SRF2023 - List of Authors (Thoeng, E.)

Paper	Title	Page
MOPMB005	Muon Spin Rotation Studies of Bilayer Superconductors and Low Temperature Baked Niobium	62
SUSPB002	use link to see paper's listing under its alternate paper code
	M. Asaduzzaman, R.E. Laxdal, R.M.L. McFadden, E. Thoeng TRIUMF, Vancouver, Canada M. Asaduzzaman, T. Junginger, R.M.L. McFadden UVIC, Victoria, Canada E. Thoeng UBC & TRIUMF, Vancouver, British Columbia, Canada
	Funding: Financial support was provided by an Natural Sciences and Engineering Research Council of Canada (NSERC) Muon spin rotation (muSR) results have shown that vortex penetration into Nb can be delayed up to the superheating field Hsh by a single layer of a material with larger London penetration depth. For low temperature baked (LTB) Nb an increase in the vortex penetration field Hvp has also been observed. While clearly exceeding the lower critical field Hc1, Hvp was found to remain significantly below Hsh for LTB niobium (Superconductor Science and Technology 30 (12), 125012). Further, magnetometry experiments suggested that there is no interface barrier in LTB Nb and that the apparent Hvp increase as observed by muSR was due to surface pinning (Scientific Reports 12 (1), 5522). By varying the implantation depth of ~4.1 MeV muons using moderating foils, new muSR measurements confirm that the apparent Hvp increase in LTB Nb is indeed due to surface pinning, while for a Nb₃Sn/Nb bilayer we find an interface barrier for flux penetration. These results confirm the potential of using superconducting bilayers to achieve a flux free Meissner state up to the superheating field of the substrate.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB005
About •	Received ※ 17 June 2023 — Revised ※ 21 June 2023 — Accepted ※ 25 June 2023 — Issue date ※ 21 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUIXA04	First Results from beta-SRF- Testing SRF Samples at High Parallel Field	374
	E. Thoeng, R. Kiefl, W.A. MacFarlane, J.O. Ticknor UBC & TRIUMF, Vancouver, British Columbia, Canada M. Asaduzzaman, S.R. Dunsiger, D. Fujimoto, T. Junginger, V.L. Karner, P. Kolb, R.E. Laxdal, R. Li, R.M.L. McFadden, G. Morris, M. Stachura TRIUMF, Vancouver, Canada T. Junginger, R.M.L. McFadden UVIC, Victoria, Canada
	The new ¿-SRF facility at TRIUMF has recently been commissioned. A new 1 m extension has been added to an existing ¿-NMR beamline with a large Helmholtz coil to produce fields up to 200 mT parallel to sample surfaces. The ¿-NMR technique allows depth dependent characterization of the local magnetic field in the first 100 nm of the sample surface making the probe ideal for studying Meissner screen- ing in heat treated Niobium or layered SRF materials. First measurements of Meissner screening at fields up to 200 mT have been analyzed. The results show clear differences in the Meissner screening of baseline treatments compared to mid-T baked (O-doped) Niobium.
	Slides TUIXA04 [1.644 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIXA04
About •	Received ※ 24 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 06 July 2023 — Issue date ※ 09 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPMB005

Muon Spin Rotation Studies of Bilayer Superconductors and Low Temperature Baked Niobium

62

SUSPB002

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

M. Asaduzzaman, R.E. Laxdal, R.M.L. McFadden, E. Thoeng
TRIUMF, Vancouver, Canada
M. Asaduzzaman, T. Junginger, R.M.L. McFadden
UVIC, Victoria, Canada
E. Thoeng
UBC & TRIUMF, Vancouver, British Columbia, Canada

Funding: Financial support was provided by an Natural Sciences and Engineering Research Council of Canada (NSERC)
Muon spin rotation (muSR) results have shown that vortex penetration into Nb can be delayed up to the superheating field Hsh by a single layer of a material with larger London penetration depth. For low temperature baked (LTB) Nb an increase in the vortex penetration field Hvp has also been observed. While clearly exceeding the lower critical field Hc1, Hvp was found to remain significantly below Hsh for LTB niobium (Superconductor Science and Technology 30 (12), 125012). Further, magnetometry experiments suggested that there is no interface barrier in LTB Nb and that the apparent Hvp increase as observed by muSR was due to surface pinning (Scientific Reports 12 (1), 5522). By varying the implantation depth of ~4.1 MeV muons using moderating foils, new muSR measurements confirm that the apparent Hvp increase in LTB Nb is indeed due to surface pinning, while for a Nb₃Sn/Nb bilayer we find an interface barrier for flux penetration. These results confirm the potential of using superconducting bilayers to achieve a flux free Meissner state up to the superheating field of the substrate.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB005

About •

Received ※ 17 June 2023 — Revised ※ 21 June 2023 — Accepted ※ 25 June 2023 — Issue date ※ 21 July 2023

Cite •

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

TUIXA04

First Results from beta-SRF- Testing SRF Samples at High Parallel Field

374

E. Thoeng, R. Kiefl, W.A. MacFarlane, J.O. Ticknor
UBC & TRIUMF, Vancouver, British Columbia, Canada
M. Asaduzzaman, S.R. Dunsiger, D. Fujimoto, T. Junginger, V.L. Karner, P. Kolb, R.E. Laxdal, R. Li, R.M.L. McFadden, G. Morris, M. Stachura
TRIUMF, Vancouver, Canada
T. Junginger, R.M.L. McFadden
UVIC, Victoria, Canada

The new ¿-SRF facility at TRIUMF has recently been commissioned. A new 1 m extension has been added to an existing ¿-NMR beamline with a large Helmholtz coil to produce fields up to 200 mT parallel to sample surfaces. The ¿-NMR technique allows depth dependent characterization of the local magnetic field in the first 100 nm of the sample surface making the probe ideal for studying Meissner screen- ing in heat treated Niobium or layered SRF materials. First measurements of Meissner screening at fields up to 200 mT have been analyzed. The results show clear differences in the Meissner screening of baseline treatments compared to mid-T baked (O-doped) Niobium.

Slides TUIXA04 [1.644 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIXA04

About •

Received ※ 24 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 06 July 2023 — Issue date ※ 09 July 2023

Cite •

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