JPS6267803A - superconducting coil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a coil, and particularly to a support structure for an insulating spacer suitable for a superconducting coil.

[Background of the invention]

Figure 2 is a schematic structural diagram of an immersion-cooled superconducting coil, Figure 3 is a mounting part of the insulating spacer of the coil in Figure 2, and Figure 4 is a cross section taken along the It is a diagram.

The superconducting magnet coil 1 is made by winding four superconducting bodies 1, each having a superconducting wire embedded in a copper base, in a circular shape while applying an interlayer insulating layer 2 to form a disk 3 of a unit coil. A predetermined number of insulating spacers 5 are provided between the disks of this unit coil to form liquid helium flow paths 4 for electrical insulation and coil cooling, and a predetermined number of disks are stacked, and a lining is provided for the purpose of insulating the ground between the coils. The magnet coil 1 is provided with insulation 6, and is housed within a coil support ring 7 and a coil frame 8 made of SUS.

For the disk 3 of the unit coil, a resin-impregnated glass cloth prepreg tape or a hardened glass cloth tape coated with resin is used as interlayer insulation. These interlayer insulations are continuously inserted between the fill conductors, applying pressure to the conductor and winding it a predetermined number of times. After winding, the interlayer insulation is solidified under pressure, forming the interlayer insulation layer 2, and forming a unit coil. It becomes disk 3 of .

Generally, the insulating spacer 5 has a mechanical %i at cryogenic temperatures.
Glass fiber reinforced plastics (hereinafter referred to as GFR, P) having a thickness of about 2 to 5 cm are used. This GFRP
is cut into a predetermined size and shape, arranged so as to extend in the radial direction of the disks of the unit coil, and fixed between the disks of the unit coil with adhesive resin 9.

During operation, the coil housed in the cryostat is immersed in liquid helium, cooled to around 4.2°k, and energized and excited.

When a magnet coil is excited with a high current density and a high magnetic field, there is a strong compressive stress due to electromagnetic stress in the axial direction of the coil and the axial direction of the insulating spacer, and a strong compressive stress due to electromagnetic stress in the circumferential direction. works. For this reason, shear stress is generated at the bonded part of the insulating spacer bonded to the disk of the unit coil.
Unable to withstand electromagnetic stress, fracture easily occurs. When this happens, play occurs in the entire coil, and due to repeated magnetic stress, the insulating spacers move instead of staying in their normal positions, and the distance between the spacers becomes wider. The expanded spacer serves as a fulcrum and bending stress is applied to the conductor due to compressive stress in the axial direction), and the interlayer insulation layer between the conductors can easily peel off, causing a short circuit between the disks. was there.

[Purpose of the invention]

An object of the present invention is to provide a superconducting coil that is strong against electromagnetic stress by providing recesses radially in the width direction of the interlayer insulating material and arranging insulating spacer materials in the recesses across the unit coil disk. Our goal is to provide.

[Summary of the invention]

The insulating spacers of conventional superconducting magnet coils are fixed with adhesive resin between disks of unit coils made of interlayer insulating layers with the same width as the superconducting conductor. Since the conductor width and the interlayer insulation layer width are the same, the adhesive part of the insulation spacer peels off due to repeated electromagnetic stress due to coil excitation.
There was a risk that the insulating spacer would move. as a solution.

A method was adopted in which recesses were provided radially in the width direction of the interlayer insulating material, and insulating spacers were placed in the recesses so as to cross the disks of the unit coils.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to FIG.

FIG. 1 shows a disk of a unit coil of a superconducting magnet according to an embodiment of the present invention.

The superconducting conductor 1 is made into a circular shape by applying pressure with a pending roller, and is wound a predetermined number of times while inserting an interlayer insulating material 2 having a width f1 larger than the conductor width coated with resin between the conductors.
The disk 3 of the unit coil is completed by curing the resin at room temperature or by heating without releasing the E-force. Thereafter, the insulating spacers 5 are inserted radially into the recesses 10 minutes apart at intervals in the radial direction, and the spacers are firmly adhered to the recesses with resin. At this time, the protrusion of the five-layer insulating material toward the insulating spacer is preferably less than half the thickness of the insulating spacer so as not to impede the flow of liquid helium.

The coil 1 is completed by stacking a predetermined number of disks of unit coils thus completed, adhesively fixing the unit coils to each other via insulating spacers, storing them in a coil frame 8, and applying lining insulation 6.

The coil manufactured in this manner is strong and unaffected by the electromagnetic stress F1 or hoop force F2 caused by excitation of the coil.

According to this embodiment, a recess is provided in the interlayer insulating layer.

Because the insulating spacer was inserted into this recess in a kind of wedge shape, 1! Since it firmly suppresses the expansion of the coil due to magnetic stress, it is strong against electromagnetic stress, provides a coil that does not loosen, and contributes to safe long-term operation of the coil.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the coil from expanding due to the electromagnetic stress or hoop force caused by the excitation of the superconducting magnet, thereby making the coil stronger as a whole.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a disk of a unit coil of a superconducting magnet according to an embodiment of the present invention, Fig. 2 is a perspective view of an immersion-cooled superconducting magnet coil, and Fig. 3 is a portion of the insulating spacer of the coil shown in Fig. 2. The perspective view and FIG. 4 are cross-sectional views taken along the line IV-IV in FIG. 3. DESCRIPTION OF SYMBOLS 1... Superconducting conductor, 2... Interlayer insulating layer, 3... Disk of unit coil, 4... Liquid helium flow path, 5
. . . Absolute spacer, 6. Insulation lining, 7. Coil support ring, 8. Coil frame, 9. Adhesive resin, 1o. Recess.

Claims (1)

[Claims] 1. A superconducting conductor made by embedding a superconducting wire in a copper base is wound in the radial direction while applying an interlayer insulation material to complete a disk of a unit coil, and an insulating spacer is interposed between the disks of the unit coil. In the case where the interlayer insulation material is laminated to form a coil, the width of the interlayer insulating material is larger than the width of the superconducting conductor, and recesses for fixing the insulating spacers are provided at certain intervals, and the insulating material is placed in the recesses. A superconducting coil characterized by inserting a spacer.