JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@inproceedings{gregory:srf2023-mopmb023, author = {R.R. Gregory and T. Junginger and P. Kolb and R.E. Laxdal and M.W. McMullin and Z.Y. Yao}, title = {{Magnetic Flux Expulsion in TRIUMF’s Multi-Mode Coaxial Cavities}}, % booktitle = {Proc. SRF'23}, booktitle = {Proc. 21th Int. Conf. RF Supercond. (SRF'23)}, pages = {135--140}, eid = {MOPMB023}, language = {english}, keywords = {cavity, simulation, SRF, experiment, controls}, venue = {Grand Rapids, MI, USA}, series = {International Conference on RF Superconductivity}, number = {21}, publisher = {JACoW Publishing, Geneva, Switzerland}, month = {09}, year = {2023}, issn = {2673-5504}, isbn = {978-3-95450-234-9}, doi = {10.18429/JACoW-SRF2023-MOPMB023}, url = {https://jacow.org/srf2023/papers/mopmb023.pdf}, abstract = {{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.}}, }