SRF2021 - List of Authors (Vidal Garcia, P.)

Paper	Title	Page
TUPTEV009	Seamless 1.3 GHz Copper Cavities for Nb Coatings: Cold Test Results of Two Different Approaches	498
	L. Vega Cid, S. Atieh, L.M.A. Ferreira, L. Laín-Amador, C. Pereira Carlos, G.J. Rosaz, K. Scibor, W. Venturini Delsolaro, P. Vidal García CERN, Meyrin, Switzerland S.B. Leith University Siegen, Siegen, Germany
	A necessary condition for high SRF performances in thin film coated cavities is the absence of substrate defects. For instance, in the past, defects originated around electron beam welds in high magnetic field areas have been shown to be the cause of performance limitations in Nb/Cu cavities. Seamless cavities are therefore good candidates to allow an optimization of the coating parameters without the pitfalls of a changing substrate. In this work, we present the first results of two different methods to produce seamless cavities applied to 1.3 GHz copper single cells coated with thin Nb films by means of HIPIMS. A first method consists in electroplating the copper resonator on precisely machined aluminum mandrels, which are then dissolved chemically. As an alternative and a cross check, one cavity was machined directly from the bulk. Both cavities were coated with HIPIMS Nb films using the same coating parameters and the SRF performance was measured down to 1.8 K with a variable coupler to minimize the measurement uncertainty.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV009
About •	Received ※ 21 June 2021 — Revised ※ 28 October 2021 — Accepted ※ 18 November 2021 — Issue date ※ 10 February 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

Seamless 1.3 GHz Copper Cavities for Nb Coatings: Cold Test Results of Two Different Approaches

498

L. Vega Cid, S. Atieh, L.M.A. Ferreira, L. Laín-Amador, C. Pereira Carlos, G.J. Rosaz, K. Scibor, W. Venturini Delsolaro, P. Vidal García
CERN, Meyrin, Switzerland
S.B. Leith
University Siegen, Siegen, Germany

A necessary condition for high SRF performances in thin film coated cavities is the absence of substrate defects. For instance, in the past, defects originated around electron beam welds in high magnetic field areas have been shown to be the cause of performance limitations in Nb/Cu cavities. Seamless cavities are therefore good candidates to allow an optimization of the coating parameters without the pitfalls of a changing substrate. In this work, we present the first results of two different methods to produce seamless cavities applied to 1.3 GHz copper single cells coated with thin Nb films by means of HIPIMS. A first method consists in electroplating the copper resonator on precisely machined aluminum mandrels, which are then dissolved chemically. As an alternative and a cross check, one cavity was machined directly from the bulk. Both cavities were coated with HIPIMS Nb films using the same coating parameters and the SRF performance was measured down to 1.8 K with a variable coupler to minimize the measurement uncertainty.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV009

About •

Received ※ 21 June 2021 — Revised ※ 28 October 2021 — Accepted ※ 18 November 2021 — Issue date ※ 10 February 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)