| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Refractory Metals 2020
|
| Presentation Title |
Effect of Dislocations and Grain Boundaries on Magnetic Flux Trapping in High-purity Niobium used for Superconducting Radio Frequency Cavities |
| Author(s) |
Mingmin Wang, Shreyas Balachandran, Santosh Chetri, Anatolii Polyanskii, Peter Lee, Thomas Bieler |
| On-Site Speaker (Planned) |
Thomas Bieler |
| Abstract Scope |
High-purity niobium is used for superconducting radio-frequency (SRF) cavities for particle accelerators with potential applications from water treatment to materials science. Trapped magnetic flux due to dislocations and grain boundaries in niobium can degrade the performance of SRF cavities, and hence is a scientific topic of growing interest. However, it is still unclear what defects actually trap magnetic flux, and which processing paths can minimize defects and ensure consistently high cavity performance. To investigate the mechanism of flux trapping by dislocations and grain boundaries, bi-crystal niobium samples with strategically chosen tensile axes were strained to about 5% to introduce dislocations. Electron channeling contrast imaging (ECCI) was used to characterize dislocation structures before and after the deformation, followed by magnetic flux observations at superconducting temperatures using magneto-optical (MO) imaging. The effect of dislocation density on flux trapping and conditions that increase the tendency to trap flux are discussed. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |