| Title |
The Effect of Process Parameters on the Surface Properties of Niobium During Plasma Etching |
| Authors |
- J.J. Peshl, S. Popović, L. Vušković
ODU, Norfolk, Virginia, USA
- J. Upadhyay
LANL, Los Alamos, New Mexico, USA
- A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA
|
| Abstract |
We have shown that plasma etching using an electronegative Ar/Cl2 discharge can effectively remove surface oxide layers on Nb samples as well as bulk Nb from single cell SRF cavities*. With accelerating fields on the order of wet etching processes and a decrease in field emission the use of plasma assisted etching for bulk Nb processing is a worthwhile endeavor. We are presenting the surface properties of plasma etched Nb. Cavity grade Nb coupons were made by water jet cutting, and then polished to achieve surface roughness equivalent to electropolishing (<1 micron). The coupons were plasma etched while process parameters (rf power, gas pressure, temperature and DC bias voltage) are varied. These samples are placed on the inner surface of the cylindrical cavity to be etched. The experimental setup is similar to the single cell cavity plasma etching setup. Each sample is weighed and scanned before and after plasma processing with an AFM, SEM, and digital optical microscope that provide both atomic composition and surface roughness profiles. Comparing the scans allows us to make conclusions about the effect of each parameter on the surface roughness.
|
| Footnotes & References |
J. Upadhyay et. al. 'Cryogenic rf test of the first plasma etched SRF cavity,' arXiv: 1605.06494 [physics.acc-ph] (2016). |
| Funding |
This work is supported by the Department of Energy, Grant DE-SC0014397. |
| Paper |
download TUPB098.PDF [1.063 MB / 3 pages] |
| Export |
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| Conference |
SRF2017, Lanzhou, China |
| Series |
International Conference on RF Superconductivity (18th) |
| Proceedings |
Link to full SRF2017 Proccedings |
| Session |
Poster Session |
| Date |
18-Jul-17 14:00–17:00 |
| Main Classification |
SRF Technology R&D |
| Sub Classification |
Cavity processing |
| Keywords |
ion, plasma, cavity, experiment, SRF |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Volker RW Schaa (GSI, Darmstadt, Germany); Yuan He (IMP, Lanzhou, China); Lu Li (IMP, Lanzhou, China); Ning Zhao (IHEP, Beijing, China) |
| ISBN |
978-3-95450-191-5 |
| Published |
January 2018 |
| Copyright |
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