SRF2021 - List of Keywords (accelerating-gradient)

Paper	Title	Other Keywords	Page
SUPCAV003	Dynamic Temperature Mapping of Nb₃Sn Cavities	cavity, SRF, site, multipactoring	6
	R.D. Porter, N. Banerjee, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Niobium-3 Tin (Nb₃Sn) is the most promising alternative material to niobium for SRF accelerator cavities. The material promises nearly twice the potential accelerating gradients (~100 MV/m in TESLA elliptical cavities), increased quality factors, and 4.2 K operation. Current state of the art Nb₃Sn cavities reach quality factors of 2 x 10¹⁰ at 4.2 K and have reached 24 MV/m. Determining the cause of the premature field limitation is the topic of ongoing research. Cornell University has recently developed a high-speed temperature mapping system that can examine cavity quench mechanisms in never before achieved ways. Here we present high-speed temperature map results of Nb₃Sn cavities and examine the quench mechanism and dynamic heating. We show an initial multipacting quench and sudden temperature jumps at multiple locations on the cavity.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV003
About •	Received ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 31 August 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

SUPCAV010	Design of Third-Harmonic Superconducting Cavity for Shen-Zhen Industry Synchrotyon Radiation Source7	cavity, superconducting-cavity, acceleration, electron	32
	N. Yuan, L. Lu, W. Ma Sun Yat-sen University, Zhuhai, Guangdong, People’s Republic of China G.M. Liu SINAP, Shanghai, People’s Republic of China L. Yang, Z. Zhang IMP/CAS, Lanzhou, People’s Republic of China
	Shenzhen industry synchrotron radiation source is the fourth generation of medium energy light source with beam energy of 3GeV. It has the characteristics of low emittance and high brightness. In the design, the beam lifetime is one of the most important parameters. The main factor that affects its beam lifetime is the scattering of electron collisions inside the beam. To solve this problem, a harmonic radio frequency system is used. The third harmonic superconducting elliptical cavity is de-signed to stretch beam length to improve beam quality and beam lifetime. The present work is mainly about the shape optimization of 1.5 GHz 2-cell third harmonic superconducting elliptical cavity. Firstly, the principle of harmonic cavity in dual high frequency system is introduced, and the resonant frequency and acceleration gradient of superconducting cavity are given. Then, CST, electromagnetic field simulation software is used to optimize the cavity parameters to obtain the high performance and high frequency parameters that meet the requirements.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV010
About •	Received ※ 21 June 2021 — Revised ※ 21 November 2021 — Accepted ※ 18 February 2022 — Issue date ※ 03 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

SUPTEV001	Magnetic Field Penetration Technique to Study High Field Shielding of Multilayered Superconductors	cavity, SRF, niobium, site	112
	I.H. Senevirathne, J.R. Delayen, A.V. Gurevich ODU, Norfolk, Virginia, USA J.R. Delayen, A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: NSF Grants PHY-1734075 and PHY-1416051, and DOE Awards DE-SC0010081 and DE-SC0019399 The SIS structure which consists of alternative thin layers of superconductors and insulators on a bulk niobium has been proposed to shield niobium cavity surface from high magnetic field and hence increase the accelerating gradient. The study of the behavior of multilayer super-conductors in an external magnetic field is essential to optimize their SRF performance. In this work we report the development of a simple and efficient technique to measure penetration of magnetic field into bulk, thin film and multilayer superconductors. Experimental setup contains a small superconducting solenoid which can produce a parallel surface magnetic field up to 0.5 T and Hall probes to detect penetrated magnetic field across the superconducting sample. This system was calibrated and used to study the effect of niobium sample thickness on the field of full magnetic flux penetration. We determined the optimum thickness of the niobium substrate to fabricate the multilayer structure for the measurements in our setup. This technique was used to measure penetration fields of Nb₃Sn thin films and Nb₃Sn/Al₂O₃ multi-layers deposited on Al₂O₃ wafers.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPTEV001
About •	Received ※ 22 June 2021 — Revised ※ 15 August 2021 — Accepted ※ 20 September 2021 — Issue date ※ 28 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPCAV013	LCLS-II-HE Vertical Acceptance Testing Plans	cavity, multipactoring, cryomodule, HOM	291
	J.T. Maniscalco, S. Aderhold, J.D. Fuerst, D. Gonnella SLAC, Menlo Park, California, USA T.T. Arkan, M. Checchin, J.A. Kaluzny, S. Posen Fermilab, Batavia, Illinois, USA J. Hogan, A.D. Palczewski, C.E. Reece, K.M. Wilson JLab, Newport News, Virginia, USA
	LCLS-II-HE has performance requirements similar to but generally more demanding than those of LCLS-II, with an operating gradient of 21 MV/m (up from 16 MV/m in LCLS-II) and tighter restrictions on field emission and multipacting. In this paper, we outline the requirements for the 1.3 GHz cavities and the plans for qualification of these cavities by vertical test. We discuss lessons learned from LCLS-II and highlight the changes implemented in the vertical test procedure for the new project.
	Poster MOPCAV013 [0.418 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV013
About •	Received ※ 21 June 2021 — Revised ※ 12 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 02 May 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPFAV003	Stable Beam Operation at 33 MV/m in STF-2 Cryomodules at KEK	cavity, operation, radiation, cryomodule	382
	Y. Yamamoto, M. Akemoto, D.A. Arakawa, A. Araki, S. Araki, A. Aryshev, T. Dohmae, M. Egi, M.K. Fukuda, K. Hara, H. Hayano, Y. Honda, T. Honma, H. Ito, E. Kako, H. Katagiri, R. Katayama, M. Kawamura, N. Kimura, Y. Kojima, Y. Kondou, T. Konomi, M. Masuzawa, T. Matsumoto, S. Michizono, Y. Morikawa, H. Nakai, H. Nakajima, K. Nakanishi, M. Omet, T. Oyama, T. Saeki, H. Sakai, H. Shimizu, S.I. Takahara, R. Ueki, K. Umemori, A. Yamamoto KEK, Ibaraki, Japan S. Aramoto Hiroshima University, Higashi-Hiroshima, Japan M. Kuriki Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan Z.J. Liptak HU/AdSM, Higashi-Hiroshima, Japan K. Sakaue The University of Tokyo, The School of Engineering, Tokyo, Japan A. Yamamoto CERN, Meyrin, Switzerland
	In STF at KEK, as the operational demonstration of the SRF accelerator for ILC, the STF-2 cryomodules (CM¹⁺CM2a: one and half size CM with 12 cavities) have achieved 33 MV/m as average accelerating gradient with 7 cavities in Mar/2019. After that, one cavity with the lowest performance installed in CM2a was replaced with one N-infused cavity developed for High-Q/High-G R&D between Japan and US. From this April, the beam operation started again and those CMs achieved 33 MV/m as average accelerating gradient with 9 cavities including one N-infused cavity again. This is the very important milestone for ILC. In this report, the detailed results will be presented.
	Poster TUPFAV003 [3.020 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV003
About •	Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 01 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPCAV009	Conceptual Design of Balloon Double Spoke Resonator	cavity, electron, linac, multipactoring	604
	Z.Y. Yao, R.E. Laxdal TRIUMF, Vancouver, Canada
	Funding: TRIUMF receives funding via a contribution through the National Research Council Canada. The balloon variant of the spoke resonator was proposed to eliminate the intensive multipacting (MP) barriers around the operating field level by modifying the local electro-magnetic (EM) fields. TRIUMF has previously reported the prototyping of a 325MHz β=0.3 single spoke resonator (SSR) that demonstrated the principle of the balloon concept. To extend the benefits of the balloon variant to multi-spoke resonators, this paper will report a conceptual design of a 325MHz β=0.5 balloon double spoke resonator (DSR). The consequences from the balloon SSR design, such as the relations between EM field distributions and the field levels of the MP barriers, were applied to the DSR design. Other particular geometry features were also added due to the characters of DSRs. The simulated MP barriers were significantly squeezed to the lower field level compared to a conventional DSR design. Simulation results and conceptual design will be reported.
	Poster WEPCAV009 [2.264 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV009
About •	Received ※ 22 June 2021 — Revised ※ 20 December 2021 — Accepted ※ 01 March 2022 — Issue date ※ 18 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPCAV009	Statistical Modeling of Peak Accelerating Gradients in LCLS-II and LCLS-II-HE	cavity, cryomodule, multipactoring, simulation	804
	J.T. Maniscalco, S. Aderhold, J.D. Fuerst, D. Gonnella SLAC, Menlo Park, California, USA T.T. Arkan, M. Checchin, J.A. Kaluzny, S. Posen Fermilab, Batavia, Illinois, USA J. Hogan, A.D. Palczewski, C.E. Reece, K.M. Wilson JLab, Newport News, Virginia, USA
	In this report, we study the vertical test gradient performance and the gradient degradation between vertical test and cryomodule test for the 1.3 GHz LCLS-II cavities. We develop a model of peak gradient statistics, and use our understanding of the LCLS-II results and the changes implemented for LCLS-II-HE to estimate the expected gradient statistics for the new machine. Finally, we lay out a plan to ensure that the LCLS-II-HE cryomodule gradient specifications are met while minimizing cavity disqualification by introducing a variable acceptance threshold for the accelerating gradient.
	Poster THPCAV009 [1.311 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV009
About •	Received ※ 21 June 2021 — Revised ※ 14 September 2021 — Accepted ※ 02 November 2021 — Issue date ※ 23 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

SUPCAV003

Dynamic Temperature Mapping of Nb₃Sn Cavities

cavity, SRF, site, multipactoring

6

R.D. Porter, N. Banerjee, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Niobium-3 Tin (Nb₃Sn) is the most promising alternative material to niobium for SRF accelerator cavities. The material promises nearly twice the potential accelerating gradients (~100 MV/m in TESLA elliptical cavities), increased quality factors, and 4.2 K operation. Current state of the art Nb₃Sn cavities reach quality factors of 2 x 10¹⁰ at 4.2 K and have reached 24 MV/m. Determining the cause of the premature field limitation is the topic of ongoing research. Cornell University has recently developed a high-speed temperature mapping system that can examine cavity quench mechanisms in never before achieved ways. Here we present high-speed temperature map results of Nb₃Sn cavities and examine the quench mechanism and dynamic heating. We show an initial multipacting quench and sudden temperature jumps at multiple locations on the cavity.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV003

About •

Received ※ 09 July 2021 — Accepted ※ 12 August 2021 — Issue date ※ 31 August 2021

Cite •

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

SUPCAV010

Design of Third-Harmonic Superconducting Cavity for Shen-Zhen Industry Synchrotyon Radiation Source7

cavity, superconducting-cavity, acceleration, electron

32

N. Yuan, L. Lu, W. Ma
Sun Yat-sen University, Zhuhai, Guangdong, People’s Republic of China
G.M. Liu
SINAP, Shanghai, People’s Republic of China
L. Yang, Z. Zhang
IMP/CAS, Lanzhou, People’s Republic of China

Shenzhen industry synchrotron radiation source is the fourth generation of medium energy light source with beam energy of 3GeV. It has the characteristics of low emittance and high brightness. In the design, the beam lifetime is one of the most important parameters. The main factor that affects its beam lifetime is the scattering of electron collisions inside the beam. To solve this problem, a harmonic radio frequency system is used. The third harmonic superconducting elliptical cavity is de-signed to stretch beam length to improve beam quality and beam lifetime. The present work is mainly about the shape optimization of 1.5 GHz 2-cell third harmonic superconducting elliptical cavity. Firstly, the principle of harmonic cavity in dual high frequency system is introduced, and the resonant frequency and acceleration gradient of superconducting cavity are given. Then, CST, electromagnetic field simulation software is used to optimize the cavity parameters to obtain the high performance and high frequency parameters that meet the requirements.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV010

About •

Received ※ 21 June 2021 — Revised ※ 21 November 2021 — Accepted ※ 18 February 2022 — Issue date ※ 03 May 2022

Cite •

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

SUPTEV001

Magnetic Field Penetration Technique to Study High Field Shielding of Multilayered Superconductors

cavity, SRF, niobium, site

112

I.H. Senevirathne, J.R. Delayen, A.V. Gurevich
ODU, Norfolk, Virginia, USA
J.R. Delayen, A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

Funding: NSF Grants PHY-1734075 and PHY-1416051, and DOE Awards DE-SC0010081 and DE-SC0019399
The SIS structure which consists of alternative thin layers of superconductors and insulators on a bulk niobium has been proposed to shield niobium cavity surface from high magnetic field and hence increase the accelerating gradient. The study of the behavior of multilayer super-conductors in an external magnetic field is essential to optimize their SRF performance. In this work we report the development of a simple and efficient technique to measure penetration of magnetic field into bulk, thin film and multilayer superconductors. Experimental setup contains a small superconducting solenoid which can produce a parallel surface magnetic field up to 0.5 T and Hall probes to detect penetrated magnetic field across the superconducting sample. This system was calibrated and used to study the effect of niobium sample thickness on the field of full magnetic flux penetration. We determined the optimum thickness of the niobium substrate to fabricate the multilayer structure for the measurements in our setup. This technique was used to measure penetration fields of Nb₃Sn thin films and Nb₃Sn/Al₂O₃ multi-layers deposited on Al₂O₃ wafers.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPTEV001

About •

Received ※ 22 June 2021 — Revised ※ 15 August 2021 — Accepted ※ 20 September 2021 — Issue date ※ 28 April 2022

Cite •

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

MOPCAV013

LCLS-II-HE Vertical Acceptance Testing Plans

cavity, multipactoring, cryomodule, HOM

291

J.T. Maniscalco, S. Aderhold, J.D. Fuerst, D. Gonnella
SLAC, Menlo Park, California, USA
T.T. Arkan, M. Checchin, J.A. Kaluzny, S. Posen
Fermilab, Batavia, Illinois, USA
J. Hogan, A.D. Palczewski, C.E. Reece, K.M. Wilson
JLab, Newport News, Virginia, USA

LCLS-II-HE has performance requirements similar to but generally more demanding than those of LCLS-II, with an operating gradient of 21 MV/m (up from 16 MV/m in LCLS-II) and tighter restrictions on field emission and multipacting. In this paper, we outline the requirements for the 1.3 GHz cavities and the plans for qualification of these cavities by vertical test. We discuss lessons learned from LCLS-II and highlight the changes implemented in the vertical test procedure for the new project.

Poster MOPCAV013 [0.418 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV013

About •

Received ※ 21 June 2021 — Revised ※ 12 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 02 May 2022

Cite •

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

TUPFAV003

Stable Beam Operation at 33 MV/m in STF-2 Cryomodules at KEK

cavity, operation, radiation, cryomodule

382

Y. Yamamoto, M. Akemoto, D.A. Arakawa, A. Araki, S. Araki, A. Aryshev, T. Dohmae, M. Egi, M.K. Fukuda, K. Hara, H. Hayano, Y. Honda, T. Honma, H. Ito, E. Kako, H. Katagiri, R. Katayama, M. Kawamura, N. Kimura, Y. Kojima, Y. Kondou, T. Konomi, M. Masuzawa, T. Matsumoto, S. Michizono, Y. Morikawa, H. Nakai, H. Nakajima, K. Nakanishi, M. Omet, T. Oyama, T. Saeki, H. Sakai, H. Shimizu, S.I. Takahara, R. Ueki, K. Umemori, A. Yamamoto
KEK, Ibaraki, Japan
S. Aramoto
Hiroshima University, Higashi-Hiroshima, Japan
M. Kuriki
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
Z.J. Liptak
HU/AdSM, Higashi-Hiroshima, Japan
K. Sakaue
The University of Tokyo, The School of Engineering, Tokyo, Japan
A. Yamamoto
CERN, Meyrin, Switzerland

In STF at KEK, as the operational demonstration of the SRF accelerator for ILC, the STF-2 cryomodules (CM¹⁺CM2a: one and half size CM with 12 cavities) have achieved 33 MV/m as average accelerating gradient with 7 cavities in Mar/2019. After that, one cavity with the lowest performance installed in CM2a was replaced with one N-infused cavity developed for High-Q/High-G R&D between Japan and US. From this April, the beam operation started again and those CMs achieved 33 MV/m as average accelerating gradient with 9 cavities including one N-infused cavity again. This is the very important milestone for ILC. In this report, the detailed results will be presented.

Poster TUPFAV003 [3.020 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV003

About •

Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 01 November 2021

Cite •

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

WEPCAV009

Conceptual Design of Balloon Double Spoke Resonator

cavity, electron, linac, multipactoring

604

Z.Y. Yao, R.E. Laxdal
TRIUMF, Vancouver, Canada

Funding: TRIUMF receives funding via a contribution through the National Research Council Canada.
The balloon variant of the spoke resonator was proposed to eliminate the intensive multipacting (MP) barriers around the operating field level by modifying the local electro-magnetic (EM) fields. TRIUMF has previously reported the prototyping of a 325MHz β=0.3 single spoke resonator (SSR) that demonstrated the principle of the balloon concept. To extend the benefits of the balloon variant to multi-spoke resonators, this paper will report a conceptual design of a 325MHz β=0.5 balloon double spoke resonator (DSR). The consequences from the balloon SSR design, such as the relations between EM field distributions and the field levels of the MP barriers, were applied to the DSR design. Other particular geometry features were also added due to the characters of DSRs. The simulated MP barriers were significantly squeezed to the lower field level compared to a conventional DSR design. Simulation results and conceptual design will be reported.

Poster WEPCAV009 [2.264 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV009

About •

Received ※ 22 June 2021 — Revised ※ 20 December 2021 — Accepted ※ 01 March 2022 — Issue date ※ 18 April 2022

Cite •

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

THPCAV009

Statistical Modeling of Peak Accelerating Gradients in LCLS-II and LCLS-II-HE

cavity, cryomodule, multipactoring, simulation

804

J.T. Maniscalco, S. Aderhold, J.D. Fuerst, D. Gonnella
SLAC, Menlo Park, California, USA
T.T. Arkan, M. Checchin, J.A. Kaluzny, S. Posen
Fermilab, Batavia, Illinois, USA
J. Hogan, A.D. Palczewski, C.E. Reece, K.M. Wilson
JLab, Newport News, Virginia, USA

In this report, we study the vertical test gradient performance and the gradient degradation between vertical test and cryomodule test for the 1.3 GHz LCLS-II cavities. We develop a model of peak gradient statistics, and use our understanding of the LCLS-II results and the changes implemented for LCLS-II-HE to estimate the expected gradient statistics for the new machine. Finally, we lay out a plan to ensure that the LCLS-II-HE cryomodule gradient specifications are met while minimizing cavity disqualification by introducing a variable acceptance threshold for the accelerating gradient.

Poster THPCAV009 [1.311 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-THPCAV009

About •

Received ※ 21 June 2021 — Revised ※ 14 September 2021 — Accepted ※ 02 November 2021 — Issue date ※ 23 November 2021

Cite •

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