Publications
Publication Information
| Title | An experimental analysis of effective EP parameters for low-frequency cylindrical Nb cavities | ||
| Authors | Charles Reece | ||
| JLAB number | JLAB-ACC-19-2986 | ||
| LANL number | (None) | ||
| Other number | DOE/OR/23177-4742 | ||
| Document Type(s) | (Meeting) | ||
| Associated with EIC: | No | ||
| Supported by Jefferson Lab LDRD Funding: | No | ||
| Funding Source: | Basic Energy Sciences (BES) | ||
|
Meeting Poster compiled for SRF 2019 (19th International Conference on RF Superconductivity) Proceedings Proceedings of SRF 2019 Edited By Peter Michel, André Arnold, Volker RW Schaa JACOW (2019) Page(s) 472 | |||
| Publication Abstract: | While the basic process of electropolishing niobium with 1:9 HF:H2SO4 electrolyte has been well characterized, the specific process parameters used to electropolish different superconducting radio frequency (SRF) cavity geometries requires thoughtful attention. One seeks to realize confidently local diffusion-limited polishing at each point on the surface while maximizing uniformity of removal rate. Since the reaction rate is temperature dependent, this implies that one must manage the cavity surface temperature during polishing. Too-high applied voltage aggravates temperature and thus removal non-uniformity, but too-low applied voltage risks placing the large-diameter locations ?off the current plateau,? yielding etching rather than polishing. The majority of recent experience has been with elliptical L-band SRF cavities and some half-wave cavities at ANL. Lower frequency cavities with increased surface area and larger cathode-to-equator distance require fresh analysis and optimization. In preparation for the SNS PPU project, JLab performed some EP process development runs with SNS high beta cavities to help identify viable parameter regimes for communication to cavity vendors. Results from this study are presented. | ||
| Experiment Numbers: | |||
| Group: | SRF Research & Dev | ||
| Document: | |||
| DOI: | https://doi.org/10.18429/JACoW-SRF2019-TUP029 | ||
| Accepted Manuscript: | tup029.pdf | ||
| Supporting Documents: | |||
|
|||
| Supporting Datasets: | |||