University of Twente Student Theses
Normal zone propagation in a YBCO superconductor at 4.2 K. and above
Hesselink, A.R. (2015) Normal zone propagation in a YBCO superconductor at 4.2 K. and above.
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Abstract: | The normal zone propagation velocity and minimum quench energy of a 2-mm wide YBCO superconductin 'coated conductor' tape are investigated at temperatures between 4.2 and 29 K, at three different magnetic field strengths and at varying operating currents. Confirming earlier observations on a wider tape at higher temperatures and in contrast to the simplest and most widely used theoretical model, it was found that the normal zone propagation velocity predominately depends on the current and hardly so on temperature or magnetic field. In agreement with theoretical predictions, the minimum quench energy was found to depend on both temperature and current, while the collected data do not allow to make a reliable conclusion about its magnetic field dependence. A more sophisticated analytical and a numerical model confirm the temperature independence of the normal zone propagation velocity for temperatures below 25 K. Comparison between the absolute value of the normal zone propagation velocity show a quantitative difference of 50% between the 2-mm and 4-mm wide sample. Although several likely causes were investigated, this difference remains as yet unexplained. |
Item Type: | Essay (Master) |
Faculty: | TNW: Science and Technology |
Subject: | 33 physics |
Programme: | Applied Physics MSc (60436) |
Link to this item: | https://purl.utwente.nl/essays/67101 |
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