JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Gregory, R.R. AU - Junginger, T. AU - Kolb, P. AU - Laxdal, R.E. AU - McMullin, M.W. AU - Yao, Z.Y. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Magnetic Flux Expulsion in TRIUMF’s Multi-Mode Coaxial Cavities J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - The external magnetic flux sensitivity of SRF cavities is an important characteristic of SRF accelerator design. Previous studies have shown that n-doped elliptical cavities are very sensitive to external fields, resulting in stringent requirements for residual field and cavity cool-down speed. Few such studies have been done on HWRs and QWRs. The impact of applied field direction and cool-down speed of flux expulsion for these cavities is poorly understood. This study explores the effect of these cool-down characteristics on TRIUMF¿s QWR using COMSOL ® simulations and experimental results. This study seeks to maximize the flux expulsion that occurs when a cavity is cooled down through its superconducting temperature. Flux expulsion is affected by the cool-down speed, temperature gradient, and orientation of the cavity relative to an applied magnetic field. It was found that for a vertically applied magnetic field the cool-down speed and temperature gradient did not have a significant effect on flux expulsion. Contrarily, a horizontal magnetic field can be nearly completely expelled by a fast, high temperature gradient cool-down. PB - JACoW Publishing CP - Geneva, Switzerland SP - 135 EP - 140 KW - cavity KW - simulation KW - SRF KW - experiment KW - controls DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB023 UR - https://jacow.org/srf2023/papers/mopmb023.pdf ER -