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TY - CONF AU - Maniscalco, J.T. AU - Arias, T. AU - Ge, M. AU - Koufalis, P.N. AU - Liarte, D. AU - Liepe, M. AU - Sethna, J.P. AU - Sitaraman, N. ED - Michel, Peter ED - Arnold, André ED - Schaa, Volker RW TI - The Field-Dependent Surface Resistance of Doped Niobium: New Experimental and Theoretical Results 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 - We present systematic work investigating how different doping and post-doping treatments affect the BCS surface resistance at 1.3~GHz and higher frequencies. We examine the field-dependent BCS resistance at many temperatures as well as the field-dependent residual resistance and use the results to reveal how impurity species and concentration levels affect the field-dependent RF properties. We further demonstrate the importance of thermal effects and their direct dependence on doping level. We use the tools of Density Functional Theory to work towards an {\em ab initio} model of electron overheating to theoretically confirm the impact of doping, create a full model that includes thermal effects to predict the field dependent resistance, and show that the predictions of the model agree with results from doped and non-doped cavities ({\em e.g.} the strength of the anti-Q-slope and the high-field Q slope). Finally, we use our experimental results to systematically assess and compare theories of the field-dependent BCS resistance, showing that the current theory on smearing of the density of states is incomplete. PB - JACoW Publishing CP - Geneva, Switzerland SP - 340 EP - 346 KW - cavity KW - SRF KW - niobium KW - electron KW - ECR DA - 2019/08 PY - 2019 SN - "" SN - 978-3-95450-211-0 DO - doi:10.18429/JACoW-SRF2019-TUFUA1 UR - http://jacow.org/srf2019/papers/tufua1.pdf ER -