Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma
Abstract
An apparatus and a method for etching of the inner surfaces of superconducting radio frequency (SRF) accelerator cavities are described. The apparatus is based on the reactive ion etching performed in an Ar/Cl2 cylindrical capacitive discharge with reversed asymmetry. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity was used. The single cell cavity was mechanically polished and buffer chemically etched and then rf tested at cryogenic temperatures to provide a baseline characterization. The cavity’s inner wall was then exposed to the capacitive discharge in a mixture of Argon and Chlorine. The inner wall acted as the grounded electrode, while kept at elevated temperature. The processing was accomplished by axially moving the dc-biased, corrugated inner electrode and the gas flow inlet in a step-wise manner to establish a sequence of longitudinally segmented discharges. The cavity was then tested in a standard vertical test stand at cryogenic temperatures. The rf tests and surface condition results, including the electron field emission elimination, are presented.
- Authors:
-
- Old Dominion Univ., Norfolk, VA (United States)
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Publication Date:
- Research Org.:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP); USDOE Office of Science (SC), High Energy Physics (HEP)
- OSTI Identifier:
- 1641619
- Alternate Identifier(s):
- OSTI ID: 1414016
- Report Number(s):
- JLAB-ACC-16-2299; DOE/OR/23177-3878; arXiv:1605.06494
Journal ID: ISSN 2158-3226; TRN: US2201868
- Grant/Contract Number:
- SC0014397; AC05-06OR23177
- Resource Type:
- Journal Article: Accepted Manuscript
- Journal Name:
- AIP Advances
- Additional Journal Information:
- Journal Volume: 7; Journal Issue: 12; Journal ID: ISSN 2158-3226
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Vacuum apparatus; Physics of gases; Etching; Electrical properties and parameters; Plasma processing; Cryogenics; Chemical elements; Surface collisions; Superconductivity; Transition metals
Citation Formats
Upadhyay, J., Palczewski, A., Popović, S., Valente-Feliciano, A.-M., Im, Do, Phillips, H. L., and Vušković, L. Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma. United States: N. p., 2017.
Web. doi:10.1063/1.4991888.
Upadhyay, J., Palczewski, A., Popović, S., Valente-Feliciano, A.-M., Im, Do, Phillips, H. L., & Vušković, L. Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma. United States. https://doi.org/10.1063/1.4991888
Upadhyay, J., Palczewski, A., Popović, S., Valente-Feliciano, A.-M., Im, Do, Phillips, H. L., and Vušković, L. 2017.
"Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma". United States. https://doi.org/10.1063/1.4991888. https://www.osti.gov/servlets/purl/1641619.
@article{osti_1641619,
title = {Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma},
author = {Upadhyay, J. and Palczewski, A. and Popović, S. and Valente-Feliciano, A.-M. and Im, Do and Phillips, H. L. and Vušković, L.},
abstractNote = {An apparatus and a method for etching of the inner surfaces of superconducting radio frequency (SRF) accelerator cavities are described. The apparatus is based on the reactive ion etching performed in an Ar/Cl2 cylindrical capacitive discharge with reversed asymmetry. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity was used. The single cell cavity was mechanically polished and buffer chemically etched and then rf tested at cryogenic temperatures to provide a baseline characterization. The cavity’s inner wall was then exposed to the capacitive discharge in a mixture of Argon and Chlorine. The inner wall acted as the grounded electrode, while kept at elevated temperature. The processing was accomplished by axially moving the dc-biased, corrugated inner electrode and the gas flow inlet in a step-wise manner to establish a sequence of longitudinally segmented discharges. The cavity was then tested in a standard vertical test stand at cryogenic temperatures. The rf tests and surface condition results, including the electron field emission elimination, are presented.},
doi = {10.1063/1.4991888},
url = {https://www.osti.gov/biblio/1641619},
journal = {AIP Advances},
issn = {2158-3226},
number = 12,
volume = 7,
place = {United States},
year = {Tue Dec 19 00:00:00 EST 2017},
month = {Tue Dec 19 00:00:00 EST 2017}
}
Web of Science
Figures / Tables:
Works referenced in this record:
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Works referencing / citing this record:
Effect of self-bias on cylindrical capacitive discharge for processing of inner walls of tubular structures—Case of SRF cavities
journal, August 2018
- Upadhyay, J.; Peshl, J.; Popović, S.
- AIP Advances, Vol. 8, Issue 8
Argon metastable and resonant level densities in Ar and Ar/Cl2 discharges used for the processing of bulk niobium
journal, September 2019
- Peshl, Jeremy; McNeill, Roderick; Sukenik, Charles I.
- Journal of Applied Physics, Vol. 126, Issue 10
Figures / Tables found in this record: