SRF2023 - List of Authors (Venturini Delsolaro, W.)

Paper	Title	Page
WEIXA02	Results of the R&D RF Testing Campaign of 1.3 GHz Nb/Cu Cavities	621
	L. Vega Cid, S. Atieh, G. Bellini, A. Bianchi, L.M.A. Ferreira, C. Pereira Carlos, G.J. Rosaz, W. Venturini Delsolaro CERN, Meyrin, Switzerland S.B. Leith European Organization for Nuclear Research (CERN), Geneva, Switzerland
	In the context of the R&D program on Nb/Cu carried out at CERN, a total of 25 tests have been performed since 2021. This talk will present these results. Three different manufacturing techniques have been used to produce the copper substrates, in order to investigate which is the most suitable in terms of quality and economy of scale. On one hand, the focus has been on optimizing the surface resistance at 4.2K, as this will be the operating temperature of FCC. The results at this temperature are encouraging, showing repeatable and optimized RF performance. On the other hand, RF tests have been done at 1.85 K too aiming at deepening the knowledge of the mechanisms behind the Q slope. This is key to work on the mitigation of this phenomenon and ultimately to extend the application of this technology to high energy, high gradient accelerators. The influence of the thermal cycles has been thoroughly investigated. A systematic improvement has been observed of both the Q slope and the residual resistance with slow thermal cycles.
	Slides WEIXA02 [5.385 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEIXA02
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 02 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB048	Geometry Optimization for a Quadrupole Resonator at Jefferson Lab	670
	S. Bira, M. Ge, A-M. Valente-Feliciano JLab, Newport News, Virginia, USA L. Vega Cid, W. Venturini Delsolaro CERN, Meyrin, Switzerland
	Funding: This manuscript is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-6OR23177 with Jefferson Science Associates The quadrupole resonator (QPR) is a sample characterization tool to measure the RF properties of superconducting materials using the calorimetry method at different temperatures, magnetic fields, and frequencies. Such resonators are currently operating at CERN and HZB but suffer from Lorentz force detuning and modes overlapping, resulting in higher uncertainties in surface resistance measurement. Using the two CERN’s QPR model iterations, the geometry was optimized via electromagnetic and mechanical simulations to eliminate these issues. The new QPR version was modeled for an increasing range of magnetic fields. The magnetic field is concentrated at the center of the sample to reduce the uncertainty in surface resistance measurements significantly. This paper will discuss the QPR geometry optimization for the new version of QPR, which is now progressing towards fabrication.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB048
About •	Received ※ 19 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 21 August 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Results of the R&D RF Testing Campaign of 1.3 GHz Nb/Cu Cavities

621

L. Vega Cid, S. Atieh, G. Bellini, A. Bianchi, L.M.A. Ferreira, C. Pereira Carlos, G.J. Rosaz, W. Venturini Delsolaro
CERN, Meyrin, Switzerland
S.B. Leith
European Organization for Nuclear Research (CERN), Geneva, Switzerland

In the context of the R&D program on Nb/Cu carried out at CERN, a total of 25 tests have been performed since 2021. This talk will present these results. Three different manufacturing techniques have been used to produce the copper substrates, in order to investigate which is the most suitable in terms of quality and economy of scale. On one hand, the focus has been on optimizing the surface resistance at 4.2K, as this will be the operating temperature of FCC. The results at this temperature are encouraging, showing repeatable and optimized RF performance. On the other hand, RF tests have been done at 1.85 K too aiming at deepening the knowledge of the mechanisms behind the Q slope. This is key to work on the mitigation of this phenomenon and ultimately to extend the application of this technology to high energy, high gradient accelerators. The influence of the thermal cycles has been thoroughly investigated. A systematic improvement has been observed of both the Q slope and the residual resistance with slow thermal cycles.

Slides WEIXA02 [5.385 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEIXA02

About •

Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 02 July 2023

Cite •

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

WEPWB048

Geometry Optimization for a Quadrupole Resonator at Jefferson Lab

670

S. Bira, M. Ge, A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA
L. Vega Cid, W. Venturini Delsolaro
CERN, Meyrin, Switzerland

Funding: This manuscript is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-6OR23177 with Jefferson Science Associates
The quadrupole resonator (QPR) is a sample characterization tool to measure the RF properties of superconducting materials using the calorimetry method at different temperatures, magnetic fields, and frequencies. Such resonators are currently operating at CERN and HZB but suffer from Lorentz force detuning and modes overlapping, resulting in higher uncertainties in surface resistance measurement. Using the two CERN’s QPR model iterations, the geometry was optimized via electromagnetic and mechanical simulations to eliminate these issues. The new QPR version was modeled for an increasing range of magnetic fields. The magnetic field is concentrated at the center of the sample to reduce the uncertainty in surface resistance measurements significantly. This paper will discuss the QPR geometry optimization for the new version of QPR, which is now progressing towards fabrication.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB048

About •

Received ※ 19 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 21 August 2023

Cite •

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