SRF2017 - List of Authors (Oikawa, H.)

Paper	Title	Page
THPB058	R&D of Thin Film Coating on Superconductors	877
	Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, T. Kubo, T. Saeki KEK, Ibaraki, Japan M. Hino Kyoto University, Research Reactor Institute, Osaka, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	Funding: This research is partially supported by Grant-in-Aid for Exploratory Research JSPS KAKENHI Grant Number 26600142, and Photon and Quantum Basic Research Coordinated Development Program from the MEXT. Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB058
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THPB077	Design Study of Mushroom Shaped Cavity for Evaluation of RF Critical Magnetic Field of Thin-film Superconductor	914
	H. Oikawa Utsunomiya University, Utsunomiya, Japan H. Hayano KEK, Ibaraki, Japan T. Higashiguchi Center for Optical Research and Education, Utsunomiya University, Utsunomiya, Japan
	For future accelerator, superconducting RF cavity has high gradient of 45 MV/m or more is demanded. To obtain such a higher gradient, there has been proposed a method of increasing an RF critical magnetic field of the cavity inner surface by coating of multi-layer thin-film superconductor. Their thickness is close to the London penetration depth. By producing a multilayer film structure in cavity inner surface, it is believed to improve the RF critical magnetic field, and to connect directly to high gradient. To demonstrate a creation of a thin film on a surface of Nb samples, an RF cavity with a thin film coated Nb sample is needed to measure the RF critical field of the sample. To adapt it to the cavity, to cool to cryogenic temperature and to establish the sample to supply the RF power, it is necessary to design a cavity to produce a strong RF magnetic field parallel to the surface of the thin film sample. We designed a mushroom shaped cavity made of Nb and input coupler. Resonant frequency is 5.2 GHz by calculation. We calculated the resonant frequency and the field distribution, compared with the measured values for the model cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB077
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

R&D of Thin Film Coating on Superconductors

877

Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, T. Kubo, T. Saeki
KEK, Ibaraki, Japan
M. Hino
Kyoto University, Research Reactor Institute, Osaka, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

Funding: This research is partially supported by Grant-in-Aid for Exploratory Research JSPS KAKENHI Grant Number 26600142, and Photon and Quantum Basic Research Coordinated Development Program from the MEXT.
Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB058

Export •

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

THPB077

Design Study of Mushroom Shaped Cavity for Evaluation of RF Critical Magnetic Field of Thin-film Superconductor

914

H. Oikawa
Utsunomiya University, Utsunomiya, Japan
H. Hayano
KEK, Ibaraki, Japan
T. Higashiguchi
Center for Optical Research and Education, Utsunomiya University, Utsunomiya, Japan

For future accelerator, superconducting RF cavity has high gradient of 45 MV/m or more is demanded. To obtain such a higher gradient, there has been proposed a method of increasing an RF critical magnetic field of the cavity inner surface by coating of multi-layer thin-film superconductor. Their thickness is close to the London penetration depth. By producing a multilayer film structure in cavity inner surface, it is believed to improve the RF critical magnetic field, and to connect directly to high gradient. To demonstrate a creation of a thin film on a surface of Nb samples, an RF cavity with a thin film coated Nb sample is needed to measure the RF critical field of the sample. To adapt it to the cavity, to cool to cryogenic temperature and to establish the sample to supply the RF power, it is necessary to design a cavity to produce a strong RF magnetic field parallel to the surface of the thin film sample. We designed a mushroom shaped cavity made of Nb and input coupler. Resonant frequency is 5.2 GHz by calculation. We calculated the resonant frequency and the field distribution, compared with the measured values for the model cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB077

Export •

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