The School of Mechanical and Materials Engineering Seminar Series, “Understanding physical metallurgy of high-purity Niobium to high-quality factor superconducting radio frequency resonators” Presented by Dr. Shreyas Balachandran
About the event
Understanding physical metallurgy of high-purity Niobium to high-quality factor superconducting radio frequency resonators.
Presented by Dr. Shreyas Balachandran, Associate Professor, Department of Mechanical Engineering and Department of Materials Science and Engineering, College of Engineering, FAMU-FSU
Abstract: High purity Niobium (Nb), also known as RRR Nb is technologically important for superconducting radio frequency (SRF) structures due to its high critical temperature (Tc ~9K) for a pure metal, as well as a high critical superheating field (Hsh ~ 200 mT). The high formability of Nb into various shapes, combined with well-developed processing methods, enables the achievement of very high purities with low interstitial (C, H, O, N) content, making it an essential component of current linear accelerators for high-energy and nuclear physics experiments. In this talk, I will provide a brief introduction and background of SRF, three-dimensional Nb resonators, and their performance metrics. Next, the primary focus of the talk will be on the work relating to the performance metric improvements in high-quality factors (Q0) that have been made possible by understanding Nb microstructure, defects, and surface microchemistry. Finally, I will highlight the need for the development of surface and subsurface material science required for emerging low-temperature resonator applications.
Acknowledgements: This work is supported through the US, Department of Energy- Office of Science, accelerator stewardship program grants (DE-SC0009960). Portions of this work are performed at: 1) National High Magnetic Field Laboratory, which is supported by the National Science Foundation NSF-DMR-2128556 and the State of Florida, and 2) Thomas Jefferson National Accelerator Facility (TJNAF), U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Biography:
Dr. Shreyas Balachandran is an Associate Professor at the FAMU- FSU, College of Engineering, with joint appointments in the Department of Mechanical and Aerospace Engineering and the new Department of Materials Science and Engineering. He obtained his Ph.D in Mechanical Engineering from Texas A&M University, College Station, TX, and then a post-doc at the National High Magnetic Field Laboratory, Tallahassee, FL. Before joining the faculty at the Joint College of Engineering, he was a staff scientist at Jefferson Lab.
His current research focuses on superconducting systems and the development of cryogenic materials and systems for energy and accelerator applications.
His contributions to the field have been recognized, including the Jan Evetts SUST Award (2019) for excellence in superconductivity research and the ICMC Cryogenic Materials Award for Excellence (2023), awarded for advancing the understanding of cryogenic materials