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TY - CPAPER AU - Eremeev, G.V. AU - Kelley, M.J. AU - Pudasaini, U. AU - Reece, C.E. AU - Tuggle, J. TI - Progress With Multi-Cell Nb3Sn Cavity Development Linked With Sample Materials Characterization J2 - Proc. of International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 AB - 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. PB - JACoW CY - Geneva, Switzerland SP - 505 EP - 511 KW - cavity KW - niobium KW - vacuum KW - SRF KW - factory DA - 2015/12 PY - 2015 SN - 978-3-95450-178-6 DO - 10.18429/JACoW-SRF2015-TUBA05 UR - http://srf2015.vrws.de/papers/tuba05.pdf ER -