JPS639903A - Pancake magnet - Google Patents

Abstract

PURPOSE:To increase winding turns of a superconducting tape and improve performance and realize size reduction by a method wherein the end surfaces of the bobbin of a pancake coil are mutually coupled with neighbouring bobbins directly or with coupling rings between. CONSTITUTION:A plurality of pancake coils 2 and 2' are arranged coaxially and protruded coupling parts 11 and recessed coupling parts 11' which are provided on the bobbins 1 of the pancake coils 2 and 2' are butted on each other and a large number of the winding frames 1 of neighbouring pancake coils 2 and 2' are couplied coaxially with each other with insulating spacers 5 between. Flanges 6 and 6' are attached to both the ends of the pancake coils 2 and 2' and are unified by fitting stay bolts 7 and the pancake coils 2 and 2' are tightened along the axial direction by pushing bolts 10 through springs 8 and pushing plates 9 and unified. with this constitution, a center pipe can be eliminated and the number of turns of a superconducting tape can be increased so that high magnetic field can be obtained and, moreover, the outer diameter can be reduced so that the necessary volume of the superconducting tape can be reduced and size reduction can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a pancake magnet in which a plurality of pancake coils are coaxially arranged.

(Prior art and its problems) Superconducting wires that have been put into practical use as superconducting magnets include alloy superconductors such as NbTi and Nb5SnsV.
There are compound superconductors such as Ca. Among these, the compound superconducting wire that generates a high magnetic field is a compound superconducting wire, but because the compound is mechanically fragile, the wire is wound entirely in a solenoid, or it is wound as a tape-shaped conductor into a coil in the shape of a pancake. Cake magnets have been put into practical use.

This pancake magnet has a structure as shown in FIGS. 5 and 6.

That is, as shown in Fig. 5, a single pancake coil (2) is formed by fully winding the compound superconducting tape on a winding frame (1) made of non-magnetic metal such as brass, and then a single pancake coil (2) is formed from an insulating material such as FRP or Bakelite. A double pancake coil is formed by winding a compound superconducting tape in the same way through a spacer (5). A non-magnetic metal center pipe insulated with a film of resin such as epoxy, Kapton, polyester, etc. The above pancake coils as cores are arranged coaxially with insulating spacers (5) alternately. The flanges (6) and (6) are attached to both ends of the center pipe, and are integrated with the stay bolts (7), and the spring (8) and push plate (9) are attached.
), each pancake coil is tightened in the axial direction with a push bolt αQ to form a pancake magnet.

The above center pipe 0) is used to eliminate radial misalignment of each pancake coil when assembling the pancake coils coaxially, and also to prevent the sample inserted into the inner diameter part of the center pipe while the magnet is in operation, and the inside of the pancake coil. The role of this material is to ensure electrical insulation from the conductor. However, this center pipe is usually 2
It has a wall thickness of ~51 m, and if the outer diameter of the pancake coil was constant, the number of turns of the coil would be reduced by this wall thickness, making it a disadvantage in obtaining a high central magnetic field. .

(Means for Solving the Problems) The present invention has been made focusing on the above points, and is a pancake magnet in which a plurality of pancake coils are coaxially arranged. It's a magnet.

That is, in the pancake magnet of the present invention, as shown in FIG. A shaped fitting part α force and a concave fitting part (11') on the other end surface.
B5Sn, '/aGa compound superconducting tape is wound to form a single pancake coil (2), and FRP is
Similarly, a compound superconducting tape is wound through a spacer (3) made of an insulator such as Bakelite to form a single pancake coil (2') and a double pancake coil. As shown in the figure, the pancake coil winding frames described above are installed, and then the convex fitting part and the concave fitting part are brought into contact with each other, and the winding frames of adjacent pancake coils are coaxially connected through the insulating spacer (5). Multiple mating. 7 lunges (6), (6
To install the lever, integrate it with the stay bolt (7), and connect the spring (8) and push plate (9) fr: with the push bolt αQ.
Each pancake coil is tightened in the axial direction and integrated to form a pancake magnet. When assembling the winding frame, the pancake coil winding frame can be efficiently assembled by using a pipe or the like that is slightly thinner than the inner diameter of the winding frame, inserting the pancake coil winding frame into this, and pulling out the pipe after assembly. The above-mentioned pancake coil winding frame is a case in which the winding frames are directly fitted together by providing unevenness on the end face of the winding frame, but as shown in Figs. 5 and 4, both end faces of the winding frame (1) The winding frame (
1) Full fitting is also possible.

In addition, as shown in Fig. 4, a joining ring α4 with a square cross section
It is also possible to fit the winding frame (1) through.

The above-mentioned winding frame (1) and joining ring can be made of non-magnetic materials such as ceramic, GFRP, and brass.

(Operations and Effects) According to the present invention, since the center pipe is not required, the number of turns of the superconducting tape can be increased by the thickness of the center pipe, and a higher magnetic field can be generated than in the conventional case. Furthermore, since the outer diameter can be made smaller in order to obtain the same central magnetic field, the amount of superconducting tape used can be reduced, and a small, high-performance, low-cost magnet can be obtained.

The present invention applies not only to pancake magnets using compound superconducting tape, but also to cases in which a plurality of pancake coils are coaxially combined, such as in cases in which alloy superconducting tape is used, and in cases in which a rectangular conductor is used instead of the tape. It is also applicable.

(Example) An embodiment of the present invention will be described below.

As shown in Figure 1, the inner diameter is 50 yaa and the outer diameter is 33 mm.
A superconducting tape made of bs Sn with a width of 5 B and a thickness of 0.165 mm.
A pancake coil (2) was made by winding it in 18 g turns with an outer diameter of 95 mm. Using an assembled pipe with an outer diameter smaller than the inner diameter of the entire winding frame of this pancake coil, the coil was assembled as shown in Fig. 2. As shown, eight coaxially adjacent pancake coils (2) (two winding frames) were fitted together through FRP spacers (5).

Next, attach flanges (6) to both ends of the pancake coils (stay bolts σ are used to install the 6 pieces), and attach each pancake coil to the axis using the push bolts (11) via the springs (8) and push plates (9). Tighten it in the direction to integrate it, then pull out the assembled pipe and use it as a pancake magnet.

We also made a traditional pancake magnet and used it as a water bottle.
As is clear from Table 1, the coil inner diameter of the present invention can be increased by 5 mm compared to the conventional coil, and as a result, the central magnetic field can be improved by about 10%.

(Effects) According to the present invention, the total number of turns of superconducting tape can be increased, and the performance can be significantly improved. A compact, high-performance, and low-cost superconducting magnet can be obtained, which is an industrially significant effect. It is something that plays.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the pancake coil of the invention, FIG. 2 is a sectional view of the pancake magnet of the invention, FIGS. 3 and 4 are sectional views of the pancake coil of the invention, and FIG. 5 is a sectional view of the pancake coil of the invention. A sectional view of a conventional pancake coil, and FIG. 6 is a sectional view of a conventional pancake magnet. 1... winding frame, 2. 2'...Pancake coil, 5
... Spacer, I... Center pipe, 5...
Insulating spacer, 6.6'...flange, 7...stay bolt, 8...sufu' IJ song 9...push plate, 1o...push bolt, 11...convex fitting part ,1
11...Concave fitting part, 1...Concave fitting part, 13...
Convex joint ring, 1ヰ...square joint ring

Claims (1)

[Claims] A pancake magnet in which a plurality of pancake coils are coaxially arranged is characterized in that the end faces of the winding frames of the pancake coils engage the winding frames of adjacent pancake coils directly or through a joining ring. pancake magnet