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TY - UNPB AU - Gonnella, D. ED - Schaa, Volker RW ED - He, Yuan ED - Li, Lu ED - Zhao, Ning TI - Results and New Insights from Vertical Testing of LCLS-II Production Cavities J2 - Proc. of SRF2017, Lanzhou, China, July 17-21, 2017 C1 - Lanzhou, China T2 - International Conference on RF Superconductivity T3 - 18 LA - english AB - Production of 9-cell cavities for LCLS-II is now well underway. 280 cavities will be produced by the conclusion of the project and will be tested by Fermilab and Jefferson Lab prior to cryomodule string assembly. The cavities have been manufactured by Research Instruments GmbH and Ettore Zanon S.p.a. and represent the first industrially produced nitrogen-doped cavities. Here the results from the vertical tests of the cavities received so far are presented. First results show that nitrogen-doping leads to the highest Q0 values achieved in SRF cavities produced for a large-scale project. This has been not without challenges however, and we discuss new findings with regards to flux expulsion, intrinsic residual resistance, and cavity preparation techniques that limited cavity performance in the beginning of production. These new findings and material studies are important for future accelerators so that high Q0 performance can be reliably achieved for large projects. PB - JACoW CP - Geneva, Switzerland ER -