SRF2023 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOPMB063	Multipacting Processing in Cryomodules for LCLS-II and LCLS-II-HE	cavity, cryomodule, linac, multipactoring	259
	A.T. Cravatta, T.T. Arkan, D. Bafia, J.A. Kaluzny, S. Posen Fermilab, Batavia, Illinois, USA S. Aderhold, M. Checchin, D. Gonnella, J. Hogan, J.T. Maniscalco, J. Nelson, R.D. Porter, L.M. Zacarias SLAC, Menlo Park, California, USA M.A. Drury, H. Vennekate JLab, Newport News, Virginia, 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. Multipacting (MP) is a phenomenon which can affect stability in particle accelerators and limit performance in superconducting radio frequency cavities. In the TESLA shaped, 1.3 GHz, 9-cell cavities used in the LCLS-II (L2) and LCLS-II-HE (HE) projects, the MP-band (~17-24 MV/m) lies within the required accelerating gradients. For HE, the operating gradient of 20.8 MV/m lies well within the MP-band and cryomodule testing has confirmed that this is an issue. As such, MP processing for the HE cryomodule test program will be discussed. Early results on MP processing in cryomodules installed in the L2 linac will also be presented, demonstrating that the methods used in cryomodule acceptance testing are also successful at conditioning MP in the accelerator and that this processing is preserved in the mid-term.
	Poster MOPMB063 [1.066 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB063
About •	Received ※ 25 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 30 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB070	Development of a Non-Intrusive Leak Detection Method for SRF Linacs	cryomodule, ISOL, SRF, operation	275
	P. Pizzol, R.L. Geng ORNL, Oak Ridge, Tennessee, USA R. Afanador, J.D. Mammosser, V.S. Morozov, D.M. Vandygriff ORNL RAD, Oak Ridge, Tennessee, USA
	The SNS accelerator has been vital in delivering high-impact research for the world scientific community since 2006, with an availability of 99%. This high availability rate is crucial to the success of the facility, and after 16 years of operations, the aging of the components could start to impact this parameter. To mitigate this, condi-tion-based maintenance can be applied to areas of the LINAC to reduce or nullify the possibility of unwanted events that may damage the accelerator functionality. In this work, we describe the development of a non-intrusive leak detection methodology that verifies the health condition of the cryomodule isolation gate valve seals. In case of a sudden vacuum leak in a warm section between the cryomodules, these valves act as a final line of defense to protect the SRF cavities from atmosphere gases contamination, hence knowing their sealing integ-rity condition is paramount. Data taken from the ma-chine during different maintenance periods will be pre-sented, together with the analysis done, to verify the robustness of the numerical method vs. the experimental findings.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB070
About •	Received ※ 16 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 02 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB072	LCLS-II-HE Cavity Qualification Testing	cavity, cryomodule, SRF, accelerating-gradient	279
	J.T. Maniscalco, S. Aderhold, M. Checchin, D. Gonnella, J. Hogan, R.D. Porter SLAC, Menlo Park, California, USA T.T. Arkan, D. Bafia, A.T. Cravatta, J.A. Kaluzny, S. Posen Fermilab, Batavia, Illinois, USA M.E. Bevins, A.J. Grabowski, C.E. Reece, H. Vennekate JLab, Newport News, Virginia, USA
	Acceptance testing of the LCLS-II-HE production cavities is approximately 65% complete. In this report, we present details of the test results, including summaries of the quench fields, intrinsic quality factors, and experience with field emission. We also offer an outlook on the remaining tests to be performed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB072
About •	Received ※ 20 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 03 July 2023 — Issue date ※ 07 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB075	Provision of High Beta Cavities for European Spallation Source by UKRI-STFC Daresbury Laboratory	cavity, ion-source, cryomodule, accelerating-gradient	286
	A.E. Wheelhouse, A.E.T. Akintola, A.J. Blackett-May, M.J. Ellis, S. Hitchen, P.C. Hornickel, C.R. Jenkins, P.A. McIntosh, K.J. Middleman, S.M. Pattalwar, M.D. Pendleton, J.O.W. Poynton, I.M. Skachko, P.A. Smith, S. Wilde STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom M. Lowe, D.A. Mason, G. Miller, J. Mutch, A. Oates, N. Templeton, J.T.G. Wilson STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D. Reschke, L. Steder, M. Wiencek DESY, Hamburg, Germany
	As part of the requirement for the European Spallation Source (ESS) facility in Lund, Sweden, a project has been undertaken by Accelerator Science and Technology Cen-tre (ASTeC) as part of a UK In Kind Contribution to pro-vide 84 704 MHz High-Beta superconducting RF cavities. The project has included the procurement of niobium and the testing of cavities at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY), in prepara-tion for integration into the cryomodules which is being performed at Commissariat à l¿Energie Atomique et aux Energies Alternatives (CEA) Saclay, France. To date all the cavities have been manufactured in industry apart from the final cavity and 3 cavities remain to be tested. An overview of the experiences for the provision of these cavities is described.
	Poster MOPMB075 [1.428 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB075
About •	Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 08 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB082	SRF Accelerating Modules Upgrade for Flash Linac at DESY	cavity, SRF, FEL, linac	306
	D. Kostin, S. Barbanotti, J. Eschke, K. Jensch, N. Krupka, A. Muhs, D. Reschke, S. Saegebarth, J. Schaffran, P. Schilling, M. Schmökel, L. Steder, N. Steinhau-Kühl, A. Sulimov, E. Vogel, H. Weise, M. Wiencek, B. van der Horst DESY, Hamburg, Germany
	SRF accelerating modules with 8 TESLA-type 1.3 GHz SRF cavities are the main part of the linear accelerators currently in user operation at DESY, FLASH [1, 2] and the European XFEL [3, 4]. For the FLASH upgrade in 2022 [5] two accelerating modules have been exchanged in order to enhance the beam energy to 1.3 GeV. The two modules have been prototype modules for the European XFEL. After reassembly both modules were successfully tested and installed in the FLASH linac. Data taken during the commissioning at the end of 2022 did confirm the test results. This paper presents described efforts and their conclusions since last two years and continues the presentation given at SRF 2021 [6].
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB082
About •	Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 27 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTB060	Reconstruction of Field Emission Pattern for PIP-II LB650 Cavity	cavity, electron, experiment, site	554
	E. Del Core, M. Bertucci, A. Bosotti, A.T. Grimaldi, L. Monaco, C. Pagani, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	Field emission (FE) is a key limiting phenomenon in SRF cavities. An algorithm exploiting a self-consistent model of cavity FE has been developed. This method exploits experimental observables (such as Q value , X-ray endpoint, and dose rate) to reconstruct emitter position and size as well as the field enhancement factor. To demonstrate the model effectiveness, the algorithm has been applied to a data set of the PIP-II LB650 prototype cavity.
	Poster TUPTB060 [0.956 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB060
About •	Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 28 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB054	In Situ Plasma Processing of Superconducting Cavities at JLab, 2023 Update	cavity, plasma, cryomodule, HOM	701
	T. Powers, N.C. Brock, T.D. Ganey JLab, Newport News, Virginia, USA
	Jefferson Lab has an ongoing R&D program in plasma processing which just completed a round of production processing in the CEBAF accelerator. Plasma processing is a common technique for removing hydrocarbons from surfaces, which increases the work function and reduces the secondary emission coefficient. Unlike helium processing which relies on ion bombardment of the field emitters, plasma processing uses free oxygen produced in the plasma to break down the hydrocarbons on the surface of the cavity. The initial focus of the effort was processing C100 cavities by injecting RF power into the HOM coupler ports. Results from processing cryomodules in the CEBAF accelerator as well as vertical test results will be presented. The goal will be to improve the operational gradients and the energy margin of the linacs. This work will describe the systems and methods used at JLAB for processing cavities using an argon-oxygen gas mixture as well as a helium-oxygen gas mixture. Before and after plasma processing results will also be presented. Funding provided by SC Nuclear Physics Program through DOE SC Lab funding announcement DE-FOA-0002670.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB054
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 01 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB067	HB650 Cryomodule Design: From Prototype to Production	cryomodule, cavity, SRF, vacuum	741
	V. Roger, S.K. Chandrasekaran, C.J. Grimm, J.P. Holzbauer, O. Napoly, J.P. Ozelis, 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. In early 2023 the assembly of the prototype HB650 cryomodule (pHB650 CM) was completed and cold tests started to evaluate its performance. The lessons learned from the design, assembly and preliminary cold tests of this cryomodule, and from the design of the SSR2 pre-production cryomodule played a fundamental role during the design optimization process of the production HB650 cryomodule (HB650 CM). Several workshops have been organized to share experiences and solve problems. This paper presents the main design changes from pHB650 to the HB650 production cryomodules and their impact on the heat loads.
	Poster WEPWB067 [2.178 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB067
About •	Received ※ 18 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 01 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THIAA02	RF Performance Results of RF Double Quarter Wave Resonators for LHC High Luminosity Project	cavity, HOM, luminosity, vacuum	925
	K. Turaj, J. Bastard, R. Calaga, S.J. Calvo, O. Capatina, A. Castilla, M. Chiodini, C. Duval, A.V. Edwards, L.M.A. Ferreira, M. Gourragne, P. Kohler, E. Montesinos, C. Pasquino, G. Pechaud, N. Stapley, N. Valverde Alonso, J.D. Walker CERN, Meyrin, Switzerland A. Castilla JLAB, Newport News, USA A.V. Edwards Lancaster University, Lancaster, United Kingdom
	The LHC High Luminosity (HL-LHC) project includes, among other key items, the installation of superconducting crab cavities in the LHC machine. The Double Quarter Wave (DQW) crab cavity will be utilised to compensate for the effects of the vertical crossing angle. Two bare DQW series cavities were manufactured in Germany by RI Research Instruments and validated successfully at CERN through a cold test at 2K. Two DQW series cavities were produced in-house at CERN, integrated into a titanium helium tank, and equipped with RF ancillaries. This paper addresses the cavities preparation processes and summarizes the results of cryogenic tests of DQW cavities at CERN
	Slides THIAA02 [10.840 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA02
About •	Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRIBA02	Instrumentation for High Performance Cavities and Cryomodule Field Emission Analysis	cavity, electron, neutron, simulation	978
	G. Devanz CEA-IRFU, Gif-sur-Yvette, France M. Baudrier, E. Cenni, L. Maurice, O. Piquet CEA-DRF-IRFU, France
	Field emission (FE) is one of the main reasons for the degradation of accelerator cryomodules, as field emitted current tends to become more severe during the beam operation. It is essential to better understand how this phenomenon is generated and evolves from the SRF cavity preparation in the clean room, through their assembly in the cryomodule until their final test and operation. Due to the shielding environment of a cavity in its vertical test stand, or the architecture of a cryomodule, the more faint radiation occurring at the FE onset remains undetected. More precise diagnostic and analysis tools are required to gain more information. We present the developpement of dedicated time-resolved detectors for the FE radiation which aim at improving its coverage in terms of solid angle and lower energy threshold sensitivity. We approach this topic through detailed simulation based on the Geant4 toolkit in order to analyse the interaction of FE radiation with the cavity environement and optimize the detectors with respect to their application in cryomodule or vertical test stands. We illustrate by analysing recent cryomodule experimental test data.
	Slides FRIBA02 [9.606 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-FRIBA02
About •	Received ※ 27 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 05 July 2023 — Issue date ※ 09 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPMB063

Multipacting Processing in Cryomodules for LCLS-II and LCLS-II-HE

cavity, cryomodule, linac, multipactoring

259

A.T. Cravatta, T.T. Arkan, D. Bafia, J.A. Kaluzny, S. Posen
Fermilab, Batavia, Illinois, USA
S. Aderhold, M. Checchin, D. Gonnella, J. Hogan, J.T. Maniscalco, J. Nelson, R.D. Porter, L.M. Zacarias
SLAC, Menlo Park, California, USA
M.A. Drury, H. Vennekate
JLab, Newport News, Virginia, 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.
Multipacting (MP) is a phenomenon which can affect stability in particle accelerators and limit performance in superconducting radio frequency cavities. In the TESLA shaped, 1.3 GHz, 9-cell cavities used in the LCLS-II (L2) and LCLS-II-HE (HE) projects, the MP-band (~17-24 MV/m) lies within the required accelerating gradients. For HE, the operating gradient of 20.8 MV/m lies well within the MP-band and cryomodule testing has confirmed that this is an issue. As such, MP processing for the HE cryomodule test program will be discussed. Early results on MP processing in cryomodules installed in the L2 linac will also be presented, demonstrating that the methods used in cryomodule acceptance testing are also successful at conditioning MP in the accelerator and that this processing is preserved in the mid-term.

Poster MOPMB063 [1.066 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB063

About •

Received ※ 25 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 30 June 2023

Cite •

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

MOPMB070

Development of a Non-Intrusive Leak Detection Method for SRF Linacs

cryomodule, ISOL, SRF, operation

275

P. Pizzol, R.L. Geng
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, J.D. Mammosser, V.S. Morozov, D.M. Vandygriff
ORNL RAD, Oak Ridge, Tennessee, USA

The SNS accelerator has been vital in delivering high-impact research for the world scientific community since 2006, with an availability of 99%. This high availability rate is crucial to the success of the facility, and after 16 years of operations, the aging of the components could start to impact this parameter. To mitigate this, condi-tion-based maintenance can be applied to areas of the LINAC to reduce or nullify the possibility of unwanted events that may damage the accelerator functionality. In this work, we describe the development of a non-intrusive leak detection methodology that verifies the health condition of the cryomodule isolation gate valve seals. In case of a sudden vacuum leak in a warm section between the cryomodules, these valves act as a final line of defense to protect the SRF cavities from atmosphere gases contamination, hence knowing their sealing integ-rity condition is paramount. Data taken from the ma-chine during different maintenance periods will be pre-sented, together with the analysis done, to verify the robustness of the numerical method vs. the experimental findings.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB070

About •

Received ※ 16 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 02 July 2023

Cite •

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

MOPMB072

LCLS-II-HE Cavity Qualification Testing

cavity, cryomodule, SRF, accelerating-gradient

279

J.T. Maniscalco, S. Aderhold, M. Checchin, D. Gonnella, J. Hogan, R.D. Porter
SLAC, Menlo Park, California, USA
T.T. Arkan, D. Bafia, A.T. Cravatta, J.A. Kaluzny, S. Posen
Fermilab, Batavia, Illinois, USA
M.E. Bevins, A.J. Grabowski, C.E. Reece, H. Vennekate
JLab, Newport News, Virginia, USA

Acceptance testing of the LCLS-II-HE production cavities is approximately 65% complete. In this report, we present details of the test results, including summaries of the quench fields, intrinsic quality factors, and experience with field emission. We also offer an outlook on the remaining tests to be performed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB072

About •

Received ※ 20 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 03 July 2023 — Issue date ※ 07 July 2023

Cite •

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

MOPMB075

Provision of High Beta Cavities for European Spallation Source by UKRI-STFC Daresbury Laboratory

cavity, ion-source, cryomodule, accelerating-gradient

286

A.E. Wheelhouse, A.E.T. Akintola, A.J. Blackett-May, M.J. Ellis, S. Hitchen, P.C. Hornickel, C.R. Jenkins, P.A. McIntosh, K.J. Middleman, S.M. Pattalwar, M.D. Pendleton, J.O.W. Poynton, I.M. Skachko, P.A. Smith, S. Wilde
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M. Lowe, D.A. Mason, G. Miller, J. Mutch, A. Oates, N. Templeton, J.T.G. Wilson
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D. Reschke, L. Steder, M. Wiencek
DESY, Hamburg, Germany

As part of the requirement for the European Spallation Source (ESS) facility in Lund, Sweden, a project has been undertaken by Accelerator Science and Technology Cen-tre (ASTeC) as part of a UK In Kind Contribution to pro-vide 84 704 MHz High-Beta superconducting RF cavities. The project has included the procurement of niobium and the testing of cavities at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY), in prepara-tion for integration into the cryomodules which is being performed at Commissariat à l¿Energie Atomique et aux Energies Alternatives (CEA) Saclay, France. To date all the cavities have been manufactured in industry apart from the final cavity and 3 cavities remain to be tested. An overview of the experiences for the provision of these cavities is described.

Poster MOPMB075 [1.428 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB075

About •

Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 08 July 2023

Cite •

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

MOPMB082

SRF Accelerating Modules Upgrade for Flash Linac at DESY

cavity, SRF, FEL, linac

306

D. Kostin, S. Barbanotti, J. Eschke, K. Jensch, N. Krupka, A. Muhs, D. Reschke, S. Saegebarth, J. Schaffran, P. Schilling, M. Schmökel, L. Steder, N. Steinhau-Kühl, A. Sulimov, E. Vogel, H. Weise, M. Wiencek, B. van der Horst
DESY, Hamburg, Germany

SRF accelerating modules with 8 TESLA-type 1.3 GHz SRF cavities are the main part of the linear accelerators currently in user operation at DESY, FLASH [1, 2] and the European XFEL [3, 4]. For the FLASH upgrade in 2022 [5] two accelerating modules have been exchanged in order to enhance the beam energy to 1.3 GeV. The two modules have been prototype modules for the European XFEL. After reassembly both modules were successfully tested and installed in the FLASH linac. Data taken during the commissioning at the end of 2022 did confirm the test results. This paper presents described efforts and their conclusions since last two years and continues the presentation given at SRF 2021 [6].

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB082

About •

Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 27 June 2023

Cite •

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

TUPTB060

Reconstruction of Field Emission Pattern for PIP-II LB650 Cavity

cavity, electron, experiment, site

554

E. Del Core, M. Bertucci, A. Bosotti, A.T. Grimaldi, L. Monaco, C. Pagani, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

Field emission (FE) is a key limiting phenomenon in SRF cavities. An algorithm exploiting a self-consistent model of cavity FE has been developed. This method exploits experimental observables (such as Q value , X-ray endpoint, and dose rate) to reconstruct emitter position and size as well as the field enhancement factor. To demonstrate the model effectiveness, the algorithm has been applied to a data set of the PIP-II LB650 prototype cavity.

Poster TUPTB060 [0.956 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB060

About •

Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 28 June 2023

Cite •

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

WEPWB054

In Situ Plasma Processing of Superconducting Cavities at JLab, 2023 Update

cavity, plasma, cryomodule, HOM

701

T. Powers, N.C. Brock, T.D. Ganey
JLab, Newport News, Virginia, USA

Jefferson Lab has an ongoing R&D program in plasma processing which just completed a round of production processing in the CEBAF accelerator. Plasma processing is a common technique for removing hydrocarbons from surfaces, which increases the work function and reduces the secondary emission coefficient. Unlike helium processing which relies on ion bombardment of the field emitters, plasma processing uses free oxygen produced in the plasma to break down the hydrocarbons on the surface of the cavity. The initial focus of the effort was processing C100 cavities by injecting RF power into the HOM coupler ports. Results from processing cryomodules in the CEBAF accelerator as well as vertical test results will be presented. The goal will be to improve the operational gradients and the energy margin of the linacs. This work will describe the systems and methods used at JLAB for processing cavities using an argon-oxygen gas mixture as well as a helium-oxygen gas mixture. Before and after plasma processing results will also be presented.
Funding provided by SC Nuclear Physics Program through DOE SC Lab funding announcement DE-FOA-0002670.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB054

About •

Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 01 July 2023

Cite •

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

WEPWB067

HB650 Cryomodule Design: From Prototype to Production

cryomodule, cavity, SRF, vacuum

741

V. Roger, S.K. Chandrasekaran, C.J. Grimm, J.P. Holzbauer, O. Napoly, J.P. Ozelis, 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.
In early 2023 the assembly of the prototype HB650 cryomodule (pHB650 CM) was completed and cold tests started to evaluate its performance. The lessons learned from the design, assembly and preliminary cold tests of this cryomodule, and from the design of the SSR2 pre-production cryomodule played a fundamental role during the design optimization process of the production HB650 cryomodule (HB650 CM). Several workshops have been organized to share experiences and solve problems. This paper presents the main design changes from pHB650 to the HB650 production cryomodules and their impact on the heat loads.

Poster WEPWB067 [2.178 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB067

About •

Received ※ 18 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 01 July 2023

Cite •

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

THIAA02

RF Performance Results of RF Double Quarter Wave Resonators for LHC High Luminosity Project

cavity, HOM, luminosity, vacuum

925

K. Turaj, J. Bastard, R. Calaga, S.J. Calvo, O. Capatina, A. Castilla, M. Chiodini, C. Duval, A.V. Edwards, L.M.A. Ferreira, M. Gourragne, P. Kohler, E. Montesinos, C. Pasquino, G. Pechaud, N. Stapley, N. Valverde Alonso, J.D. Walker
CERN, Meyrin, Switzerland
A. Castilla
JLAB, Newport News, USA
A.V. Edwards
Lancaster University, Lancaster, United Kingdom

The LHC High Luminosity (HL-LHC) project includes, among other key items, the installation of superconducting crab cavities in the LHC machine. The Double Quarter Wave (DQW) crab cavity will be utilised to compensate for the effects of the vertical crossing angle. Two bare DQW series cavities were manufactured in Germany by RI Research Instruments and validated successfully at CERN through a cold test at 2K. Two DQW series cavities were produced in-house at CERN, integrated into a titanium helium tank, and equipped with RF ancillaries. This paper addresses the cavities preparation processes and summarizes the results of cryogenic tests of DQW cavities at CERN

Slides THIAA02 [10.840 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA02

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Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023

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

FRIBA02

Instrumentation for High Performance Cavities and Cryomodule Field Emission Analysis

cavity, electron, neutron, simulation

978

G. Devanz
CEA-IRFU, Gif-sur-Yvette, France
M. Baudrier, E. Cenni, L. Maurice, O. Piquet
CEA-DRF-IRFU, France

Field emission (FE) is one of the main reasons for the degradation of accelerator cryomodules, as field emitted current tends to become more severe during the beam operation. It is essential to better understand how this phenomenon is generated and evolves from the SRF cavity preparation in the clean room, through their assembly in the cryomodule until their final test and operation. Due to the shielding environment of a cavity in its vertical test stand, or the architecture of a cryomodule, the more faint radiation occurring at the FE onset remains undetected. More precise diagnostic and analysis tools are required to gain more information. We present the developpement of dedicated time-resolved detectors for the FE radiation which aim at improving its coverage in terms of solid angle and lower energy threshold sensitivity. We approach this topic through detailed simulation based on the Geant4 toolkit in order to analyse the interaction of FE radiation with the cavity environement and optimize the detectors with respect to their application in cryomodule or vertical test stands. We illustrate by analysing recent cryomodule experimental test data.

Slides FRIBA02 [9.606 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-FRIBA02

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Received ※ 27 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 05 July 2023 — Issue date ※ 09 July 2023

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