Electrically conductive shield for refrigerator

Abstract

A cryogenic magnet system, comprising a cryogenic vessel (1) housing a magnet winding, a vacuum jacket (3) enclosing the cryogenic vessel and a refrigerator (4) at least partially housed within the vacuum jacket and thermally linked (6) to the cryogenic vessel. In particular, the system further comprises an electromagnetic shield.

Description

technical field [0001] The invention relates to a cryogenic magnet arrangement for generating a uniform magnetic field. In particular, the present invention relates to a shield disposed around a cryogenic refrigerator to reduce the effect of the cryogenic refrigerator on the stability of a synthetic magnetic field. Background technique [0002] MRI magnet systems typically include cryogenic magnet arrangements and are used for medical diagnosis. MRI magnets require a stable, uniform magnetic field. To achieve stability, superconducting magnet systems are typically employed that operate at very low temperatures, which are typically maintained by cooling the superconductor by immersing it in a cryogenic fluid, usually liquid helium. Cryogenic fluids, especially helium, are expensive and it is desirable that the magnet system be designed and operated in such a way that the use of this cryogenic fluid is minimized. [0003] The superconducting magnet system generally includes...

AI Technical Summary

Problems solved by technology

The disadvantage of such a shield is that the bismuth alloy shield itself can be permanently magnetized; the bismuth alloy used is relatively expensive and does not have sufficient thermal conductivity

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