SRF2021 - List of Keywords (collider)

Paper	Title	Other Keywords	Page
MOPCAV004	Mechanical Properties of Directly Sliced Medium Grain Niobium for 1.3 GHz SRF Cavity	cavity, niobium, SRF, cryogenics	259
	A. Kumar, K. Abe, T. Dohmae, S. Michizono, T. Saeki, Y. Watanabe, A. Yamamoto, M. Yamanaka KEK, Ibaraki, Japan A. Fajardo, N. Lannoy ATI, Albany, Oregon, USA G.R. Myneni JLab, Newport News, Virginia, USA G.R. Myneni BSCE, Yorktown, Virginia, USA
	At KEK, research is being conducted to manufacture cost-effective 1.3 GHz superconducting radio frequency cavities based on the fine grain (FG) and large grain (LG) Niobium (Nb) materials. Medium grain (MG) Nb has been proposed and developed as an alternative to the FG and LG Nb, being expected to have better mechanical stability with a cost-effective and clean manufacturing approach. MG Nb has an average grain size of 200 - 300 µm, which is approximately 100 times smaller than the LG Nb, however, there are occasional grains as large as 1-2 mm. As such, it is expected to have isotropic properties rather than the anisotropic properties of LG Nb. In this paper, we will outline the mechanical properties of the directly sliced high RRR MG Nb material (manufactured by ATI), and a comparative study will be presented with respect to FG and LG Nb. Moreover, the viability of MG Nb for the global high-pressure regulation for 1.3 GHz SRF cavity will be presented.
	Poster MOPCAV004 [1.796 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV004
About •	Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 25 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPFDV007	Surface Impedance of Nb₃Sn and YBa₂Cu₃O_7-δ in High Magnetic Fields	impedance, cavity, radio-frequency, framework	416
	N. Pompeo, A. Alimenti, E. Silva, K. Torokhtii Università degli Studi Roma III, Roma, Italy G. Celentano, V. Pinto, F. Rizzo ENEA C.R. Frascati, Frascati (Roma), Italy R. Flükiger UNIGE, Geneva, Switzerland T. Spina Fermilab, Batavia, Illinois, USA
	Funding: This work has been partially carried out within the framework of the EUROfusion consortium, funding from the Euratom research and training programme 2014-18 and 2019-20 under grant agreement No 633053 New potential rf applications of superconductors emerged with the need to operate in high dc magnetic fields (up to 16 T) where vortex motion dictates the response: the beam screen coating of the Future Circular Collider (FCC) [1] and haloscopes, i.e. rf cavities for the axions detection [2]. However, very few data are available in the required regimes. We present in this work measurements of the surface impedance Z up to 12 T on bulk Nb₃Sn and YBCO thin films grown by different techniques. The measurements are performed with a dielectric loaded resonator operating at 15 GHz. We obtained the vortex motion resistivity and extracted the high frequency vortex motion parameters [3]: the depinning frequency, the flux-flow resistivity and the pinning constant, as well as their temperature and field dependences. Substantial differences are highlighted in the high frequency pinning properties of the studied materials, providing useful information on possible improvements in view of applications. A comparison with the results obtained in the microwave frequency range at lower fields (up to 1 T) is given. [1] S. Calatroni, IEEE Trans. Appl. Supercond., vol. 26 p. 3500204, 2016. [2] D. Alesini et al., Phys. Rev. D, vol. 99, p. 101101, 2019. [3] J.I. Gittleman and B. Rosenblum, Phys. Rev. Lett., vol. 16, p.734, 1966.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFDV007
About •	Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 02 January 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPCAV004

Mechanical Properties of Directly Sliced Medium Grain Niobium for 1.3 GHz SRF Cavity

cavity, niobium, SRF, cryogenics

259

A. Kumar, K. Abe, T. Dohmae, S. Michizono, T. Saeki, Y. Watanabe, A. Yamamoto, M. Yamanaka
KEK, Ibaraki, Japan
A. Fajardo, N. Lannoy
ATI, Albany, Oregon, USA
G.R. Myneni
JLab, Newport News, Virginia, USA
G.R. Myneni
BSCE, Yorktown, Virginia, USA

At KEK, research is being conducted to manufacture cost-effective 1.3 GHz superconducting radio frequency cavities based on the fine grain (FG) and large grain (LG) Niobium (Nb) materials. Medium grain (MG) Nb has been proposed and developed as an alternative to the FG and LG Nb, being expected to have better mechanical stability with a cost-effective and clean manufacturing approach. MG Nb has an average grain size of 200 - 300 µm, which is approximately 100 times smaller than the LG Nb, however, there are occasional grains as large as 1-2 mm. As such, it is expected to have isotropic properties rather than the anisotropic properties of LG Nb. In this paper, we will outline the mechanical properties of the directly sliced high RRR MG Nb material (manufactured by ATI), and a comparative study will be presented with respect to FG and LG Nb. Moreover, the viability of MG Nb for the global high-pressure regulation for 1.3 GHz SRF cavity will be presented.

Poster MOPCAV004 [1.796 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV004

About •

Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 25 March 2022

Cite •

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

TUPFDV007

Surface Impedance of Nb₃Sn and YBa₂Cu₃O_7-δ in High Magnetic Fields

impedance, cavity, radio-frequency, framework

416

N. Pompeo, A. Alimenti, E. Silva, K. Torokhtii
Università degli Studi Roma III, Roma, Italy
G. Celentano, V. Pinto, F. Rizzo
ENEA C.R. Frascati, Frascati (Roma), Italy
R. Flükiger
UNIGE, Geneva, Switzerland
T. Spina
Fermilab, Batavia, Illinois, USA

Funding: This work has been partially carried out within the framework of the EUROfusion consortium, funding from the Euratom research and training programme 2014-18 and 2019-20 under grant agreement No 633053
New potential rf applications of superconductors emerged with the need to operate in high dc magnetic fields (up to 16 T) where vortex motion dictates the response: the beam screen coating of the Future Circular Collider (FCC) [1] and haloscopes, i.e. rf cavities for the axions detection [2]. However, very few data are available in the required regimes. We present in this work measurements of the surface impedance Z up to 12 T on bulk Nb₃Sn and YBCO thin films grown by different techniques. The measurements are performed with a dielectric loaded resonator operating at 15 GHz. We obtained the vortex motion resistivity and extracted the high frequency vortex motion parameters [3]: the depinning frequency, the flux-flow resistivity and the pinning constant, as well as their temperature and field dependences. Substantial differences are highlighted in the high frequency pinning properties of the studied materials, providing useful information on possible improvements in view of applications. A comparison with the results obtained in the microwave frequency range at lower fields (up to 1 T) is given.
[1] S. Calatroni, IEEE Trans. Appl. Supercond., vol. 26 p. 3500204, 2016.
[2] D. Alesini et al., Phys. Rev. D, vol. 99, p. 101101, 2019.
[3] J.I. Gittleman and B. Rosenblum, Phys. Rev. Lett., vol. 16, p.734, 1966.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFDV007

About •

Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 02 January 2022

Cite •

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