperature of the cold shield, the greater the radiated heat to the superconducting magnet. May cause superconducting magnets not to work properly

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