JPH0812820B2 - Superconducting magnet - Google Patents

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is made from a large single crystal bulk material composed of RE (Y-containing rare earth elements and combinations thereof), Ba and Cu oxides obtained by the melting (QMG) method. For superconducting magnets.

[0002]

2. Description of the Related Art At present, the most promising method for producing a superconducting magnet using an oxide superconductor is to use a bismuth-based silver sheath wire as a magnet, which has been studied by many institutions. However, bismuth-based superconductors have an extremely low current density at liquid nitrogen temperature (77K), and there is no prospect of a superconducting magnet using liquid nitrogen as a refrigerant. On the other hand, for the Y-based superconducting material, a method for producing a large single crystal bulk material by conducting unidirectional crystal growth by the QMG method, which is a kind of melting method, has been studied. This QMG material has a critical current density exceeding 10 ⁴ A / cm ² even in a magnetic field of 77 K and 1 T, and has a property that liquid nitrogen can be magnetized as a refrigerant.

[0003]

The QMG material grown in one direction and enlarged has the excellent superconducting properties as described above, but it is difficult to wind it into a wire and then wind it around a magnet. Extremely difficult due to workability. In order to apply the QMG material to the magnet, it is necessary to make it into a magnet by a method that does not go through a wire rod. The present invention has been made in view of the above problems, and an object thereof is to provide a superconducting magnet directly manufactured from a superconducting bulk material.

[0004]

The present invention is based on RE (one kind of rare earth element including Y or a combination thereof), Ba, C.
In a REBa ₂ Cu ₃ O _7-x oxide superconducting magnet made of an oxide of u, a central portion of a single crystal bulk body having a structure in which RE ₂ BaCuO ₅ is finely dispersed is opened, and a solenoid-shaped A superconducting magnet characterized by being cut so as to form a coil, and current-introducing terminals being installed at both ends of the coil. Furthermore, RE (Y is one of rare earth elements including Y or The combination), in a REBa ₂ Cu ₃ O _7-x oxide superconducting magnet composed of Ba and Cu oxides, a simple structure having RE ₂ BaCuO ₅ finely dispersed.
The central portion of the crystalline bulk body is opened, and the slit processing is performed so as to form a solenoid coil having a closed circuit in a part, and current introduction terminals are installed at both ends of the coil. The gist is that the magnet is a superconducting magnet.

[0005]

[Function] To magnetize one single crystal bulk, make a hole in the bulk crystal of a cylindrical superconductor so that the superconducting current flows while drawing a loop, and make a notch to make a solenoidal current path. Good. The superconducting magnets thus produced can be roughly classified into two types in terms of current circuits. One is a magnet that has two current-introducing ends and has only one path for superconducting current between them, and a magnet that is continuous while drawing a loop like a solenoid. The other is a current path in the superconducting material. A magnet that has a closed circuit and is continuous and that has a current introduction terminal therein is conceivable.

A detailed description will be given below with reference to the drawings. FIG.
Indicates a superconducting magnet having a cylindrical bulk body 1 having a hole 3 in the center thereof, a slit 2 formed therein, and holding two current introducing terminals 4a and 4b, and having a solenoidal current path 5. 2 shows an equivalent circuit of the magnet shown in FIG. A magnet having a circuit as shown in FIG. 2 can excite the magnet by supplying a current from an external power source.

In FIG. 3, a notch 12 is made in a cylindrical bulk body 11 having a hole 13 in the center to keep a closed current path, and a solenoid current path and two current terminals 14c and 14b are provided in the middle thereof. The superconducting magnet which it has is shown, and the figure when it cut | disconnects by the surface shown by a dashed-dotted line is shown. The portion having the solenoid is shown in (a). (B) shows a portion around the heating element 17 without a solenoid. The portion shown in (a) has a current path similar to that in FIG. Further, the black-painted portion 16 shows the surface where the superconductors in the portions shown in (a) and (b) were continuous. Further, (c) shows a cross-sectional view of the original state of the magnet, that is, the superconductor shown in (a) and (b) taken along the line cc 'in (a). By such a cutting process, a closed circuit having a solenoid can be formed.

FIG. 4 shows an equivalent circuit of the magnet shown in FIG. A magnet having a closed circuit as shown in FIG. 4 is in a superconducting state between current introducing terminals having a solenoid portion and is in a normal electric state by passing a current between the current introducing terminals having no solenoid to the heating element 17, By introducing an electric current, a superconducting current can be made to flow and excited in the solenoid portion. After that, by cutting off the current to the heating element in the circuit between the electrodes having no solenoid portion, the state is changed to the superconducting state, so that the permanent current can be continuously supplied to the magnet.

[0009]

Example 1 A single-crystal bulk superconducting material having a diameter of about 2.8 cm and a height of about 4 cm in which fine 211 phases were dispersed in 123 phases was perforated and cut as shown in FIG. Was applied. At this time, the inner diameter was about 1 cm, and three slits were provided at 1 cm intervals, and a magnet with four turns was produced so that the loop of the current path was selected four times. Next, two current introduction terminals were produced after vapor deposition of silver and connected to a constant current power source. After cooling the magnet in liquid nitrogen, a maximum current of 60 A was passed. 0.7 Kgau at the center due to this excitation
The magnetic field of ss magnetic flux density could be obtained.

Example 2 A single crystal bulk superconducting material having a diameter of about 2.8 cm and a height of about 4 cm in which fine 211 phases were dispersed in 123 phases was subjected to perforation and notching as shown in FIG. gave. At this time, the inner diameter is about 1 cm and 3 at 1 cm intervals.
Insert a book slit, and further cut it so that the loop of the current path can be marked 4 times, and cut it so that the width of the superconductor between the current introducing terminals is about 2.3 cm, and make a 4-turn magnet with a closed circuit. did. Next, two current introduction terminals were produced after vapor deposition of silver and connected to a constant current power source. Furthermore, a heating element was wound around the superconductor between the terminals. After the magnet was cooled in liquid nitrogen, the heating element was energized to transfer the superconducting portion near the heating element to normal conduction. After that, a maximum current of 60 A was passed. 0.6 at the center due to this excitation
A magnetic field of Kgauss magnetic flux density could be obtained. Next, the power supply to the heating element was stopped, and the entire magnet was put into a superconducting state so that the current from the constant current power supply was reduced to zero. By the above operation, a permanent current could be passed through the closed circuit, and a magnetic field having a magnetic flux density of 0.4 Kgauss could be obtained at the center.

[0011]

As described above, the present invention enables the production of oxide superconducting magnets, which has been impossible up to now, and can be applied in various fields as a molded product, which is extremely industrially effective. large. Specific examples include motors, accelerators, silicon lifting, nuclear magnetic resonance,
Wide application is possible.

[Brief description of drawings]

FIG. 1 is a solenoidal superconducting magnet according to the present invention.

2 is an equivalent circuit of the magnet shown in FIG.

FIG. 3 is a development view of a superconducting magnet having a closed circuit according to the present invention.

FIG. 4 is an equivalent circuit of the magnet shown in FIG.

FIG. 5 is a prototype solenoidal superconducting magnet.

FIG. 6 is a development view of a prototype superconducting magnet having a closed circuit. 1,11 Bulk material 2,12 Cut 3,13 Hole 4,14 Current introduction terminal

Claims (2)

[Claims] 1. REBa consisting of RE (one kind of rare earth element including Y or a combination thereof), Ba and Cu oxides.
RE in ₂ Cu ₃ O _7-x oxide superconducting magnet
₂ The central portion of a single crystal bulk body having a structure in which BaCuO ₅ is finely dispersed is opened, and cut processing is performed so as to form a solenoid coil, and current is introduced to both ends of the coil. A superconducting magnet with terminals installed. 2. REBa consisting of RE (one kind of rare earth element including Y or a combination thereof), Ba and Cu oxides.
RE in ₂ Cu ₃ O _7-x oxide superconducting magnet
₂ The central portion of a single crystal bulk body having a structure in which BaCuO ₅ is finely dispersed is opened, and a slit process is performed so as to form a solenoid coil having a closed circuit in a part thereof, A superconducting magnet, wherein current introducing terminals are installed at both ends of the coil.