| Title |
Progress With Multi-Cell Nb3Sn Cavity Development Linked With Sample Materials Characterization |
| Authors |
- G.V. Eremeev, M.J. Kelley, C.E. Reece
JLab, Newport News, Virginia, USA
- M.J. Kelley, U. Pudasaini
The College of William and Mary, Williamsburg, Virginia, USA
- J. Tuggle
Virginia Polytechnic Institute and State University, Blacksburg, USA
|
| Abstract |
Exploiting both the new Nb3Sn coating system and the materials characterization tools nearby, we report our progress in low-loss Nb3Sn films development. Nb3Sn films a few micrometers thick were grown on Nb coupons as well as single- and multi-cell cavities by the Sn-diffusion technique. Films structure and composition were investigated on coated samples and cavity cutouts with characterization tools including SEM/EDS/EBSD, AFM, XPS, SIMS towards correlating film growth and RF loss to material properties and deposition parameters. Cavity coating efforts focused on establishing techniques for coating progressively more complicated RF structures, and understanding limiting mechanisms in coated cavities. Nb3Sn coated 1.5 GHz 1-cell and 1.3 GHz 2-cell cavities have shown quality factors of 10¹⁰ at 4.3 K, with several cavities reaching above Eacc = 10 MV/m. The dominant limiting mechanisms were low field quenches and quality factor degradation above 8 MV/m. The surface data indicates a near-stoichiometric Nb3Sn consistent with the transition temperature and gap measurements. The Nb3Sn layer is covered with Nb2O5 and SnO2 native oxides and has little memory of the pre-coating surface.
|
| Funding |
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. |
| Paper |
download TUBA05.PDF [1.558 MB / 7 pages] |
| Slides |
download TUBA05_TALK.PDF [2.423 MB] |
| Conference |
SRF2015, Whistler, BC, Canada |
| Series |
International Conference on RF Superconductivity (17th) |
| Proceedings |
Link to full SRF2015 Proccedings |
| Session |
Fundamentals II - Beyond Nb |
| Date |
15-Sep-15 10:40–13:00 |
| Main Classification |
Fundamentals SRF R&D - Other Materials |
| Keywords |
cavity, niobium, vacuum, SRF, factory |
| 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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