SRF2021 - List of Authors (Kugeler, O.)

Paper	Title	Page
SUPCAV007	Thick Film Morphology and SC Characterizations of 6 GHz Nb/Cu Cavities	18
	V.A. Garcia Diaz, O. Azzolini, E. Chyhyrynets, G. Keppel, C. Pira, F. Stivanello, M. Zanierato INFN/LNL, Legnaro (PD), Italy E. Chyhyrynets Università degli Studi di Padova, Padova, Italy D. Fonnesu CERN, Meyrin, Switzerland O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom M. Vogel University Siegen, Siegen, Germany
	Funding: European Union’s H2020 Framework Programme under Grant Agreement no. 764879 Thick films deposited in long pulse DCMS mode onto 6 GHz copper cavities have demonstrated the mitigation of the Q-slope at low accelerating fields. The Nb thick films (~40 microns) show the possibility to reproduce the bulk niobium superconducting properties and morpholo-gy characterizations exhibited dense and void-free films that are encouraging for the scaling of the process to 1.3 GHz cavities. In this work a full characterization of thick films by DC magnetometry, computer tomography, SEM and RF characterizations are presented.
	Poster SUPCAV007 [1.012 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV007
About •	Received ※ 21 June 2021 — Revised ※ 07 July 2021 — Accepted ※ 16 February 2022 — Issue date ※ 08 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

SUPCAV013	Multipacting Analysis of the Quadripolar Resonator (QPR) at HZB	42
	S. Bira, D. Longuevergne Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France Y. Kalboussi CEA-IRFU, Gif-sur-Yvette, France S. Keckert, J. Knobloch, O. Kugeler HZB, Berlin, Germany Th. Proslier CEA-DRF-IRFU, France
	Multipacting (MP) is a resonating electron discharge, often plaguing radio-frequency (RF) structures, produced by the synchronization of emitted electrons with the RF fields and the electron multiplication at the impact point with the surface structure. The electron multiplication can take place only if the secondary emission yield (SEY, i.e. the number of electrons emitted due to the impact of one incoming electron), , is higher than 1. The SEY value depends strongly on the material and the surface contamination. Multipacting simulations are crucial in high-frenquency (HF) vacuum structures to localize and potentially improve the geometry. In this work, multipacting simulations were carried out on the geometry of the Quadrupole Resonator (QPR) in operation at HZB using the Spark 3D module in Microwave Studio suite (CST). These simulations helped to understand a particular behavior observed during the QPR tests, and furthermore made it possible to suggest enhancement ways in order to limit this phenomenon and facilitate its operation.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV013
About •	Received ※ 09 July 2021 — Revised ※ 09 July 2021 — Accepted ※ 09 April 2022 — Issue date ※ 07 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

SUPFDV006	Investigation of SIS Multilayer Films at HZB	72
	D.B. Tikhonov, S. Keckert, J. Knobloch, O. Kugeler HZB, Berlin, Germany E. Chyhyrynets, C. Pira INFN/LNL, Legnaro (PD), Italy J. Knobloch University of Siegen, Siegen, Germany S.B. Leith, M. Vogel University Siegen, Siegen, Germany
	Funding: The manufacture of the QPR samples received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871 The systematic study of multilayer SIS films (Superconductor-Insulator-Superconductor) is being conducted in Helmholtz-Zentrum Berlin. Such films theoretically should boost the performance of superconducting cavities, and reduce some problems related to bulk Nb such as magnetic flux trapping. Up to now such films have been presented in theory, but the RF performance of those structures have not been widely studied. In this contribution we present the results of the latest tests of AlN-NbN films, deposited on micrometers-thick Nb layers on copper. It has, also, been shown previously at HZB that such SIS films may show some unexpected behavior in surface resistance versus temperature parameter space. In this contribution we continue to investigate those effects with the variation of different parameters of films (such as insulator thickness) and production recipes.
	Poster SUPFDV006 [2.234 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV006
About •	Received ※ 21 June 2021 — Revised ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 21 December 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

SUPFDV012	The Development of HiPIMS Multilayer SIS Film Coatings on Copper for SRF Applications	86
	S.B. Leith, X. Jiang, A.Ö. Sezgin, M. Vogel University Siegen, Siegen, Germany B. Butz, Y. Li, J. Müller MNaF, Siegen, Germany S. Keckert, J. Knobloch, O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany J. Knobloch University of Siegen, Siegen, Germany R. Ries, E. Seiler Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
	Funding: Authors acknowledge both the EASITrain, Marie Sklodowska-Curie Action (MSCA) Innovative Training Network (ITN), Grant Agreement no. 764879 and the ARIES collaboration, Grant Agreement no. 730871 In recent years, the use of alternatives to bulk Nb in the fabrication of SRF cavities, including novel materials and/or fabrication techniques, have been extensively explored by the SRF community. One of these new methodologies is the use of a superconductor-insulator-superconductor (SIS) multilayer structure. Typically, these have been envisaged for use with bulk Nb cavities. However, it is conceivable to combine the benefits of SIS structures with the benefits of coated Cu cavities. It is also clear that the use of energetic deposition techniques such as high power impulse magnetron sputtering (HiPIMS), provide significant benefits over typical DC magnetron sputtering (MS) coatings, in terms of SRF performance. In light of this, two series of multilayer SIS film coatings, with a Nb-AlN-NbN structure, were deposited onto electropolished OFHC Cu samples, with the use of HiPIMS, in order to determine the efficacy of this approach. This contribution details the development of these coatings and the required optimization of the coating parameters of the separate material systems, through the use of multiple material and superconducting characterization techniques.
	Poster SUPFDV012 [2.061 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV012
About •	Received ※ 20 June 2021 — Accepted ※ 21 December 2021 — Issue date ※ 27 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTEV006	Synchrotron XPS Study of Niobium Treated with Nitrogen Infusion	211
	A.L. Prudnikava, J. Knobloch, O. Kugeler, Y. Tamashevich HZB, Berlin, Germany V. Aristov, O. Molodtsova DESY, Hamburg, Germany S. Babenkov LIDYL, Gif sur Yvette, France A. Makarova FUB, Berlin, Germany D. Smirnov Technische Universität Dresden, Dresden, Germany
	Processing of niobium cavities with the so-called ni-trogen infusion treatment demonstrates the improve-ment of efficiency and no degradation of maximal accelerating gradients. However, the chemical compo-sition of the niobium surface and especially the role of nitrogen gas in this treatment has been the topic of many debates. While our study of the infused niobium using synchrotron X-ray Photoelectron Spectroscopy (XPS) showed modification of the surface sub-oxides surprisingly there was no evidence of nitrogen con-centration build up during the 120°C baking step, irre-spectively of N₂ supply. Noteworthy, that the niobium contamination with carbon and nitrogen took place during a prolonged high-temperature anneal even in a high vacuum condition (10-8-10^-9 mbar). Evidently, the amount of such contamination appears to play a key role in the final cavity performance
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPTEV006
About •	Received ※ 21 June 2021 — Revised ※ 13 July 2021 — Accepted ※ 19 August 2021 — Issue date ※ 05 September 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPFDV003	Measuring Flux Trapping Using Flat Samples	326
	F. Kramer, S. Keckert, J. Knobloch, O. Kugeler HZB, Berlin, Germany J. Knobloch University of Siegen, Siegen, Germany
	With modern superconducting cavities flux trapping is a limiting factor for the achievable quality factor. Flux trapping is influenced by various parameters such as geometry, material, and cooldown dynamics. At SRF2019 we presented data showing the magnetic field surrounding a cavity. We now present supplemental simulations for this data focusing on geometric effects. As these simulations are inconclusive, we have designed a new setup to measure trapped flux in superconducting samples which is presented as well. The advantages compared to a cavity test are the simpler sample geometry, and quicker sample production, as well as shorter measurement times. With this setup we hope to identify fundamental mechanisms of flux trapping, including geometry effects, different materials, and different treatments. First results are presented along with the setup itself.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPFDV003
About •	Received ※ 21 June 2021 — Accepted ※ 03 April 2022 — Issue date ※ 02 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPFDV007	Main Highlights of ARIES WP15 Collaboration	571
	O.B. Malyshev, P. Goudket, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.Z. Antoine CEA-IRFU, Gif-sur-Yvette, France O. Azzolini, E. Chyhyrynets, G. Keppel, C. Pira, F. Stivanello INFN/LNL, Legnaro (PD), Italy G. Burt, D.J. Seal, D.A. Turner Cockcroft Institute, Lancaster University, Lancaster, United Kingdom G. Burt, B.S. Sian Lancaster University, Lancaster, United Kingdom O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany S.B. Leith, A.Ö. Sezgin, M. Vogel University Siegen, Siegen, Germany A. Medvids, P. Onufrijevs Riga Technical University, Riga, Latvia R. Ries, E. Seiler Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic B.S. Sian Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Sublet, G. Vandoni, L. Vega Cid, W. Venturini Delsolaro, P. Vidal García CERN, Meyrin, Switzerland D.A. Turner STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: European Commission’s ARIES collaboration H2020 Research and Innovation Programme under Grant Agreement no. 730871 An international collaboration of research teams from CEA (France), CERN (Switzerland), INFN/LNL (Italy), HZB and USI (Germany), IEE (Slovakia), RTU (Latvia) and STFC/DL (UK), are working together on better understanding of how to improve the properties of superconducting thin films (ScTF) for RF cavities. The collaboration has been formed as WP15 in the H2020 ARIES project funded by EC. The systematic study of ScTF covers: Cu substrate polishing with different techniques (EP, SUBU, EP+SUBU, tumbling, laser), Nb, NbN, Nb₃Sn and SIS film deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application of all obtained knowledge on polishing, deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application to the QPR samples for testing the films at RF conditions. The preparation, deposition and characterisation of each sample involves 3-5 partners enhancing the capability of each other and resulting in a more complete analysis of each film. The talk will give an overview of the collaborative research and will be an introduction to the detailed talks given by the team members.
	Poster WEPFDV007 [2.013 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPFDV007
About •	Received ※ 19 June 2021 — Accepted ※ 12 February 2022 — Issue date ※ 10 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FROFDV06	Synthesis of Nb and Alternative Superconducting Film to Nb for SRF Cavity as Single Layer	893
	R. Valizadeh, P. Goudket, A.N. Hannah, O.B. Malyshev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.Z. Antoine CEA-DRF-IRFU, France C.Z. Antoine CEA-IRFU, Gif-sur-Yvette, France E. Chyhyrynets, C. Pira INFN/LNL, Legnaro (PD), Italy P. Goudket, O.B. Malyshev, D.J. Seal, B.S. Sian, D.A. Turner Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Kugeler, D.B. Tikhonov HZB, Berlin, Germany S.B. Leith, A.Ö. Sezgin, M. Vogel University Siegen, Siegen, Germany A. Medvids, P. Onufrijevs Riga Technical University, Riga, Latvia D.J. Seal, B.S. Sian, D.A. Turner Lancaster University, Lancaster, United Kingdom G.B.G. Stenning STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom A. Sublet, G. Vandoni, L. Vega Cid, W. Venturini Delsolaro, P. Vidal García CERN, Meyrin, Switzerland
	"Bulk niobium (Nb) has been the material of choice for superconducting RF (SRF) cavities but for further improvement in cavity RF performance, one may have to turn to films of Nb and to other superconducting materials deposited on copper as thermal and mechanical support. Other materials known as A15, such as Nb₃Sn or V₃Si and B1 such as NbTiN and NbN are much easier to synthesise in thin films rather than being made as bulk cavity. The potential benefits of using materials other than Nb would be a higher Tc, a potentially higher critical held Hc, leading to potentially significant cryogenics cost reduction if the cavity operation temperature is 4.2 K or higher. We report on optimising deposition parameters and effect of substrate treatment prior to deposition for successful synthesising of Nb and the alternative superconducting thin film with high superconducting properties (Tc and Hsh) on flat substrates and QPR samples in single layer. The DC and RF SC properties have been tested using PPMS and QPR measurements. This work is part of the H2020 ARIES collaboration. We further report on preparation of RF cavities employing these alternative material for future cavity production."
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-FROFDV06
About •	Received ※ 21 June 2021 — Accepted ※ 05 January 2022 — Issue date ※ 28 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Thick Film Morphology and SC Characterizations of 6 GHz Nb/Cu Cavities

18

V.A. Garcia Diaz, O. Azzolini, E. Chyhyrynets, G. Keppel, C. Pira, F. Stivanello, M. Zanierato
INFN/LNL, Legnaro (PD), Italy
E. Chyhyrynets
Università degli Studi di Padova, Padova, Italy
D. Fonnesu
CERN, Meyrin, Switzerland
O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M. Vogel
University Siegen, Siegen, Germany

Funding: European Union’s H2020 Framework Programme under Grant Agreement no. 764879
Thick films deposited in long pulse DCMS mode onto 6 GHz copper cavities have demonstrated the mitigation of the Q-slope at low accelerating fields. The Nb thick films (~40 microns) show the possibility to reproduce the bulk niobium superconducting properties and morpholo-gy characterizations exhibited dense and void-free films that are encouraging for the scaling of the process to 1.3 GHz cavities. In this work a full characterization of thick films by DC magnetometry, computer tomography, SEM and RF characterizations are presented.

Poster SUPCAV007 [1.012 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV007

About •

Received ※ 21 June 2021 — Revised ※ 07 July 2021 — Accepted ※ 16 February 2022 — Issue date ※ 08 April 2022

Cite •

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

SUPCAV013

Multipacting Analysis of the Quadripolar Resonator (QPR) at HZB

42

S. Bira, D. Longuevergne
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
Y. Kalboussi
CEA-IRFU, Gif-sur-Yvette, France
S. Keckert, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
Th. Proslier
CEA-DRF-IRFU, France

Multipacting (MP) is a resonating electron discharge, often plaguing radio-frequency (RF) structures, produced by the synchronization of emitted electrons with the RF fields and the electron multiplication at the impact point with the surface structure. The electron multiplication can take place only if the secondary emission yield (SEY, i.e. the number of electrons emitted due to the impact of one incoming electron), , is higher than 1. The SEY value depends strongly on the material and the surface contamination. Multipacting simulations are crucial in high-frenquency (HF) vacuum structures to localize and potentially improve the geometry. In this work, multipacting simulations were carried out on the geometry of the Quadrupole Resonator (QPR) in operation at HZB using the Spark 3D module in Microwave Studio suite (CST). These simulations helped to understand a particular behavior observed during the QPR tests, and furthermore made it possible to suggest enhancement ways in order to limit this phenomenon and facilitate its operation.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV013

About •

Received ※ 09 July 2021 — Revised ※ 09 July 2021 — Accepted ※ 09 April 2022 — Issue date ※ 07 May 2022

Cite •

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

SUPFDV006

Investigation of SIS Multilayer Films at HZB

72

D.B. Tikhonov, S. Keckert, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
E. Chyhyrynets, C. Pira
INFN/LNL, Legnaro (PD), Italy
J. Knobloch
University of Siegen, Siegen, Germany
S.B. Leith, M. Vogel
University Siegen, Siegen, Germany

Funding: The manufacture of the QPR samples received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871
The systematic study of multilayer SIS films (Superconductor-Insulator-Superconductor) is being conducted in Helmholtz-Zentrum Berlin. Such films theoretically should boost the performance of superconducting cavities, and reduce some problems related to bulk Nb such as magnetic flux trapping. Up to now such films have been presented in theory, but the RF performance of those structures have not been widely studied. In this contribution we present the results of the latest tests of AlN-NbN films, deposited on micrometers-thick Nb layers on copper. It has, also, been shown previously at HZB that such SIS films may show some unexpected behavior in surface resistance versus temperature parameter space. In this contribution we continue to investigate those effects with the variation of different parameters of films (such as insulator thickness) and production recipes.

Poster SUPFDV006 [2.234 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV006

About •

Received ※ 21 June 2021 — Revised ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 21 December 2021

Cite •

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

SUPFDV012

The Development of HiPIMS Multilayer SIS Film Coatings on Copper for SRF Applications

86

S.B. Leith, X. Jiang, A.Ö. Sezgin, M. Vogel
University Siegen, Siegen, Germany
B. Butz, Y. Li, J. Müller
MNaF, Siegen, Germany
S. Keckert, J. Knobloch, O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
J. Knobloch
University of Siegen, Siegen, Germany
R. Ries, E. Seiler
Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic

Funding: Authors acknowledge both the EASITrain, Marie Sklodowska-Curie Action (MSCA) Innovative Training Network (ITN), Grant Agreement no. 764879 and the ARIES collaboration, Grant Agreement no. 730871
In recent years, the use of alternatives to bulk Nb in the fabrication of SRF cavities, including novel materials and/or fabrication techniques, have been extensively explored by the SRF community. One of these new methodologies is the use of a superconductor-insulator-superconductor (SIS) multilayer structure. Typically, these have been envisaged for use with bulk Nb cavities. However, it is conceivable to combine the benefits of SIS structures with the benefits of coated Cu cavities. It is also clear that the use of energetic deposition techniques such as high power impulse magnetron sputtering (HiPIMS), provide significant benefits over typical DC magnetron sputtering (MS) coatings, in terms of SRF performance. In light of this, two series of multilayer SIS film coatings, with a Nb-AlN-NbN structure, were deposited onto electropolished OFHC Cu samples, with the use of HiPIMS, in order to determine the efficacy of this approach. This contribution details the development of these coatings and the required optimization of the coating parameters of the separate material systems, through the use of multiple material and superconducting characterization techniques.

Poster SUPFDV012 [2.061 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV012

About •

Received ※ 20 June 2021 — Accepted ※ 21 December 2021 — Issue date ※ 27 April 2022

Cite •

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

MOPTEV006

Synchrotron XPS Study of Niobium Treated with Nitrogen Infusion

211

A.L. Prudnikava, J. Knobloch, O. Kugeler, Y. Tamashevich
HZB, Berlin, Germany
V. Aristov, O. Molodtsova
DESY, Hamburg, Germany
S. Babenkov
LIDYL, Gif sur Yvette, France
A. Makarova
FUB, Berlin, Germany
D. Smirnov
Technische Universität Dresden, Dresden, Germany

Processing of niobium cavities with the so-called ni-trogen infusion treatment demonstrates the improve-ment of efficiency and no degradation of maximal accelerating gradients. However, the chemical compo-sition of the niobium surface and especially the role of nitrogen gas in this treatment has been the topic of many debates. While our study of the infused niobium using synchrotron X-ray Photoelectron Spectroscopy (XPS) showed modification of the surface sub-oxides surprisingly there was no evidence of nitrogen con-centration build up during the 120°C baking step, irre-spectively of N₂ supply. Noteworthy, that the niobium contamination with carbon and nitrogen took place during a prolonged high-temperature anneal even in a high vacuum condition (10-8-10^-9 mbar). Evidently, the amount of such contamination appears to play a key role in the final cavity performance

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPTEV006

About •

Received ※ 21 June 2021 — Revised ※ 13 July 2021 — Accepted ※ 19 August 2021 — Issue date ※ 05 September 2021

Cite •

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

MOPFDV003

Measuring Flux Trapping Using Flat Samples

326

F. Kramer, S. Keckert, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
J. Knobloch
University of Siegen, Siegen, Germany

With modern superconducting cavities flux trapping is a limiting factor for the achievable quality factor. Flux trapping is influenced by various parameters such as geometry, material, and cooldown dynamics. At SRF2019 we presented data showing the magnetic field surrounding a cavity. We now present supplemental simulations for this data focusing on geometric effects. As these simulations are inconclusive, we have designed a new setup to measure trapped flux in superconducting samples which is presented as well. The advantages compared to a cavity test are the simpler sample geometry, and quicker sample production, as well as shorter measurement times. With this setup we hope to identify fundamental mechanisms of flux trapping, including geometry effects, different materials, and different treatments. First results are presented along with the setup itself.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPFDV003

About •

Received ※ 21 June 2021 — Accepted ※ 03 April 2022 — Issue date ※ 02 May 2022

Cite •

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

WEPFDV007

Main Highlights of ARIES WP15 Collaboration

571

O.B. Malyshev, P. Goudket, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.Z. Antoine
CEA-IRFU, Gif-sur-Yvette, France
O. Azzolini, E. Chyhyrynets, G. Keppel, C. Pira, F. Stivanello
INFN/LNL, Legnaro (PD), Italy
G. Burt, D.J. Seal, D.A. Turner
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
G. Burt, B.S. Sian
Lancaster University, Lancaster, United Kingdom
O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
S.B. Leith, A.Ö. Sezgin, M. Vogel
University Siegen, Siegen, Germany
A. Medvids, P. Onufrijevs
Riga Technical University, Riga, Latvia
R. Ries, E. Seiler
Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
B.S. Sian
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Sublet, G. Vandoni, L. Vega Cid, W. Venturini Delsolaro, P. Vidal García
CERN, Meyrin, Switzerland
D.A. Turner
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

Funding: European Commission’s ARIES collaboration H2020 Research and Innovation Programme under Grant Agreement no. 730871
An international collaboration of research teams from CEA (France), CERN (Switzerland), INFN/LNL (Italy), HZB and USI (Germany), IEE (Slovakia), RTU (Latvia) and STFC/DL (UK), are working together on better understanding of how to improve the properties of superconducting thin films (ScTF) for RF cavities. The collaboration has been formed as WP15 in the H2020 ARIES project funded by EC. The systematic study of ScTF covers: Cu substrate polishing with different techniques (EP, SUBU, EP+SUBU, tumbling, laser), Nb, NbN, Nb₃Sn and SIS film deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application of all obtained knowledge on polishing, deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application to the QPR samples for testing the films at RF conditions. The preparation, deposition and characterisation of each sample involves 3-5 partners enhancing the capability of each other and resulting in a more complete analysis of each film. The talk will give an overview of the collaborative research and will be an introduction to the detailed talks given by the team members.

Poster WEPFDV007 [2.013 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPFDV007

About •

Received ※ 19 June 2021 — Accepted ※ 12 February 2022 — Issue date ※ 10 April 2022

Cite •

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

FROFDV06

Synthesis of Nb and Alternative Superconducting Film to Nb for SRF Cavity as Single Layer

893

R. Valizadeh, P. Goudket, A.N. Hannah, O.B. Malyshev
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.Z. Antoine
CEA-DRF-IRFU, France
C.Z. Antoine
CEA-IRFU, Gif-sur-Yvette, France
E. Chyhyrynets, C. Pira
INFN/LNL, Legnaro (PD), Italy
P. Goudket, O.B. Malyshev, D.J. Seal, B.S. Sian, D.A. Turner
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Kugeler, D.B. Tikhonov
HZB, Berlin, Germany
S.B. Leith, A.Ö. Sezgin, M. Vogel
University Siegen, Siegen, Germany
A. Medvids, P. Onufrijevs
Riga Technical University, Riga, Latvia
D.J. Seal, B.S. Sian, D.A. Turner
Lancaster University, Lancaster, United Kingdom
G.B.G. Stenning
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
A. Sublet, G. Vandoni, L. Vega Cid, W. Venturini Delsolaro, P. Vidal García
CERN, Meyrin, Switzerland

"Bulk niobium (Nb) has been the material of choice for superconducting RF (SRF) cavities but for further improvement in cavity RF performance, one may have to turn to films of Nb and to other superconducting materials deposited on copper as thermal and mechanical support. Other materials known as A15, such as Nb₃Sn or V₃Si and B1 such as NbTiN and NbN are much easier to synthesise in thin films rather than being made as bulk cavity. The potential benefits of using materials other than Nb would be a higher Tc, a potentially higher critical held Hc, leading to potentially significant cryogenics cost reduction if the cavity operation temperature is 4.2 K or higher. We report on optimising deposition parameters and effect of substrate treatment prior to deposition for successful synthesising of Nb and the alternative superconducting thin film with high superconducting properties (Tc and Hsh) on flat substrates and QPR samples in single layer. The DC and RF SC properties have been tested using PPMS and QPR measurements. This work is part of the H2020 ARIES collaboration. We further report on preparation of RF cavities employing these alternative material for future cavity production."

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reference for this paper ※ doi:10.18429/JACoW-SRF2021-FROFDV06

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Received ※ 21 June 2021 — Accepted ※ 05 January 2022 — Issue date ※ 28 April 2022

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