SRF2021 - List of Keywords (factory)

Paper	Title	Other Keywords	Page
SUPCAV009	First Nb₃Sn Coating and Cavity Performance Result at KEK	cavity, SRF, radio-frequency, experiment	27
	K. Takahashi, T. Okada Sokendai, Ibaraki, Japan H. Ito, E. Kako, T. Konomi, H. Sakai, K. Umemori KEK, Ibaraki, Japan
	At KEK, Nb₃Sn vapor diffusion R&D for High-Q has just started. We have performed Nb₃Sn coating on niobium samples and characterized these samples. We optimized the cavity coating parameter from the result of characterized samples. After optimizing the parameter, we have performed Nb₃Sn coating on a TESLA-like single-cell Nb cavity and measured cavity performance in vertical tests. This presentation presents the result of the cavity coating and performance results.
	Poster SUPCAV009 [1.481 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV009
About •	Received ※ 21 June 2021 — Accepted ※ 18 March 2022 — Issue date ※ 16 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPFAV002	Calibration of SRF Cavity Voltage by Measurement of Synchrotron Frequency in SuperKEKB	cavity, operation, SRF, pick-up	376
	M. Nishiwaki, K. Akai, T. Furuya, T. Kobayashi, S. Mitsunobu, Y. Morita, T. Okada KEK, Ibaraki, Japan
	Eight SRF cavity modules, which have been operated in KEKB for more than ten years, are stably operating also in SuperKEKB. As for calibration of the cavity voltage Vc, non-negligible discrepancy was observed between the results obtained from two different methods: one is using external Q value (Q_ext) of pickup ports, and the other is using loaded Q value (QL) of the cavities. The discrepancy comes from inaccuracy of power measurement in high power RF system and uncertainty of the Q_ext or QL values. In order to solve the discrepancy by improving the accuracy of the calibration for each individual cavity, we investigated a method by measuring synchrotron frequency fs of stored beam. With this method, Vc calibration can be performed without affected by inaccuracy of high-power measurement or uncertainty of the Q_ext or QL values. The fs measurement studies were carried out in SuperKEKB. With these studies, Vc calibration was obtained with a high accuracy of about 1%. The results are applied to the SuperKEKB operation.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV002
About •	Received ※ 21 June 2021 — Revised ※ 13 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 14 October 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPCAV010	Application of the ASME Boiler and Pressure Vessel Code in the Design of SRF Cavities at Fermilab	cavity, SRF, GUI, niobium	460
	C.S. Narug, M. Parise, D. Passarelli Fermilab, Batavia, Illinois, USA
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Jacketed Superconducting Radio Frequency (SRF) cavities structurally comprise of an inner niobium vessel surrounded by a liquid helium containment vessels. The pressure of the helium bath and/or its volume might be such that a jacketed SRF cavity shall be considered a system of pressure vessels. Thus, methods described in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) should be used to analyze the structural soundness of jacketed SRF cavities. This paper will report the use of the set of rules developed at Fermilab for the design of SRF cavities, such as jacketed 1.3 GHz cavities for LCLS-II HE and jacketed Single Spoke Resonator type~2 (SSR2) for PIP-II, to ensure a similar level of safety as prescribed by the ASME BPVC.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV010
About •	Received ※ 22 June 2021 — Accepted ※ 23 August 2021 — Issue date ※ 12 December 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTEV013	Managing Sn-Supply to Tune Surface Characteristics of Vapor-Diffusion Coating of Nb₃Sn	cavity, SRF, experiment, niobium	516
	U. Pudasaini, C.E. Reece JLab, Newport News, Virginia, USA J.K. Tiskumara ODU, Norfolk, Virginia, USA
	Funding: Authored by Jefferson Science Associates under contract no. DE¬AC05¬06OR23177 Nb₃Sn promises better RF performance (Q and E_acc) than niobium at any given temperature because of superior superconducting properties. Nb₃Sn-coated SRF cavities are now produced routinely by growing a few microns thick Nb₃Sn films inside Nb cavities via the tin vapor diffusion technique. Sn evaporation and consumption during the growth process notably affect the quality of the coating. Aiming at favorable surface characteristics that could enhance the RF performance, many coatings were produced by varying Sn sources and temperature profiles. Coupon samples were examined using different material characterization techniques, and a selected few sets of coating parameters were used to coat 1.3 GHz single-cell cavities for RF testing. The Sn supply’s careful tuning is essential to manage the microstructure, roughness, and overall surface characteristics of the coating. We summarize the material analysis of witness samples and discuss the performance of several Nb₃Sn-coated single-cell cavities linked to Sn-source characteristics and observed Sn consumption during the film growth process.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV013
About •	Received ※ 21 June 2021 — Revised ※ 09 October 2021 — Accepted ※ 15 December 2021 — Issue date ※ 22 February 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

SUPCAV009

First Nb₃Sn Coating and Cavity Performance Result at KEK

cavity, SRF, radio-frequency, experiment

27

K. Takahashi, T. Okada
Sokendai, Ibaraki, Japan
H. Ito, E. Kako, T. Konomi, H. Sakai, K. Umemori
KEK, Ibaraki, Japan

At KEK, Nb₃Sn vapor diffusion R&D for High-Q has just started. We have performed Nb₃Sn coating on niobium samples and characterized these samples. We optimized the cavity coating parameter from the result of characterized samples. After optimizing the parameter, we have performed Nb₃Sn coating on a TESLA-like single-cell Nb cavity and measured cavity performance in vertical tests. This presentation presents the result of the cavity coating and performance results.

Poster SUPCAV009 [1.481 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV009

About •

Received ※ 21 June 2021 — Accepted ※ 18 March 2022 — Issue date ※ 16 May 2022

Cite •

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

TUPFAV002

Calibration of SRF Cavity Voltage by Measurement of Synchrotron Frequency in SuperKEKB

cavity, operation, SRF, pick-up

376

M. Nishiwaki, K. Akai, T. Furuya, T. Kobayashi, S. Mitsunobu, Y. Morita, T. Okada
KEK, Ibaraki, Japan

Eight SRF cavity modules, which have been operated in KEKB for more than ten years, are stably operating also in SuperKEKB. As for calibration of the cavity voltage Vc, non-negligible discrepancy was observed between the results obtained from two different methods: one is using external Q value (Q_ext) of pickup ports, and the other is using loaded Q value (QL) of the cavities. The discrepancy comes from inaccuracy of power measurement in high power RF system and uncertainty of the Q_ext or QL values. In order to solve the discrepancy by improving the accuracy of the calibration for each individual cavity, we investigated a method by measuring synchrotron frequency fs of stored beam. With this method, Vc calibration can be performed without affected by inaccuracy of high-power measurement or uncertainty of the Q_ext or QL values. The fs measurement studies were carried out in SuperKEKB. With these studies, Vc calibration was obtained with a high accuracy of about 1%. The results are applied to the SuperKEKB operation.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV002

About •

Received ※ 21 June 2021 — Revised ※ 13 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 14 October 2021

Cite •

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

TUPCAV010

Application of the ASME Boiler and Pressure Vessel Code in the Design of SRF Cavities at Fermilab

cavity, SRF, GUI, niobium

460

C.S. Narug, M. Parise, D. Passarelli
Fermilab, Batavia, Illinois, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
Jacketed Superconducting Radio Frequency (SRF) cavities structurally comprise of an inner niobium vessel surrounded by a liquid helium containment vessels. The pressure of the helium bath and/or its volume might be such that a jacketed SRF cavity shall be considered a system of pressure vessels. Thus, methods described in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) should be used to analyze the structural soundness of jacketed SRF cavities. This paper will report the use of the set of rules developed at Fermilab for the design of SRF cavities, such as jacketed 1.3 GHz cavities for LCLS-II HE and jacketed Single Spoke Resonator type~2 (SSR2) for PIP-II, to ensure a similar level of safety as prescribed by the ASME BPVC.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV010

About •

Received ※ 22 June 2021 — Accepted ※ 23 August 2021 — Issue date ※ 12 December 2021

Cite •

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

TUPTEV013

Managing Sn-Supply to Tune Surface Characteristics of Vapor-Diffusion Coating of Nb₃Sn

cavity, SRF, experiment, niobium

516

U. Pudasaini, C.E. Reece
JLab, Newport News, Virginia, USA
J.K. Tiskumara
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates under contract no. DE¬AC05¬06OR23177
Nb₃Sn promises better RF performance (Q and E_acc) than niobium at any given temperature because of superior superconducting properties. Nb₃Sn-coated SRF cavities are now produced routinely by growing a few microns thick Nb₃Sn films inside Nb cavities via the tin vapor diffusion technique. Sn evaporation and consumption during the growth process notably affect the quality of the coating. Aiming at favorable surface characteristics that could enhance the RF performance, many coatings were produced by varying Sn sources and temperature profiles. Coupon samples were examined using different material characterization techniques, and a selected few sets of coating parameters were used to coat 1.3 GHz single-cell cavities for RF testing. The Sn supply’s careful tuning is essential to manage the microstructure, roughness, and overall surface characteristics of the coating. We summarize the material analysis of witness samples and discuss the performance of several Nb₃Sn-coated single-cell cavities linked to Sn-source characteristics and observed Sn consumption during the film growth process.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV013

About •

Received ※ 21 June 2021 — Revised ※ 09 October 2021 — Accepted ※ 15 December 2021 — Issue date ※ 22 February 2022

Cite •

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