超导复合线接头质量的低温实验性评价

EXPERIMENTAL EVALUATION ON THE JOINT BETWEEN SUPERCONDUCTING MULTIFILAMENTARY WIRES

本文介绍了一种采用电流衰减法测定超导接头样品电阻的实验系统。该实验系统由一个可闭环运行的５Ｔ背场超导磁体和可更换样品的超导变压器组成。超导接头样品为一单匝环，构成变压器的次级绕组。通过对原边绕组充放电的控制，可在超导样品环内感应出持续流动的衰减电流。由低温霍耳传感器检测出的电流波形信号，可对样品中的超导接头电阻进行定性和定量评价。本文最后给出了利用该系统对几种ＮｂＴｉ复合超导线接头类型的实验测量结果。

An experimental system based on the transformer induction method is established for the evaluation of superconducting joint between multifilamentary NbTi wires.It consists of a 5T split magnet operating in the PCS mode and a removable superconducting transformer device which facilitates the replacement of joint specimens. A single turn superconducting specimen in which the joint is formed between the two ends of a short wire acts as the secondary of the transformer.In the experiment,three specimens are prepared for determining their joint resistance.The results are compared and analyzed based on the flux creep model and LR circuit. The fast decay of initial induced current is confirmed and explained qualitatively for a superconducting joint specimen.