SRF2023 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOIAA01	FRIB Transition to User Operations, Power Ramp Up, and Upgrade Perspectives	cavity, cryomodule, operation, target	1
	J. Wei, H. Ao, B. Arend, S. Beher, G. Bollen, N.K. Bultman, F. Casagrande, W. Chang, Y. Choi, S. Cogan, C. Compton, M. Cortesi, J.C. Curtin, K.D. Davidson, X.J. Du, K. Elliott, B. Ewert, A. Facco, A. Fila, K. Fukushima, V. Ganni, A. Ganshyn, T.N. Ginter, T. Glasmacher, J.-W. Guo, Y. Hao, W. Hartung, N.M. Hasan, M. Hausmann, K. Holland, H.-C. Hseuh, M. Ikegami, D.D. Jager, S. Jones, N. Joseph, T. Kanemura, S.H. Kim, C. Knowles, T. Konomi, B.R. Kortum, E. Kwan, T. Lange, M. Larmann, T.L. Larter, K. Laturkar, R.E. Laxdal, J. LeTourneau, Z. Li, S.M. Lidia, G. Machicoane, C. Magsig, P.E. Manwiller, F. Marti, T. Maruta, E.S. Metzgar, S.J. Miller, Y. Momozaki, D.G. Morris, M. Mugerian, I.N. Nesterenko, C. Nguyen, P.N. Ostroumov, M.S. Patil, A.S. Plastun, L. Popielarski, M. Portillo, J. Priller, X. Rao, M.A. Reaume, K. Saito, B.M. Sherrill, M.K. Smith, J. Song, M. Steiner, A. Stolz, O. Tarasov, B.P. Tousignant, R. Walker, X. Wang, J.D. Wenstrom, G. West, K. Witgen, M. Wright, T. Xu, Y. Yamazaki, T. Zhang, Q. Zhao, S. Zhao FRIB, East Lansing, Michigan, USA K. Hosoyama KEK, Ibaraki, Japan P. Hurh Fermilab, Batavia, Illinois, USA M.P. Kelly, Y. Momozaki ANL, Lemont, Illinois, USA R.E. Laxdal TRIUMF, Vancouver, Canada S.O. Prestemon LBNL, Berkeley, California, USA M. Wiseman JLab, Newport News, Virginia, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. After project completion on scope, on cost, and ahead of schedule, the Facility for Rare Isotope Beams began operations for scientific users in May of 2022. During the first 12 months of user operations, the FRIB accelerator complex delivered 5250 beam hours, including 1528 hours to nine science experiments conducted with primary beams of 36Ar, 48Ca, 70Zn, 82Se, 124Xe, and 198Pt at beam energies >200 MeV/u; 2724 hours for beam developments, studies, and tuning; and 998 hours to industrial users and non-scientific programs using the FRIB Single Event Effect (FSEE) beam line. The ramp-up to a beam power of 400 kW is planned over a six-year period; 1 kW was delivered for initial user runs from in 2022, and 5 kW was delivered as of February 2023. Upgrade plans include doubling the primary-beam energy to 400 MeV/nucleon for enhanced discovery potential (¿FRIB 400¿). This talk reports on FRIB status and progress since SRF2021, emphasizing lessons learned during the transition from beam commissioning to machine operations, challenges and resolutions for the power ramp-up, progress with accelerator improvements, and R&D for the energy upgrade.
	Slides MOIAA01 [7.037 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIAA01
About •	Received ※ 20 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 03 July 2023 — Issue date ※ 19 July 2023
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MOIAA03	Progresses in the ESS Superconducting Linac Installation	cryomodule, MMI, operation, cryogenics	9
	H. Przybilski ESS, Lund, Sweden
	The ESS Linac is progressing into the technical commissioning phase. The normal conducting linac up to the first 4 tanks of the DTL is being commissioned with beam. All the 13 spoke cryomodules and the 9 elliptical modules (7 MB+2 HB) foreseen for the first operation at 570 MeV on the beam dump in summer 2024 are available in Lund and waiting the completion of the cryogenic distribution system (CDS) commissioning. The test program of all the 30 elliptical cryomodules that will enable the 5 MW potential operation after the target commissioning is progressing well, as well as the installation of the RF power stations necessary up to the 2 MW stage of the first project phase. Pilot installation of one spoke and one elliptical CM in the tunnel is in progress. The talk will cover the status of the component deliveries from the partners, the CM preparation and SRF activities at the ESS test stands, with the resolution of several non-conformities, and the experience of the pilot installations and technical commissioning activities in the accelerator tunnel.
	Slides MOIAA03 [9.000 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIAA03
About •	Received ※ 26 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 13 July 2023
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MOIXA02	PIP-II Project Overview and Status	cryomodule, cavity, SRF, controls	19
	R.P. Stanek, C. Boffo, S.K. Chandrasekaran, S.J. Dixon, E.R. Harms, L. Kokoska, I. Kourbanis, J.R. Leibfritz, O. Napoly, D. Passarelli, E. Pozdeyev, A.M. Rowe Fermilab, Batavia, Illinois, USA
	Funding: Prepared by PIP-II Project using resources of the Fermi National Accelerator Laboratory, a U.S. DOE facility, managed by Fermi Research Alliance, LLC, acting under Contract No. DE-AC02-07CH11359. The Proton Improvement Plan II (PIP-II) project is an essential upgrade to Fermilab’s particle accelerator complex to enable the world’s most intense neutrino beam for LBNF/DUNE and a broad particle physics program for many decades to come. PIP-II will deliver 1.2 MW of proton beam power from the Main Injector, upgradeable to multi-MW capability. The central element of PIP-II is an 800 MeV superconducting radio frequency (SRF) linac, which comprises a room temperature front end followed by an SRF section. The SRF section consists of five different flavors of cavities/cryomodules, including Half Wave Resonators (HWR), Single Spoke and elliptical resonators operating at, or above, state-of-the-art parameters. The first two PIP-II cryomodules, Half Wave Resonator (HWR) and Single Spoke Resonator 1 (SSR1) were installed in the PIP-II Injector Test facility (PIP2IT) and have accelerated beam to above 17 MeV. PIP-II is the first U.S. accelerator project that will be constructed with significant contributions from international partners, including India, Italy, France, United Kingdom and Poland. The project was baselined in April 2022, and the construction phase is underway.
	Slides MOIXA02 [3.353 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA02
About •	Received ※ 07 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 16 July 2023
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MOIXA03	Proton Power Upgrade Project Progress and Plans at the Spallation Neutron Source in Oak Ridge Tennessee	target, cryomodule, cavity, operation	25
	J.D. Mammosser, M.J. Dayton, D.D. Kraft, R. Maekawa, L. Pinion, B.E. Robertson ORNL RAD, Oak Ridge, Tennessee, USA R. Afanador, D.L. Barnhart, M.S. Champion, B. DeGraff, M. Doleans, J. Galambos, S.W. Gold, M.N. Greenwood, G.A. Hine, M.P. Howell, S.-H. Kim, C.J. McMahan, P. Pizzol, S.E. Stewart, D.J. Vandygriff, D.M. Vandygriff ORNL, Oak Ridge, Tennessee, USA A. Bitter, K.B. Bolz, A. Navitski, L. Zweibäumer RI Research Instruments GmbH, Bergisch Gladbach, Germany E.F. Daly, G.K. Davis, P. Dhakal, J.F. Fischer, D. Forehand, N.A. Huque, K.M. Wilson JLab, Newport News, Virginia, USA
	Funding: Work Supported by UT-Battelle, LLC, under contract DE-AC05-00OR22725 The Proton Power Upgrade project is well underway at the Spallation Neutron Source (SNS) facility in Oak Ridge, Tennessee. This project aims at increasing the proton beam power capability from 1.4 to 2.8 MW, by adding linac energy, increasing the beam current and implementing target developments to handle the increased beam power. This talk will cover the current status of increasing the beam energy, issues encountered along the way, operational experience with the new SRF cryomodules and target improvements and results from operation with beam so far.
	Slides MOIXA03 [3.327 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA03
About •	Received ※ 09 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 08 July 2023
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MOIXA04	Operational Experience for RIKEN Superconducting Linear Accelerator	operation, cyclotron, heavy-ion, vacuum	30
	K. Yamada, M. Fujimaki, H. Imao, O. Kamigaito, M. Komiyama, K. Kumagai, T. Nagatomo, T. Nishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe RIKEN Nishina Center, Wako, Japan
	The RIKEN superconducting heavy-ion linac, so-called SRILAC, has been successfully operating for almost four years, and continuously deliver a heavy ion beam for a super-heavy-element synthesis experiment. The effects of a broken coupler in the early days and four years of operation have resulted in increased X-ray emission levels in several superconducting cavities, which have been successfully corrected by pulse conditioning. This talk will share the experiences and lessons learned from four-year operation with low beta SC-cavities.
	Slides MOIXA04 [4.517 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA04
About •	Received ※ 06 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023
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MOIXA06	Operational Experience with the European XFEL SRF Linac	operation, cavity, FEL, LLRF	43
	Ch. Schmidt, M. Bousonville, J. Branlard, M. Diomede, S. Göller, D. Kostin, M. Scholz, V. Vogel (Fogel), N. Walker DESY, Hamburg, Germany
	The European X-ray Free Electron laser (EuXFEL) is a 3.4 km long research facility which generates ultrashort X-ray flashes of outstanding brilliance since 2017. Up to 27000 electron bunches per second are accelerated in a 1.3 km long superconducting radio frequency (SRF) linac to a maximum energy of 17.6 GeV. Within this time, operational experience with a pulsed RF machine has been gained and new operation modes simultaneously delivering electron bunches to 3 different SASE undulator beamlines have been successfully implemented. Recent activities on increasing the linac availability, power efficiency and duty cycle are discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA06
About •	Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 06 July 2023
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MOPMB008	In-Situ Quality Factor Measurements of SRF Cavities at S-DALINAC	cavity, SRF, coupling, resonance	70
	R. Grewe, M. Arnold, A. Brauch, M. Dutine, L.E. Jürgensen, N. Pietralla, F. Schließmann, D. Schneider TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by DFG (GRK 2128) and the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006) The Superconducting Darmstadt Linear Accelerator (S-DALINAC) is a thrice recirculating electron accelerator wich can be operated in a multi-turn energy recovery mode. The design parameters for kinetic energy and beam current are up to 130 MeV and up to 20 uA respectively. The injector consists of a six-cell capture cavity and two 20-cell srf cavities. The main linac consists of eight 20-cell cavities. The cavities are operated at a temperature of 2 K with a frequency of 2.9972(1) GHz. Monitoring of the srf cavities is important for the overall performance of the accelerator. A key parameter for the rating of the srf cavity performance is the intrinsic quality factor Q. At the S-DALINAC it is measured for selected cavities during the yearly maintenance procedures. The unique design of the rf input coupler allows for a wide tuning range for the input coupling strength. This makes in-situ quality factor measurements using the decay time measurement method* possible. The contribution illustrates the principal design of the input couplers and the benefits it yields for Q measurements. Recent results including the progression of the quality factors over time will be presented. Felix Schliessmann et al., Nat. Phys. 19, 597-602 (2023). *Tom Powers, Proc. of SRF’05, Cornell University, Ithaca, New York, USA, 2005, p.40.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB008
About •	Received ※ 19 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 04 August 2023
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MOPMB029	Exploring the Dynamics of Transverse Inter-Planar Coupling in the Superconducting Section of the PIP-II Linac	coupling, space-charge, lattice, quadrupole	155
	A. Pathak Fermilab, Batavia, Illinois, USA E. Pozdeyev JLab, Newport News, USA
	This study investigates the crucial role that an accurate understanding of inter-planar coupling in the transverse plane plays in regulating charged particle dynamics in a high-intensity linear accelerator and minimizing foil/septum impacts during injection from the linac to a ring. We in-depth analyze the emergence and evolution of transverse inter-planar coupling through multiple active lattice elements, taking into account space charge and field nonlinearities in the superconducting section of the PIP-II linac. The article compares various analytical, numerical, and experimental techniques for measuring transverse coupling using beam and lattice matrices and provides insight into effective strategies for its mitigation prior to ring injectio
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB029
About •	Received ※ 21 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 05 July 2023
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MOPMB055	CEA Contribution to the PIP-II Linear Accelerator	cryomodule, cavity, SRF, controls	234
	N. Bazin, S. Berry, J. Drant, M. Fontaine, P. Garin, H. Jenhani, A. Raut, P. Sahuquet, C. Simon CEA-DRF-IRFU, France J. Belorgey, Q. Bertrand, P. Brédy, E. Cenni, C. Cloué, R. Cubizolles, S. Ladegaillerie, A. Le Baut, A. Moreau, O. Piquet, J. Plouin CEA-IRFU, Gif-sur-Yvette, France
	The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018 and will deliver 10 low-beta cryomodules as In-Kind Contributions to the PIP-II project, with cavities supplied by LASA-INFN (Italy) and VECC-DAE (India), and power couplers and tuning systems supplied by Fermilab. An important milestone was reached in March 2023 with the Final Design Review of the cryomodule, launching the pre-production phase. This paper presents the status CEA activities on the design, manufacturing, assembly and tests of the cryomodules and the upgrade of the existing infrastructures to the PIP-II requirements.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB055
About •	Received ※ 25 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 03 July 2023
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MOPMB063	Multipacting Processing in Cryomodules for LCLS-II and LCLS-II-HE	cavity, cryomodule, radiation, 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
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MOPMB080	Dedicate SRF Cryomodule Test Facilities for S3FEL	cryomodule, FEL, electron, SRF	298
	H. Li, C.F. He Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China X.L. Wang, W.M. Yue, W.Q. Zhang IASF, Shenzhen, Guangdong, People’s Republic of China
	Shenzhen Superconducting Soft-X-Ray Free Electron Laser (S3FEL) has been proposed to build a continuous wave (CW) superconducting linear accelerator and produce FEL in the soft X-ray wavelength region. The proposed S3FEL LINAC consists of twenty-eight SRF cryomodules to accelerate beam energy up to 2.5 GeV. Prior to the cryomodules installed in the tunnel, SRF cavities and cryomodules will be conditioned and tested at a delicate SRF Cryomodule Test Facility (SMTF).The SMTF for S3FEL is currently under design which equipped with two vertical cryostats and three horizontal test benches. R&D work for the SMTF and its corresponding cryomodule assembly procedure is now on going. This paper describes the full set of layout design and implementation of the SMTF for S3FEL project as well as its latest status.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB080
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 07 July 2023
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MOPMB081	Microphonics in the LCLS-II Superconducting Linac	cryomodule, cavity, operation, vacuum	302
	R.D. Porter, S. Aderhold, L.E. Alsberg, D. Gonnella, J. Nelson, N.R. Neveu, L.M. Zacarias SLAC, Menlo Park, California, USA A.T. Cravatta, J.P. Holzbauer, S. Posen Fermilab, Batavia, Illinois, USA M.A. Drury, M.D. McCaughan, C.M. Wilson JLab, Newport News, Virginia, USA G. Gaitan, N.A. Stilin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Work supported by the LCLS-II project The LCLS-II project has installed a new superconducting linac at SLAC that consists of 35 1.3 GHz cryomodules and 2 3.9 GHz cryomodules. The linac will provide a 4 GeV electron beam for generating soft and hard X-ray pulses. Cavity detuning induced by microphonics was a significant design challenge for the LCLS-II cryomodules. Cryomodules were produced that were within the detuning specification (10 Hz for 1.3 GHz cryomodules) on test stands. Here we present first measurements of the microphonics in the installed LCLS-II superconducting linac. Overall, the microphonics in the linac are manageable with 94% of cavities coming within the detune specification. Only two cavities are gradient limited due to microphonics. We identify a leaking cool down valve as the source of microphonics limiting those two cavities.
	Poster MOPMB081 [1.284 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB081
About •	Received ※ 18 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 01 July 2023
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MOPMB082	SRF Accelerating Modules Upgrade for Flash Linac at DESY	cavity, SRF, FEL, radiation	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
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MOPMB084	FRIB Driver Linac Integration to Support Operations and Protect SRF Cryomodules	operation, cryomodule, SRF, vacuum	316
	H. Ao, K. Elliott, D.D. Jager, S.H. Kim, L. Popielarski FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The driver linac for the Facility for Rare Isotope Beams (FRIB) at Michigan State University includes 324 superconducting radio-frequency (SRF) cavities, and the SRF particle-free beamline spans approximately 300 meters. Protecting the beamlines against contamination is critical to FRIB operations, and thus, various administrative and engineered controls have been put in place to protect the SRF cryomodules. These controls include local vacuum interlocks for cryomodule isolation, accelerator-wide interlocks, and software controls to safeguard the cryomodules and beamlines. Meanwhile, efforts are being made to provide training and develop programs with the goal of preventing critical failures during maintenance. This paper discusses the measures and approaches used for both system integration to support operations and SRF beamline protection.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB084
About •	Received ※ 14 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 18 July 2023
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MOPMB090	Measuring Q₀ in LCLS-II Cryomodules Using Helium Liquid Level	cavity, cryomodule, MMI, SRF	327
	L.M. Zacarias, S. Aderhold, D. Gonnella, J.T. Maniscalco, J. Nelson, R.D. Porter SLAC, Menlo Park, California, USA A.T. Cravatta, J.P. Holzbauer, S. Posen Fermilab, Batavia, Illinois, USA M.A. Drury, M.D. McCaughan, C.M. Wilson JLab, Newport News, Virginia, USA
	The nitrogen-doped cavities used in the Linac Coherent Light Source II (LCLS-II) cryomodules have shown an unprecedented high Q₀ in vertical and cryomodule testing compared with cavities prepared with standard methods. While demonstration of high Q₀ in the test stand has been achieved, maintaining that performance in the linac is critical to the success of LCLS-II and future accelerator projects. The LCLS-II cryomodules required a novel method of measuring Q₀, due to hardware incompatibilities with existing procedures. Initially developed at Jefferson Lab during cryomodule acceptance testing before being used in the tunnel at SLAC, we use helium liquid level data to estimate the heat generated by cavities. We first establish the relationship between the rate of helium evaporation from known heat loads using electric heaters, and then use that relationship to determine heat from an RF load. Here we present the full procedure along with the development process, lessons learned, and reproducibility while demonstrating for the first time that world record Q₀ can be maintained within the real accelerator environment.
	Poster MOPMB090 [1.867 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB090
About •	Received ※ 20 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 13 July 2023
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MOPMB092	Performance of Contaminated Superconducting Linac after Vacuum Excursion	cavity, cryomodule, vacuum, ISAC	332
	Z.Y. Yao, R.E. Laxdal TRIUMF, Vancouver, Canada
	ISAC-II superconducting heavy ion linac is the high energy section of TRIUMF ISAC facility to accelerate rare isotopes with A/q <= 6 from 1.5 MeV/u to above the Cou-lomb barrier for experiments. There was a vacuum excur-sion caused by an operational error and the failure of the fast protection system in summer 2022. The beamline downstream to the SC linac was vented with atmosphere air from the experimental hall resulting in pollution of the linac. This paper reports the RF performance of the con-taminated linac. The typical cavity performance changes, the average magnitude of degradation, the impact range in the SC linac, the observations in the recovery processes and the analyses on the most distinct cavity are discussed. The cavity refurbishment in the recent winter shutdown with the observations and outcomes is also reported. The ISAC-II event provided a unique data set for the SRF community.
	Poster MOPMB092 [6.186 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB092
About •	Received ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 02 July 2023
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TUIAA01	Twenty Years of Cryogenic Operation of the Flash Superconducting Linac	cryomodule, cavity, FEL, operation	347
	S. Barbanotti, DESY. Abassi, Y. Bozhko, K. Honkavaara, K. Jensch, D. Kostin, S. Lederer, T. Schnautz, S. Schreiber, A. Wagner, H. Weise DESY, Hamburg, Germany J. Roßbach University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany J. Zajac Linde Kryotechnik AG, Büro DESY Hamburg, Hamburg, Germany
	The FLASH superconducting linac is in operation at DESY since more than 20 years. Many changes and upgrades took place to transform a test stand for single cryomodules to a successful free electron laser. We summarize here the main steps of the FLASH history from the cryogenic point of view including the latest major upgrade that took place in 2022. We also give an overview of cryomodule performances like cavity gradient and heat load measurements and their evolution over the time.
	Slides TUIAA01 [6.861 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA01
About •	Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023
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TUPTB035	Design, Fabrication, and Test of a 175 MHz, β = 0.18, Half Wave Resonator for the IFMIF-DONES SRF-Linac	cavity, SRF, multipactoring, target	477
	J. Plouin, M. Baudrier, S. Chel, G. Devanz, A. Madur, L. Maurice, C. Servouin CEA-DRF-IRFU, France N. Bazin, G. Jullien CEA-IRFU, Gif-sur-Yvette, France
	The IFMIF-DONES facility will serve as a fusion-like neutron source for the assessment of materials damage in future fusion reactors. The neutron flux will be generated by the interaction between the lithium curtain and the deuteron beam from an RF linear accelerator at 40 MeV and nominal CW current of 125 mA. The last accelerating stage is a superconducting (SRF) Linac hosting five cryomodules. This SRF-Linac is equipped of two types of 175 MHz half wave superconducting cavities (HWRs). The first type of cavities (cryomodules 1 and 2), characterized by beta equal to 0.11, have been studied and qualified in the frame of IFMIF/EVEDA project. The development of the second type of cavities (cryomodules 3, 4 and 5), with higher beta of 0.18 is presented in this paper. A prototype has been designed, fabricated and tested in a vertical cryostat at CEA. The measured quality factor at nominal accelerating field (4.5 MV/m) is 2.3 10⁹ and keeps higher than 109 up to 10 MV/m, which gives confidence in the cavity design and preparation to reach the expected performances after integration in the SRF linac.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB035
About •	Received ※ 20 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 15 July 2023
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TUPTB036	Equidistant Optimization of Elliptical SRF Standing Wave Cavities	cavity, SRF, ECR, acceleration	480
	V.D. Shemelin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	A record accelerating rate was achieved earlier in standing wave (SW) SRF cavities when their shape was optimized for lower peak surface magnetic field. In view of new materials with higher limiting magnetic fields, expected for SRF cavities, in the first line Nb₃Sn, the approach to optimization of cavity shape should be revised. A method of equidistant optimization, offered earlier for traveling wave cavities is applied to SW cavities. It is shown here that without limitation by magnetic field, the maximal accelerating rate is defined to a significant degree by the cavity shape. For example, for a cavity with the aperture radius Ra = 35 mm the minimal ratio of the peak surface electric field to the accelerating rate is about Epk/E_acc = 1.54. So, with the maximal surface field experimentally achieved E_pk ¿ 125 MV/m, the maximal achievable accelerating rate is about 80 MeV/m even if there are no restrictions by the magnetic field. Another opportunity ¿ optimization for a low magnetic field, is opening for the same material, Nb₃Sn, with the purpose to have a high quality factor and increased accelerating rate that can be used for industrial linacs.
	Poster TUPTB036 [0.787 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB036
About •	Received ※ 15 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 08 July 2023
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TUPTB041	Visual, Optical and Replica Inspections: Surface Preparation of 650 MHz Nb Cavity for PIP-II Linac	cavity, SRF, niobium, embedded	507
	V. Chouhan, D.J. Bice, D.A. Burk, M.K. Ng, G. Wu Fermilab, Batavia, Illinois, USA
	Surface preparation of niobium superconducting RF cavities is a critical step for achieving good RF performance under the superconducting state. Surface defect, roughness, and contamination affect the accelerating gradient and quality factor of the cavities. We report surface inspection methods used to control the surface processing of 650 MHz cavities that will be used in the pre-production cryomodule for PIP-II linac. The cavity surface was routinely inspected visually, with an optical camera, and by microscopic scanning of surface replicas. This article covers details on the surface inspection methods and surface polishing process used to repair the surface.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB041
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 12 July 2023
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TUPTB045	PIP-II SSR2 Cavities Fabrication and Processing Experience	cavity, SRF, niobium, target	526
	M. Parise, P. Berrutti, D. Passarelli Fermilab, Batavia, Illinois, USA P. Duchesne, D. Longuevergne Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	The Proton Improvement Plan-II (PIP-II) linac will include 35 Single Spoke Resonators type 2 (SSR2). A pre-production SSR2 cryomodule will contain 5 jacketed cavities. Several units are already manufactured and prepared for cold testing. In this work, data collected from the fabrication, processing and preparation of the cavities will be presented and the improvements implemented after the completion of the first unit will be highlighted.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB045
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 08 July 2023
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TUPTB061	Status of the ESS Medium Beta Cavities at INFN LASA	cavity, cryomodule, simulation, SRF	559
	D. Sertore, M. Bertucci, M. Bonezzi, A. Bosotti, D. Cardelli, A. D’Ambros, E. Del Core, F. Fiorina, A.T. Grimaldi, L. Monaco, C. Pagani, R. Paparella, G.M. Zaggia INFN/LASA, Segrate (MI), Italy
	The INFN LASA’s contribution to the ESS Medium Beta Superconducting Linac consists of 36 cavities that raise the proton beam energy from 216 MeV to 571 MeV. Out of the 36 cavities, 28 have been successfully qualified and delivered for assembly into a cryomodule at CEA Saclay. The remaining cavities have been reprocessed in order to bring them up to ESS specifications. To mitigate further delays in the delivery of the cavities, four new ones are currently under construction. We are reporting on the current status of both the recovery actions we have developed so far and the performance of the newly produced resonators.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB061
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 14 July 2023
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TUPTB067	Fabrication and Surface Treatment of Superconducting Rf Single Spoke Cavities for the Myrrha Project	cavity, niobium, simulation, MMI	578
	M. Moretti, Y.N. Hoerstensmeyer, A. Navitski RI Research Instruments GmbH, Bergisch Gladbach, Germany F. Marhauser SCK•CEN, Mol, Belgium
	The MYRRHA project, based at SCK•CEN (Belgium), aims at coupling a 600 MeV proton accelerator to a subcritical fission core with a maximal output of 100 MWth. The first phase of the project, MINERVA, includes the design, construction, and commissioning of a 100 MeV superconducting RF linac in order to demonstrate the machine requirements in terms of reliability and fault tolerance. The MINERVA linac comprises several cryomodules, each containing two Single Spoke 352.2 MHz cavities made out of high RRR niobium and operating at 2K. The fabrication and surface treatment of the Single Spoke RF Cavities is currently ongoing and completely carried out by RI Research Instruments GmbH (Germany); the first pre-series cavities were completed and delivered for cold testing. Main highlights of the fabrication include the deep-drawing of complex shapes, such as central spokes and outer caps of the cavity, which was successfully accomplished. As for the surface treatment, RI has commissioned, tested, and effectively started utilizing a new rotational buffered chemical polishing facility; this is required to polish the cavity inner surface, while ensuring an almost uniform material removal.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB067
About •	Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 09 July 2023
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WEPWB058	Contribution of IN2P3 to PIP-II Project: Plans and Progress	cavity, SRF, vacuum, status	714
	D. Longuevergne, N. Bippus, P. Duchesne, N. Gandolfo, D. Le Dréan, G. Mavilla, T. Pépin-Donat, S. Roset, L.M. Vogt, S. Wallon Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France P. Berrutti, J. Helsper, S. Kazakov, M. Parise, D. Passarelli, N. Solyak, A.I. Sukhanov Fermilab, Batavia, Illinois, USA
	Funding: Work supported by IN2P3. Work supported, in part, by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under U.S. DOE Contract No. DE-AC02-07CH11359. IJCLab is one of the labs of IN2P3 (National institute of nuclear and particle physics), one of the ten research institutes composing the French National Center for Scientific Research (CNRS). Since 2018, IJCLab has been involved in the PIP-II project, assisting with the design, development, and qualification of accelerator components for the SSR2 (Single Spoke Resonator type 2) section of the superconducting linac. The first pre-production components (cavity, coupler, and tuner) have been fabricated, and some of the first qualification tests have been performed at IJCLab. This paper will summarize the complete scope of IJCLab¿s contributions to PIP-II and give updates on the performances of the first pre-production components.
	Poster WEPWB058 [1.727 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB058
About •	Received ※ 24 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 05 July 2023 — Issue date ※ 10 July 2023
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WEPWB068	Characterization of Additive Manufacturing Materials for String Assembly in Cleanroom	cryomodule, cavity, SRF, detector	746
	J. Bernardini, M. Parise, D. Passarelli Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Fermi Research Alliance, LLC under Contract No. DEAC02- 07CH11359 with the United States Department of Energy, Office of Science, Office of High Energy Physics. Beamline components, such as superconducting radio frequency cavities and focusing lenses, need to be assembled together in a string while in a cleanroom environment. The present contribution identifies and characterizes materials for additive manufacturing that can be used in a cleanroom. The well known advantages of additive manufacturing processes would highly benefit the design and development of tooling needed for the mechanical support and alignment of string components. Cleanliness, mechanical properties, and leak tightness of the chosen materials are the main focus of this contribution, which also paves the way for the integration of such materials in cryomodule assemblies. Results reported here were obtained in the framework of the PIP-II project at Fermilab.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB068
About •	Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 04 July 2023
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WEPWB070	Test Shipment of the PIP-II 650 MHz Transport Frame Between FNAL to STFC-UKRI	cryomodule, ISOL, SRF, acceleration	750
	J.P. Holzbauer, S.K. Chandrasekaran, C.J. Grimm, J.P. Ozelis, R. Thiede, A.D. Wixson Fermilab, Batavia, Illinois, USA M.T.W. Kane STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Work supported by Fermi Research Alliance, LLC under Contract No. DEAC02- 07CH11359 with the United States Department of Energy The PIP-II Project will receive fully assembled cryomodules from CEA and STFC-UKRI as in-kind contributions. Damage to these cryomodules during transport is understood to be a significant risk to the project, so an extensive testing and validation program is in process to mitigate this risk. The centerpiece of this effort is the eventual shipment from FNAL to STFC-UKRI and back of a prototype HB650 cryomodule with cold testing before and after shipment to verify no functionality changes from shipment. Most recently, a test shipment to the UK and back using a cryomodule analog was completed using realistic logistics, handling, instrumentation, and planning. The process of executing this test shipment, lessons learned, and plan moving forward will be presented here.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB070
About •	Received ※ 18 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 17 July 2023
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WEPWB083	Basic Design and Consideration of Li-Vapor Contamination for A-FNS SRF	SRF, cavity, solenoid, operation	773
	T. Ebisawa, K. Hasegawa, A. Kasugai, M. Oyaidzu, S. Sato QST Rokkasho, Aomori, Japan E. Kako, H. Sakai, K. Umemori KEK, Ibaraki, Japan
	The Advanced Fusion Neutron Source (A-FNS) project is in progressing in Japan, QST Rokkasho institute. A-FNS will demonstrate a performance of the DEMO DT fusion reactor material. In order to perform the test, a high intensity deuteron beam accelerator will be used to produce a high flux neutron field which is similar to the 14 MeV DT neutron. The Superconducting Radio-Frequency linear accelerator (SRF) is one component of the A-FNS accelerator system. Although the A-FNS accelerator system design is based on the IFMIF design, the improvement of some subsystem has been considering by taking into account the lessons learnt from the LIPAc project. In order to keep a high stability and availability of the SRF performance, we plan to increase the number of SRF cavities and cryomodules considering the trouble or degradation of the cavity performance and modify the engineering design of some components. In addition, changing of the beam transport line design and Li vapor contamination study of SRF cavity are conducting. In this presentation, the progress of the SRF design and related activities for A-FNS in QST will be presented.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB083
About •	Received ※ 28 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 17 August 2023
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WEPWB093	Transportation Fatigue Testing of the pHB650 Power Coupler Antenna for the PIP-II Project at Fermilab	vacuum, SRF, cryomodule, resonance	801
	J. Helsper, S.K. Chandrasekaran, J.P. Holzbauer, N. Solyak 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. The PIP-II Project will see international shipment of cryomodules from Europe to the United States, and as such, the shocks which can occur during shipment pose a risk to the internal components. Of particular concern is the coupler ceramic window and surrounding brazes, which can see relatively high stress during an excitation event. Since the antenna design is new, and because of the setback failure would create, a cyclic stress test was devised for the antenna. This paper presents the experimental methods, setup, and results of the test.
	Poster WEPWB093 [2.913 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB093
About •	Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 03 July 2023
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WEPWB101	Present Status of RIKEN Power Couplers for SRILAC	vacuum, Windows, SRF, operation	823
	K. Ozeki, O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada RIKEN Nishina Center, Wako, Japan
	The heavy ion linac of the RIKEN, utilizing superconducting technology, began operations in September 2019. Over the following 13 months, two of the ten superconducting accelerating cavities experienced vacuum leaks from the vacuum windows of the fundamental power couplers (FPCs). Currently, additional vacuum windows are installed on all ten FPCs and the beam supply continues without encountering any major issues with the FPCs. Additionally, the fabrication of ten replacement FPCs has been completed, addressing the underlying issues that led to the deterioration of the vacuum window strength. Currently, we are conducting radio frequency (RF) process of the new FPCs. In addition, we are designing a bias applying component to suppress multipacting in the FPCs. This paper reports the status of these issues related to the FPCs at the RIKEN.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB101
About •	Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 14 July 2023
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WEPWB105	Improved Study of the Multipactor Phenomenon for the MYRRHA 80 kW CW RF Couplers	multipactoring, electron, coupling, cavity	838
	Y. Gómez Martínez, P.-O. Dumont LPSC, Grenoble Cedex, France P. Duchesne, N. ElKamchi, C. Joly, W. Kaabi Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France C. Lhomme IJCLab, ORSAY, France C. Lhomme ACS, Orsay, France
	MYRRHA (Multi Purpose Hybrid Reactor for High Tech Applications) is an Accelerator Driven System (ADS) project. Its superconducting linac will provide a 600 MeV - 4 mA proton beam. The first project phase based on a 100 MeV linac is launched. The Radio-Frequency (RF) couplers have been designed to handle 80 kW CW (Continuous Wave) at 352.2 MHz. This paper describes the multipactor studies on the coupler when it does not work in the nominal configuration without reflected power.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB105
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 12 July 2023
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WEPWB126	First Results from Nanoindentation of Vapor Diffused Nb₃Sn Films on Nb	cavity, SRF, experiment, accelerating-gradient	888
	U. Pudasaini JLab, Newport News, Virginia, USA S. Cheban, G.V. Eremeev Fermilab, Batavia, Illinois, USA
	Funding: U.S. Department of Energy, Office of Science, Office of Nuclear Physics & Office of High Energy Physics. The mechanical vulnerability of the Nb₃Sn-coated cavities is identified as one of the significant technical hurdles toward deploying them in practical accelerator applications in the not-so-distant future. It is crucial to characterize the material’s mechanical properties in ways to address such vulnerability. Nanoindentation is a widely used technique for measuring the mechanical properties of thin films that involves indenting the film with a small diamond tip and measuring the force-displacement response to calculate the film’s elastic modulus, hardness, and other mechanical properties. The nanoindentation analysis was performed on multiple vapor-diffused Nb₃Sn samples coated at Jefferson Lab and Fermilab coating facilities for the first time. This contribution will discuss the first results obtained from the nanoindentation of Nb₃Sn-coated Nb samples prepared via the Sn vapor diffusion technique.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB126
About •	Received ※ 19 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 16 July 2023
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WEPWB128	Experimental Study of Mechanical Dampers for the FRIB β=0.041 Quarter-Wave Resonators	cavity, damping, operation, ECR	898
	J. Brown, W. Chang, W. Hartung, S.H. Kim, T. Xu FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the US Department of Energy, Office of Science, High Energy Physics under Cooperative Agreement award numbers DE-SC0018362 and DE-SC0000661 and Michigan State University. The ’pendulum’ mechanical mode of quarter-wave resonators (QWR) often causes an issue with microphonics and/or ponderomotive instability unless otherwise the inner conductors are properly stiffened and/or damped. FRIB QWRs are equipped with a Legnaro-style frictional damper installed inside of the inner conductor such that it counteracts the oscillations of the inner conductor. In cryomodule tests and linac operation, we observed that the damping efficiency is different for a few β=0.041 QWRs. This study aimed to experimentally characterize the damping efficacy as a function of damper mass and surface roughness. We present damping measurements at room temperature and at two different masses and surface roughness as well as discuss future studies for damper re-optimization based on this follow-on study.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB128
About •	Received ※ 20 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 04 August 2023
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THIAA01	Development of 3.9 GHz 9-Cell Cavities at SHINE	cavity, electron, FEL, laser	921
	X.W. Wu Zhangjiang Lab, Shanghai, People’s Republic of China J.F. Chen, P.C. Dong, Y.F. Liu, X.H. Ouyang, S. Sun, J.N. Wu, S. Xing, Y.X. Zhang, S.J. Zhao, Y.L. Zhao SARI-CAS, Pudong, Shanghai, People’s Republic of China X. Huang, Z. Wang, Y. Zong SINAP, Shanghai, People’s Republic of China Y.W. Huang, R.Z. Xia ShanghaiTech University, Shanghai, People’s Republic of China
	The Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) Linac requires two 3.9~GHz crymodules to linearize energy distribution before the bunch compressor. As a key component to the project, studies of 3.9~GHz cavities were conducted in the past few years. The first 3.9~GHz 9-cell prototype cavity has been fabricated, tested, and qualified. It reached Q₀=3.5×10⁹ at 13.1~MV/m and a maximum accelerating gradient of 25.0~MV/m during the vertical test of the bare cavity. The prototype has been helium tank integrated and reached Q₀=2.9×10⁹ at 13.1~MV/m in the vertical test, with a large margin with respect to the SHINE specification. The second prototype has been fabricated and is planned to be tested in 2023. This paper will cover the fabrication, surface treatment, and RF test of the 3.9~GHz cavities.
	Slides THIAA01 [7.573 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA01
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 18 July 2023
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THCAA01	Development of Single-spoke Cavities for ADS at JAEA	cavity, SRF, emittance, proton	947
	Y. Kondo JAEA, Ibaraki-ken, Japan T. Dohmae, E. Kako, H. Sakai, K. Umemori KEK, Ibaraki, Japan F. Maekawa, S.I. Meigo, J. Tamura, B. Yee-Rendón JAEA/J-PARC, Tokai-mura, Japan
	Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven system (ADS) as a future nuclear system to efficiently reduce the high-level radioactive waste generated at nuclear power plants. As the first step toward the full-scale CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. Because there is no experience in manufacturing superconducting spoke cavities in Japan, prototyping and performance testing of the cavity are essential to ensure the feasibility of the JAEA-ADS. The dimensional parameters of the prototype spoke cavity were optimized to obtain higher cavity performance. The actual cavity fabrication started in 2020. Most of the cavity parts were fabricated in fiscal year 2020 by press-forming and machining. In 2021, we started welding the cavity parts together. After investigating the optimum welding conditions using mock-up test pieces, each cavity part was joined with smooth welding beads. Currently, the cavity’s body section and the beam port sections have been assembled. This paper presents the current status of the JAEA-ADS and it’s cavity prototyping.
	Slides THCAA01 [8.433 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-THCAA01
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 10 July 2023
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FRIBA05	Automation of FRIB SRF Cavities and SC Solenoids Turn-on/off	cavity, cryomodule, solenoid, SRF	999
	W. Chang, Y. Choi, X.J. Du, W. Hartung, S.H. Kim, T. Konomi, S.R. Kunjir, H. Nguyen, K. Saito, T. Xu, S. Zhao FRIB, East Lansing, Michigan, USA A. Facco INFN/LNL, Legnaro (PD), Italy
	The superconducting driver Linac for the Facility for Rare Isotope Beams (FRIB) is a heavy ion accelerator that accelerate ions to 200 MeV per nucleon. The Linac has 46 cryomodules that contain 324 superconducting radio frequency (SRF) cavities and 69 superconducting (SC) solenoid packages. For operation of all cryomodules with high efficiency and reliability, automation for SRF cavity and SC solenoid fast turn-on/off is essentially. Based on cryomodule commissioning results and expert experience, all manual cavity and solenoid turn-on/off procedures and steps have been replaced by automatic programs for FRIB linac operation. This allows the operators to turn the systems on and off without expert-level training. Automation reduces the risk of human error, speeds up beam recovery after user access to experimental areas, and increases beam availability. The cavity turn-on procedure makes sure that the cavity can operate at low field with expected read backs, ramps up the field, and makes sure that the RF amplitude and phase are stable. The design, implementation, and operating experience with automation will be presented.
	Slides FRIBA05 [3.503 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-FRIBA05
About •	Received ※ 29 June 2023 — Revised ※ 16 August 2023 — Accepted ※ 21 August 2023 — Issue date ※ 21 August 2023
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Paper

Title

Other Keywords

Page

MOIAA01

FRIB Transition to User Operations, Power Ramp Up, and Upgrade Perspectives

cavity, cryomodule, operation, target

1

J. Wei, H. Ao, B. Arend, S. Beher, G. Bollen, N.K. Bultman, F. Casagrande, W. Chang, Y. Choi, S. Cogan, C. Compton, M. Cortesi, J.C. Curtin, K.D. Davidson, X.J. Du, K. Elliott, B. Ewert, A. Facco, A. Fila, K. Fukushima, V. Ganni, A. Ganshyn, T.N. Ginter, T. Glasmacher, J.-W. Guo, Y. Hao, W. Hartung, N.M. Hasan, M. Hausmann, K. Holland, H.-C. Hseuh, M. Ikegami, D.D. Jager, S. Jones, N. Joseph, T. Kanemura, S.H. Kim, C. Knowles, T. Konomi, B.R. Kortum, E. Kwan, T. Lange, M. Larmann, T.L. Larter, K. Laturkar, R.E. Laxdal, J. LeTourneau, Z. Li, S.M. Lidia, G. Machicoane, C. Magsig, P.E. Manwiller, F. Marti, T. Maruta, E.S. Metzgar, S.J. Miller, Y. Momozaki, D.G. Morris, M. Mugerian, I.N. Nesterenko, C. Nguyen, P.N. Ostroumov, M.S. Patil, A.S. Plastun, L. Popielarski, M. Portillo, J. Priller, X. Rao, M.A. Reaume, K. Saito, B.M. Sherrill, M.K. Smith, J. Song, M. Steiner, A. Stolz, O. Tarasov, B.P. Tousignant, R. Walker, X. Wang, J.D. Wenstrom, G. West, K. Witgen, M. Wright, T. Xu, Y. Yamazaki, T. Zhang, Q. Zhao, S. Zhao
FRIB, East Lansing, Michigan, USA
K. Hosoyama
KEK, Ibaraki, Japan
P. Hurh
Fermilab, Batavia, Illinois, USA
M.P. Kelly, Y. Momozaki
ANL, Lemont, Illinois, USA
R.E. Laxdal
TRIUMF, Vancouver, Canada
S.O. Prestemon
LBNL, Berkeley, California, USA
M. Wiseman
JLab, Newport News, Virginia, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
After project completion on scope, on cost, and ahead of schedule, the Facility for Rare Isotope Beams began operations for scientific users in May of 2022. During the first 12 months of user operations, the FRIB accelerator complex delivered 5250 beam hours, including 1528 hours to nine science experiments conducted with primary beams of 36Ar, 48Ca, 70Zn, 82Se, 124Xe, and 198Pt at beam energies >200 MeV/u; 2724 hours for beam developments, studies, and tuning; and 998 hours to industrial users and non-scientific programs using the FRIB Single Event Effect (FSEE) beam line. The ramp-up to a beam power of 400 kW is planned over a six-year period; 1 kW was delivered for initial user runs from in 2022, and 5 kW was delivered as of February 2023. Upgrade plans include doubling the primary-beam energy to 400 MeV/nucleon for enhanced discovery potential (¿FRIB 400¿). This talk reports on FRIB status and progress since SRF2021, emphasizing lessons learned during the transition from beam commissioning to machine operations, challenges and resolutions for the power ramp-up, progress with accelerator improvements, and R&D for the energy upgrade.

Slides MOIAA01 [7.037 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIAA01

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Received ※ 20 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 03 July 2023 — Issue date ※ 19 July 2023

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MOIAA03

Progresses in the ESS Superconducting Linac Installation

cryomodule, MMI, operation, cryogenics

9

H. Przybilski
ESS, Lund, Sweden

The ESS Linac is progressing into the technical commissioning phase. The normal conducting linac up to the first 4 tanks of the DTL is being commissioned with beam. All the 13 spoke cryomodules and the 9 elliptical modules (7 MB+2 HB) foreseen for the first operation at 570 MeV on the beam dump in summer 2024 are available in Lund and waiting the completion of the cryogenic distribution system (CDS) commissioning. The test program of all the 30 elliptical cryomodules that will enable the 5 MW potential operation after the target commissioning is progressing well, as well as the installation of the RF power stations necessary up to the 2 MW stage of the first project phase. Pilot installation of one spoke and one elliptical CM in the tunnel is in progress. The talk will cover the status of the component deliveries from the partners, the CM preparation and SRF activities at the ESS test stands, with the resolution of several non-conformities, and the experience of the pilot installations and technical commissioning activities in the accelerator tunnel.

Slides MOIAA03 [9.000 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIAA03

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Received ※ 26 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 13 July 2023

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MOIXA02

PIP-II Project Overview and Status

cryomodule, cavity, SRF, controls

19

R.P. Stanek, C. Boffo, S.K. Chandrasekaran, S.J. Dixon, E.R. Harms, L. Kokoska, I. Kourbanis, J.R. Leibfritz, O. Napoly, D. Passarelli, E. Pozdeyev, A.M. Rowe
Fermilab, Batavia, Illinois, USA

Funding: Prepared by PIP-II Project using resources of the Fermi National Accelerator Laboratory, a U.S. DOE facility, managed by Fermi Research Alliance, LLC, acting under Contract No. DE-AC02-07CH11359.
The Proton Improvement Plan II (PIP-II) project is an essential upgrade to Fermilab’s particle accelerator complex to enable the world’s most intense neutrino beam for LBNF/DUNE and a broad particle physics program for many decades to come. PIP-II will deliver 1.2 MW of proton beam power from the Main Injector, upgradeable to multi-MW capability. The central element of PIP-II is an 800 MeV superconducting radio frequency (SRF) linac, which comprises a room temperature front end followed by an SRF section. The SRF section consists of five different flavors of cavities/cryomodules, including Half Wave Resonators (HWR), Single Spoke and elliptical resonators operating at, or above, state-of-the-art parameters. The first two PIP-II cryomodules, Half Wave Resonator (HWR) and Single Spoke Resonator 1 (SSR1) were installed in the PIP-II Injector Test facility (PIP2IT) and have accelerated beam to above 17 MeV. PIP-II is the first U.S. accelerator project that will be constructed with significant contributions from international partners, including India, Italy, France, United Kingdom and Poland. The project was baselined in April 2022, and the construction phase is underway.

Slides MOIXA02 [3.353 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA02

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Received ※ 07 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 16 July 2023

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MOIXA03

Proton Power Upgrade Project Progress and Plans at the Spallation Neutron Source in Oak Ridge Tennessee

target, cryomodule, cavity, operation

25

J.D. Mammosser, M.J. Dayton, D.D. Kraft, R. Maekawa, L. Pinion, B.E. Robertson
ORNL RAD, Oak Ridge, Tennessee, USA
R. Afanador, D.L. Barnhart, M.S. Champion, B. DeGraff, M. Doleans, J. Galambos, S.W. Gold, M.N. Greenwood, G.A. Hine, M.P. Howell, S.-H. Kim, C.J. McMahan, P. Pizzol, S.E. Stewart, D.J. Vandygriff, D.M. Vandygriff
ORNL, Oak Ridge, Tennessee, USA
A. Bitter, K.B. Bolz, A. Navitski, L. Zweibäumer
RI Research Instruments GmbH, Bergisch Gladbach, Germany
E.F. Daly, G.K. Davis, P. Dhakal, J.F. Fischer, D. Forehand, N.A. Huque, K.M. Wilson
JLab, Newport News, Virginia, USA

Funding: Work Supported by UT-Battelle, LLC, under contract DE-AC05-00OR22725
The Proton Power Upgrade project is well underway at the Spallation Neutron Source (SNS) facility in Oak Ridge, Tennessee. This project aims at increasing the proton beam power capability from 1.4 to 2.8 MW, by adding linac energy, increasing the beam current and implementing target developments to handle the increased beam power. This talk will cover the current status of increasing the beam energy, issues encountered along the way, operational experience with the new SRF cryomodules and target improvements and results from operation with beam so far.

Slides MOIXA03 [3.327 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA03

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Received ※ 09 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 08 July 2023

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MOIXA04

Operational Experience for RIKEN Superconducting Linear Accelerator

operation, cyclotron, heavy-ion, vacuum

30

K. Yamada, M. Fujimaki, H. Imao, O. Kamigaito, M. Komiyama, K. Kumagai, T. Nagatomo, T. Nishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe
RIKEN Nishina Center, Wako, Japan

The RIKEN superconducting heavy-ion linac, so-called SRILAC, has been successfully operating for almost four years, and continuously deliver a heavy ion beam for a super-heavy-element synthesis experiment. The effects of a broken coupler in the early days and four years of operation have resulted in increased X-ray emission levels in several superconducting cavities, which have been successfully corrected by pulse conditioning. This talk will share the experiences and lessons learned from four-year operation with low beta SC-cavities.

Slides MOIXA04 [4.517 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA04

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Received ※ 06 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023

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MOIXA06

Operational Experience with the European XFEL SRF Linac

operation, cavity, FEL, LLRF

43

Ch. Schmidt, M. Bousonville, J. Branlard, M. Diomede, S. Göller, D. Kostin, M. Scholz, V. Vogel (Fogel), N. Walker
DESY, Hamburg, Germany

The European X-ray Free Electron laser (EuXFEL) is a 3.4 km long research facility which generates ultrashort X-ray flashes of outstanding brilliance since 2017. Up to 27000 electron bunches per second are accelerated in a 1.3 km long superconducting radio frequency (SRF) linac to a maximum energy of 17.6 GeV. Within this time, operational experience with a pulsed RF machine has been gained and new operation modes simultaneously delivering electron bunches to 3 different SASE undulator beamlines have been successfully implemented. Recent activities on increasing the linac availability, power efficiency and duty cycle are discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA06

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Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 06 July 2023

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MOPMB008

In-Situ Quality Factor Measurements of SRF Cavities at S-DALINAC

cavity, SRF, coupling, resonance

70

R. Grewe, M. Arnold, A. Brauch, M. Dutine, L.E. Jürgensen, N. Pietralla, F. Schließmann, D. Schneider
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG (GRK 2128) and the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006)
The Superconducting Darmstadt Linear Accelerator (S-DALINAC) is a thrice recirculating electron accelerator wich can be operated in a multi-turn energy recovery mode*. The design parameters for kinetic energy and beam current are up to 130 MeV and up to 20 uA respectively. The injector consists of a six-cell capture cavity and two 20-cell srf cavities. The main linac consists of eight 20-cell cavities. The cavities are operated at a temperature of 2 K with a frequency of 2.9972(1) GHz. Monitoring of the srf cavities is important for the overall performance of the accelerator. A key parameter for the rating of the srf cavity performance is the intrinsic quality factor Q. At the S-DALINAC it is measured for selected cavities during the yearly maintenance procedures. The unique design of the rf input coupler allows for a wide tuning range for the input coupling strength. This makes in-situ quality factor measurements using the decay time measurement method** possible. The contribution illustrates the principal design of the input couplers and the benefits it yields for Q measurements. Recent results including the progression of the quality factors over time will be presented.
*Felix Schliessmann et al., Nat. Phys. 19, 597-602 (2023).
**Tom Powers, Proc. of SRF’05, Cornell University, Ithaca, New York, USA, 2005, p.40.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB008

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Received ※ 19 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 04 August 2023

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MOPMB029

Exploring the Dynamics of Transverse Inter-Planar Coupling in the Superconducting Section of the PIP-II Linac

coupling, space-charge, lattice, quadrupole

155

A. Pathak
Fermilab, Batavia, Illinois, USA
E. Pozdeyev
JLab, Newport News, USA

This study investigates the crucial role that an accurate understanding of inter-planar coupling in the transverse plane plays in regulating charged particle dynamics in a high-intensity linear accelerator and minimizing foil/septum impacts during injection from the linac to a ring. We in-depth analyze the emergence and evolution of transverse inter-planar coupling through multiple active lattice elements, taking into account space charge and field nonlinearities in the superconducting section of the PIP-II linac. The article compares various analytical, numerical, and experimental techniques for measuring transverse coupling using beam and lattice matrices and provides insight into effective strategies for its mitigation prior to ring injectio

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB029

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Received ※ 21 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 05 July 2023

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MOPMB055

CEA Contribution to the PIP-II Linear Accelerator

cryomodule, cavity, SRF, controls

234

N. Bazin, S. Berry, J. Drant, M. Fontaine, P. Garin, H. Jenhani, A. Raut, P. Sahuquet, C. Simon
CEA-DRF-IRFU, France
J. Belorgey, Q. Bertrand, P. Brédy, E. Cenni, C. Cloué, R. Cubizolles, S. Ladegaillerie, A. Le Baut, A. Moreau, O. Piquet, J. Plouin
CEA-IRFU, Gif-sur-Yvette, France

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018 and will deliver 10 low-beta cryomodules as In-Kind Contributions to the PIP-II project, with cavities supplied by LASA-INFN (Italy) and VECC-DAE (India), and power couplers and tuning systems supplied by Fermilab. An important milestone was reached in March 2023 with the Final Design Review of the cryomodule, launching the pre-production phase. This paper presents the status CEA activities on the design, manufacturing, assembly and tests of the cryomodules and the upgrade of the existing infrastructures to the PIP-II requirements.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB055

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Received ※ 25 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 03 July 2023

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MOPMB063

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

cavity, cryomodule, radiation, 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]

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

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

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MOPMB080

Dedicate SRF Cryomodule Test Facilities for S3FEL

cryomodule, FEL, electron, SRF

298

H. Li, C.F. He
Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China
X.L. Wang, W.M. Yue, W.Q. Zhang
IASF, Shenzhen, Guangdong, People’s Republic of China

Shenzhen Superconducting Soft-X-Ray Free Electron Laser (S3FEL) has been proposed to build a continuous wave (CW) superconducting linear accelerator and produce FEL in the soft X-ray wavelength region. The proposed S3FEL LINAC consists of twenty-eight SRF cryomodules to accelerate beam energy up to 2.5 GeV. Prior to the cryomodules installed in the tunnel, SRF cavities and cryomodules will be conditioned and tested at a delicate SRF Cryomodule Test Facility (SMTF).The SMTF for S3FEL is currently under design which equipped with two vertical cryostats and three horizontal test benches. R&D work for the SMTF and its corresponding cryomodule assembly procedure is now on going. This paper describes the full set of layout design and implementation of the SMTF for S3FEL project as well as its latest status.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB080

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 07 July 2023

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MOPMB081

Microphonics in the LCLS-II Superconducting Linac

cryomodule, cavity, operation, vacuum

302

R.D. Porter, S. Aderhold, L.E. Alsberg, D. Gonnella, J. Nelson, N.R. Neveu, L.M. Zacarias
SLAC, Menlo Park, California, USA
A.T. Cravatta, J.P. Holzbauer, S. Posen
Fermilab, Batavia, Illinois, USA
M.A. Drury, M.D. McCaughan, C.M. Wilson
JLab, Newport News, Virginia, USA
G. Gaitan, N.A. Stilin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Work supported by the LCLS-II project
The LCLS-II project has installed a new superconducting linac at SLAC that consists of 35 1.3 GHz cryomodules and 2 3.9 GHz cryomodules. The linac will provide a 4 GeV electron beam for generating soft and hard X-ray pulses. Cavity detuning induced by microphonics was a significant design challenge for the LCLS-II cryomodules. Cryomodules were produced that were within the detuning specification (10 Hz for 1.3 GHz cryomodules) on test stands. Here we present first measurements of the microphonics in the installed LCLS-II superconducting linac. Overall, the microphonics in the linac are manageable with 94% of cavities coming within the detune specification. Only two cavities are gradient limited due to microphonics. We identify a leaking cool down valve as the source of microphonics limiting those two cavities.

Poster MOPMB081 [1.284 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB081

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Received ※ 18 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 01 July 2023

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MOPMB082

SRF Accelerating Modules Upgrade for Flash Linac at DESY

cavity, SRF, FEL, radiation

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

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

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MOPMB084

FRIB Driver Linac Integration to Support Operations and Protect SRF Cryomodules

operation, cryomodule, SRF, vacuum

316

H. Ao, K. Elliott, D.D. Jager, S.H. Kim, L. Popielarski
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The driver linac for the Facility for Rare Isotope Beams (FRIB) at Michigan State University includes 324 superconducting radio-frequency (SRF) cavities, and the SRF particle-free beamline spans approximately 300 meters. Protecting the beamlines against contamination is critical to FRIB operations, and thus, various administrative and engineered controls have been put in place to protect the SRF cryomodules. These controls include local vacuum interlocks for cryomodule isolation, accelerator-wide interlocks, and software controls to safeguard the cryomodules and beamlines. Meanwhile, efforts are being made to provide training and develop programs with the goal of preventing critical failures during maintenance. This paper discusses the measures and approaches used for both system integration to support operations and SRF beamline protection.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB084

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Received ※ 14 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 18 July 2023

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MOPMB090

Measuring Q₀ in LCLS-II Cryomodules Using Helium Liquid Level

cavity, cryomodule, MMI, SRF

327

L.M. Zacarias, S. Aderhold, D. Gonnella, J.T. Maniscalco, J. Nelson, R.D. Porter
SLAC, Menlo Park, California, USA
A.T. Cravatta, J.P. Holzbauer, S. Posen
Fermilab, Batavia, Illinois, USA
M.A. Drury, M.D. McCaughan, C.M. Wilson
JLab, Newport News, Virginia, USA

The nitrogen-doped cavities used in the Linac Coherent Light Source II (LCLS-II) cryomodules have shown an unprecedented high Q₀ in vertical and cryomodule testing compared with cavities prepared with standard methods. While demonstration of high Q₀ in the test stand has been achieved, maintaining that performance in the linac is critical to the success of LCLS-II and future accelerator projects. The LCLS-II cryomodules required a novel method of measuring Q₀, due to hardware incompatibilities with existing procedures. Initially developed at Jefferson Lab during cryomodule acceptance testing before being used in the tunnel at SLAC, we use helium liquid level data to estimate the heat generated by cavities. We first establish the relationship between the rate of helium evaporation from known heat loads using electric heaters, and then use that relationship to determine heat from an RF load. Here we present the full procedure along with the development process, lessons learned, and reproducibility while demonstrating for the first time that world record Q₀ can be maintained within the real accelerator environment.

Poster MOPMB090 [1.867 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB090

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Received ※ 20 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 13 July 2023

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MOPMB092

Performance of Contaminated Superconducting Linac after Vacuum Excursion

cavity, cryomodule, vacuum, ISAC

332

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

ISAC-II superconducting heavy ion linac is the high energy section of TRIUMF ISAC facility to accelerate rare isotopes with A/q <= 6 from 1.5 MeV/u to above the Cou-lomb barrier for experiments. There was a vacuum excur-sion caused by an operational error and the failure of the fast protection system in summer 2022. The beamline downstream to the SC linac was vented with atmosphere air from the experimental hall resulting in pollution of the linac. This paper reports the RF performance of the con-taminated linac. The typical cavity performance changes, the average magnitude of degradation, the impact range in the SC linac, the observations in the recovery processes and the analyses on the most distinct cavity are discussed. The cavity refurbishment in the recent winter shutdown with the observations and outcomes is also reported. The ISAC-II event provided a unique data set for the SRF community.

Poster MOPMB092 [6.186 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB092

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Received ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 02 July 2023

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TUIAA01

Twenty Years of Cryogenic Operation of the Flash Superconducting Linac

cryomodule, cavity, FEL, operation

347

S. Barbanotti, DESY. Abassi, Y. Bozhko, K. Honkavaara, K. Jensch, D. Kostin, S. Lederer, T. Schnautz, S. Schreiber, A. Wagner, H. Weise
DESY, Hamburg, Germany
J. Roßbach
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
J. Zajac
Linde Kryotechnik AG, Büro DESY Hamburg, Hamburg, Germany

The FLASH superconducting linac is in operation at DESY since more than 20 years. Many changes and upgrades took place to transform a test stand for single cryomodules to a successful free electron laser. We summarize here the main steps of the FLASH history from the cryogenic point of view including the latest major upgrade that took place in 2022. We also give an overview of cryomodule performances like cavity gradient and heat load measurements and their evolution over the time.

Slides TUIAA01 [6.861 MB]

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reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA01

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Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023

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TUPTB035

Design, Fabrication, and Test of a 175 MHz, β = 0.18, Half Wave Resonator for the IFMIF-DONES SRF-Linac

cavity, SRF, multipactoring, target

477

J. Plouin, M. Baudrier, S. Chel, G. Devanz, A. Madur, L. Maurice, C. Servouin
CEA-DRF-IRFU, France
N. Bazin, G. Jullien
CEA-IRFU, Gif-sur-Yvette, France

The IFMIF-DONES facility will serve as a fusion-like neutron source for the assessment of materials damage in future fusion reactors. The neutron flux will be generated by the interaction between the lithium curtain and the deuteron beam from an RF linear accelerator at 40 MeV and nominal CW current of 125 mA. The last accelerating stage is a superconducting (SRF) Linac hosting five cryomodules. This SRF-Linac is equipped of two types of 175 MHz half wave superconducting cavities (HWRs). The first type of cavities (cryomodules 1 and 2), characterized by beta equal to 0.11, have been studied and qualified in the frame of IFMIF/EVEDA project. The development of the second type of cavities (cryomodules 3, 4 and 5), with higher beta of 0.18 is presented in this paper. A prototype has been designed, fabricated and tested in a vertical cryostat at CEA. The measured quality factor at nominal accelerating field (4.5 MV/m) is 2.3 10⁹ and keeps higher than 109 up to 10 MV/m, which gives confidence in the cavity design and preparation to reach the expected performances after integration in the SRF linac.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB035

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Received ※ 20 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 15 July 2023

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TUPTB036

Equidistant Optimization of Elliptical SRF Standing Wave Cavities

cavity, SRF, ECR, acceleration

480

V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

A record accelerating rate was achieved earlier in standing wave (SW) SRF cavities when their shape was optimized for lower peak surface magnetic field. In view of new materials with higher limiting magnetic fields, expected for SRF cavities, in the first line Nb₃Sn, the approach to optimization of cavity shape should be revised. A method of equidistant optimization, offered earlier for traveling wave cavities is applied to SW cavities. It is shown here that without limitation by magnetic field, the maximal accelerating rate is defined to a significant degree by the cavity shape. For example, for a cavity with the aperture radius Ra = 35 mm the minimal ratio of the peak surface electric field to the accelerating rate is about Epk/E_acc = 1.54. So, with the maximal surface field experimentally achieved E_pk ¿ 125 MV/m, the maximal achievable accelerating rate is about 80 MeV/m even if there are no restrictions by the magnetic field. Another opportunity ¿ optimization for a low magnetic field, is opening for the same material, Nb₃Sn, with the purpose to have a high quality factor and increased accelerating rate that can be used for industrial linacs.

Poster TUPTB036 [0.787 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB036

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Received ※ 15 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 08 July 2023

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TUPTB041

Visual, Optical and Replica Inspections: Surface Preparation of 650 MHz Nb Cavity for PIP-II Linac

cavity, SRF, niobium, embedded

507

V. Chouhan, D.J. Bice, D.A. Burk, M.K. Ng, G. Wu
Fermilab, Batavia, Illinois, USA

Surface preparation of niobium superconducting RF cavities is a critical step for achieving good RF performance under the superconducting state. Surface defect, roughness, and contamination affect the accelerating gradient and quality factor of the cavities. We report surface inspection methods used to control the surface processing of 650 MHz cavities that will be used in the pre-production cryomodule for PIP-II linac. The cavity surface was routinely inspected visually, with an optical camera, and by microscopic scanning of surface replicas. This article covers details on the surface inspection methods and surface polishing process used to repair the surface.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB041

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 12 July 2023

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TUPTB045

PIP-II SSR2 Cavities Fabrication and Processing Experience

cavity, SRF, niobium, target

526

M. Parise, P. Berrutti, D. Passarelli
Fermilab, Batavia, Illinois, USA
P. Duchesne, D. Longuevergne
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France

The Proton Improvement Plan-II (PIP-II) linac will include 35 Single Spoke Resonators type 2 (SSR2). A pre-production SSR2 cryomodule will contain 5 jacketed cavities. Several units are already manufactured and prepared for cold testing. In this work, data collected from the fabrication, processing and preparation of the cavities will be presented and the improvements implemented after the completion of the first unit will be highlighted.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB045

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 08 July 2023

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TUPTB061

Status of the ESS Medium Beta Cavities at INFN LASA

cavity, cryomodule, simulation, SRF

559

D. Sertore, M. Bertucci, M. Bonezzi, A. Bosotti, D. Cardelli, A. D’Ambros, E. Del Core, F. Fiorina, A.T. Grimaldi, L. Monaco, C. Pagani, R. Paparella, G.M. Zaggia
INFN/LASA, Segrate (MI), Italy

The INFN LASA’s contribution to the ESS Medium Beta Superconducting Linac consists of 36 cavities that raise the proton beam energy from 216 MeV to 571 MeV. Out of the 36 cavities, 28 have been successfully qualified and delivered for assembly into a cryomodule at CEA Saclay. The remaining cavities have been reprocessed in order to bring them up to ESS specifications. To mitigate further delays in the delivery of the cavities, four new ones are currently under construction. We are reporting on the current status of both the recovery actions we have developed so far and the performance of the newly produced resonators.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB061

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 14 July 2023

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TUPTB067

Fabrication and Surface Treatment of Superconducting Rf Single Spoke Cavities for the Myrrha Project

cavity, niobium, simulation, MMI

578

M. Moretti, Y.N. Hoerstensmeyer, A. Navitski
RI Research Instruments GmbH, Bergisch Gladbach, Germany
F. Marhauser
SCK•CEN, Mol, Belgium

The MYRRHA project, based at SCK•CEN (Belgium), aims at coupling a 600 MeV proton accelerator to a subcritical fission core with a maximal output of 100 MWth. The first phase of the project, MINERVA, includes the design, construction, and commissioning of a 100 MeV superconducting RF linac in order to demonstrate the machine requirements in terms of reliability and fault tolerance. The MINERVA linac comprises several cryomodules, each containing two Single Spoke 352.2 MHz cavities made out of high RRR niobium and operating at 2K. The fabrication and surface treatment of the Single Spoke RF Cavities is currently ongoing and completely carried out by RI Research Instruments GmbH (Germany); the first pre-series cavities were completed and delivered for cold testing. Main highlights of the fabrication include the deep-drawing of complex shapes, such as central spokes and outer caps of the cavity, which was successfully accomplished. As for the surface treatment, RI has commissioned, tested, and effectively started utilizing a new rotational buffered chemical polishing facility; this is required to polish the cavity inner surface, while ensuring an almost uniform material removal.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB067

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Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 09 July 2023

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WEPWB058

Contribution of IN2P3 to PIP-II Project: Plans and Progress

cavity, SRF, vacuum, status

714

D. Longuevergne, N. Bippus, P. Duchesne, N. Gandolfo, D. Le Dréan, G. Mavilla, T. Pépin-Donat, S. Roset, L.M. Vogt, S. Wallon
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
P. Berrutti, J. Helsper, S. Kazakov, M. Parise, D. Passarelli, N. Solyak, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Funding: Work supported by IN2P3. Work supported, in part, by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under U.S. DOE Contract No. DE-AC02-07CH11359.
IJCLab is one of the labs of IN2P3 (National institute of nuclear and particle physics), one of the ten research institutes composing the French National Center for Scientific Research (CNRS). Since 2018, IJCLab has been involved in the PIP-II project, assisting with the design, development, and qualification of accelerator components for the SSR2 (Single Spoke Resonator type 2) section of the superconducting linac. The first pre-production components (cavity, coupler, and tuner) have been fabricated, and some of the first qualification tests have been performed at IJCLab. This paper will summarize the complete scope of IJCLab¿s contributions to PIP-II and give updates on the performances of the first pre-production components.

Poster WEPWB058 [1.727 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB058

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Received ※ 24 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 05 July 2023 — Issue date ※ 10 July 2023

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WEPWB068

Characterization of Additive Manufacturing Materials for String Assembly in Cleanroom

cryomodule, cavity, SRF, detector

746

J. Bernardini, M. Parise, D. Passarelli
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC under Contract No. DEAC02- 07CH11359 with the United States Department of Energy, Office of Science, Office of High Energy Physics.
Beamline components, such as superconducting radio frequency cavities and focusing lenses, need to be assembled together in a string while in a cleanroom environment. The present contribution identifies and characterizes materials for additive manufacturing that can be used in a cleanroom. The well known advantages of additive manufacturing processes would highly benefit the design and development of tooling needed for the mechanical support and alignment of string components. Cleanliness, mechanical properties, and leak tightness of the chosen materials are the main focus of this contribution, which also paves the way for the integration of such materials in cryomodule assemblies. Results reported here were obtained in the framework of the PIP-II project at Fermilab.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB068

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Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 04 July 2023

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WEPWB070

Test Shipment of the PIP-II 650 MHz Transport Frame Between FNAL to STFC-UKRI

cryomodule, ISOL, SRF, acceleration

750

J.P. Holzbauer, S.K. Chandrasekaran, C.J. Grimm, J.P. Ozelis, R. Thiede, A.D. Wixson
Fermilab, Batavia, Illinois, USA
M.T.W. Kane
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Work supported by Fermi Research Alliance, LLC under Contract No. DEAC02- 07CH11359 with the United States Department of Energy
The PIP-II Project will receive fully assembled cryomodules from CEA and STFC-UKRI as in-kind contributions. Damage to these cryomodules during transport is understood to be a significant risk to the project, so an extensive testing and validation program is in process to mitigate this risk. The centerpiece of this effort is the eventual shipment from FNAL to STFC-UKRI and back of a prototype HB650 cryomodule with cold testing before and after shipment to verify no functionality changes from shipment. Most recently, a test shipment to the UK and back using a cryomodule analog was completed using realistic logistics, handling, instrumentation, and planning. The process of executing this test shipment, lessons learned, and plan moving forward will be presented here.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB070

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Received ※ 18 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 17 July 2023

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WEPWB083

Basic Design and Consideration of Li-Vapor Contamination for A-FNS SRF

SRF, cavity, solenoid, operation

773

T. Ebisawa, K. Hasegawa, A. Kasugai, M. Oyaidzu, S. Sato
QST Rokkasho, Aomori, Japan
E. Kako, H. Sakai, K. Umemori
KEK, Ibaraki, Japan

The Advanced Fusion Neutron Source (A-FNS) project is in progressing in Japan, QST Rokkasho institute. A-FNS will demonstrate a performance of the DEMO DT fusion reactor material. In order to perform the test, a high intensity deuteron beam accelerator will be used to produce a high flux neutron field which is similar to the 14 MeV DT neutron. The Superconducting Radio-Frequency linear accelerator (SRF) is one component of the A-FNS accelerator system. Although the A-FNS accelerator system design is based on the IFMIF design, the improvement of some subsystem has been considering by taking into account the lessons learnt from the LIPAc project. In order to keep a high stability and availability of the SRF performance, we plan to increase the number of SRF cavities and cryomodules considering the trouble or degradation of the cavity performance and modify the engineering design of some components. In addition, changing of the beam transport line design and Li vapor contamination study of SRF cavity are conducting. In this presentation, the progress of the SRF design and related activities for A-FNS in QST will be presented.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB083

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Received ※ 28 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 17 August 2023

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WEPWB093

Transportation Fatigue Testing of the pHB650 Power Coupler Antenna for the PIP-II Project at Fermilab

vacuum, SRF, cryomodule, resonance

801

J. Helsper, S.K. Chandrasekaran, J.P. Holzbauer, N. Solyak
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.
The PIP-II Project will see international shipment of cryomodules from Europe to the United States, and as such, the shocks which can occur during shipment pose a risk to the internal components. Of particular concern is the coupler ceramic window and surrounding brazes, which can see relatively high stress during an excitation event. Since the antenna design is new, and because of the setback failure would create, a cyclic stress test was devised for the antenna. This paper presents the experimental methods, setup, and results of the test.

Poster WEPWB093 [2.913 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB093

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Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 03 July 2023

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WEPWB101

Present Status of RIKEN Power Couplers for SRILAC

vacuum, Windows, SRF, operation

823

K. Ozeki, O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada
RIKEN Nishina Center, Wako, Japan

The heavy ion linac of the RIKEN, utilizing superconducting technology, began operations in September 2019. Over the following 13 months, two of the ten superconducting accelerating cavities experienced vacuum leaks from the vacuum windows of the fundamental power couplers (FPCs). Currently, additional vacuum windows are installed on all ten FPCs and the beam supply continues without encountering any major issues with the FPCs. Additionally, the fabrication of ten replacement FPCs has been completed, addressing the underlying issues that led to the deterioration of the vacuum window strength. Currently, we are conducting radio frequency (RF) process of the new FPCs. In addition, we are designing a bias applying component to suppress multipacting in the FPCs. This paper reports the status of these issues related to the FPCs at the RIKEN.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB101

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Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 14 July 2023

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WEPWB105

Improved Study of the Multipactor Phenomenon for the MYRRHA 80 kW CW RF Couplers

multipactoring, electron, coupling, cavity

838

Y. Gómez Martínez, P.-O. Dumont
LPSC, Grenoble Cedex, France
P. Duchesne, N. ElKamchi, C. Joly, W. Kaabi
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
C. Lhomme
IJCLab, ORSAY, France
C. Lhomme
ACS, Orsay, France

MYRRHA (Multi Purpose Hybrid Reactor for High Tech Applications) is an Accelerator Driven System (ADS) project. Its superconducting linac will provide a 600 MeV - 4 mA proton beam. The first project phase based on a 100 MeV linac is launched. The Radio-Frequency (RF) couplers have been designed to handle 80 kW CW (Continuous Wave) at 352.2 MHz. This paper describes the multipactor studies on the coupler when it does not work in the nominal configuration without reflected power.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB105

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Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 12 July 2023

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WEPWB126

First Results from Nanoindentation of Vapor Diffused Nb₃Sn Films on Nb

cavity, SRF, experiment, accelerating-gradient

888

U. Pudasaini
JLab, Newport News, Virginia, USA
S. Cheban, G.V. Eremeev
Fermilab, Batavia, Illinois, USA

Funding: U.S. Department of Energy, Office of Science, Office of Nuclear Physics & Office of High Energy Physics.
The mechanical vulnerability of the Nb₃Sn-coated cavities is identified as one of the significant technical hurdles toward deploying them in practical accelerator applications in the not-so-distant future. It is crucial to characterize the material’s mechanical properties in ways to address such vulnerability. Nanoindentation is a widely used technique for measuring the mechanical properties of thin films that involves indenting the film with a small diamond tip and measuring the force-displacement response to calculate the film’s elastic modulus, hardness, and other mechanical properties. The nanoindentation analysis was performed on multiple vapor-diffused Nb₃Sn samples coated at Jefferson Lab and Fermilab coating facilities for the first time. This contribution will discuss the first results obtained from the nanoindentation of Nb₃Sn-coated Nb samples prepared via the Sn vapor diffusion technique.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB126

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Received ※ 19 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 16 July 2023

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WEPWB128

Experimental Study of Mechanical Dampers for the FRIB β=0.041 Quarter-Wave Resonators

cavity, damping, operation, ECR

898

J. Brown, W. Chang, W. Hartung, S.H. Kim, T. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the US Department of Energy, Office of Science, High Energy Physics under Cooperative Agreement award numbers DE-SC0018362 and DE-SC0000661 and Michigan State University.
The ’pendulum’ mechanical mode of quarter-wave resonators (QWR) often causes an issue with microphonics and/or ponderomotive instability unless otherwise the inner conductors are properly stiffened and/or damped. FRIB QWRs are equipped with a Legnaro-style frictional damper installed inside of the inner conductor such that it counteracts the oscillations of the inner conductor. In cryomodule tests and linac operation, we observed that the damping efficiency is different for a few β=0.041 QWRs. This study aimed to experimentally characterize the damping efficacy as a function of damper mass and surface roughness. We present damping measurements at room temperature and at two different masses and surface roughness as well as discuss future studies for damper re-optimization based on this follow-on study.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB128

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Received ※ 20 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 04 August 2023

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THIAA01

Development of 3.9 GHz 9-Cell Cavities at SHINE

cavity, electron, FEL, laser

921

X.W. Wu
Zhangjiang Lab, Shanghai, People’s Republic of China
J.F. Chen, P.C. Dong, Y.F. Liu, X.H. Ouyang, S. Sun, J.N. Wu, S. Xing, Y.X. Zhang, S.J. Zhao, Y.L. Zhao
SARI-CAS, Pudong, Shanghai, People’s Republic of China
X. Huang, Z. Wang, Y. Zong
SINAP, Shanghai, People’s Republic of China
Y.W. Huang, R.Z. Xia
ShanghaiTech University, Shanghai, People’s Republic of China

The Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) Linac requires two 3.9~GHz crymodules to linearize energy distribution before the bunch compressor. As a key component to the project, studies of 3.9~GHz cavities were conducted in the past few years. The first 3.9~GHz 9-cell prototype cavity has been fabricated, tested, and qualified. It reached Q₀=3.5×10⁹ at 13.1~MV/m and a maximum accelerating gradient of 25.0~MV/m during the vertical test of the bare cavity. The prototype has been helium tank integrated and reached Q₀=2.9×10⁹ at 13.1~MV/m in the vertical test, with a large margin with respect to the SHINE specification. The second prototype has been fabricated and is planned to be tested in 2023. This paper will cover the fabrication, surface treatment, and RF test of the 3.9~GHz cavities.

Slides THIAA01 [7.573 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA01

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 18 July 2023

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THCAA01

Development of Single-spoke Cavities for ADS at JAEA

cavity, SRF, emittance, proton

947

Y. Kondo
JAEA, Ibaraki-ken, Japan
T. Dohmae, E. Kako, H. Sakai, K. Umemori
KEK, Ibaraki, Japan
F. Maekawa, S.I. Meigo, J. Tamura, B. Yee-Rendón
JAEA/J-PARC, Tokai-mura, Japan

Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven system (ADS) as a future nuclear system to efficiently reduce the high-level radioactive waste generated at nuclear power plants. As the first step toward the full-scale CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. Because there is no experience in manufacturing superconducting spoke cavities in Japan, prototyping and performance testing of the cavity are essential to ensure the feasibility of the JAEA-ADS. The dimensional parameters of the prototype spoke cavity were optimized to obtain higher cavity performance. The actual cavity fabrication started in 2020. Most of the cavity parts were fabricated in fiscal year 2020 by press-forming and machining. In 2021, we started welding the cavity parts together. After investigating the optimum welding conditions using mock-up test pieces, each cavity part was joined with smooth welding beads. Currently, the cavity’s body section and the beam port sections have been assembled. This paper presents the current status of the JAEA-ADS and it’s cavity prototyping.

Slides THCAA01 [8.433 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-THCAA01

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Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 10 July 2023

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FRIBA05

Automation of FRIB SRF Cavities and SC Solenoids Turn-on/off

cavity, cryomodule, solenoid, SRF

999

W. Chang, Y. Choi, X.J. Du, W. Hartung, S.H. Kim, T. Konomi, S.R. Kunjir, H. Nguyen, K. Saito, T. Xu, S. Zhao
FRIB, East Lansing, Michigan, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy

The superconducting driver Linac for the Facility for Rare Isotope Beams (FRIB) is a heavy ion accelerator that accelerate ions to 200 MeV per nucleon. The Linac has 46 cryomodules that contain 324 superconducting radio frequency (SRF) cavities and 69 superconducting (SC) solenoid packages. For operation of all cryomodules with high efficiency and reliability, automation for SRF cavity and SC solenoid fast turn-on/off is essentially. Based on cryomodule commissioning results and expert experience, all manual cavity and solenoid turn-on/off procedures and steps have been replaced by automatic programs for FRIB linac operation. This allows the operators to turn the systems on and off without expert-level training. Automation reduces the risk of human error, speeds up beam recovery after user access to experimental areas, and increases beam availability. The cavity turn-on procedure makes sure that the cavity can operate at low field with expected read backs, ramps up the field, and makes sure that the RF amplitude and phase are stable. The design, implementation, and operating experience with automation will be presented.

Slides FRIBA05 [3.503 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-FRIBA05

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Received ※ 29 June 2023 — Revised ※ 16 August 2023 — Accepted ※ 21 August 2023 — Issue date ※ 21 August 2023

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