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TY - CONF AU - Hall, D.L. AU - Liarte, D. AU - Liepe, M. AU - Sethna, J.P. ED - Schaa, Volker RW ED - Arduini, Gianluigi ED - Pranke, Juliana ED - Seidel, Mike ED - Lindroos, Mats TI - Impact of Trapped Magnetic Flux and Thermal Gradients on the Performance of Nb3Sn Cavities J2 - Proc. of IPAC2017, Copenhagen, Denmark, 14â19 May, 2017 C1 - Copenhagen, Denmark T2 - International Particle Accelerator Conference T3 - 8 LA - english AB - Trapped magnetic flux is known to degrade the quality factor of superconducting cavities by increasing the surface losses ascribed to the residual resistance. In Nb3Sn cavities, which consist of a thin layer of Nb3Sn coated on a bulk niobium substrate, the bimetallic interface results in a thermal current being generated in the presence of a thermal gradient, which will in turn generate flux that can be trapped. In this paper we quantify the impact of trapped flux, from either ambient fields or thermal gradients, on the performance of the cavity. We discover that the sensitivity to trapped flux, a measure of the increase in residual resistance as a function of the amount of flux trapped, is a function of the accelerating gradient. A theoretical framework to explain this phenomenon is proposed, and the impact on the requirements for operating a Nb3Sn cavity in a cryomodule are considered. PB - JACoW CP - Geneva, Switzerland SP - 1127 EP - 1129 DA - 2017/05 PY - 2017 SN - 978-3-95450-182-3 DO - 10.18429/JACoW-IPAC2017-MOPVA118 UR - http://jacow.org/ipac2017/papers/mopva118.pdf ER -