SRF2021 - List of Authors (Rosaz, G.J.)

Paper	Title	Page
SUPFDV018	CERN Based T_c Measurement Station for Thin-Film Coated Copper Samples and Results on Related Studies	105
	D. Fonnesu, J. Bremer, T. Koettig, L. Laín-Amador, C. Pereira Carlos, G.J. Rosaz, A.P.O. Vaaranta CERN, Meyrin, Switzerland
	Funding: EASITrain - European Advanced Superconductivity Innovation and Training. This MSCA ITN has received funding from the European Union’s H2020 Framework Programme under GA no. 764879. In the framework of The Future Circular Collider (FCC) Study, the development of thin-film coated superconducting radio-frequency (SRF) cavities capable of providing higher accelerating fields (10 to 20 MV/m against 5 MV/m of LHC) represents a major challenge. In this work, we present the development of a test stand commissioned at CERN for the inductive measurement of the critical temperature (T_c) of SC thin-film deposited on copper samples for SRF applications. Based on new studies for the production of Non Evaporable Getters (NEG) coated chambers [1], we also present the first results of an alternative forming method for seamless copper cavities with niobium layer integrated in the production process. [1] doi:10.1116/1.4999539
	Poster SUPFDV018 [1.616 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV018
About •	Received ※ 21 June 2021 — Revised ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 01 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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)

Paper

Title

Page

CERN Based T_c Measurement Station for Thin-Film Coated Copper Samples and Results on Related Studies

105

D. Fonnesu, J. Bremer, T. Koettig, L. Laín-Amador, C. Pereira Carlos, G.J. Rosaz, A.P.O. Vaaranta
CERN, Meyrin, Switzerland

Funding: EASITrain - European Advanced Superconductivity Innovation and Training. This MSCA ITN has received funding from the European Union’s H2020 Framework Programme under GA no. 764879.
In the framework of The Future Circular Collider (FCC) Study, the development of thin-film coated superconducting radio-frequency (SRF) cavities capable of providing higher accelerating fields (10 to 20 MV/m against 5 MV/m of LHC) represents a major challenge. In this work, we present the development of a test stand commissioned at CERN for the inductive measurement of the critical temperature (T_c) of SC thin-film deposited on copper samples for SRF applications. Based on new studies for the production of Non Evaporable Getters (NEG) coated chambers [1], we also present the first results of an alternative forming method for seamless copper cavities with niobium layer integrated in the production process.
[1] doi:10.1116/1.4999539

Poster SUPFDV018 [1.616 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV018

About •

Received ※ 21 June 2021 — Revised ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 01 May 2022

Cite •

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

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)