The effect of longitudinal compressive strain on critical current in HTS tapes

Analysis and testing were performed to study the effect of longitudinal compressive strains an the critical current of BSCCO-2223 high-temperature superconducting (HTS) tapes. These strains result from two main factors: (1) lamination interactions within the HTS tape and (2) differential thermal contraction between the HTS wire and surrounding materials. Analytical models were developed to predict the amount of compressive strain developed in various configurations. Two different tests were performed to study this effect: (1) coupon tests-small samples of wires bonded to various materials and (2) I/sub c/ vs. compression test-wire potted into support and compressively loaded. The results provide guidance in the proper design of HTS coils.