A Numerical and Experimental Analysis of the Temperature Dependence of the n-Index for 2G HTS Tape Surrounding the 77 K Temperature Range

Woo Seung Lee, Seokho Nam, Jinsub Kim, Jeyull Lee, Tae Kuk Ko

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Most superconducting devices are designed for a fixed operating temperature range, however, temperature varia- tions are inevitable in some situations. For example, the temperature of a resistive-type superconducting fault current limiter becomes higher during fault cycle operation. Therefore, knowledge of the temperature dependence of the current-to-voltage characteristic is necessary for accurate simulation or design processes. This paper explores the temperature dependence of the n-index, which describes sharpness of superconductivity to normal transition, using a second-generation high-temperature superconducting tape sample under a liquid nitrogen surrounded environment. The voltage across the sample according to given current and temperature is measured by establishing a measurement system with a protection system. The average of the data from multiple measurements is calculated and compared with three different n-index models. Constant, inversely proportional, and modified inversely proportional models are analyzed. The modified inversely proportional model showed the least error when compared to the measurement data.

Original languageEnglish
Article number7015572
JournalIEEE Transactions on Applied Superconductivity
Issue number3
Publication statusPublished - 2015 Jun 1


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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