Abstract
High temperature superconducting tapes with big n values are preferred in high temperature superconducting apparatuses to secure a speeded superconducting-normal transition, a shorten quench detection and protection response time because small n values are associated with unstable resistive behaviors. This paper reports our measurement results of n values distributions along long Bi2223/Ag tapes at 77 K. The results show that the variation of n values is more distinct than that of critical currents along a long Bi2223/Ag tape. And the variation of local n values has more effect on the overall n value and the overall critical current of a long Bi2223/Ag tape than that of local critical currents. As a result, the overall n value is an easy-to-get and reliable parameter to evaluate the critical current homogeneity along a long Bi2223/Ag tape.