Bending characteristics of a transposed cable (Xcable) with in-plane bending of REBCO tapes

A compact High Temperature Superconducting (HTS) cable, which is achieved by in-plane bending stacked REBCO tapes directly to realize the transposition(X-cable), has been designed and successfully fabricated by the Institute of High Energy Physics, Chinese Academy of Sciences (IHEP, CAS) for the application in high-field accelerator magnets. The high current carrying capacity and low AC loss of the X-cable have been investigated in our previous studies. In this paper, the bendability of the X-cable was studied at 77 K and self-field, especially the minimum bending radius without performance degradation. The critical current (Ic) of each tape contained in the full-scale strand in the cable was powered individually at different bending radii. By analyzing the single tape's Ic as a function of bending radius, the test results demonstrate a good bending performance of the cable. The inter-tape resistance (Rc) is also investigated as a function of bending radius, which becomes more uniform and smaller after bending. Meanwhile, the dome-like shape of Rc explains that the copper film wrapped outside the stack can help share the current to improve the stability of the cable. The cable's parameters, bending performance test, and results analysis are presented in this work.