SRF2023 - List of Authors (Seal, D.J.)

Paper	Title	Page
MOPMB011	Deposition and Characterisation of V₃Si films for SRF Applications	84
	C. Benjamin, J.A. Conlon, O.B. Malyshev, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt, O.B. Malyshev, D.J. Seal, R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom G. Burt, D.J. Seal Lancaster University, Lancaster, United Kingdom N.L. Leicester, H.S. Marks Cockcroft Institute, Lancaster University, Lancaster, United Kingdom L.G.P. Smith STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 101004730. A15 superconducting materials, like V₃Si and Nb₃Sn, are potential alternatives to Nb for next generation thin film SRF cavities when operated at 4 K. Their relatively high Tc and superconducting properties could allow for higher accelerating gradients and elevated operating temperatures. We present work on the deposition of V₃Si thin films on planar Cu substrates and an open structure 6 GHz cavity, using physical vapour deposition (PVD) and a V₃Si single target. The surface structure, composition and DC superconducting properties of two planar samples were characterised via secondary electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and in a magnetic field penetration facility. Furthermore, the first deposition using PVD of a V₃Si film on a 6 GHz split cavity and the RF performance is presented.
	Poster MOPMB011 [7.496 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB011
About •	Received ※ 16 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 19 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB062	Optimisation of Niobium Thin Film Deposition Parameters for SRF Cavities	253
SUSPB023	use link to see paper's listing under its alternate paper code
	D.J. Seal, O.B. Malyshev, R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom J.A. Conlon, O.B. Malyshev, K.T. Morrow, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	In order to accelerate the progression of thin film (TF) development for future SRF cavities, it is desirable to optimise material properties on small flat samples. Most importantly, this requires the ability to measure their superconducting properties. At Daresbury Laboratory, it has been possible for many years to characterise these films under DC conditions; however, it is not yet fully understood whether this correlates with RF measurements. Recently, a high-throughput RF facility was commissioned that uses a novel 7.8 GHz choke cavity. The facility is able to evaluate the RF performance of planar-coated TF samples at low peak magnetic fields with a high throughput rate of 2-3 samples per week. Using this facility, an optimisation study of the deposition parameters of TF Nb samples deposited by HiPIMS has begun. The ultimate aim is to optimise TF Nb as a base layer for multilayer studies and replicate planar magnetron depositions on split 6 GHz cavities. The initial focus of this study was to investigate the effect of substrate temperature during deposition. A review of the RF facility used and results of this study will be presented.
	Poster MOPMB062 [2.395 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB062
About •	Received ※ 17 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 24 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WECAA01	Progress in European Thin Film Activities	607
	C. Pira, O. Azzolini, R. Caforio, E. Chyhyrynets, D. Fonnesu, D. Ford, V.A. Garcia, G. Keppel, G. Marconato, A. Salmaso, F. Stivanello INFN/LNL, Legnaro (PD), Italy C.Z. Antoine, Y. Kalboussi, Th. Proslier CEA-IRFU, Gif-sur-Yvette, France C. Benjamin, O.B. Malyshev, N. Marks, B.S. Sian, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C. Benjamin, J.W. Bradley, G. Burt, O.B. Malyshev, N. Marks, D.J. Seal, B.S. Sian, S. Simon, D.A. Turner, R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom S. Berry CEA-DRF-IRFU, France R. Berton, D. Piccoli, F. Piccoli, G. Squizzato, F. Telatin Piccoli, Noale (VE), Italy M. Bertucci, R. Paparella INFN/LASA, Segrate (MI), Italy M. Bonesso, S. Candela, V. Candela, R. Dima, G. Favero, A. Pepato, P. Rebesan, M. Romanato INFN- Sez. di Padova, Padova, Italy J.W. Bradley, S. Simon The University of Liverpool, Liverpool, United Kingdom G. Burt, D.J. Seal, D.A. Turner Lancaster University, Lancaster, United Kingdom O. Hryhorenko, D. Longuevergne Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France X. Jiang, T. Staedler, A.O. Zubtsovskii University Siegen, Siegen, Germany S. Keckert, J. Knobloch, O. Kugeler HZB, Berlin, Germany J. Knobloch University of Siegen, Siegen, Germany N.L. Leicester Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A. Medvids, A. Mychko, P. Onufrijevs Riga Technical University, Riga, Latvia S. Prucnal, S. Zhou HZDR, Dresden, Germany R. Ries Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic E. Seiler IEE, Bratislava, Slovak Republic L.G.P. Smith STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: This project has received funding from the European Union s Horizon 2020 Research and Innovation programme under Grant Agreement No 101004730. Thin-film cavities with higher Tc superconductors (SC) than Nb promise to move the operating temperature from 2 to 4.5 K with savings 3 orders of magnitude in cryogenic power consumption. Several European labs are coordinating their efforts to obtain a first 1.3 GHz cavity prototype through the I.FAST collaboration and other informal collaborations with CERN and DESY. R&D covers the entire production chain. In particular, new production techniques of seamless Copper and Niobium elliptical cavities via additive manufacturing are studied and evaluated. New acid-free polishing techniques to reduce surface roughness in a more sustainable way such as plasma electropolishing and metallographic polishing have been tested. Optimization of coating parameters of higher Tc SC than Nb (Nb₃Sn, V₃Si, NbTiN) via PVD and multilayer via ALD are on the way. Finally, rapid heat treatments such as Flash Lamp Annealing and Laser Annealing are used to avoid or reduce Cu diffusion in the SC film. The development and characterization of SC coatings is done on planar samples, 6 GHz cavities, choke cavities, QPR and 1.3 GHz cavities. This work presents the progress status of these coordinated efforts.
	Slides WECAA01 [15.846 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WECAA01
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 02 September 2023 — Issue date ※ 02 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB001	Development and Testing of Split 6 GHz Cavities With Niobium Coatings	51
	N.L. Leicester, G. Burt, H.S. Marks Cockcroft Institute, Lancaster University, Lancaster, United Kingdom E. Chyhyrynets, C. Pira INFN/LNL, Legnaro (PD), Italy J.A. Conlon, O.B. Malyshev, B.S. Sian, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D.J. Seal Lancaster University, Lancaster, United Kingdom
	Superconducting thin-films on a copper substrate are used in accelerator RF cavities as an alternative to bulk Nb due to the high thermal conductivity of copper and the lower production costs. Although thin-film coated RF cavities can match, or even exceed the performance of bulk Nb, there are some challenges around the deposition. The RF cavities are often produced as two half-cells with a weld across the centre where the RF surface current is highest, which could reduce cavity performance. To avoid this, a cavity can be produced in 2 longitudinally split halves, with the join parallel to the surface current. As the current doesn’t cross the join a simpler weld can be performed far from the fields, simplifying the manufacturing process, and potentially improving the cavities performance. This additionally allows for different deposition techniques and coating materials to be used, as well as easier post-deposition quality control. This paper discusses the development and testing of 6 GHz cavities that have been designed and coated at the Cockcroft Institute, using low temperature RF techniques to characterise cavities with different substrate preparations and coating techniques.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB001
About •	Received ※ 18 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 04 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Deposition and Characterisation of V₃Si films for SRF Applications

84

C. Benjamin, J.A. Conlon, O.B. Malyshev, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt, O.B. Malyshev, D.J. Seal, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G. Burt, D.J. Seal
Lancaster University, Lancaster, United Kingdom
N.L. Leicester, H.S. Marks
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
L.G.P. Smith
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 101004730.
A15 superconducting materials, like V₃Si and Nb₃Sn, are potential alternatives to Nb for next generation thin film SRF cavities when operated at 4 K. Their relatively high Tc and superconducting properties could allow for higher accelerating gradients and elevated operating temperatures. We present work on the deposition of V₃Si thin films on planar Cu substrates and an open structure 6 GHz cavity, using physical vapour deposition (PVD) and a V₃Si single target. The surface structure, composition and DC superconducting properties of two planar samples were characterised via secondary electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and in a magnetic field penetration facility. Furthermore, the first deposition using PVD of a V₃Si film on a 6 GHz split cavity and the RF performance is presented.

Poster MOPMB011 [7.496 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB011

About •

Received ※ 16 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 19 July 2023

Cite •

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

MOPMB062

Optimisation of Niobium Thin Film Deposition Parameters for SRF Cavities

253

SUSPB023

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

D.J. Seal, O.B. Malyshev, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
J.A. Conlon, O.B. Malyshev, K.T. Morrow, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

In order to accelerate the progression of thin film (TF) development for future SRF cavities, it is desirable to optimise material properties on small flat samples. Most importantly, this requires the ability to measure their superconducting properties. At Daresbury Laboratory, it has been possible for many years to characterise these films under DC conditions; however, it is not yet fully understood whether this correlates with RF measurements. Recently, a high-throughput RF facility was commissioned that uses a novel 7.8 GHz choke cavity. The facility is able to evaluate the RF performance of planar-coated TF samples at low peak magnetic fields with a high throughput rate of 2-3 samples per week. Using this facility, an optimisation study of the deposition parameters of TF Nb samples deposited by HiPIMS has begun. The ultimate aim is to optimise TF Nb as a base layer for multilayer studies and replicate planar magnetron depositions on split 6 GHz cavities. The initial focus of this study was to investigate the effect of substrate temperature during deposition. A review of the RF facility used and results of this study will be presented.

Poster MOPMB062 [2.395 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB062

About •

Received ※ 17 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 24 July 2023

Cite •

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

WECAA01

Progress in European Thin Film Activities

607

C. Pira, O. Azzolini, R. Caforio, E. Chyhyrynets, D. Fonnesu, D. Ford, V.A. Garcia, G. Keppel, G. Marconato, A. Salmaso, F. Stivanello
INFN/LNL, Legnaro (PD), Italy
C.Z. Antoine, Y. Kalboussi, Th. Proslier
CEA-IRFU, Gif-sur-Yvette, France
C. Benjamin, O.B. Malyshev, N. Marks, B.S. Sian, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C. Benjamin, J.W. Bradley, G. Burt, O.B. Malyshev, N. Marks, D.J. Seal, B.S. Sian, S. Simon, D.A. Turner, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom
S. Berry
CEA-DRF-IRFU, France
R. Berton, D. Piccoli, F. Piccoli, G. Squizzato, F. Telatin
Piccoli, Noale (VE), Italy
M. Bertucci, R. Paparella
INFN/LASA, Segrate (MI), Italy
M. Bonesso, S. Candela, V. Candela, R. Dima, G. Favero, A. Pepato, P. Rebesan, M. Romanato
INFN- Sez. di Padova, Padova, Italy
J.W. Bradley, S. Simon
The University of Liverpool, Liverpool, United Kingdom
G. Burt, D.J. Seal, D.A. Turner
Lancaster University, Lancaster, United Kingdom
O. Hryhorenko, D. Longuevergne
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
X. Jiang, T. Staedler, A.O. Zubtsovskii
University Siegen, Siegen, Germany
S. Keckert, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
J. Knobloch
University of Siegen, Siegen, Germany
N.L. Leicester
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A. Medvids, A. Mychko, P. Onufrijevs
Riga Technical University, Riga, Latvia
S. Prucnal, S. Zhou
HZDR, Dresden, Germany
R. Ries
Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
E. Seiler
IEE, Bratislava, Slovak Republic
L.G.P. Smith
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

Funding: This project has received funding from the European Union s Horizon 2020 Research and Innovation programme under Grant Agreement No 101004730.
Thin-film cavities with higher Tc superconductors (SC) than Nb promise to move the operating temperature from 2 to 4.5 K with savings 3 orders of magnitude in cryogenic power consumption. Several European labs are coordinating their efforts to obtain a first 1.3 GHz cavity prototype through the I.FAST collaboration and other informal collaborations with CERN and DESY. R&D covers the entire production chain. In particular, new production techniques of seamless Copper and Niobium elliptical cavities via additive manufacturing are studied and evaluated. New acid-free polishing techniques to reduce surface roughness in a more sustainable way such as plasma electropolishing and metallographic polishing have been tested. Optimization of coating parameters of higher Tc SC than Nb (Nb₃Sn, V₃Si, NbTiN) via PVD and multilayer via ALD are on the way. Finally, rapid heat treatments such as Flash Lamp Annealing and Laser Annealing are used to avoid or reduce Cu diffusion in the SC film. The development and characterization of SC coatings is done on planar samples, 6 GHz cavities, choke cavities, QPR and 1.3 GHz cavities. This work presents the progress status of these coordinated efforts.

Slides WECAA01 [15.846 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WECAA01

About •

Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 02 September 2023 — Issue date ※ 02 September 2023

Cite •

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

MOPMB001

Development and Testing of Split 6 GHz Cavities With Niobium Coatings

51

N.L. Leicester, G. Burt, H.S. Marks
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
E. Chyhyrynets, C. Pira
INFN/LNL, Legnaro (PD), Italy
J.A. Conlon, O.B. Malyshev, B.S. Sian, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Seal
Lancaster University, Lancaster, United Kingdom

Superconducting thin-films on a copper substrate are used in accelerator RF cavities as an alternative to bulk Nb due to the high thermal conductivity of copper and the lower production costs. Although thin-film coated RF cavities can match, or even exceed the performance of bulk Nb, there are some challenges around the deposition. The RF cavities are often produced as two half-cells with a weld across the centre where the RF surface current is highest, which could reduce cavity performance. To avoid this, a cavity can be produced in 2 longitudinally split halves, with the join parallel to the surface current. As the current doesn’t cross the join a simpler weld can be performed far from the fields, simplifying the manufacturing process, and potentially improving the cavities performance. This additionally allows for different deposition techniques and coating materials to be used, as well as easier post-deposition quality control. This paper discusses the development and testing of 6 GHz cavities that have been designed and coated at the Cockcroft Institute, using low temperature RF techniques to characterise cavities with different substrate preparations and coating techniques.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB001

About •

Received ※ 18 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 04 July 2023

Cite •

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