Speaker
Description
Electropolishing (EP) is a critical surface treatment for pushing the performance limits of superconducting radio-frequency (SRF) cavities in modern CW accelerators. However, localized pitting defects caused by hydrogen bubble stagnation remain a major limiting factor. In this work, we established a scalable, circulation-free beaker EP setup utilizing magnetic stirring and external water-bath thermal control. Initial experimental results demonstrate the in-situ nucleation of hydrogen bubbles on the Nb anode surface rather than mechanical migration from the Al cathode. Hydrodynamic analysis indicates that macroscopic fluid shear in low flow rate is insufficient to overcome the capillary adhesion of micro-bubbles. By optimizing fluid dynamics and applying a duty-cycle voltage, this highly simplified approach successfully yielded ultra-smooth Nb surfaces with a roughness of Ra∼50 nm, proving its efficacy for fundamental mechanistic studies.
| I have read and accept the Privacy Policy Statement | Yes |
|---|