Measurement apparatus and measurement method for critical current and n value index of high-temperature superconductive tape

Abstract

The invention discloses a measurement apparatus and measurement method for a critical current and an n value index of a high-temperature superconductive tape. The apparatus comprises a liquid nitrogen tank, a heater, a continuous transmission apparatus, a four-lead assembly, a magnetic induction assembly, an external stepping motor, a control device, and a collection device. According to the invention, with the continuous transmission apparatus having a tape rewinding function and a pressing type four-lead method, probes slide to adjust the length of each tape needing measurement and a critical current and an n value index at each segment of length are measured one segment by one segment; and after completion of measurement of the whole tape, tape rewinding is carried out at a constant speed. A current-carrying capability changing curve of the whole tape is obtained by using a magnetic induction method. Results from the two kinds of methods are recorded at one graph; and the detailed information of the critical currents of the tape can be watched visually and accurately from the graph, and whether a bad point exists is discriminated. According to the invention, the structure of the apparatus is reasonable; the usage is convenient; functions are diversified; the measurement is carried out in a mild mode; the result is precise, comprehensive, and visual; the tape can be prevented from being damaged; and the tape after measurement can still be used normally.

Description

technical field [0001] The invention belongs to the field of superconducting engineering, and in particular relates to a measuring device and a measuring method for the critical current and n-value index of a high-temperature superconducting strip. Background technique [0002] Superconducting magnet technology has developed rapidly in recent years. Due to the limitation of the critical magnetic field of superconducting materials, magnets below 20T are generally made of low-temperature superconducting materials, while high-field superconducting magnets above 20T require high-temperature superconducting materials, mainly the first and second generation high-temperature superconducting materials. Guide tape. The first-generation strip has poor elasticity, and large bending should be avoided; the second-generation strip is a coated conductor, and it is easy to delaminate after repeated bending, resulting in an irreversible decline in performance. Both are fragile and require ...

AI Technical Summary

Problems solved by technology

The traditional four-lead measurement method needs to weld the strip to the lead, and the strip at the solder joint cannot be used any more after the test; and the results obtained by only measuring the short sample cannot know the uniformity of the entire strip, whether there is no defect, etc.

The non-contact method is a new type of detection method. The critical current or n-value index can be obtained indirectly through the calculation of the magnetic induction method. This method can understand the uniformity of the strip and detect whether there is a defect in the strip, but the result is not accurate enough. Moreover, only one of the critical current and n-value index of each device can be measured, and the function is single

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