Title |
Cavity Quench Studies in Nb3Sn Using Temperature Mapping and Surface Analysis of Cavity Cut-outs |
Authors |
- D.L. Hall, M. Liepe, R.D. Porter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
- P. Cueva, D. Liarte, D.A. Muller, J.P. Sethna
Cornell University, Ithaca, New York, USA
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Abstract |
Previous experimental studies on single-cell Nb3Sn cavities have shown that the cause of quench is isolated to a localised defect on the cavity surface. Here, cavity temperature mapping has been used to investigate cavity quench behaviour in an Nb3Sn cavity by measuring the temperature at the quench location as the RF field approaches the quench field. The heating profile observed at the quench location prior to quench appears to suggest quantised vortex entry at a defect. To investigate further, the quench region has been removed from the cavity and analysed using SEM methods. These results are compared to theoretical models describing two vortex entry defect candidates: regions of thin-layer tin-depleted Nb3Sn on the cavity surface that lower the flux entry field, and grain boundaries acting as Josephson junctions with a lower critical current than the surrounding material. A theoretical model of layer growth developed using density functional theory is used to discuss alterations to the coating process that could mitigate the formation of such defects.
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Paper |
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Conference |
SRF2017, Lanzhou, China |
Series |
International Conference on RF Superconductivity (18th) |
Proceedings |
Link to full SRF2017 Proccedings |
Session |
Poster Session |
Date |
20-Jul-17 14:00–17:00 |
Main Classification |
Fundamental SRF R&D |
Sub Classification |
Other than bulk Nb |
Keywords |
ion, cavity, detector, niobium, electron |
Publisher |
JACoW, Geneva, Switzerland |
Editors |
Volker RW Schaa (GSI, Darmstadt, Germany); Yuan He (IMP, Lanzhou, China); Lu Li (IMP, Lanzhou, China); Ning Zhao (IHEP, Beijing, China) |
ISBN |
978-3-95450-191-5 |
Published |
January 2018 |
Copyright |
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