Cooling system for cryogenic storage container and operating method therefor

Abstract

A cryogenic storage container is provided with a storage container, a vacuum container containing the storage container, and a heat shield. The cryogenic storage container is coupled to a cooling source equipped with a cryogenic freezer via transport piping so that the vibration of the cryogenic freezer cannot be directly delivered to the cryogenic storage container. The vibration can be further reduced by providing a bellows unit for transport piping.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a cooling system for a cryogenic storage container and its operating method, and more specifically to a cooling system for a cryogenic storage container by using a coolant such as a liquid helium for cooling at a cryogenic temperature and its operating method.[0003]2. Description of Related Art[0004]Recently, there is an increasing demand for a device requiring a high magnetic field such as an MRI and an NMR. Such a device uses a superconductive magnet for generating a high magnetic field. In addition, a device using superconductivity is applied to measure a weak magnetic field. These objects to be cooled are cooled as soaked in a low temperature coolant, and normally liquid helium having a boiling point of 4.2 K (−269° C.) is used as a coolant.[0005]Liquid helium is low in evaporation latent heat, and the evaporation latent heat of the liquid helium under an atmospheric pressure is 20.7...

AI Technical Summary

Benefits of technology

[0015]The insulating function of a cryogenic coolant storage container is improved by utilizing a cryogenic freezer. However, a cryogenic freezer necessarily generates a vibration although at different levels depending on the difference in the structure of a freezer and a cooling system. Therefore, it is difficult to apply it to a living body magnetic measurement and a magnet for an NMR in which a slight vibration can affect the sensitivity.

[0017]The object of the present invention is to provide a cooling system for a cryogenic storage container capable of solving the problem of the vibration occurring when a heat shield is cooled using a cryogenic freezer, and an operating method for suppressing the amount of evaporation of a coolant from a cryogenic storage container.

[0045]The present invention can solve the problem of the vibration occurring when a cryogenic freezer is used, and can suppress the amount of evaporation of the liquid helium from the coolant storage container on the cryogenic storage container.

Problems solved by technology

However, a cryogenic freezer necessarily generates a vibration although at different levels depending on the difference in the structure of a freezer and a cooling system.

Therefore, it is difficult to apply it to a living body magnetic measurement and a magnet for an NMR in which a slight vibration can affect the sensitivity.

However, there has been the problem with a multi-channel superconductive device and a higher magnetic field of a superconductive magnet that the surface area of the portion for which only one heat shield can be provided becomes large, and the radiant heat from the heat shield to the storage container increases.

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