NAPAC2019 - List of Authors (Porter, R.D.)

Paper	Title	Page
MOYBB3	Progress in Nb₃Sn SRF Cavities at Cornell University	37
SUPLS08	use link to see paper's listing under its alternate paper code
	R.D. Porter, H. Hu, M. Liepe, N.A. Stilin, Z. Sun, M.J. Tao Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Niobium-3 Tin (NbSn) is the most promising alternative material for next-generation SRF cavities. The material can obtain high quality factors (> 10¹⁰) at 4.2 K and could theoretically support ~ 96 MV/m operation of a TESLA elliptical style cavity. Current Nb₃Sn cavities made at Cornell University achieve high quality factors but are limited to about 17 MV/m in CW operation due to the presence of a surface defect. Here we examine recent results on studying the quench mechanism and propose that surface roughness is a major limiter for accelerating gradients. Furthermore, we discuss recent work on reducing the surface roughness including chemical polishing, modification of material growth, and tin electroplating.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBB3
About •	paper received ※ 02 September 2019 paper accepted ※ 12 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLM60	Fast Sn-Ion Transport on Nb Surface for Generating NbxSn Thin Films and XPS Depth Profiling	727
	Z. Sun, M. Liepe, J.T. Maniscalco, T.E. Oseroff, R.D. Porter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA X. Deng University of Virginia, Charlottesville, Virginia, USA D. Zhang Cornell University, Ithaca, New York, USA
	Funding: U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams In this work, we propose and demonstrate a fast and facile approach for NbxSn thin film deposition through the ion exchange reaction. By simply dipping a tin precursor on the Nb substrate surface, a ~600 nm thin film is generated due to the electronegativity differ-ence between Sn and Nb. Through X-ray photoelec-tron spectroscopy (XPS) depth profiling, the composi-tional information as a function of film thickness was obtained. Results showed a Sn layer on the film sur-face, Sn-rich and Nb-rich NbxSn layers as the majority of the film, and a ~60 nm Nb₃Sn layer at the film/substrate interface. Quantitative analysis con-firmed stoichiometric Nb/Sn ratio for the Nb₃Sn layer. This deposition method is demonstrated to be an alter-native choice for Nb₃Sn film growth.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM60
About •	paper received ※ 05 September 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOYBB3

Progress in Nb₃Sn SRF Cavities at Cornell University

37

SUPLS08

use link to see paper's listing under its alternate paper code

R.D. Porter, H. Hu, M. Liepe, N.A. Stilin, Z. Sun, M.J. Tao
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Niobium-3 Tin (NbSn) is the most promising alternative material for next-generation SRF cavities. The material can obtain high quality factors (> 10¹⁰) at 4.2 K and could theoretically support ~ 96 MV/m operation of a TESLA elliptical style cavity. Current Nb₃Sn cavities made at Cornell University achieve high quality factors but are limited to about 17 MV/m in CW operation due to the presence of a surface defect. Here we examine recent results on studying the quench mechanism and propose that surface roughness is a major limiter for accelerating gradients. Furthermore, we discuss recent work on reducing the surface roughness including chemical polishing, modification of material growth, and tin electroplating.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBB3

About •

paper received ※ 02 September 2019 paper accepted ※ 12 September 2019 issue date ※ 08 October 2019

Export •

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

WEPLM60

Fast Sn-Ion Transport on Nb Surface for Generating NbxSn Thin Films and XPS Depth Profiling

727

Z. Sun, M. Liepe, J.T. Maniscalco, T.E. Oseroff, R.D. Porter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
X. Deng
University of Virginia, Charlottesville, Virginia, USA
D. Zhang
Cornell University, Ithaca, New York, USA

Funding: U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams
In this work, we propose and demonstrate a fast and facile approach for NbxSn thin film deposition through the ion exchange reaction. By simply dipping a tin precursor on the Nb substrate surface, a ~600 nm thin film is generated due to the electronegativity differ-ence between Sn and Nb. Through X-ray photoelec-tron spectroscopy (XPS) depth profiling, the composi-tional information as a function of film thickness was obtained. Results showed a Sn layer on the film sur-face, Sn-rich and Nb-rich NbxSn layers as the majority of the film, and a ~60 nm Nb₃Sn layer at the film/substrate interface. Quantitative analysis con-firmed stoichiometric Nb/Sn ratio for the Nb₃Sn layer. This deposition method is demonstrated to be an alter-native choice for Nb₃Sn film growth.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM60

About •

paper received ※ 05 September 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019

Export •

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