JPS5914616A - Cooling of superconductive magnet by superfluid helium - Google Patents

Abstract

PURPOSE:To effectively cool a superconductive magnet and generate high magnetic field by providing a cavity in the course of the flowing path of superfluid He at the inside of cooling body of superconductive magnet. CONSTITUTION:A superconductive magnet A is formed by stacking in several layers a coil C formed by winding a conductive lead wire in the constant diameter R and a constant thickness through the waving disks 2 formed like doughnuts. A desirable number of recesses 3 for cavity are formed at the desired area on the disk 2 of this magnet A. According to this structure, on the occasion of cooling the magnet A by the overcooling superfluid He used as the coolant, if heat is abruptly generated within the magnet A, such heat can be absorbed by a large amount of overcooling fluid He within the recess 3. Thereby, the magnet A is efficiently cooled and provides high magnetic field and a more stable superconductive magnet can be obtained with a high thermal conductivity of superfluid He.

Description

[Detailed Description of the Invention] A superconducting magnet made of superfluid helium that can absorb heat suddenly released from a solid such as a superconducting magnet and maintain the object to be cooled at a constant temperature at an extremely low temperature. The present invention relates to a cooling method.

A superconducting magnet cooled by normal superfluid helium is a superconducting magnet cooled by normal liquid helium (4.2Katl aim).
It is possible to generate a higher magnetic field than that cooled by supercurrent helium, and the high thermal conductivity of supercurrent helium makes it a more stable superconducting magnet. Therefore, if a superconducting magnet is kept at an extremely low temperature of 1.8 K using supercooled superfluid helium, for example 1.8 K at 1 atm, the transition temperature of superfluid helium to normal helium, the lambda temperature (2.163 K at 1 atm), It becomes possible to utilize the enthalpy difference up to 1.8K as a heat absorption and damper.

However, the amount of superfluid helium that permeates between the tightly wound superconducting wires (coils) in superconducting magnets is small, and the amount of superfluid helium that is infiltrated between the inside and outside of the superconducting magnets currently used is small. Because the flow path is narrow and narrow, even with the high thermal conductivity of superfluid helium, it is difficult to transport the sudden heat from inside to the large amount of superfluid helium outside the superconducting magnet, and the internal temperature of the superconducting magnet is lower than normal. The temperature may exceed the conductive transition temperature.

The present application was invented in order to eliminate this drawback, and to explain its embodiment now, a conductive wire with a constant diameter (f
The donut of superconducting magnet (A) formed by superconducting a coil 0 wound to a constant thickness φ () in several stages through a corrugated donut-shaped disk (2) which is radially bent into uneven stripes. An appropriate number of cavity recesses (3
).

The present application is based on the above-mentioned structure, and when a superconducting magnet (5) is cooled using a supercooled superfluid helium refrigerant, when sudden heat generation occurs inside the superconducting magnet (A), the recess for the cavity (3 ) can absorb heat by a large amount of supercooled superfluid helium.

As mentioned above, this application uses supercooled superfluid helium as a refrigerant.
In cryogenic equipment such as superconducting magnets that are cooled, a cavity of an appropriate volume is provided in the middle of the superfluid helium flow path inside the object to be cooled in the superconducting magnet, and sudden heat generation from inside the object to be cooled is absorbed by the cavity. Superconducting magnets are characterized by absorption by cooled superfluid helium (
It has characteristics such as being able to generate a strong magnetic field when cooled, and also being able to be used as a more stable superconducting magnet due to the high thermal conductivity of superfluid helium.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an example of a conductive magnet for explaining the invention of the present application, and Fig. 2 is a perspective view of a commonly used helium distribution device and a donut-shaped disk.Patent applicant: Toyo Sanso Co., Ltd. 1. Figure 2 procedural amendment (voluntary) September J, 1933 Kazuo Wakasugi, Commissioner of the Patent Office 4, Representative 5, Date of amendment order: Month, Day 6, 1939.
Number of inventions increased by amendment

Claims (1)

[Claims] (1) In a cryogenic device such as a superconducting magnet that is cooled using supercooled superfluid helium as a refrigerant, a cavity of an appropriate volume is provided in the middle of the superfluid helium channel inside the object to be cooled in the superconducting magnet, and the inside of the object to be cooled is A method for cooling superconducting magnets, etc. using superfluid helium, which is characterized by absorbing sudden waste heat from superfluid helium in this cavity.