December 10, 2024
Coating the interior of superconducting radiofrequency (SRF) cavities with a Nb3Sn film can drastically enhance the efficiency and performance of particle accelerator infrastructure. However, imperfections in the deposited Nb3Sn coating, especially near the surface, limit its implementation as a next-generation SRF material.
A study by the Sibener group, in collaboration with Cornell University and Brigham Young University, brought together researchers from condensed matter physics, surface chemistry, and accelerator physics to explore how imperfections, specifically areas with too much or too little tin, form during the coating process and how they can affect SRF performance. Using both experiments and computer simulations, the team studied how tiny defects on the nanoscale, like tin-rich islands or periodic corrugations in tin-deficient areas, can cause issues during operation by creating points where magnetic vortices form and degrade the cavity's performance.
The findings show that just knowing the amount of tin in a surface is not enough to predict how well Nb3Sn will work in an SRF cavity. The shape and size of surface defects also play a critical role. By combining theoretical predictions with experimental observations, this collaborative work provides a model for predicting how to improve the quality of Nb3Sn films, helping to develop better materials for next-generation particle accelerators.
This work was supported by funding from the NSF Science and Technology Center anchored at Cornell.
Reference:
S. A. Willson, A. V. Harbick, L. Shpani, V. Do, H. Lew-Kiedrowska, M. U. Liepe, M. K. Transtrum, and S. J. Sibener, “Impact of submicron Nb3Sn stoichiometric surface defects on high-field superconducting radiofrequency cavity performance,” Phys. Rev. Res., vol. 6, no. 4, p. 043133, Nov. 2024, doi: 10.1103/PhysRevResearch.6.043133.
Adapted from a story published by the Center for Bright Beams, a National Science Foundation Science & Technology Center.