| Title |
An Experimental Analysis of Effective EP Parameters for Low-Frequency Cylindrical Nb Cavities |
| Authors |
- C.E. Reece
JLab, Newport News, Virginia, USA
|
| 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 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.
|
| Funding |
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Work supported by the U.S. DoE, Office of Science, Office of Basic Energy Sciences. |
| Paper |
download TUP029.PDF [1.953 MB / 5 pages] |
| Export |
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| Conference |
SRF2019 |
| Series |
International Conference on RF Superconductivity (19th) |
| Location |
Dresden, Germany |
| Date |
30 June-05 July 2019 |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editorial Board |
Peter Michel (HZDR, Dresden, Germany); André Arnold (HZDR, Dresden, Germany); Volker RW Schaa (GSI, Darmstadt, Germany) |
| Online ISBN |
978-3-95450-211-0 |
| Online ISSN |
"" |
| Received |
23 June 2019 |
| Accepted |
29 June 2019 |
| Issue Date |
14 August 2019 |
| DOI |
doi:10.18429/JACoW-SRF2019-TUP029 |
| Pages |
472-476 |
| Copyright |
 Published by JACoW Publishing under the terms of the Creative Commons Attribution 3.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI. |
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