IPAC2021 - List of Authors (Reece, C.E.)

Paper	Title	Page
MOPAB384	Nb₃Sn Coating of Twin Axis Cavity for Accelerator Applications	1175
	J.K. Tiskumara, S.U. De Silva, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen, H. Park, U. Pudasaini, C.E. Reece JLab, Newport News, Virginia, USA G.V. Eremeev Fermilab, Batavia, Illinois, USA
	Funding: Research supported by DOE Office of Science Accelerator Stewardship Program Award DE- SC0019399. Partially authored by Jefferson Science Associates under contract no. DEAC0506OR23177 A Superconducting twin axis cavity consisting of two identical beam pipes that can accelerate and decelerate beams within the same structure has been proposed for the Energy Recovery Linac (ERL) applications. There are two niobium twin axis cavities at JLab fabricated with the intention of later Nb₃Sn coating and now we are progressing to coat them using vapor diffusion method. Nb₃Sn is a potential alternate material for replacing Nb in SRF cavities for better performance and reducing operational costs. Because of advanced geometry, larger surface area, increased number of ports and hard to reach areas of the twin axis cavities, the usual coating approach developed for typical elliptical single-axis cavities must be evaluated and requires to be adjusted. In this contribution, we report the first results from the coating of a twin axis cavity and discuss current challenges with an outlook for the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB384
About •	paper received ※ 19 May 2021 paper accepted ※ 24 May 2021 issue date ※ 27 August 2021
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TUXC02	The LCLS-II-HE R&D Program: New Insights into Improving the Performance of Nitrogen-Doped SRF Cavities
	D. Gonnella, S. Aderhold, J.T. Maniscalco, M.C. Ross SLAC, Menlo Park, California, USA D. Bafia, M. Checchin, A. Grassellino, S. Posen Fermilab, Batavia, Illinois, USA A.D. Palczewski, C.E. Reece JLab, Newport News, Virginia, USA
	Funding: US DOE and the LCLS-II-HE Project Nitrogen doping has now been demonstrated to produce SRF cavities of unprecedented Q₀ values when manufactured in an industrial setting. LCLS-II has shown over 300 cavities with an average Q₀ of more than 3·10¹⁰ at 16 MV/m and represents an overwhelming success of the doping protocol. LCLS-II-HE will add an additional 23 superconducting cryomodules to the LCLS-II linac, requiring cavities to operate at similar levels of high Q₀ but at 21 MV/m instead of 16 MV/m. Nitrogen-doped cavities have been historically plagued by lower quench fields than other cavity preparation methods. Therefore, an R&D effort was launched to improve upon the quench fields of doped cavities while maintaining the high Q₀. Here we present results on single-cells and 9-cells from new doping recipe pursuits, transfer of these new recipes to cavity vendors, and results on vendor-produced 9-cell cavities. This program has led to the discovery of the importance of the cold electropolish for producing higher quench fields. Finally, we will show results from the first cryomodule produced with these new cavities operating at HE gradients.
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Paper

Title

Page

Nb₃Sn Coating of Twin Axis Cavity for Accelerator Applications

1175

J.K. Tiskumara, S.U. De Silva, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
J.R. Delayen, H. Park, U. Pudasaini, C.E. Reece
JLab, Newport News, Virginia, USA
G.V. Eremeev
Fermilab, Batavia, Illinois, USA

Funding: Research supported by DOE Office of Science Accelerator Stewardship Program Award DE- SC0019399. Partially authored by Jefferson Science Associates under contract no. DEAC0506OR23177
A Superconducting twin axis cavity consisting of two identical beam pipes that can accelerate and decelerate beams within the same structure has been proposed for the Energy Recovery Linac (ERL) applications. There are two niobium twin axis cavities at JLab fabricated with the intention of later Nb₃Sn coating and now we are progressing to coat them using vapor diffusion method. Nb₃Sn is a potential alternate material for replacing Nb in SRF cavities for better performance and reducing operational costs. Because of advanced geometry, larger surface area, increased number of ports and hard to reach areas of the twin axis cavities, the usual coating approach developed for typical elliptical single-axis cavities must be evaluated and requires to be adjusted. In this contribution, we report the first results from the coating of a twin axis cavity and discuss current challenges with an outlook for the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB384

About •

paper received ※ 19 May 2021 paper accepted ※ 24 May 2021 issue date ※ 27 August 2021

Export •

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

TUXC02

The LCLS-II-HE R&D Program: New Insights into Improving the Performance of Nitrogen-Doped SRF Cavities

D. Gonnella, S. Aderhold, J.T. Maniscalco, M.C. Ross
SLAC, Menlo Park, California, USA
D. Bafia, M. Checchin, A. Grassellino, S. Posen
Fermilab, Batavia, Illinois, USA
A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA

Funding: US DOE and the LCLS-II-HE Project
Nitrogen doping has now been demonstrated to produce SRF cavities of unprecedented Q₀ values when manufactured in an industrial setting. LCLS-II has shown over 300 cavities with an average Q₀ of more than 3·10¹⁰ at 16 MV/m and represents an overwhelming success of the doping protocol. LCLS-II-HE will add an additional 23 superconducting cryomodules to the LCLS-II linac, requiring cavities to operate at similar levels of high Q₀ but at 21 MV/m instead of 16 MV/m. Nitrogen-doped cavities have been historically plagued by lower quench fields than other cavity preparation methods. Therefore, an R&D effort was launched to improve upon the quench fields of doped cavities while maintaining the high Q₀. Here we present results on single-cells and 9-cells from new doping recipe pursuits, transfer of these new recipes to cavity vendors, and results on vendor-produced 9-cell cavities. This program has led to the discovery of the importance of the cold electropolish for producing higher quench fields. Finally, we will show results from the first cryomodule produced with these new cavities operating at HE gradients.

Export •

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