In-situ plasma processing to increase the accelerating gradients of SRF cavities
Abstract
A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.
- Authors:
-
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- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1234337
- Alternate Identifier(s):
- OSTI ID: 1251772
- Grant/Contract Number:
- AC05-00OR22725
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
- Additional Journal Information:
- Journal Volume: 812; Journal ID: ISSN 0168-9002
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 43 PARTICLE ACCELERATORS; 42 ENGINEERING; linear accelerator; SRF technology; plasma processing
Citation Formats
Doleans, Marc, Afanador, Ralph, Barnhart, Debra L., Degraff, Brian D., Gold, Steven W., Hannah, Brian S., Howell, Matthew P., Kim, Sang-Ho, Mammosser, John, McMahan, Christopher J., Neustadt, Thomas S., Saunders, Jeffrey W., Tyagi, Puneet V., Vandygriff, Daniel J., Vandygriff, David M., Ball, Jeffrey Allen, Blokland, Willem, Crofford, Mark T., Lee, Sung-Woo, Stewart, Stephen, and Strong, William Herb. In-situ plasma processing to increase the accelerating gradients of SRF cavities. United States: N. p., 2015.
Web. doi:10.1016/j.nima.2015.12.043.
Doleans, Marc, Afanador, Ralph, Barnhart, Debra L., Degraff, Brian D., Gold, Steven W., Hannah, Brian S., Howell, Matthew P., Kim, Sang-Ho, Mammosser, John, McMahan, Christopher J., Neustadt, Thomas S., Saunders, Jeffrey W., Tyagi, Puneet V., Vandygriff, Daniel J., Vandygriff, David M., Ball, Jeffrey Allen, Blokland, Willem, Crofford, Mark T., Lee, Sung-Woo, Stewart, Stephen, & Strong, William Herb. In-situ plasma processing to increase the accelerating gradients of SRF cavities. United States. https://doi.org/10.1016/j.nima.2015.12.043
Doleans, Marc, Afanador, Ralph, Barnhart, Debra L., Degraff, Brian D., Gold, Steven W., Hannah, Brian S., Howell, Matthew P., Kim, Sang-Ho, Mammosser, John, McMahan, Christopher J., Neustadt, Thomas S., Saunders, Jeffrey W., Tyagi, Puneet V., Vandygriff, Daniel J., Vandygriff, David M., Ball, Jeffrey Allen, Blokland, Willem, Crofford, Mark T., Lee, Sung-Woo, Stewart, Stephen, and Strong, William Herb. Thu .
"In-situ plasma processing to increase the accelerating gradients of SRF cavities". United States. https://doi.org/10.1016/j.nima.2015.12.043. https://www.osti.gov/servlets/purl/1234337.
@article{osti_1234337,
title = {In-situ plasma processing to increase the accelerating gradients of SRF cavities},
author = {Doleans, Marc and Afanador, Ralph and Barnhart, Debra L. and Degraff, Brian D. and Gold, Steven W. and Hannah, Brian S. and Howell, Matthew P. and Kim, Sang-Ho and Mammosser, John and McMahan, Christopher J. and Neustadt, Thomas S. and Saunders, Jeffrey W. and Tyagi, Puneet V. and Vandygriff, Daniel J. and Vandygriff, David M. and Ball, Jeffrey Allen and Blokland, Willem and Crofford, Mark T. and Lee, Sung-Woo and Stewart, Stephen and Strong, William Herb},
abstractNote = {A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.},
doi = {10.1016/j.nima.2015.12.043},
journal = {Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment},
number = ,
volume = 812,
place = {United States},
year = {2015},
month = {12}
}
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Works referencing / citing this record:
Plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavities
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