CN-122025338-A - Superconductor with twisting structure

Abstract

A superconductor (10, 30) has a lay configuration and is adapted to form a winding in a superconducting coil. The superconductor (10, 30) includes at least one superconductor wire. The superconductor also includes at least one elongate electrically insulating element (18, 37). The elongate electrically insulating element(s) (18, 37) are twisted together with or around the superconductor wire(s) so as to form a separation distance from adjacent superconductor wires in adjacent windings. The elongate electrically insulating element(s) (18, 37) and the superconductor wire(s) may be twisted in the same twisting operation.

Inventors

• C. Durst
• J. Mestadah

Assignees

• 贝卡尔特公司

Dates

Publication Date

20260512

Application Date

20190708

Priority Date

20180719

Claims (10)

1. 1. A superconductor having a twisted structure and adapted to form a winding in a superconducting coil, The superconductor comprises at least one superconductor wire, The superconductor also includes at least one elongate electrically insulating element, It is characterized in that the method comprises the steps of, The at least one elongate electrically insulating element is twisted together with or around the at least one superconductor wire so as to form a separation distance from adjacent superconductor wires in adjacent windings.
2. 2. The superconductor according to claim 1, Wherein the superconductor has only one superconductor filament.
3. 3. The superconductor according to any of the preceding claims, The superconductor is a superconductor cable and comprises at least two superconductor filaments twisted with each other and with the at least one elongated electrically insulating element.
4. 4. The superconductor according to claim 3, Wherein the at least two superconductor filaments are twisted to each other with a first twisting step, Wherein the at least one elongated electrically insulating element has a second twist step, The first twisting step length is equal to the second twisting step length.
5. 5. The superconductor according to any of the preceding claims, Wherein the at least one elongated electrically insulating element is made of a polymer or glass.
6. 6. The superconductor according to any of the preceding claims, Wherein the separation distance is in the range from 30 μm to 300 μm.
7. 7. The superconductor according to any of the preceding claims, The superconductor also includes thermally and electrically conductive materials.
8. 8. The superconductor according to claim 7, Wherein the superconductor has a core + n + m structure, N and m are integers and are used to determine the total number, The core is formed from the thermally and electrically conductive material or from superconductor filaments, N superconductor filaments are twisted around the core, M elongate electrically insulating elements are twisted around the core with the n superconductor filaments.
9. 9. The superconductor according to claim 8, Wherein n is equal to m, Wherein n and m are greater than 3, And wherein each elongated electrically insulating element faces two superconductor filaments.
10. 10. The superconductor according to any of the preceding claims, Wherein the superconductor wire includes MgB 2 as a superconducting material.

Description

Superconductor with twisting structure The present application is a divisional application of application number 201980047857.X, entitled "superconductor with twist structure". Technical Field The present invention relates to a superconductor and a method of manufacturing a superconductor. Background Superconductors have zero resistance at very low temperatures. In some applications, such as in a magnetic resonance imaging device or scanner (MRI), superconductors are wound in various windings to form coils. These coils are impregnated with resin. The various windings need to be physically isolated and electrically and thermally isolated from each other. Physical isolation is required to allow resin impregnation. It is desirable to electrically isolate adjacent windings to avoid shorting. A certain but not too high degree of thermal insulation between adjacent windings is required, as thermal disturbances have to propagate relatively fast within the winding package, thereby becoming detectable. Furthermore, the insulating material and the resin must have dielectric strength as high as possible. In the prior art, different techniques may be used for such insulation. One prior art technique is to use an insulating varnish that surrounds the superconductor. Another technique is to use a fabric, woven fabric or knit fabric with polymer or glass fibers, which is wrapped around the superconductor. All prior art suffers from the fact that applying insulating material around the superconductor is very cumbersome and time consuming. Disclosure of Invention The main object of the present invention is to alleviate the drawbacks of the prior art. It is a particular object of the invention to provide insulation on superconductors in a simple manner. It is a further object of the invention to apply insulation to superconductors in accordance with other manufacturing steps. In contrast to batch processes, the term "consistent" herein refers to a continuous process. According to a first aspect of the present invention there is provided a superconductor having a twisted structure and adapted to form a winding in a superconducting coil. The superconductor includes at least one superconductor filament. The superconductor also includes at least one elongate electrically insulating element. The elongate electrically insulating element is twisted together with or around the superconductor filaments so as to form a separation distance from adjacent superconductor filaments in adjacent windings. The twisting operation is such that one or more elongate insulating elements are wound or twisted together with or around one or more superconductor filaments without the elongate insulating elements crossing each other. The elongated insulating elements may overlap each other or may have windings that overlap each other. Such twisting operations may be performed in concert with other upstream or downstream manufacturing steps. The superconductor filaments may have a circular or rounded square or rectangular shaped cross section. The elongated insulating element may have a cross section that is circular, or square, or rectangular, or any other suitable shape that enables twisting. The superconductor filaments may be multifilament filaments or monofilament filaments. Multifilament filaments physically form a filament in which the superconducting filaments are embedded in a non-superconducting matrix, such as MgB 2 filaments with or without a diffusion barrier and embedded in a copper matrix. In a preferred embodiment of the invention, the superconductor is a superconductor cable having two or more superconductor filaments twisted with each other. One or more elongated electrically insulating elements are twisted together with or around the superconductor filaments. The twisted superconductor filaments are particularly advantageous in the case of sintering operations after twisting. Two or more metal tubes with powder (Mg, B and/or MgB 2) twist with each other without difficulty because of the brittle continuous material that has not yet formed MgB 2. The heat treatment is applied only after twisting to produce brittle ceramic MgB 2. This is especially the case with the in situ route of MgB 2. Since MgB 2 is a brittle material, it may be more difficult to reverse the order of these steps (i.e., first sinter and then twist the superconductor). For ease of understanding, the in situ route starts with the addition of unreacted powders Mg and B and possibly one or more dopants. A heat treatment such as sintering is required to obtain MgB 2. In contrast, the ex situ approach has employed MgB 2 powder as a starting material along with some dopants, but still requires a heat treatment such as sintering to bind the MgB 2 particles. Two or more superconductor filaments are twisted at a first twist step or twist pitch or lay length. Thus, it should be understood that the terms lay step size, lay pitch and lay length are synonymous. The elongated electr