| Title |
Understanding the Field Dependence of the Surface Resistance in Nitrogen-Doped Cavities |
| Authors |
- P.N. Koufalis, D. Gonnella, M. Liepe, J.T. Maniscalco, I. Packtor
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
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| Abstract |
An important limiting factor in the performance of superconducting radio frequency (SRF) cavities in medium and high field gradients is the intrinsic quality factor and, thus, the surface resistance of the cavity. The exact dependence of the surface resistance on the magnitude of the RF field is not well understood. We present an analysis of experimental data of LT1-3 and LT1-4, 1.3 GHz single-cell nitrogen-doped cavities prepared and tested at Cornell. Most interestingly, the cavities display anti-Q slopes in the medium-field region (i.e. Rs decreases with increasing accelerating field). We extract the temperature dependent surface resistances of the cavities, analyze field dependencies, and compare with theoretical predictions. These comparisons and analyses provide new insights into the field dependence of the surface resistance and improve our understanding of the mechanisms behind the effect.
|
| Funding |
NSF Grant PHYS-1416318 |
| Paper |
download MOPB004.PDF [2.165 MB / 3 pages] |
| Conference |
SRF2015, Whistler, BC, Canada |
| Series |
International Conference on RF Superconductivity (17th) |
| Proceedings |
Link to full SRF2015 Proccedings |
| Session |
Poster Session |
| Date |
14-Sep-15 14:20–17:30 |
| Main Classification |
Fundamental SRF R&D - Bulk Nb |
| Keywords |
simulation, radio-frequency, cavity, vacuum, impedance |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Robert E. Laxdal (TRIUMF, Vancouver, BC, Canada); Jana Thomson (TRIUMF, Vancouver, BC, Canada); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-178-6 |
| Published |
December 2015 |
| Copyright |
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