SRF2019 - List of Authors (Tikhonov, D.B.)

Paper	Title	Page
TUP073	Superconducting Thin Films Characterization at HZB with the Quadrupole Resonator	616
	D.B. Tikhonov, S. Keckert, J. Knobloch, O. Kugeler, Y. Tamashevich HZB, Berlin, Germany A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: EASITrain - European Advanced Superconductivity Innovation and Training. This Marie Sklodowska-Curie Action Innovative Training Networks founded by H₂020 under Grant Agreement no. 764879 Superconducting thin films have great potential as post-Nb material for use in SRF applications in future accelerators and industry. To test the RF-performance of such films in practice, would require the building and coating of a full RF cavity. Deposition of thin films on such scales in test facilities are challenging, in particular when curved surfaces have to be coated. This greatly complicates their systematic research. In this contribution we report on the method we use to characterize small and flat thin film samples (Deposited onto both Nb and Cu substrates) in an actual cavity named the Quadrupole Resonator (QPR). We also summarize the latest measurement results of NbTiN thin films. The Quadrupole Resonator at HZB is a tool that is able to perform SRF characterizations at frequencies ~415, 847, 1300 MHz with RF fields using an RF-DC power compensation technique.
	Poster TUP073 [2.318 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP073
About •	paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019
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THFUA1	RF Characterization of an S-I-S’ Multilayer Sample	800
	S. Keckert, J. Knobloch, O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	S-I-S’ multilayers promise to boost the performance of bulk superconductors in terms of maximum field and surface resistance. At HZB, RF-surface resistance measurements were performed with a Quadrupole Resonator (QPR) and an S-I-S’ sample (75 nm NbTiN on 15 nm AlN insulator on bulk Nb) prepared at JLab. Measurements were performed at 414, 845, and 1286 MHz at sample temperatures from 2 K up to well above the transition temperature of NbTiN of ~17.3 K. The Rs exhibits an unexpected temperature dependence: Rather than rising monotonically, as expected from BCS theory, a local maximum is observed. There is a temperature range where Rs decreases with increasing temperature. Such behavior indicates that an additional interaction between the superconducting layers may have to be included in the surface resistance model. Measurements of the baseline Nb sample prior to coating exhibited no such behavior; hence systematic measurement errors can be excluded as the explanation. The maximum field was limited by a hard magnetic quench near 20 mT, close to Hc1 of NbTiN, suggesting that the sample is limited by early flux penetration.
	Slides THFUA1 [1.004 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THFUA1
About •	paper received ※ 22 June 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019
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THFUA3	Material and Superconducting Properties of NbTiN/AlN Multilayer Films
	A-M. Valente-Feliciano, D.R. Beverstock, C.E. Reece JLab, Newport News, Virginia, USA C.Z. Antoine CEA-DRF-IRFU, France S. Keckert, O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany M.J. Kelley The College of William and Mary, Williamsburg, Virginia, USA R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DARPA-BAA MIPR No. HD0011728910 In the pursuit of increasing the range of surface magnetic fields sustainable in SRF cavities, new standards in quality of thin multi-layer superconductor/insulator/superconductor (SIS) structures are being achieved. With the synergistic development of multilayered metamaterials based on 3 to 1 nm NbTiN and AlN films, the interface between films is improved. Based on bulk film values, the maximum magnetic field contour plot is also established for NbTiN to guide the choice of each layer thickness and quickly converge to optimized SIS structures. The delayed DC flux entry is measured for standalone NbTiN films and multilayer stacked structures on ideal substrates and Nb substrates. Some SIS structures along with standalone NbTiN films have been deposited on Nb and their superconducting properties and RF surface impedance are evaluated.
	Slides THFUA3 [28.515 MB]
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THP004	Design and Fabrication of a Quadrupole-Resonator for Sample R&D	838
SUSP042	use link to see paper's listing under its alternate paper code
	R. Monroy-Villa, D. Reschke, M. Wenskat DESY, Hamburg, Germany W. Hillert, R. Monroy-Villa, M. Wenskat University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany S. Keckert, O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany P. Putek, S.G. Zadeh, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany U. van Rienen University of Rostock, Rostock, Germany
	Being able to obtain BCS and material properties from the same surface is necessary to gain a fundamental understanding of the evolution of SRF surfaces. A test resonator which will allow to obtain BCS properties from samples is currently under development at the University of Hamburg and DESY and is based on the Quadrupole Resonators developed and operated at CERN and HZB. The current status of the necessary infrastructure, the procurement process and design considerations are shown. In addition, an outline of the planed R&D project with the Quadrupole Resonator will be presented and first RF measurements and surface analysis results of samples will be shown
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP004
About •	paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Superconducting Thin Films Characterization at HZB with the Quadrupole Resonator

616

D.B. Tikhonov, S. Keckert, J. Knobloch, O. Kugeler, Y. Tamashevich
HZB, Berlin, Germany
A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

Funding: EASITrain - European Advanced Superconductivity Innovation and Training. This Marie Sklodowska-Curie Action Innovative Training Networks founded by H₂020 under Grant Agreement no. 764879
Superconducting thin films have great potential as post-Nb material for use in SRF applications in future accelerators and industry. To test the RF-performance of such films in practice, would require the building and coating of a full RF cavity. Deposition of thin films on such scales in test facilities are challenging, in particular when curved surfaces have to be coated. This greatly complicates their systematic research. In this contribution we report on the method we use to characterize small and flat thin film samples (Deposited onto both Nb and Cu substrates) in an actual cavity named the Quadrupole Resonator (QPR). We also summarize the latest measurement results of NbTiN thin films. The Quadrupole Resonator at HZB is a tool that is able to perform SRF characterizations at frequencies ~415, 847, 1300 MHz with RF fields using an RF-DC power compensation technique.

Poster TUP073 [2.318 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP073

About •

paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019

Export •

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

THFUA1

RF Characterization of an S-I-S’ Multilayer Sample

800

S. Keckert, J. Knobloch, O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

S-I-S’ multilayers promise to boost the performance of bulk superconductors in terms of maximum field and surface resistance. At HZB, RF-surface resistance measurements were performed with a Quadrupole Resonator (QPR) and an S-I-S’ sample (75 nm NbTiN on 15 nm AlN insulator on bulk Nb) prepared at JLab. Measurements were performed at 414, 845, and 1286 MHz at sample temperatures from 2 K up to well above the transition temperature of NbTiN of ~17.3 K. The Rs exhibits an unexpected temperature dependence: Rather than rising monotonically, as expected from BCS theory, a local maximum is observed. There is a temperature range where Rs decreases with increasing temperature. Such behavior indicates that an additional interaction between the superconducting layers may have to be included in the surface resistance model. Measurements of the baseline Nb sample prior to coating exhibited no such behavior; hence systematic measurement errors can be excluded as the explanation. The maximum field was limited by a hard magnetic quench near 20 mT, close to Hc1 of NbTiN, suggesting that the sample is limited by early flux penetration.

Slides THFUA1 [1.004 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THFUA1

About •

paper received ※ 22 June 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019

Export •

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

THFUA3

Material and Superconducting Properties of NbTiN/AlN Multilayer Films

A-M. Valente-Feliciano, D.R. Beverstock, C.E. Reece
JLab, Newport News, Virginia, USA
C.Z. Antoine
CEA-DRF-IRFU, France
S. Keckert, O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
M.J. Kelley
The College of William and Mary, Williamsburg, Virginia, USA
R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DARPA-BAA MIPR No. HD0011728910
In the pursuit of increasing the range of surface magnetic fields sustainable in SRF cavities, new standards in quality of thin multi-layer superconductor/insulator/superconductor (SIS) structures are being achieved. With the synergistic development of multilayered metamaterials based on 3 to 1 nm NbTiN and AlN films, the interface between films is improved. Based on bulk film values, the maximum magnetic field contour plot is also established for NbTiN to guide the choice of each layer thickness and quickly converge to optimized SIS structures. The delayed DC flux entry is measured for standalone NbTiN films and multilayer stacked structures on ideal substrates and Nb substrates. Some SIS structures along with standalone NbTiN films have been deposited on Nb and their superconducting properties and RF surface impedance are evaluated.

Slides THFUA3 [28.515 MB]

Export •

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

THP004

Design and Fabrication of a Quadrupole-Resonator for Sample R&D

838

SUSP042

use link to see paper's listing under its alternate paper code

R. Monroy-Villa, D. Reschke, M. Wenskat
DESY, Hamburg, Germany
W. Hillert, R. Monroy-Villa, M. Wenskat
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
S. Keckert, O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
P. Putek, S.G. Zadeh, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
U. van Rienen
University of Rostock, Rostock, Germany

Being able to obtain BCS and material properties from the same surface is necessary to gain a fundamental understanding of the evolution of SRF surfaces. A test resonator which will allow to obtain BCS properties from samples is currently under development at the University of Hamburg and DESY and is based on the Quadrupole Resonators developed and operated at CERN and HZB. The current status of the necessary infrastructure, the procurement process and design considerations are shown. In addition, an outline of the planed R&D project with the Quadrupole Resonator will be presented and first RF measurements and surface analysis results of samples will be shown

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP004

About •

paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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