SRF2017 - List of Authors (Liu, K.X.)

Paper	Title	Page
TUPB099	Vertical Test System for Superconducting RF Cavities at Peking University	631
	D. Zhou, J.E. Chen, W. Cheng, L.W. Feng, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan, F. Wang, H.M. Xie, F. Zhu, D.H. Zhuang PKU, Beijing, People's Republic of China
	A new vertical test system (VTS) for superconducting RF cavities has been designed and constructed at Peking University. This facility is designed to operate at a temperature of 2K and with pumping speed of 10g/s for helium gas at 30 mbar. In this paper, we present the structure design, modification of 2K system, ambient magnetic field and radiation shielding, LLRF and the test run of this VTS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB099
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THXA04	Fabrication, Treatment and Test of Large Grain Cavities	700
	J.K. Hao, J.E. Chen, L.W. Feng, L. Lin, K.X. Liu, S.W. Quan, F. Wang, H.M. Xie, F. Zhu PKU, Beijing, People's Republic of China
	Development of SRF technology has been included in the project of Soft X-ray FEL (SXFEL) for a hard X-ray FEL plan in China which would be operated in CW mode. Six 9-cell TESLA type cavities as well as several single-cell cavities made of Ningxia large grain niobium material have been fabricated by Peking University for achieving high gradient and high intrinsic quality factor Q0. The measurements of gradient and Q0 have been carried out with a new vertical test system at PKU. The process of fabrication, surface treatment and test results of these large grain cavities will be presented.
	Slides THXA04 [7.911 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THXA04
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THPB028	Flux Pinning Study of OTIC Niobium Material	797
	S. Chen, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan PKU, Beijing, People's Republic of China
	The performance of superconducting cavities is influenced by the trapped flux during the cooling down through critical temperature, especially for nitrogen doped cavities which are more sensitive to flux trapping. We have investigated the flux trapping of OTIC niobium samples with different grain size. Samples were prepared and heat treated at 800°C and 900°C, followed with different surface removal by BCP. A series of measurements, including MPMS, TOF-SIMS, were carried out on the niobium samples. The results and analysis will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB028
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THPB078	Fabrication of Large-area MgB2 Films on Copper Substrates	917
	X. Guo, K.X. Liu, Z. Ni PKU, Beijing, People's Republic of China Q. Feng, C. Yang Peking University, Beijing, People's Republic of China
	Magnesium diboride (MgB2) is a promising candidate material for SRF cavities because of its higher transition temperature and critical field compared with niobium. To meet the demand of RF test devices, the fabrication of large-area MgB2 films on metal substrates is needed. In this work, MgB2 films with 50-mm diameter were fabri-cated on Cu substrates by using an improved HPCVD setups at Peking University. The transition temperatures of MgB2 film on Cu substrate and with Mo buffer layer on Cu substrate are 36.2 K and 36.5 K, respectively. The fabrication processes, surface morphology, superconduct-ing properties of these large-area MgB2 films are present-ed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB078
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Paper

Title

Page

Vertical Test System for Superconducting RF Cavities at Peking University

631

D. Zhou, J.E. Chen, W. Cheng, L.W. Feng, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan, F. Wang, H.M. Xie, F. Zhu, D.H. Zhuang
PKU, Beijing, People's Republic of China

A new vertical test system (VTS) for superconducting RF cavities has been designed and constructed at Peking University. This facility is designed to operate at a temperature of 2K and with pumping speed of 10g/s for helium gas at 30 mbar. In this paper, we present the structure design, modification of 2K system, ambient magnetic field and radiation shielding, LLRF and the test run of this VTS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB099

Export •

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

THXA04

Fabrication, Treatment and Test of Large Grain Cavities

700

J.K. Hao, J.E. Chen, L.W. Feng, L. Lin, K.X. Liu, S.W. Quan, F. Wang, H.M. Xie, F. Zhu
PKU, Beijing, People's Republic of China

Development of SRF technology has been included in the project of Soft X-ray FEL (SXFEL) for a hard X-ray FEL plan in China which would be operated in CW mode. Six 9-cell TESLA type cavities as well as several single-cell cavities made of Ningxia large grain niobium material have been fabricated by Peking University for achieving high gradient and high intrinsic quality factor Q0. The measurements of gradient and Q0 have been carried out with a new vertical test system at PKU. The process of fabrication, surface treatment and test results of these large grain cavities will be presented.

Slides THXA04 [7.911 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THXA04

Export •

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

THPB028

Flux Pinning Study of OTIC Niobium Material

797

S. Chen, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan
PKU, Beijing, People's Republic of China

The performance of superconducting cavities is influenced by the trapped flux during the cooling down through critical temperature, especially for nitrogen doped cavities which are more sensitive to flux trapping. We have investigated the flux trapping of OTIC niobium samples with different grain size. Samples were prepared and heat treated at 800°C and 900°C, followed with different surface removal by BCP. A series of measurements, including MPMS, TOF-SIMS, were carried out on the niobium samples. The results and analysis will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB028

Export •

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

THPB078

Fabrication of Large-area MgB2 Films on Copper Substrates

917

X. Guo, K.X. Liu, Z. Ni
PKU, Beijing, People's Republic of China
Q. Feng, C. Yang
Peking University, Beijing, People's Republic of China

Magnesium diboride (MgB2) is a promising candidate material for SRF cavities because of its higher transition temperature and critical field compared with niobium. To meet the demand of RF test devices, the fabrication of large-area MgB2 films on metal substrates is needed. In this work, MgB2 films with 50-mm diameter were fabri-cated on Cu substrates by using an improved HPCVD setups at Peking University. The transition temperatures of MgB2 film on Cu substrate and with Mo buffer layer on Cu substrate are 36.2 K and 36.5 K, respectively. The fabrication processes, surface morphology, superconduct-ing properties of these large-area MgB2 films are present-ed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB078

Export •

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