Indirect measurement of current distributions in Bi-2223/Ag tapes by pickup coil method
Indirect measurement of current distributions in Bi-2223/Ag tapes by pickup coil method
复制标题
采用拾波线圈法间接测量 Bi-2223/Ag 胶带中的电流分布
DOI：
10.1109/77.919717
复制
发表时间：
2001
影响因子：
1.8
通讯作者：
K. Arakawa
中科院分区：
文献类型：
--
作者：
S. Kawabata;K. Miyata;K. Arakawa
我们开发了一种定量测量方法来评估高T/sub /超导带中的电流分布。在我们的测量中，电流分布是间接地从一组线圈测量的自场分布的结果中得到的，该组线圈由九个小拾取线圈组成，位于胶带周围。采用一组拾取线圈对绝缘铜线组成的假导体进行测量，结果表明，该测量方法的精度和灵敏度足以测量高T/sub /超导带的电流分布。利用这种方法，我们测量了77 K时多丝银包Bi-2223带中的电流分布。对实测和数值自场分布进行了比较。实验结果与数值结果的比较表明，电流在带内的分布是不均匀的，并且随着输运电流幅值的增大而变化。此外，没有观察到电流分布的频率依赖性。进一步研究了外加磁场对电流分布的影响。在此基础上，讨论了高T/sub /超导带中电流分布的特点。
We develop a quantitative measurement method to evaluate current distributions in high T/sub c/ superconducting tapes. In our measurement the current distributions are indirectly found from the results of the self-field distributions measured by a group of coils, which is composed of nine small pickup coils, located around the tape. It is confirmed that the accuracy and the sensitivity of this measurement method, using a group of pickup coils, are good enough to measure the current distributions for the high T/sub c/ superconducting tapes by adopting it to a dummy conductor composed of insulated copper wires. Using this method, we have measured the current distributions in multifilamentary Ag-sheathed Bi-2223 tape at 77 K. Measured and numerical self-field distributions are compared. The comparison between the experimental and numerical results shows that the current distribution in the tape is not uniform and that distribution changes as the amplitude of the transport current increases. In addition, no frequency dependence of the current distributions is observed. Further, we investigate the influence of the external magnetic field on the current distributions. On the basis of the obtained results the characteristics of the current distributions in the high T/sub c/ superconducting tape are discussed.