LEAPS-MPS: Ion-beam induced defects to enhance the critical current of high-temperature superconductors

Non-technical Abstract: Copper-oxide-based high-temperature superconductors are important materials for novel technologies. Because they have high superconducting critical temperatures and high critical currents, they have been used to make superconducting electromagnets for various devices including Tokamak nuclear fusion reactors, medical device MRI, and a large hadron collider. To improve the performance of the superconducting magnets, ion-beam irradiations have been used, since ion beam-induced defects can further enhance the critical current. Therefore, the PI plans to conduct a systematic investigation to find an optimal condition for the maximum critical current of various high-temperature superconductors using ion beam irradiations. Large part of the research is performed by undergraduate students at Hope College. Students experience hands-on research skills: operating a local particle accelerator and a 4K-cryostat (cooling device), attending national conferences, and writing peer-reviewed articles. Students are trained in the PI’s research facility to become future STEM professionals. Technical Abstract: Ion-beam-induced defects act as pinning centers that can enhance the critical current by limiting the movement of magnetic vortices. The PI plans to conduct a systematic investigation to find an optimal condition for the maximum critical current of various high-temperature superconductors (YBCO-1237, BSCCO-2212, TBCCO-2212) using ion beam irradiations such as proton (0.6 ∼ 3.4 MeV) and helium (0.6 ∼ 5.1 MeV). Furthermore, the PI also plans to investigate the long-term irradiation damage issue that occurs in compact Tokamak nuclear fusion reactors. Due to the small size and poor plasma confinement of compact nuclear fusion reactors, the high-energy neutrons and secondary particles emitted during the fusion reactions continuously damage nearby superconducting magnets and make their lifespan much shorter than one year. One of the main reasons for this damage is closely related to the high susceptibility of high-temperature superconductors to particle-induced defects due to the anisotropic d-wave pairing symmetry of the order parameter. Therefore, understanding the mechanism of this long-term damage for various high temperature superconductors is a necessary step to minimize the long-term damage issue and to realize the technology of commercial compact nuclear fusion reactors. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.