JPS6156852B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to superconducting magnet devices.

A superconducting magnet device embeds a superconducting wire in a low-resistance stabilizing material such as copper. A coil wound with a superconducting conductor is immersed in a cryogenic coolant such as liquid helium and cooled to an extremely low temperature, making the superconducting wire into a superconducting state. was. In order to ensure stable operation of the magnet, when the superconducting state of the superconducting wire of the superconducting conductor transitions to the normal conducting state due to some disturbance, the current is bypassed through the stabilizing material to reduce heat generation and use a cryogenic refrigerant. The superconducting state is restored by cooling. However, due to the magnetoresistive effect of the stabilizing material, the resistance increases under high magnetic fields and generates more heat, so it is necessary to increase the cooling area and cross-sectional area of the superconducting conductor, which reduces the size of the superconducting magnet device.
It was also heavier. In addition, if forced cooling is used to increase the heat transfer coefficient, the heat transfer coefficient is a function of the flow rate, so increasing the flow rate will increase the heat transfer coefficient, but the pressure loss of the cryogenic refrigerant will increase, causing the temperature of the cryogenic refrigerant to rise and freezing. There were drawbacks such as an increase in the load capacity of the machine.

The object of the present invention is to provide a superconducting magnet device that uses immersion cooling under a low magnetic field and forced cooling under a high magnetic field to ensure stable operation, is downsized, and has a reduced refrigeration load.

An embodiment of the present invention shown in the drawings will be described below. In FIGS. 1 and 2, reference numeral 1 denotes an inner coil around which a superconducting conductor is wound, and a cryogenic coolant is passed through an axial hole provided in the superconducting conductor. 2
is an outer coil in which a superconducting conductor is wound and connected in series to the outside of the inner coil 1. 3 is inner coil 1
and a container for storing the outer coil 2; 3a is a partition plate that divides the interior of the container 3 between the inner coil 1 and the outer coil 2 into two chambers; 4 is a cryogenic refrigerant in the container 3;

Generally, the magnetic field of a superconducting magnet device is higher on the center side of the magnet, that is, on the inner coil 1. The present invention provides an inner coil 1 under a high magnetic field.
In this case, a cryogenic refrigerant is passed through the axial hole of the superconducting conductor in a vacuum or immersed in the cryogenic refrigerant for forced cooling to remove the heat necessary for stabilization, and the outer coil 2 under a low magnetic field is immersed in cooling. This results in a superconducting state. Therefore, since only the inner coil 1 is forcedly cooled, the pressure loss of the cryogenic refrigerant can be small, and the load capacity of the refrigerator can be small. For forced cooling, the outside of the superconducting conductor may be cooled by ejecting it through an axial hole in the superconducting conductor of the inner coil 1, for example, through a buried cooling pipe, and the forced cooling cryogenic refrigerant may be It may also be used as part of the immersion cooling of the outer coil 2. By using both forced cooling and immersion cooling in this way, the weight of the superconducting magnet device can be reduced, making it more compact.
Refrigeration load can be reduced. Also, partition plate 3
a can be used as a reinforcing material against strong electromagnetic force caused by a high magnetic field. Of course, the partition plate 3a may be omitted and the outside of the inner coil 1 and outer coil 2 may be cooled by immersion as shown in FIG.

As described above, in a superconducting magnet device according to the present invention, forced cooling of the inner coil and immersion cooling of the outer coil are used together, so that the inner coil has good heat transfer even in a high magnetic field and is therefore stable. It has excellent effects such as ensuring operation, being able to be made smaller, and reducing the refrigeration load.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the superconducting magnet device of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view showing another embodiment. It is a diagram. 1...Inner coil, 2...Outer coil, 3...
Container, 3a... Partition plate, 4... Cryogenic refrigerant.

Claims (1)

[Scope of Claims] 1. In a superconducting magnet device in which an inner coil and an outer coil wound with a superconducting conductor are housed in a container, the inner coil is forcedly cooled by passing a cryogenic coolant through an axial hole provided in the superconducting conductor. A superconducting magnet device, wherein the outer coil is cooled by immersion in an extremely low temperature refrigerant. 2. The superconducting magnet device according to claim 1, wherein the cryogenic refrigerant after forced cooling of the inner coil is used for immersion cooling. 3 Claim 1, characterized in that the container is provided with a partition plate between the inner coil and the outer coil.
The superconducting magnet device described in Section 1.