JPH05175034A - Superconductor magnet - Google Patents

Abstract

PURPOSE:To provide a superconductor magnet by opening the center of a single crystal cylindrical superconductor bulk material in which fine RE2BaCuO5 is dispersed, conducting the cutting to form a coil having a closed circuit to a part thereof and arranging current applying terminals at the upper and lower ends of the coil. CONSTITUTION:A cylindrical bulk superconductor material 1 consisting of a single crystal RE (rare earth element including Y and combination thereof) Ba2Cu3O7-y wherein fine 211 phase is dispered into the 123 phase undergoes opening of hole 3 and the cutting process 2. In this case, three slits are provided with an equal interval and moreover a 4-turn magnet is manufactured in such a manner as forming a circular loop of the current path 4. Next, two current application terminals 4a, 4b are formed after evaporation of silver and are connected with a constant current power supply. Thereby, an oxide superconductor magnet can be manufactured.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is manufactured from a large single crystal bulk material composed of RE (Y-containing rare earth elements and combinations thereof), Ba and Cu oxides obtained by a melting (QMG) method. Regarding 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, the bismuth-based superconductor has an extremely low current density at the 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, which is grown in one direction and has a large size, has excellent superconducting characteristics 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 the magnet by a method that does not go through the wire forming process. 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 provides RE (rare earth elements including Y and combinations thereof), Ba, Cu.
RE ₂ B in superconducting magnets made of oxides of
Single crystal REBa ₂ Cu in which aCuO ₅ is finely dispersed
_A cylindrical superconducting bulk material made of ₃ O _7-y has an opening at its center and is cut so as to form a coil. Current introducing terminals are installed at the upper and lower ends of the coil. A superconducting magnet comprising RE (a rare earth element including Y and a combination thereof), Ba, and Cu oxide, wherein a single crystal in which RE ₂ BaCuO ₅ is finely dispersed is provided. The central portion of the cylindrical superconducting bulk material made of REBa ₂ Cu ₃ O _7-y has a hole, and is cut to form a coil having a closed circuit in part, A gist of the present invention is a superconducting magnet, wherein current introducing terminals are installed at upper and lower ends of the coil.

[0005]

[Operation] To magnetize one single crystal bulk, make a hole in the bulk crystal of the cylindrical superconductor so that the superconducting current flows while drawing the loop, and make a notch to make a solenoid current path. Good. There are roughly two types of superconducting magnets produced in this way 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 marking 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. Figure 1
Is a superconducting magnet having a solenoid-shaped current path 5 in which a slit 2 is formed in a cylindrical bulk body 1 having a hole 3 in the center thereof and two current introducing terminals 4a and 4b are retained. 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 in which the heating element 17 is wound without a solenoid. The portion shown in (a) has a current path similar to that shown 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 made.

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 part, the state is changed to the superconducting state, so that the permanent current can be continuously supplied to the magnet.

[0009]

【Example】

(Example 1) Fine 211 having a diameter of about 2.8 cm and a height of about 4 cm
The single crystal bulk superconducting material in which the phases were dispersed in the 123 phase was perforated and cut as shown in FIG. 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 a constant current power source was connected. After cooling the magnet in liquid nitrogen, a maximum current of 60 A was passed.
By this excitation, a magnetic field of 0.7 Kgauss magnetic flux density could be obtained in the central part.

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 punching and notching as shown in FIG. gave. At this time, the inner diameter is about 1 cm and 3 at 1 cm intervals.
Make a slit with a book 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 a constant current power source was connected. 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 heretofore been impossible, and can be applied as a molded article in various fields, and has an extremely industrial effect. 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.

FIG. 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. In a superconducting magnet made of RE (rare earth elements including Y and combinations thereof), Ba and Cu oxides, RE ₂ BaCuO ₅ is finely dispersed in single crystal form REBa ₂ Cu ₃ O _7-. The central part of the cylindrical superconducting bulk material consisting of _y is opened, and the slitting process is performed so as to form a coil, and the current introduction terminals are installed at the upper and lower ends of the coil. Characteristic superconducting magnet. 2. In a superconducting magnet made of RE (rare earth elements including Y and combinations thereof), Ba and Cu oxides, single crystal REBa ₂ Cu ₃ O _{7- in which} RE ₂ BaCuO ₅ is finely dispersed. _A cylindrical superconducting bulk material consisting of _y has a hole in the center, and a slit is formed so as to form a coil having a closed circuit in part, and the current introducing terminals are provided at the upper and lower ends of the coil. Is a superconducting magnet.