Accepted author manuscript, 414 KB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Article number | 8012531 |
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<mark>Journal publication date</mark> | 1/10/2017 |
<mark>Journal</mark> | IEEE Transactions on Applied Superconductivity |
Issue number | 7 |
Volume | 27 |
Number of pages | 7 |
Publication Status | Published |
Early online date | 17/08/17 |
<mark>Original language</mark> | English |
Identifying the loss mechanisms of niobium cavities enables an accurate determination of applications for future accelerator projects and points to research topics required to mitigate current limitations. For several cavities an increasing surface resistance above a threshold field, saturating at higher field has been observed. Measurements on samples give evidence that this effect is caused by the surface electric field. The measured temperature and frequency dependence is consistent with a model that accounts for these losses by interface tunnel exchange between localized states in dielectric oxides and the adjacent superconductor.