IPAC2018 - List of Authors (Mammosser, J.D.)

Paper	Title	Page
THPAL065	Improving the Work Function of Nitrogen-Doped Niobium Surfaces for SRF Cavities by Plasma Processing	3802
	K.E. Tippey, R. Afanador, M. Doleans, S.-H. Kim, J.D. Mammosser, C.J. McMahan ORNL, Oak Ridge, Tennessee, USA M. Martinello Fermilab, Batavia, Illinois, USA
	Funding: DOE research grant FWP-ERKCSA2; DOE contract DE-AC05-00OR22725 Work function and surface chemistries of SiC-polished, electropolished, and nitrogen-doped niobium coupons were analyzed before and after plasma processing using a neon-oxygen gas mixture. These studies represent an initial enquiry into the feasibility of applying the plasma processing technique designed at ORNL for the Spallation Neutron Source (SNS) to the nitrogen-doped Nb cavities for the Coherent Light Source II (LCLS-II). Work function of all measured samples was increased after plasma processing, which indicates the strong potential of the plasma processing technique as a tool for increasing the accelerating gradient of nitrogen-doped cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL065
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MOZGBF4	Evolution of the Superconducting Linac Output Energy at the Spallation Neutron Source	73
	S.-H. Kim, D.E. Anderson, M.T. Crofford, M. Doleans, J. Galambos, S.W. Gold, M.P. Howell, M.A. Plum, D.J. Vandygriff ORNL, Oak Ridge, Tennessee, USA R. Afanador, D.L. Barnhart, B. DeGraff, J.D. Mammosser, C.J. McMahan, T.S. Neustadt, C.C. Peters, J. Saunders, D.M. Vandygriff ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. The SNS linac output energy has increased since the start of neutron production in FY2007. The various improvements that contributed to the increase of the linac output energy are LLRF/control system improvement, high voltage converter modulator system improvement, high-power RF system improvement, cryomodule repairs, spare cryomodule development and accelerating gradient improvement through in-situ plasma processing. In this paper, the history of the SNS SCL output energy is reported, and plans for the near-term future and for the Proton Power Upgrade (PPU) project are also presented.
	Slides MOZGBF4 [34.185 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOZGBF4
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Improving the Work Function of Nitrogen-Doped Niobium Surfaces for SRF Cavities by Plasma Processing

3802

K.E. Tippey, R. Afanador, M. Doleans, S.-H. Kim, J.D. Mammosser, C.J. McMahan
ORNL, Oak Ridge, Tennessee, USA
M. Martinello
Fermilab, Batavia, Illinois, USA

Funding: DOE research grant FWP-ERKCSA2; DOE contract DE-AC05-00OR22725
Work function and surface chemistries of SiC-polished, electropolished, and nitrogen-doped niobium coupons were analyzed before and after plasma processing using a neon-oxygen gas mixture. These studies represent an initial enquiry into the feasibility of applying the plasma processing technique designed at ORNL for the Spallation Neutron Source (SNS) to the nitrogen-doped Nb cavities for the Coherent Light Source II (LCLS-II). Work function of all measured samples was increased after plasma processing, which indicates the strong potential of the plasma processing technique as a tool for increasing the accelerating gradient of nitrogen-doped cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL065

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOZGBF4

Evolution of the Superconducting Linac Output Energy at the Spallation Neutron Source

73

S.-H. Kim, D.E. Anderson, M.T. Crofford, M. Doleans, J. Galambos, S.W. Gold, M.P. Howell, M.A. Plum, D.J. Vandygriff
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, D.L. Barnhart, B. DeGraff, J.D. Mammosser, C.J. McMahan, T.S. Neustadt, C.C. Peters, J. Saunders, D.M. Vandygriff
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
The SNS linac output energy has increased since the start of neutron production in FY2007. The various improvements that contributed to the increase of the linac output energy are LLRF/control system improvement, high voltage converter modulator system improvement, high-power RF system improvement, cryomodule repairs, spare cryomodule development and accelerating gradient improvement through in-situ plasma processing. In this paper, the history of the SNS SCL output energy is reported, and plans for the near-term future and for the Proton Power Upgrade (PPU) project are also presented.

Slides MOZGBF4 [34.185 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOZGBF4

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)