JPH0677044A - High-temperature superconducting magnet - Google Patents

Abstract

PURPOSE:To increase a current density in a coil on the section of a magnet to obtain the small-sized and high-magnetic field magnet by a method wherein an oxide high-temperature superconducting electrical wire is wound on a bobbin without having an insulating film. CONSTITUTION:An oxide high-temperature superconducting electrical wire 5 having an insulating coating is densely wound on a bobbin 1. In this case, even if a current flows through a normally conductive part, a quenching does not spread to a coil and even if the coil is quenched, the generation voltage, that is, the generation heat, is little and the quenching does never spread to a quenching of the whole coil. Moreover, as an insulating film does not exist, the space factor of a conductor on the section of a magnet is significantly increased. Thereby, a current density in the coil on the section of the magnet can be increased and the small-sized and high-magnetic field magnet cart be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet formed using a superconducting wire, and more particularly to a magnet using an oxide-based high temperature superconducting wire.

[0002]

2. Description of the Related Art As shown in FIG. 1, when a conventional metal-based superconducting wire 2 is wound around a bobbin 1 to form a magnet 3, as shown in FIG. To be covered. The reason is that when the coil is excited by the superconducting wire 2, a voltage is generated between the turns due to the inductance L of the coil. If this current is not present, the current flows to the normal conducting portion between the coil wires and heats that portion. This makes it impossible to maintain the superconducting state.

Therefore, for example, Japanese Unexamined Patent Publication (Kokai) No. 3-44909 discloses a method for manufacturing a superconducting coil, which discloses that a conductor is covered with an insulating material such as glass yarn and then formed into a coil. .

[0004]

However, when the electric wire is covered with an insulating material, a conductor portion and an insulating portion are present in the coil cross section, and when the current density of the conductor is constant, the coil is The overall current density will be low. This coating has conventionally been used to insulate the coil even when an oxide high-temperature superconducting wire is used, but such an insulator has excellent heat resistance because it needs to be heat-treated at a high temperature. It was necessary, and therefore the insulation became thicker, further reducing the current density throughout the coil. The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a compact and high magnetic field magnet by increasing the coil current density in the magnet cross section by omitting the insulating coating. .

[0005]

The present invention is characterized in that, in a magnet formed by winding a superconducting wire, an oxide type high temperature superconducting wire is wound without an insulating coating.

[0006]

As described above, when forming a coil with a superconducting wire, if insulation is not provided for each turn, the voltage generated by the inductance will flow to the normal conducting section, which will cause heat to quench the magnet. However, when a high-temperature superconducting wire is used for the coil, the quench does not spread even when current flows in the normal conducting part, and even if it is quenched, the generated voltage, that is, the generated heat is small, and it develops to quench the entire coil There is nothing to do. Therefore, it is possible to excite the high-temperature superconducting wire without covering it with an insulator. In that case, at the time of excitation, excitation is always performed while generating a quench in the part of the magnet.

[0007]

EXAMPLE FIG. 3 is a sectional view showing the structure of a high temperature superconducting magnet according to the present invention, in which a bobbin 1 is densely wound with an oxide high temperature superconducting wire 5 having no insulating coating. With this configuration, the space factor of the conductor in the cross section of the magnet can be significantly increased as compared with the case of FIG. 2 without causing quenching, and a compact and high magnetic field magnet can be obtained.

[0008]

As described above, according to the present invention, the insulating coating can be omitted because the oxide-based high temperature superconducting wire which does not develop into a serious quench even when an electric current flows between the coil wires is formed in the coil. The space factor of the conductor in the cross section of the magnet can be significantly increased as compared with the case where there is a coating, and a compact and high magnetic field magnet can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing the appearance of a magnet

FIG. 2 is a sectional view of a conventional magnet

FIG. 3 is a sectional view of the magnet of the present invention.

[Explanation of symbols]

 1 bobbin 3 magnet 5 oxide high temperature superconducting wire

Claims (1)

[Claims] 1. A high temperature superconducting magnet in which a superconducting wire is wound, and an oxide high temperature superconducting wire is wound without an insulating coating.