Radiofrequency Superconductivity for Particle Accelerators

Did you know that MRI machines in hospitals work without a continuous power source, as the current in the magnet flows without any resistance – or that superconductors enable magnetic levitation trains to reach speeds of up to 600 km/h? These are just two examples of the applications of superconductivity, a phenomenon discovered over 100 years ago through pure scientific curiosity. In this colloquium, I will begin with a basic introduction to the principles of superconductivity and then explore how this phenomenon is harnessed in particle accelerators, particularly in the design and operation of radiofrequency (RF) cavities at TRIUMF and other facilities worldwide. Superconductors behave quite differently under radiofrequency conditions compared to direct current (DC) used in magnets, necessitating specialized research in material science. Moreover, the exceptionally low energy dissipation of SRF technology has promising implications for future advancements in quantum technology.

Tobias Junginger is a faculty accelerator physicist at the University of Victoria, holding a joint appointment with TRIUMF, Canada's national particle accelerator centre. He is the only professor in Canada working in a research field in Heavy Ion Accelerator Physics and is organizing a significant education program in Accelerator Science. His primary research focuses on advancing the performance of superconducting radiofrequency (SRF) cavities, particularly addressing fundamental challenges to push beyond the current state of the art. To pursue this work, he utilizes a variety of material science techniques, including accelerator-based radioactive probes such as beta-detected nuclear magnetic resonance and muon spin rotation and relaxation. Before joining UVic, Tobias worked at several renowned accelerator facilities, including the Cockcroft Institute, Helmholtz-Zentrum Berlin, TRIUMF, and CERN. Junginger held a lecturer position at Lancaster University in the UK prior to his move to UVic.