JPS6119090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting magnet used in nuclear fusion devices and the like, and more particularly to a superconducting magnet with improved attachment of a spacer that constitutes a flow path for cooling a superconducting coil.

In recent years, devices that utilize superconductivity have been widely adopted, such as magnetic levitation, energy storage, rotating electric machines, and nuclear fusion devices.

In particular, torus-type nuclear fusion devices have significantly increased in size, and the coils used in these devices must generate a strong magnetic field to confine high-temperature plasma. Conventional normal-conducting coils have limitations in terms of the magnetic field they can generate, and large superconducting coils are essential for nuclear fusion devices that need to generate even stronger magnetic fields.

Generally, in order to create a superconducting state, a coil is cooled to an extremely low temperature using a coolant such as liquid helium or supercritical helium. For this reason,
Superconducting coils are typically housed in a vacuum-insulated container.

An example of a superconducting coil is shown in FIGS. 1 to 3. That is, it is composed of a plurality of superconducting coils 2 wound in the shape of a pancake, a cryogenic container 1 housing them, a spacer 3 located between adjacent superconducting coils, and a spacer 4 located between the coils and the cryogenic container. Ru. These spacers 3 and 4 are
It constitutes a flow path for a coolant such as liquid helium to efficiently cool the superconducting coil 2, and also provides fixation and electrical insulation between adjacent superconducting coils and between the coil and the cryogenic container.

Conventional spacers are arranged between adjacent superconducting coils as shown in FIG. 3, and are adhered to the coil surface with insulating varnish or the like. In this way, electrical insulation between adjacent superconducting coils and between the inner and outer peripheries and a coolant flow path are formed.

With the spacer 3 having the above configuration, problems such as the adhesion of the insulating varnish, heat shrinkability, characteristics at extremely low temperatures, placement of the spacer 3 due to the strength of electromagnetic force, etc., and the number of members, etc., are not found in conventional relatively small superconducting coils. were sufficiently manageable. However, in a large superconducting coil that generates a strong electromagnetic force such as a nuclear fusion device, adhesion using insulating varnish or the like alone will result in poor reliability at electromagnetic force, thermal contraction, and extremely low temperatures. For example, if a spacer peels off during the process of cooling to an extremely low temperature, there will be a region where the coolant will not flow locally and the cooling will be poor, resulting in mobility that will prevent the superconducting state. Further, due to peeling off of some of the spacers, the electromagnetic force is no longer distributed uniformly to the spacers, which may cause damage to the spacers in various parts within the coil.

An object of the present invention is to stabilize the fixation of spacers between adjacent superconducting coils.

The present invention mechanically connects spacers arranged between adjacent superconducting coils.

An embodiment of the present invention will be described with reference to FIGS. 4 to 7. That is, the spacers 3 are connected by the thin connecting member 5. The connecting member 5 is arranged concentrically with the coil 2 on the inner and outer diameter sides of the coil. The connection between the spacer 3 and the spacer connecting member 5 uses a combination of mechanical connection such as pins 6 or spigots and adhesive. By configuring as described above, the spacer 3 is connected over the entire circumference of the coil, and the spacer alone maintains its shape. Further, due to the mechanical bonding, the spacer 3 retains its shape without locally peeling off or falling off. Therefore, compared to conventional adhesive spacers, the mechanical strength is improved and positional displacement does not occur, so the superconducting coil can be operated safely without clogging the refrigerant passage.

In the above embodiment, the connecting member 5 is a thin plate, but as shown in FIG. 8, the spacers 3 may be connected by a thin connecting rod 7, so as not to block the refrigerant flow path. Since the spacers are still connected by a connecting member, the same effect as the present invention can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an external side view of a superconducting coil, Fig. 2 is a cross-sectional view along AA in Fig. 1, Fig. 3 is a cross-sectional view along BB in Fig. 2, and Fig. 4 is a cross-sectional view showing the spacer connection arrangement of the embodiment of the present invention. A plan view, Fig. 5 is a detailed perspective view of the part A in Fig. 4, Figs. 6 and 7 are sectional views CC of Fig. 5,
FIG. 8 is a perspective view showing another embodiment. 1...Cryogenic container, 2...Superconducting coil, 3...
...Spacer, 5...Connecting member.

Claims (1)

[Claims] 1. In a superconducting magnet equipped with a cryogenic container that houses a superconducting coil and a cryogenic fluid that cools the superconducting coil, a plurality of spacers arranged between adjacent superconducting coils are connected together by a connecting member. A superconducting magnet characterized by: