直流背场下高温超导带材临界电流及n值的分析

Analysis of critical current and n-value of high temperature superconducting tape under DC background magnetic field

本文在77 K温度下,采用四引线法就超导带材,分别在0~100 mT不同的外界磁场强度和0~90°不同的磁场方向下进行测量,分析第二代高温超导带材的临界电流和n值对直流背景磁场的依赖性。结果表明,随着外界磁场强度的增大,超导带材的临界电流逐渐衰减,当磁场由0°平行方向转向90°垂直方向的过程中,临界电流逐渐衰减,且衰减逐渐严重;随着磁场强度的增大,超导带材的n值减小;随着磁场与带材夹角由0°变为90°,超导带材的n值不断减小,但减小的程度逐渐缓慢。

In this paper, the superconducting tapes were measured by four-lead method at 77 K temperature under different external magnetic field intensities(0~100 mT) and different magnetic field directions(0~90 degrees), so as to analyze the dependence of critical current and n value of the second generation high temperature superconducting tapes on DC background magnetic field. The results show that the critical current of superconducting tape decreases gradually with the increase of external magnetic field intensity, and the critical current decreases gradually when the magnetic field changes from parallel direction to vertical direction. With the increase of magnetic field intensity, the n value of superconducting tape decreases. As the angle between magnetic field and tape changes from 0 to 90 degrees, the n value of superconducting tape decreases gradually, but the degree of reduction is gradually slow.