LINAC2016 - List of Keywords (superconductivity)

Paper	Title	Other Keywords	Page
MOPLR032	Preparation for Cavity Material Studies at the Vertical High-Temperature UHV-Furnace of the S-DALINAC	vacuum, niobium, simulation, SRF	209
	R. Grewe, L. Alff, J. Conrad, T. Kürzeder, M. Major, N. Pietralla TU Darmstadt, Darmstadt, Germany F. Hug IKP, Mainz, Germany
	Funding: Work supported by the Federal Ministry of Education and Research through grant No. 05H15RDRBA. Since 2005 the Institute for Nuclear Physics at the Technische Universität Darmstadt operates a high temperature vacuum furnace. It is designed to reach temperatures of up to 1800°C. It has been used for baking out several niobium superconducting RF cavities at 850°C with proven success. Current research for improving the performance of SRF cavities is focused on nitrogen treatment of such cavities. Nitrogen doping of SRF cavtities results in an up to four times higher quality-factor as compared to untreated cavities. At higher temperatures between 1300°C and 1700°C the so-called delta-phase of NbN forms, which is highly interesting for applications to superconducting accelerator technology*. The UHV-furnace at the S-DALINAC offers the possibility to treat niobium samples at considerably higher temperatures than what has been done up to now in order to study the effect of delta-phase NbN and N-doping on superconducting properties. The furnace has been refurbished and recommissioned to realize research on nitrogen treatment of niobium samples. We will report on our first experiences with operating the upgraded furnace. Araz et al., Proceedings of SRF05, 2015 Grasselino et al., Superconducting Science and Technology, 2013 *Pham Tu et al., Proceedings of SRF87, 1987
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR032
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TUPLR023	Impurity Content Optimization to Maximize Q-Factors of Superconducting Resonators	cavity, SRF, factory, niobium	515
	M. Martinello, M. Checchin, A. Grassellino, O.S. Melnychuk, S. Posen, A. Romanenko, D.A. Sergatskov Fermilab, Batavia, Illinois, USA M. Checchin Illinois Institute of Technology, Chicago, Illlinois, USA J. Zasadzinski IIT, Chicago, Illinois, USA
	Quality factor of superconducting radio-frequency (SRF) cavities is degraded whenever magnetic flux is trapped in the cavity walls during the cooldown. In this contribution we study how the trapped flux sensitivity, defined as the trapped flux surface resistance normalized for the amount of trapped flux, depends on the mean free path. A systematic study of a variety of 1.3 GHz cavities with different surface treatments (EP, 120 C bake and different N-doping) is carried out. A bell shaped trend appears for the range of mean free path studied. Over-doped cavities fall at the maximum of this curve defining the largest values of sensitivity. In addition, we have studied the trend of the BCS surface resistance contribution as a function of mean free path, showing that N-doped cavities follow close to the theoretical minimum. Adding these results together we show that the 2/6 N-doping treatment gives the highest Q-factor values at 2 K and 16 MV/m, as long as the magnetic field fully trapped during the cavity cooldown is lower than 10 mG.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR023
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TUPLR035	RF Analysis of Electropolishing for EXFEL Cavities Production at Ettore Zanon Spa	cavity, shielding, cathode, SRF	544
	A.A. Sulimov DESY, Hamburg, Germany M. Giaretta, A. Gresele, A. Visentin Ettore Zanon S.p.A., Nuclear Division, Schio, Italy
	After successful finishing of superconducting cavities mass production at Ettore Zanon S.p.A. (EZ) for the European XFEL (EXFEL), the authors had the possibility to provide a detailed analysis of the electropolishing (EP) process. The analysis of EP material removal is based on specified RF measurements and was used for the determination of both, the ratio between cavity's iris and equator and uniformity in different cells. A comparison of the RF measurements results with mechanical measurements is presented.
	Poster TUPLR035 [0.195 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR035
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TUP106004	Status of RRR Analysis for RAON Accelerator	niobium, cavity, vacuum, SRF	628
	Y. Jung, H. Kim, W.K. Kim IBS, Daejeon, Republic of Korea J. Lee, J. Seo Vitzrotech Co., Ltd., Ansan City, Kyunggi-Do, Republic of Korea
	Residual resistance ratio (RRR) of 300-grade niobium has been analyzed to find optimal welding condition for a superconducting cavity. RRR values were not only measured along the welding directions, but also perpendicular to the welding lines. In this presentation, we will show the RRR analysis as a function of the distance, the welding speed, and the welding pressure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUP106004
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THPLR030	Performances of the Two First Single Spoke Prototypes for the MYRRHA Project	cavity, cryomodule, simulation, linac	916
	D. Longuevergne, J.-L. Biarrotte, S. Blivet, P. Duchesne, G. Olry, H. Saugnac IPN, Orsay, France Y. Gómez Martínez LPSC, Grenoble Cedex, France
	Funding: This work is being supported by the Euratom research and training program 2014-2018 under grant agreement N°662186 (MYRTE project) The MYRRHA project aims at the construction of an accelerator driven system (ADS) at MOL (Belgium) for irradiation and transmutation experiment purposes. The facility will feature a superconducting LINAC able to produce a proton flux of 2.4 MW (600 MeV - 4 mA). The first section of the superconducting LINAC will be composed of 352 MHz (β = 0.37) Single Spoke Resonators (SSR) housed in short cryomodules operating at 2K. After a brief presentation of the cryomodule design, this paper will aim at presenting the RF performances of the SSR tested in vertical cryostat in the framework of European MYRTE project (MYRRHA Research and Transmutation Endeavour) and at comparing experimental results (Lorentz forces, pressure sensitivity, multipacting barriers…) to simulated values.
	Poster THPLR030 [1.610 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR030
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Paper

Title

Other Keywords

Page

MOPLR032

Preparation for Cavity Material Studies at the Vertical High-Temperature UHV-Furnace of the S-DALINAC

vacuum, niobium, simulation, SRF

209

R. Grewe, L. Alff, J. Conrad, T. Kürzeder, M. Major, N. Pietralla
TU Darmstadt, Darmstadt, Germany
F. Hug
IKP, Mainz, Germany

Funding: Work supported by the Federal Ministry of Education and Research through grant No. 05H15RDRBA.
Since 2005 the Institute for Nuclear Physics at the Technische Universität Darmstadt operates a high temperature vacuum furnace. It is designed to reach temperatures of up to 1800°C. It has been used for baking out several niobium superconducting RF cavities at 850°C with proven success*. Current research for improving the performance of SRF cavities is focused on nitrogen treatment of such cavities. Nitrogen doping of SRF cavtities results in an up to four times higher quality-factor as compared to untreated cavities**. At higher temperatures between 1300°C and 1700°C the so-called delta-phase of NbN forms, which is highly interesting for applications to superconducting accelerator technology***. The UHV-furnace at the S-DALINAC offers the possibility to treat niobium samples at considerably higher temperatures than what has been done up to now in order to study the effect of delta-phase NbN and N-doping on superconducting properties. The furnace has been refurbished and recommissioned to realize research on nitrogen treatment of niobium samples. We will report on our first experiences with operating the upgraded furnace.
*Araz et al., Proceedings of SRF05, 2015
**Grasselino et al., Superconducting Science and Technology, 2013
***Pham Tu et al., Proceedings of SRF87, 1987

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR032

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

TUPLR023

Impurity Content Optimization to Maximize Q-Factors of Superconducting Resonators

cavity, SRF, factory, niobium

515

M. Martinello, M. Checchin, A. Grassellino, O.S. Melnychuk, S. Posen, A. Romanenko, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA
M. Checchin
Illinois Institute of Technology, Chicago, Illlinois, USA
J. Zasadzinski
IIT, Chicago, Illinois, USA

Quality factor of superconducting radio-frequency (SRF) cavities is degraded whenever magnetic flux is trapped in the cavity walls during the cooldown. In this contribution we study how the trapped flux sensitivity, defined as the trapped flux surface resistance normalized for the amount of trapped flux, depends on the mean free path. A systematic study of a variety of 1.3 GHz cavities with different surface treatments (EP, 120 C bake and different N-doping) is carried out. A bell shaped trend appears for the range of mean free path studied. Over-doped cavities fall at the maximum of this curve defining the largest values of sensitivity. In addition, we have studied the trend of the BCS surface resistance contribution as a function of mean free path, showing that N-doped cavities follow close to the theoretical minimum. Adding these results together we show that the 2/6 N-doping treatment gives the highest Q-factor values at 2 K and 16 MV/m, as long as the magnetic field fully trapped during the cavity cooldown is lower than 10 mG.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR023

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

TUPLR035

RF Analysis of Electropolishing for EXFEL Cavities Production at Ettore Zanon Spa

cavity, shielding, cathode, SRF

544

A.A. Sulimov
DESY, Hamburg, Germany
M. Giaretta, A. Gresele, A. Visentin
Ettore Zanon S.p.A., Nuclear Division, Schio, Italy

After successful finishing of superconducting cavities mass production at Ettore Zanon S.p.A. (EZ) for the European XFEL (EXFEL), the authors had the possibility to provide a detailed analysis of the electropolishing (EP) process. The analysis of EP material removal is based on specified RF measurements and was used for the determination of both, the ratio between cavity's iris and equator and uniformity in different cells. A comparison of the RF measurements results with mechanical measurements is presented.

Poster TUPLR035 [0.195 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR035

Export •

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

TUP106004

Status of RRR Analysis for RAON Accelerator

niobium, cavity, vacuum, SRF

628

Y. Jung, H. Kim, W.K. Kim
IBS, Daejeon, Republic of Korea
J. Lee, J. Seo
Vitzrotech Co., Ltd., Ansan City, Kyunggi-Do, Republic of Korea

Residual resistance ratio (RRR) of 300-grade niobium has been analyzed to find optimal welding condition for a superconducting cavity. RRR values were not only measured along the welding directions, but also perpendicular to the welding lines. In this presentation, we will show the RRR analysis as a function of the distance, the welding speed, and the welding pressure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUP106004

Export •

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

THPLR030

Performances of the Two First Single Spoke Prototypes for the MYRRHA Project

cavity, cryomodule, simulation, linac

916

D. Longuevergne, J.-L. Biarrotte, S. Blivet, P. Duchesne, G. Olry, H. Saugnac
IPN, Orsay, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France

Funding: This work is being supported by the Euratom research and training program 2014-2018 under grant agreement N°662186 (MYRTE project)
The MYRRHA project aims at the construction of an accelerator driven system (ADS) at MOL (Belgium) for irradiation and transmutation experiment purposes. The facility will feature a superconducting LINAC able to produce a proton flux of 2.4 MW (600 MeV - 4 mA). The first section of the superconducting LINAC will be composed of 352 MHz (β = 0.37) Single Spoke Resonators (SSR) housed in short cryomodules operating at 2K. After a brief presentation of the cryomodule design, this paper will aim at presenting the RF performances of the SSR tested in vertical cryostat in the framework of European MYRTE project (MYRRHA Research and Transmutation Endeavour) and at comparing experimental results (Lorentz forces, pressure sensitivity, multipacting barriers…) to simulated values.

Poster THPLR030 [1.610 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR030

Export •

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