高温超导带材多场特性测试系统研制进展(Ⅱ)

Development Process of Multi-Field Characteristics Measurement System for High Temperature Superconducting Tapes(Ⅱ)

考虑到第一代高温超导带材多场特性测试系统采用液氮浸泡的方式进行材料冷却,这极大地限制了其应用范围。另外,封闭的杜瓦结构对于超导材料在变形过程中的电磁特征难以实现有效观测,这成为弄清超导材料变形导致其载流能力下降物理机制的主要瓶颈。为此,我们采用制冷机直接冷却方式,获得了最低6.59K的样品温度。采用PID温度控制,实现了从6.59K至300K样品温度的精确控制,控温精度为0.1K。采用外置式的加载装置,通过机械传动实现对试样的准静态拉伸,其最大拉伸应变可达20%。自行设计了一种高温超导导线,采用制冷机一级冷头直接冷却,实现了密闭杜瓦容器中最大可达600A的电流输入。最后,在杜瓦瓶设置直径50mm的光学观察窗,采用磁光镜像的方法实现了超导材料电磁特性的原位观测。

Application range of the first generation multi-field measurement system for high temperature superconducting tapes characteristics is greatly limited due to using liquid nitrogen immersion method to cool material. In addition, the electromagnetic characteristics of superconducting material in deformation process are difficult to achieve effective observation due to closed Dewar structure, which becomes the main bottleneck to understand the physical mechanism of current carrying capacity decline for superconducting material due to its deformation. To this end, direct cooling method was adopted by using commercial GM refrigerator, and the lowest 6. 59K sample temperature was obtained. PID temperature control was used to realize sample temperature precise control from 6.59K to 300K, with 0.1K temperature control precision. External loading device was adopted to realize quasi-static tension of specimen by mechanical transmission, and the maximum tensile strain can reach 20%. A high temperature superconducting wire was designed, by using refrigerator cold head, direct cooling was realized, based on which, the maximum input current is reached up to 600A in closed Dewar container. Finally, an optical observation window with 50mm diameter is set on Dewar flask. By using magneto optical method, in situ observation of electromagnetic properties of superconducting material is realized.