JPH0287424A - Complexed superconductive conductor - Google Patents

Abstract

PURPOSE:To reduce the bond loss caused by variation of interlinkage magnetic flux by arranging a high resistance member in an induction current circuit from a superconductive material to a stabilizer housing. CONSTITUTION:A number of superconductive filaments 6 are embedded in Cu matrix 7 to form a superconductive material 4, and around it a high resistance metal sheath 3 made of Cu-Ni alloy, etc., and jointed by solders 2 in a stabilized housing 1 divided in two pieces. This provision of high resistance metal sheath 3 in a current circuit of induction current 5 flowing between the superconductive filaments 6, different from complex superconductive conductor, increase the resistance of the current circuit of induction current to a great extent. This suppresses the induction current 5 on the basis of variation of the magnetic field in interlinkage with the complex superconductive conductor to lead to great reduction of the bond loss.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a composite superconducting body in which a superconducting material is embedded in a stabilizing housing material.

(Prior Art) In general, when the interlinkage magnetic field fluctuates in the four composite superconductors, alternating current loss occurs due to the induced current induced between the superpower filaments and the earthen floor. AC loss due to this mechanism is called coupling loss. Other types of AC loss include pinning loss and eddy current loss, but it is well known that coupling loss becomes predominant among the three types of AC loss when the fluctuation rate of the interlinking magnetic field increases to a certain extent. That's right.

In other words, as shown in Figure 3, the conventional composite superelectric body consists of a superconducting material (0) in which a large number of superconducting filaments (0) and (0) are embedded in a copper matrix (2), and a stabilizing housing material (0) divided into two.
The structure is such that the material is usually copper) and each joint is connected with solder.

Therefore, the resistance of the current path through which zero induced current flows is almost determined only by the resistivity of copper, resulting in a very large coupling loss.

Therefore, a superconducting magnet using such four composite superconducting bodies has the following problems.

For example, in a hybrid magnet that generates a high magnetic field in the center by concentrically arranging a water-cooled magnet on the inside and a superconducting magnet on the outside, if the water-cooled magnet shuts off due to a problem, the problem occurs in the superconducting magnet. There is a great possibility that the superconducting magnet will quench due to coupling loss.

In addition, even when a superconducting magnet is used alone, if the superconducting magnet is accidentally cut off due to some external factor, the evaporation of liquid helium due to the occurrence of coupling loss will be excessive, causing the rupture disc to blow, and the liquid helium will evaporate excessively due to coupling loss. This not only causes a large amount of consumption, but also often causes the entire superconducting magnet system to go down.

(Problems to be Solved by the Invention) In the conventional composite superconductor 4 body, the main reason for the large coupling loss is that the resistance value of the current circuit for the induced current is small. Therefore, composite superconductor 4 with low coupling loss
There is a demand for physical inventions.

An object of the present invention is to provide a composite superconductor 4 body which allows the resistance value of the induced current circuit to be significantly larger than that of the prior art.

[Structure of the invention]

(Means for solving problems) In order to achieve the above object, in the present invention.

A composite superconductor 4 body comprising a superconducting material embedded in a stabilizing housing material, characterized in that a high resistance member is disposed in an induced current circuit from the superconducting material to the stabilizing housing. I will provide a.

(Function) In this way, the high-resistance member suppresses the induced current and significantly reduces the coupling loss.

(Examples) Example 1 A first example of the present invention will be described below with reference to FIG. 1.

Figure 1 shows a cut end surface of a composite superconductor body according to the present invention, in which a large number of superconducting filaments 0 are embedded in a copper matrix 1, forming a superconducting material Ω), and surrounding it a Cu-Ni alloy etc. A high-resistance metal sheath (2) is placed inside the stabilized housing material (ω), which is divided into two parts, and is joined by solder (2). Induced current that causes coupling loss■
is indicated by an arrow.

Next, the operation of this first embodiment will be explained.

With the above configuration, the induced current (■) flowing between the superconducting filaments (■) is within the current circulation.

This is different from the conventional composite superconductor 4 body shown in Figure 3.

Due to the presence of the high-resistance fully bent sheath (2), the resistance of the induced current circuit increases significantly.

For example, as shown in 4.2, the specific resistance of copper at temperature is approximately 1O-8Ω・depending on the magnetic field conditions and hardness condition.
On the other hand, that of Cu-Ni alloy is 104
It is on the order of Ω/mouth. Therefore, a small thickness of Cu −
It can be seen that by employing the Ni alloy sheath as the high resistance metal sheath (2), which is a high resistance member, the above resistance increases significantly.

Therefore, the induced current (2) based on magnetic field fluctuations interlinking with the four composite superconducting bodies is suppressed, which has the effect of significantly reducing coupling loss.

The above conductor structure can be easily realized by placing the superconducting material (3) inside the high-resistance metal sheath (3) and drawing it together.

Note that the solder may be replaced with another brazing material.

Example 2 FIG. 2 shows a second embodiment of the present invention.

A high-resistance metal tape (3a), which is a high-resistance member, is inserted into the joint surfaces of the lower stabilizing housing materials (1), and each is joined with solder (2). In this case as well, unlike the conventional composite superconductor 4 shown in Figure 3, the current circuit for the induced current ■ has a large resistance layer, which suppresses the induced current ■ and has the effect of significantly reducing coupling loss. .

Here, the above-described conductor structure can be easily realized by joining the high-resistance metal tape (3a) together when the two halves of the stabilizing housing material ω are joined together with solder (2).

〔Effect of the invention〕

As explained above, according to the present invention, with a simple configuration,
It is possible to provide four composite superconducting bodies that can significantly reduce coupling loss due to flux linkage fluctuations.

[Brief explanation of drawings]

FIG. 1 is a cut end view showing a first embodiment of the four composite superconducting bodies of the present invention, FIG. 2 is a cut end view showing the second embodiment, and FIG. 3 is a cut end view showing a conventional example. It is a diagram.

Claims (1)

[Claims] A composite superconductor comprising a superconducting material embedded in a stabilizing housing material, characterized in that a high resistance member is disposed in an induced current circuit from the superconducting material to the stabilizing housing. .