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TY - CONF AU - Ge, M. AU - Arrieta, V.M. AU - Gruber, T. AU - Kaufman, J.J. AU - Liepe, M. AU - Maniscalco, J.T. AU - McNeal, S.R. AU - Oseroff, T.E. AU - Porter, R.D. AU - Sun, Z. ED - Michel, Peter ED - Arnold, André ED - Schaa, Volker RW TI - CVD Coated Copper Substrate SRF Cavity Research at Cornell University J2 - Proc. of SRF2019, Dresden, Germany, 30 June-05 July 2019 CY - Dresden, Germany T2 - International Conference on RF Superconductivity T3 - 19 LA - english AB - Chemical vapor deposition (CVD) is a promising alternative to conventional sputter techniques for coating copper substrate cavities with high-quality superconducting films. Through multiple SRF-related DOE SBIR projects, Ultramet has developed CVD processes and CVD reactor designs for SRF cavities, and Cornell University has conducted extensive RF testing of CVD coated surfaces. Here we report results from thin-film CVD Nb₃Sn coated copper test plates, and for thick-film CVD niobium on copper including full-scale single cell 1.3 GHz copper substrate cavities. Detailed optical inspection and surface characterization show high-quality and well-adhered coatings. No copper contamination is found. The Nb₃Sn coated plates have a uniform Nb₃Sn coating with a slightly low tin concentration (19 -22%), but a BCS resistance well in agreement with predictions. The CVD Nb coatings on copper plates demonstrate excellent adhesion characteristics and exceeded surface fields of 50 mT without showing signs of a strong Q-slope that is frequently observed in sputtered Nb cavities. Multiple single-cell 1.3 GHz copper cavities have been coated to date at Ultramet, and results from RF testing of these are presented and discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 381 EP - 386 KW - cavity KW - SRF KW - niobium KW - interface KW - target DA - 2019/08 PY - 2019 SN - "" SN - 978-3-95450-211-0 DO - doi:10.18429/JACoW-SRF2019-TUFUB8 UR - http://jacow.org/srf2019/papers/tufub8.pdf ER -