SRF2019 - List of Keywords (DTL)

Paper	Title	Other Keywords	Page
THFUA2	Evaluation of the Superconducting Characteristics of Multi-Layer Thin-Film Structures of NbN and SiO₂ on Pure Nb Substrate	linac, experiment	807
	R. Katayama, H. Hayano, T. Kubo, T. Saeki KEK, Ibaraki, Japan C.Z. Antoine CEA-IRFU, Gif-sur-Yvette, France H. Ito Sokendai, Ibaraki, Japan R. Ito ULVAC, Inc, Chiba, Japan Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan T. Nagata ULVAC, Inc., Tsukuba, Japan
	In recent years, it has been pointed out that the maximum accelerating gradient of a superconducting RF cavity can be increased by coating the inner surface of the cavity with a multilayer thin-film structure consisting of alternating insulating and superconducting layers. In this structure, the principal parameter that limits the performance of the cavity is the critical magnetic field or effective Hc1 at which vortices begin penetrating into the superconductor layer. This is predicted to depend on the combination of the film thickness. We made samples that have a NbN/SiO₂ thin-film structure on a pure Nb substrate with several layers of NbN film deposited using DC magnetron sputtering method. Here, we report the measurement results of effective Hc1 of NbN/SiO₂(30 nm)/Nb multilayer samples with thicknesses of NbN layers in the range from 50 nm to 800 nm by using the third-harmonic voltage method. Experimental results show that an optimum thickness exists, which increases the effective Hc1 by 23.8 %.
	Slides THFUA2 [2.333 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THFUA2
About •	paper received ※ 03 July 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Evaluation of the Superconducting Characteristics of Multi-Layer Thin-Film Structures of NbN and SiO₂ on Pure Nb Substrate

linac, experiment

807

R. Katayama, H. Hayano, T. Kubo, T. Saeki
KEK, Ibaraki, Japan
C.Z. Antoine
CEA-IRFU, Gif-sur-Yvette, France
H. Ito
Sokendai, Ibaraki, Japan
R. Ito
ULVAC, Inc, Chiba, Japan
Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
T. Nagata
ULVAC, Inc., Tsukuba, Japan

In recent years, it has been pointed out that the maximum accelerating gradient of a superconducting RF cavity can be increased by coating the inner surface of the cavity with a multilayer thin-film structure consisting of alternating insulating and superconducting layers. In this structure, the principal parameter that limits the performance of the cavity is the critical magnetic field or effective Hc1 at which vortices begin penetrating into the superconductor layer. This is predicted to depend on the combination of the film thickness. We made samples that have a NbN/SiO₂ thin-film structure on a pure Nb substrate with several layers of NbN film deposited using DC magnetron sputtering method. Here, we report the measurement results of effective Hc1 of NbN/SiO₂(30 nm)/Nb multilayer samples with thicknesses of NbN layers in the range from 50 nm to 800 nm by using the third-harmonic voltage method. Experimental results show that an optimum thickness exists, which increases the effective Hc1 by 23.8 %.

Slides THFUA2 [2.333 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THFUA2

About •

paper received ※ 03 July 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019

Export •

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