Keyword: operation
Paper Title Other Keywords Page
MOIAA01 FRIB Transition to User Operations, Power Ramp Up, and Upgrade Perspectives cavity, cryomodule, linac, 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOIAA03 Progresses in the ESS Superconducting Linac Installation cryomodule, linac, MMI, 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOIXA03 Proton Power Upgrade Project Progress and Plans at the Spallation Neutron Source in Oak Ridge Tennessee target, cryomodule, cavity, linac 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOIXA04 Operational Experience for RIKEN Superconducting Linear Accelerator linac, 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOIXA05 Operating Experience of SRF System at High Beam Current in SuperKEKB cavity, HOM, SRF, luminosity 38
 
  • M. Nishiwaki, K. Akai, T. Furuya, S. Mitsunobu, Y. Morita, T. Okada
    KEK, Ibaraki, Japan
  
  SuperKEKB aims for high luminosity on the order of 1035 cm-2s-1 with beam currents of 2.6 A for electron and 3.6 A for positron to search new physics beyond the Standard Model in the B meson regime. In recent operations, we achieved a new record of luminosity of 4.65×1034 cm-2s-1 with 1.1 A for electron and 1.3 A for positron. The SRF system that was designed for KEKB, the predecessor of SuperKEKB, is operating stably with the high beam currents owing to the measures against the large beam powers and the large higher-order-mode (HOM) powers. As a measure against the large beam powers, our SRF cavities have increased a coupling of high-power input couplers during the KEKB operation. As a measure against the large HOM power, newly developed SiC HOM dampers have been installed in the SuperKEKB ring. In addition, we have established the horizontal high-pressure rinse method to recover the cavity performance that has degraded due to vacuum works and accidents in the long-term operation. In this report, we will present our operation experience of SRF system under the high beam currents.  
slides icon Slides MOIXA05 [3.450 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA05  
About • Received ※ 19 June 2023 — Revised ※ 21 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOIXA06 Operational Experience with the European XFEL SRF Linac cavity, FEL, linac, 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB017 Development of a Thermal Conductance Instrument for Niobium at Cryogenic Temperatures cavity, niobium, ECR, cryogenics 109
 
  • C. Saribal, C. Martens
    University of Hamburg, Hamburg, Germany
  • W. Hillert, M. Wenskat
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  
  Funding: University of Hamburg
Particle accelerators form an important tool in a variety of research fields. In an effort to reduce operation costs while maintaining high energies, their accelerating structures are steadily improved towards higher accelerating fields and lower RF losses. Stable operation of such a cavity generally requires Joule-heating, generated in its walls, to be conducted to an outer helium bath. Therefore, it is of interest to experimentally evaluate how present and future cavity treatments affect thermal characteristics. We present an instrument for measuring the thermal performance of SRF cavity materials at cryogenic temperatures. Pairs of niobium disks are placed inside of a liquid helium bath and a temperature gradient is generated across them to obtain total thermal resistance for temperatures below 2 Kelvin. To get an idea of the instruments sensitivity and how standard cavity treatments influence thermal resistance, samples are tested post fabrication, polishing and 800 °C baking. The first tests show the commissioning of our newly set up system and if it is feasible to observe relevant changes and evaluate new and promising cavity treatments such as SIS structures. 		 
poster icon Poster MOPMB017 [3.217 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB017  
About • Received ※ 17 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 01 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB026 Development of Transformative Cavity Processing - Superiority of Electropolishing on High Gradient Performance over Buffered Chemical Polishing at Low Frequency (322 MHz) cavity, SRF, cryomodule, MMI 145
 
  • K. Saito, C. Compton, K. Elliott, W. Hartung, S.H. Kim, T.K. Konomi, E.S. Metzgar, S.J. Miller, L. Popielarski, A.T. Taylor, T. Xu
    FRIB, East Lansing, Michigan, USA
  
  Funding: The work is supported by DOE Awards DE-SC0022994.
A DOE grant R&D titled ¿Development of Transformative Preparation Technology to Push up High Q/G Performance of FRIB Spare HWR Cryomodule Cavities¿ is ongoing at FRIB. This R&D is for 2 years since September 2022. This project proposes four objectives: 1) Superiority on high gradient performance of electropolishing (EP) over buffered chemical polishing at low frequency (322 MHz), 2) High Qo performance by the local magnetic shield, 3) Development of HFQS-free BCP and, 4) Wet N-doping method. This paper will report the result of first object, and a local magnetic shield design and simulation to reduce the residual magnetic field < 0.1 mG in the vertical test Dewar, for the object 2. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB026  
About • Received ※ 14 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 08 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB057 Implementation of the Test Bench for the PIP-II LB650 Cryomodules at CEA cryomodule, cavity, cryogenics, SRF 243
 
  • H. Jenhani, N. Bazin, Q. Bertrand, P. Brédy, L. Maurice, O. Piquet, P. Sahuquet, C. Simon
    CEA-IRFU, Gif-sur-Yvette, France
  
  The Proton Improvement Plan II (PIP-II) at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. As a part of the French In-Kind Contributions to this project, CEA will provide ten 650 MHz low-beta cryomodules (LB650) equipped with LASA-INFN (Italy) and VECC-DAE (India) cavities and Fermilab power couplers and RF tuning systems. CEA is accordingly in charge of the design, manufacturing, assembly and testing of these cryomodules. This paper presents the future implementation of the test stand dedicated to the cryogenic and RF power testing of the LB650 cryomodules. The choice of the equipment and the current status will be detailed, as well.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB057  
About • Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 05 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB067 Design of a Cathode Insertion and Transfer System for LCLS-II-HE SRF Gun cathode, gun, SRF, insertion 267
 
  • R. Xiang, A. Arnold, S. Gatzmaga, A. Hoffmann, P. Murcek, R. Steinbrück, J. Teichert
    HZDR, Dresden, Germany
  • C. Adolphsen, J. Smedley
    SLAC, Menlo Park, California, USA
  • W. Hartung, S.H. Kim, T.K. Konomi, S.J. Miller, L. Popielarski, K. Saito, T. Xu
    FRIB, East Lansing, Michigan, USA
  • M.P. Kelly, T.B. Petersen
    ANL, Lemont, Illinois, USA
  • J.W. Lewellen
    LANL, Los Alamos, New Mexico, USA
  
  Funding: Work supported by cooperation project between MSU and HZDR RC113062 from the U.S. Department of Energy Office of Science under Cooperative Agreement DE-AC02-76SF00515.
Superconducting radio frequency photo injectors (SRF gun) offer advantages for operating in continuous wave (CW) mode and generating high-brightness and high-current beams. A new SRF gun is designed as a low emittance photo injector for LCLS-II-HE and a prototype gun is currently being developed under collaboration between SLAC, FRIB, HZDR and ANL. The aim is to demonstrate stable CW operation at a cathode gradient of 30 MV/m. One of the crucial component for successful SRF gun operation is the photocathode system. The new SRF gun will adopt the HZDR-type cathode, which includes a cathode holder fixture (cathode stalk) developed by FRIB and a sophisticated cathode exchange system designed by HZDR. This innovative cathode insertion system ensures accurate, particle-free and warm cathode exchanges. A novel alignment process targets the cathode to the stalk axis without touching cathode plug itself. To commission the prototype gun, metallic cathodes will be used. A specifically designed vacuum system ensures vacuum pressure of 10-9 mbar for transport of a single cathode from the cleanroom to the gun. Thus maintaining cathode quality. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB067  
About • Received ※ 18 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 18 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB068 Loading Test of Hom Dampers for Superconducting Cavities for High Current at Superkekb HOM, cavity, SRF, superconducting-cavity 271
 
  • T. Okada, K. Akai, T. Furuya, S. Mitsunobu, Y. Morita, M. Nishiwaki
    KEK, Ibaraki, Japan
  
  SuperKEKB is an e⁻e⁺ collider, which is an upgraded accelerator of KEKB with the aim to increase the luminosity by more than one order. The superconducting cavities are used in the electron ring. The superconducting cavities were designed as a HOM-damped structure for KEKB and were operated up to 1.4 A in KEKB. However, the design storage current of the electron ring for SuperKEKB is 2.6 A, which is about twice the achievement current of KEKB. The HOM power is estimated to increase from 16 kW, which is the performance value in KEKB, to over 35 kW. This large load is unacceptable for the ferrite HOM dampers mounted on both sides of the cavity. As a countermeasure, duct type SiC HOM dampers are inserted between the cavities. The HOM damper load tests were performed during normal beam operation with a maximum current of 1.1 A. The load on the downstream ferrite HOM damper decreased due to the HOM power absorbed by the upstream SiC damper. In addition, the load was found to be dependent on the beam filling pattern. We will present the results and discussion of beam tests on the loading of HOM dampers and the dependence on the beam filling pattern in SuperKEKB.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB068  
About • Received ※ 18 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 30 June 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB070 Development of a Non-Intrusive Leak Detection Method for SRF Linacs cryomodule, radiation, ISOL, SRF 275
 
  • P. Pizzol, R.L. Geng
    ORNL, Oak Ridge, Tennessee, USA
  • R. Afanador, J.D. Mammosser, V.S. Morozov, D.M. Vandygriff
    ORNL RAD, Oak Ridge, Tennessee, USA
  
  The SNS accelerator has been vital in delivering high-impact research for the world scientific community since 2006, with an availability of 99%. This high availability rate is crucial to the success of the facility, and after 16 years of operations, the aging of the components could start to impact this parameter. To mitigate this, condi-tion-based maintenance can be applied to areas of the LINAC to reduce or nullify the possibility of unwanted events that may damage the accelerator functionality. In this work, we describe the development of a non-intrusive leak detection methodology that verifies the health condition of the cryomodule isolation gate valve seals. In case of a sudden vacuum leak in a warm section between the cryomodules, these valves act as a final line of defense to protect the SRF cavities from atmosphere gases contamination, hence knowing their sealing integ-rity condition is paramount. Data taken from the ma-chine during different maintenance periods will be pre-sented, together with the analysis done, to verify the robustness of the numerical method vs. the experimental findings.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB070  
About • Received ※ 16 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 02 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB078 Design and Prototyping of the Electron Ion Collider Electron Storage Ring SRF Cavity cavity, simulation, HOM, electron 293
 
  • J. Guo, E.F. Daly, E. Drachuk, R.R. Fernandes, J. Henry, J. Matalevich, G.-T. Park, R.A. Rimmer, D. Savransky
    JLab, Newport News, Virginia, USA
  • D. Holmes, K.S. Smith, W. Xu, A. Zaltsman
    BNL, Upton, New York, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177
Among the EIC¿s numerous RF subsystems, the electron storage ring¿s (ESR) 591 MHz fundamental RF system is one of the most challenging. Each cavity in the system will handle up to 2.5 A of beam current and supply up to 600 kW beam power under a wide range of voltage. The EIC R&D plan includes the design, fabrication and testing of such a cavity. In this paper, we will report the latest status and findings of the ongoing design and prototyping of this cavity, including the RF and mechanical/thermal design, fabrication design, and the progress of fabrication. 		 
poster icon Poster MOPMB078 [1.489 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB078  
About • Received ※ 12 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 19 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB081 Microphonics in the LCLS-II Superconducting Linac cryomodule, cavity, linac, 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB084 FRIB Driver Linac Integration to Support Operations and Protect SRF Cryomodules linac, 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB086 Development of Non-Destructive Beam Envelope Measurements in SRILAC with Low Beta Heavy Ion Beams Using BPMs simulation, cavity, quadrupole, heavy-ion 319
 
  • T. Nishi, O. Kamigaito, N. Sakamoto, T. Watanabe, K. Yamada
    RIKEN Nishina Center, Wako, Japan
  • T. Adachi
    RIKEN, Saitama, Japan
  
  The RIKEN SRILAC* has been providing heavy ion beams of a few puA for the synthesis of new superheavy elements since June 2020, utilizing 10 superconducting quarter-wavelength resonators (SC-QWRs). Although the beam supply has been stable, it is crucial to measure and control the beam dynamics in the SRILAC to increase the beam intensity up to 10 puA. However, destructive monitors cannot be used to avoid the generation of dust particles and outgassing. Beam has been precisely tuned by monitoring the beam center using Beam Energy Position Monitors (BEPMs)** and the reactions of vacuum monitors. In our study, we are developing a method for estimating the beam envelope by combining the quadrupole moments from BEPMs, which consist of four cosine-shape electrodes, with calculations of the transfer matrix***. While this method has been applied to electron and proton beams, it has not been practically demonstrated for heavy ion beams in beta – 0.1 regions. By combining BEPM simulations, we are making the progress towards the reproduction of experimental results, overcoming specific issues associated with low beta. We will report on the current status of our developments.
* K. Yamada et al., in Proc. SRF’21, paper MOOFAV01(2021).
** T. Watanabe et al., in Proc. IBIC’20, paper FRAO04 (2020).
*** R. H. Miller et al., in Proc. HEAC’83, pp. 603–605 (1983). 		 
poster icon Poster MOPMB086 [10.338 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB086  
About • Received ※ 30 June 2023 — Revised ※ 01 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB094 Design of a 1.3 GHz High-Power RF Coupler for Conduction-Cooled Systems cavity, SRF, cryomodule, radio-frequency 342
 
  • N.A. Stilin, A.T. Holic, M. Liepe, T.I. O’Connell, P. Quigley, J. Sears, V.D. Shemelin, J. Turco
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Cornell is designing a new standalone, compact SRF cryomodule which uses cryocoolers in place of liquid helium for cooling. One of the biggest challenges in implementing such a system is designing a high-power input coupler which is able to be cooled by the cryocoolers without any additional liquid cryogenics. Due to the limited heat load capacity of the cryocoolers at 4.2 K, this requires very careful thermal isolation of the 4.2 K portion of the coupler and thorough optimization of the RF behavior to minimize losses. This paper will present the various design considerations which enabled the creating of a conduction-cooled 1.3 GHz input coupler capable of delivering up to 100 kW CW RF power.  
poster icon Poster MOPMB094 [0.964 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB094  
About • Received ※ 16 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 23 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUIAA01 Twenty Years of Cryogenic Operation of the Flash Superconducting Linac cryomodule, linac, cavity, FEL 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 icon 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUIAA02 The FLASH 2020+ Upgrade Project laser, FEL, electron, undulator 354
 
  • M. Vogt, E. Ferrari, C. Gerth, K. Honkavaara, J. Rönsch-Schulenburg, L. Schaper, S. Schreiber, J. Zemella
    DESY, Hamburg, Germany
  
  FLASH, the Soft X-Ray and Extreme-UV Free Electron Laser at DESY, is undergoing a substantial upgrade and refurbishment project, called FLASH2020+. The project will finally enable external seeded and SASE FEL operation for a wavelength range down to 4 nm with the EEHG method. A key ingredient of the upgrade was replacing two early TTF-type L-band RF cryo accelerator modules by modern, high-gradient XFEL-type ones. The beam energy range of the injector has been increased by 100 MeV. This was achieved in the first of two long shutdowns from November 2021 to August 2022. The energy increase together with an afterburner APPLE III type undulator for variable circular polarization in the FLASH2 beamline will make it possible to reach the oxygen K-edge (530 eV). This talk will report on the project and the first shutdown with emphasis on the upgraded modules.  
slides icon Slides TUIAA02 [15.921 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA02  
About • Received ※ 21 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 07 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTB013 Commissioning of a New Sample Test Cavity for Rapid RF Characterization of SRF Materials cavity, niobium, MMI, SRF 410
 
  • S. Keckert, J. Knobloch, F. Kramer, O. Kugeler
    HZB, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
  
  RaSTA, the Rapid Superconductor Test Apparatus, is a new sample test cavity that is currently being commissioned at HZB. It uses the established QPR sample geometry but with a much smaller cylindrical cavity operating in the TM020 mode at 4.8 GHz. Its compact design allows for smaller cryogenic test stands and reduced turnaround time, enabling iterative measurement campaigns for thin film R&D. Using the same calorimetric measurement technique as known from the QPR allows direct measurements of the residual resistance. We report first prototype results obtained from a niobium sample that demonstrate the capabilities of the system.  
poster icon Poster TUPTB013 [0.464 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB013  
About • Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 28 June 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTB024 Cobotisation of ESS Cryomodule Assembly at CEA cavity, cryomodule, MMI, SRF 438
 
  • S. Berry, A. Bouygues, J. Drant, C. Madec
    CEA-DRF-IRFU, France
  • A. Gonzalez-Moreau, C. Servouin
    CEA-IRFU, Gif-sur-Yvette, France
  
  The assembly of cavity string in the clean room is a tedious work that has noisy and painful steps such as cleaning the taped holes of a part. CEA together with the company INGELIANCE has developed a cobot: a collaborative robot operated by an technician one time and repeating the action without the operator. The cobot can work anytime without any operators : therefore it is working at night reducing the assembly duration by some hours. The cobot consists of a FANUC CRX10 a 6-axis arm on an Arvis cart. At CEA, the cobot is used to blow the flange holes of the cavities and bellows. This allows to reduce the noisy steps that the technicians are exposed to. The process is also more reproducible since the cobot does always the same steps. The cobot is used on ESS cavity string to clean the coupler and cavity flanges. Our activities and results will be presented in this poster.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB024  
About • Received ※ 18 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 03 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTB030 Development of Automatic Cleaning and Assembly Systems in Clean Room at KEK cavity, gun, monitoring, controls 463
 
  • Y. Yamamoto, T. Dohmae, M.H. Hiraki, H. Sakai, K. Umemori, T. Yamada
    KEK, Ibaraki, Japan
  
  At KEK, new clean work systems including vertical auto cleaning system, replacement system between blank flange and bellows, and robot arm have been developed and installed since 2020 under the collaboration between Japan and France. The main purpose is unmanned and dust-free operation in clean room to avoid performance degradation with field emission in vertical test and cryomodule test. The vertical auto cleaning system and the replacement system between blank flange and bellows have been operated successfully in 2021-2022. Currently, clean work studies related to auto cleaning and assembly is under progress by combining the blank-bellows replacement system and a robot arm. In this report, the recent status of clean works at KEK will be presented.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB030  
About • Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 30 June 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTB031 Operational Consideration in the LIPAc SRF with Potential Solenoid Failure Modes solenoid, SRF, simulation, cryomodule 467
 
  • T. Ebisawa, K. Hasegawa, A. Kasugai, K. Kondo, K. Masuda
    QST Rokkasho, Aomori, Japan
  • Y. Carin, H. Dzitko, D. Gex, G. Phillips
    F4E, Germany
  • J.K. Chambrillon
    Fusion for Energy, Garching, Germany
  • N. Chauvin
    CEA-DRF-IRFU, France
  • E. Kako, H. Sakai
    KEK, Ibaraki, Japan
  
  The commissioning of LIPAc (Linear IFMIF Prototype Accelerator) is ongoing at Rokkasho institute of QST for the engineering validation of the accelerator system up to 9 MeV/125 mA. Several SRF cryomodules will be required for IFMIF to accelerate deuterons from 5 MeV to 40 MeV. The prototype of the first of these cryomodules has been manufactured and will be installed and tested on the LIPAc. It holds the eight HWRs (Half Wave Resonator) and RF couplers to accelerate the beam and the eight superconducting solenoids to focus it. During the solenoid HPR process, carried out after fixing welding issues on the solenoid beam line bellows, some concerns appeared about the integrity of two solenoids. The examination with CT scanning of the solenoids revealed that one screw and a few pins had leaved their socket. Although it should be no critical problem, we tried the beam simulation with PIC code TraceWin to determine the location of solenoids whose impact will be minimized to manage in case of failure of solenoid as mitigation action. This paper presents the recommended locations of the suspicious solenoids in the cryomodule and resultant beam conditions through the beam dynamics study.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB031  
About • Received ※ 28 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 07 July 2023 — Issue date ※ 16 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTB069 Design and Tests of a Cathode Stalk for the LCLS-II-HE Low Emittance Injector SRF Gun cathode, gun, SRF, emittance 589
 
  • T.K. Konomi, W. Hartung, S.H. Kim, S.J. Miller, D.G. Morris, K. Saito, A.T. Taylor, T. Xu, Z.Y. Yin
    FRIB, East Lansing, Michigan, USA
  • C. Adolphsen, J. Smedley, L. Xiao
    SLAC, Menlo Park, California, USA
  • S. Gatzmaga, P. Murcek, R. Xiang
    HZDR, Dresden, Germany
  • M.P. Kelly, T.B. Petersen
    ANL, Lemont, Illinois, USA
  • J.W. Lewellen
    LANL, Los Alamos, New Mexico, USA
  
  A SRF gun can operate CW with a high gradient and ultra-low vacuum for high-quantum efficiency, low MTE photocathodes, useful features for delivery of high-brightness, high-repetition-rate beams. For these reasons, an SRF gun based photoinjector was chosen for a proposed Low Emittance Injector addition to the LCLS-II-HE facility, which will operate CW with bunch rates up to 1 MHz. For this injector, a prototype 185.7 MHz QWR gun is being developed in a collaborative effort among FRIB, HZDR, ANL and SLAC, with the goal of achieving a photocathode gradient of at least 30 MV/m. The photocathode is held by a coaxial fixture (cathode stalk) for thermal isolation from the cavity body. The system must allow for precise alignment of the photocathode, particle-free photocathode exchange, cryogenic (55-70 K) or warm (273-300 K) photocathode operating temperatures, and DC biasing to inhibit multipacting. A prototype cathode stalk has been built and bench tests are underway to validate the design. Measurements include RF power dissipation, DC bias hold-off, multipacting suppression and heat transfer effectiveness. This paper describes the cathode stalk design and the test results.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB069  
About • Received ※ 03 July 2023 — Revised ※ 27 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 20 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEIXA02 Results of the R&D RF Testing Campaign of 1.3 GHz Nb/Cu Cavities cavity, SRF, niobium, cryogenics 621
 
  • L. Vega Cid, S. Atieh, G. Bellini, A. Bianchi, L.M.A. Ferreira, C. Pereira Carlos, G.J. Rosaz, W. Venturini Delsolaro
    CERN, Meyrin, Switzerland
  • S.B. Leith
    European Organization for Nuclear Research (CERN), Geneva, Switzerland
  
  In the context of the R&D program on Nb/Cu carried out at CERN, a total of 25 tests have been performed since 2021. This talk will present these results. Three different manufacturing techniques have been used to produce the copper substrates, in order to investigate which is the most suitable in terms of quality and economy of scale. On one hand, the focus has been on optimizing the surface resistance at 4.2K, as this will be the operating temperature of FCC. The results at this temperature are encouraging, showing repeatable and optimized RF performance. On the other hand, RF tests have been done at 1.85 K too aiming at deepening the knowledge of the mechanisms behind the Q slope. This is key to work on the mitigation of this phenomenon and ultimately to extend the application of this technology to high energy, high gradient accelerators. The influence of the thermal cycles has been thoroughly investigated. A systematic improvement has been observed of both the Q slope and the residual resistance with slow thermal cycles.  
slides icon Slides WEIXA02 [5.385 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEIXA02  
About • Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 02 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB055 First Experience with Liquid Nitrogen Cleaning cavity, SRF, cryomodule, booster 706
 
  • R.J.M.Y. Ruber, A.B. Eslinger, R.L. Geng
    JLab, Newport News, Virginia, USA
  
  Field emission caused by microscopic particulate contamination is a limiting factor for the performance of superconducting RF (SRF) cavities. In an SRF accelerator, particulates may be transported over the surface of an operational SRF cavity, becoming field emitters and consequentially degrading the performance of the SRF cavity. The most commonly used method for removing particulates from cavity surfaces is high-pressure ultra-pure water rinsing. We are developing a novel high-pressure liquid nitrogen cleaning technique that may possibly enable superior cleaning power and particulate removal from cavities in a cryomodule without taking apart the cryomodule components. This technique provides cleaning mechanisms beyond what are accessible by its high-pressure water counterpart and leaves no residues on the cleaned surface. We present the test setup and first experience.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB055  
About • Received ※ 15 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 27 June 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB061 Pre-Installation Performance of the RHIC 56 MHz Superconducting System cryomodule, coupling, cavity, HOM 718
 
  • Z.A. Conway, R. Anderson, J.C. Brutus, K. Hernandez, D. Holmes, K. Mernick, G. Narayan, S. Polizzo, S.K. Seberg, F. Severino, M. Sowinski, R. Than, Q. Wu, B.P. Xiao, W. Xu, A. Zaltsman
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-SC0012704 with the U.S. Department of Energy.
Pre-installation test results for the RHIC 56 MHz superconducting RF system are presented here. The 56 MHz quarter-wave resonator achieved a stable accelerating potential of 1.1 MV with 13 W of RF loss at 4.5 K demonstrating its viability for increasing the luminosity of sPHENIX collisions. The new 120 kW travelling wave fundamental mode damper and dual 6 kW combined-function fundamental power couplers perform as expected at 3 kW but remain to be operated with the expected ~40 times greater power achievable with the RHIC sPHENIX beams. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB061  
About • Received ※ 15 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 02 July 2023 — Issue date ※ 17 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB082 Operational Experience with Turn-Key SRF Systems for Small Accelerators Like MESA SRF, cryomodule, cryogenics, cavity 768
 
  • T. Stengler, K. Aulenbacher, F. Hug, P.S. Plattner
    KPH, Mainz, Germany
  
  Funding: The work is funded by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019 and the Federal Ministry of Education and Research (BMBF) through project 05H21UMRB1
New SRF-based accelerator development at sites without long-term experience in SRF development is a major challenge. Especially in-house development of cryomodules is an almost impossible obstacle to overcome for small projects. To minimize such obstacles, turn-key SRF systems provided by industry can be of great importance. For the multiturn ERL MESA, which is currently under construction at Johannes Gutenberg-Universität Mainz, two turnkey cryomodules have been purchased from industry and successfully tested. The specifications of a design gradient of 12.5 MV/m in CW operation with an unloaded Q of 1.25*1010 at 1.8 K had to be met. Since the design of the modules had to be modified for high current CW operation, a close cooperation with the manufacturer was of great importance. By purchasing such a turn-key SRF system, the MESA project successfully established the SRF accelerator technology at the site within six years. This was achieved through close monitoring of the manufacturing process and close cooperation with the manufacturer. An overview of the experience with the successful technology transfer of a complete turn-key SRF system for small accelerators will be given. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB082  
About • Received ※ 25 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 03 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB083 Basic Design and Consideration of Li-Vapor Contamination for A-FNS SRF SRF, cavity, solenoid, linac 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB085 Degradation and Recovery of Cavity Performance in SRILAC Cryomodules at RIBF cavity, vacuum, SRF, acceleration 784
 
  • N. Sakamoto, O. Kamigaito, K. Ozeki, K. Suda, K. Yamada
    RIKEN Nishina Center, Wako, Japan
  
  The RIKEN superconducting (SC) heavy-ion linear accelerator (SRILAC) has been providing beam supply for super-heavy elements synthesis experiments since its commissioning in January 2020. However, the long-term operation of SC radio-frequency (RF) cavities leads an increase in the X-ray levels caused by field emissions resulting from changes in the inner surface conditions. More than half of the ten SC 1/4 wavelength resonators (SC-QWRs) of SRILAC, operating at a frequency of 73 MHz, have experienced an increase in X-ray levels, thus, requiring adjustments to the acceleration voltage for continuous operation. While several conditioning methods have been employed for SC cavities, a fully established technique is yet to be determined. To address this situation, a relatively simple conditioning method was implemented at RIKEN. The proposed method uses high-voltage pulsed power and imposes a low load on the cavities.  
poster icon Poster WEPWB085 [12.789 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB085  
About • Received ※ 13 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB087 Copper Plating Qualification Process for the Fundamental Power Coupler Waveguides for CEBAF Cryomodules GUI, cryomodule, SRF, cavity 790
 
  • L. Zhao, G. Cheng, G. Ciovati, K.M. Wilson
    JLab, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC, supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
To provide sufficient energy for CEBAF operation, cryomodules and components are being refurbished yearly as necessary. Copper plated fundamental power coupler waveguides are important components of the cryomodules. The integrity and quality of copper plating is critical to reduce the heat load from the waveguides into the He bath at 2.07 K. A search of copper plating resources is underway for plating or re-plating CEBAF-style waveguides. This effort ensures a continuous capability of copper plating on cryomodule components, especially on waveguides. To qualify plating vendors, the waveguide copper plating specifications were revisited, and a thorough plating evaluation process is being developed. The evaluation process ranges from coupon testing to sample waveguide qualification. Recent results are summarized and future work is planned. 		 
poster icon Poster WEPWB087 [1.582 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB087  
About • Received ※ 15 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 11 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB089 Theoretical Model of External Q Tuning for an SRF Cavity with Waveguide Tuner cavity, GUI, SRF, electron 794
 
  • W. Xu, Z.A. Conway, K.S. Smith, A. Zaltsman
    BNL, Upton, New York, USA
  • E.F. Daly, J. Guo, R.A. Rimmer
    JLab, Newport News, Virginia, USA
  
  Funding: The work is supported by by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
A wide range of electron beam energies (5 ¿ 18 GeV) and beam currents (0.2 ¿ 2.5 A) in EIC Electron Storage Ring (ESR) operating scenarios requires a capability of adjusting coupling factor up to a factor of 20 for the 591 MHz Superconducting Radio Frequency (SRF) cavities, which contains two fundamental power couplers (FPC) delivering continuous wave (CW) 800 kW RF power to the beam. Currently, adjusting external Q of a SRF cavity is done by varying protrusion of FPC¿s inner conductor in beam pipe or using three stub tuner to adjust external Q value, which either has limit on tuning range or limit on operating power. This paper presents a method of tuning the FPC external Q by a multiple-waveguide tuner, which allows for high power, wide tuning range operations. The theoretical model of matching beam impedance with waveguide tuner and detailed matching conditions and limits will be presented. Follow the theoretical model, a preliminary design of a 3D waveguide tuner will be presented.
The work is supported by by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
 		 
poster icon Poster WEPWB089 [1.269 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB089  
About • Received ※ 26 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB101 Present Status of RIKEN Power Couplers for SRILAC vacuum, Windows, SRF, linac 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB111 A New Ultra-High Vacuum Furnace for SRF R&D cavity, vacuum, niobium, SRF 855
 
  • M. Wenskat, C. Bate
    DESY, Hamburg, Germany
  • C. Bate, C. Martens
    University of Hamburg, Hamburg, Germany
  • R. Ghanbari, W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  
  Funding: This work was supported by the BMBF under the research grants 05K19GUB and 05H2021.
A new vacuum furnace has been designed and purchased by the University of Hamburg and is operating in an ISO5 cleanroom. This furnace can anneal single-cell TESLA cavities at temperatures up to 1000°C and with a pressure of less than 10-7mbar or in a nitrogen atmosphere of up to 10-2mbar. We will lay out the underlying design ideas, based on the gained experience from our previous annealing research, and present the commissioning of the furnace itself. Additionally, we will show for the first time the results of sample and cavity tests after annealing in the furnace. This will be accompanied by an overview of the intended R&D process and scientific questions to be addressed. 		 
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB111  
About • Received ※ 21 June 2023 — Revised ※ 15 July 2023 — Accepted ※ 20 August 2023 — Issue date ※ 21 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB128 Experimental Study of Mechanical Dampers for the FRIB β=0.041 Quarter-Wave Resonators cavity, damping, linac, 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
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPWB135 A Novel Twin Drive Tuner Mechanism for 1.3 GHz ILC Cavity cavity, SRF, FEL, site 914
 
  • M. Yamanaka
    KEK, Ibaraki, Japan
  
  A tuner is a device that adjusts the resonant frequency of a cavity. Here we propose a new tuner mechanism for the 1.3 GHz ILC cavity. A bellow is provided in the central portion of the helium tank in the longitudinal direction, and flanges are provided on both sides of the bellows. A linear motion actuator is fixed to the flange on one side, and the frequency is changed by pushing and pulling the flange on the opposite side. Significantly, two linear motion actuators are placed in circumference and working simultaneously. It is named a twin-drive tuner. According to the ILC specification, the cavity has a spring constant of 3 KN/mm, requiring a stroke of 2 mm to adjust the 600 kHz range. A loading force of 6 kN is required. This is shared by two linear motion actuators. We developed a prototype actuator with a loading force of 4 kN per unit. It consists of a stepping motor and a sliding screw with a plastic nut. An experimental device was constructed using this actuator and a 1.3 GHz cavity with a helium tank, and the frequency tuning was evaluated. The displacement between the flanges and the frequency are proportional, both have good linearity, and the slope is 296 kHz/mm.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB135  
About • Received ※ 17 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 17 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THIAA03 Completion of Testing Series Double-spoke Cavity Cryomodules for ESS cryomodule, cavity, vacuum, SRF 932
 
  • R. Santiago Kern, K. Fransson, K.J. Gajewski, L. Hermansson, H. Li, T. Lofnes, A. Miyazaki, M. Olvegård, I.P. Profatilova, R.J.M.Y. Ruber, C.D.I. Svanberg, M. Zhovner
    Uppsala University, Uppsala, Sweden
  
  The FREIA Laboratory at Uppsala University, Sweden, has completed the evaluation of 13 double-spoke cavity cryomodules for ESS. This is the first time double-spoke cavities will be deployed in a real machine. This paper summarizes testing procedures and statistics of the results and lessons learned.  
slides icon Slides THIAA03 [4.687 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA03  
About • Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 29 June 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THIAA04 Performance Analysis of Spoke Resonators, Statistics from Cavity Fabrication to Cryomodule Testing cavity, SRF, cryomodule, proton 940
 
  • A. Miyazaki, P. Duchesne, D. Le Dréan, D. Longuevergne, G. Olry
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  Irène Joliot-Curie Laboratory (IJCLab) has been leading the development of spoke resonators in multiple interna- tional SRF projects, from fundamental R&D, prototyping, to series production. The European Spallation Source (ESS) superconducting linac is the first of its kind to put into op- eration the spoke resonators. After three prototype cavities, 29 ESS production cavities have been processed, tested, as- sembled into cryomodules at IJCLab, and then shipped to Uppsala for the site acceptance test. Seven prototypes for two other major projects, Multi-purpose hYbrid Research Reactor for High-tech Application (MYRRHA) and Proton Improvement Plan II (PIP-II), designed in collaboration with external institutions, have as well been processed and tested at IJCLab. A new challenge is to fully process series cavi- ties in industry, following the successful implementation of 1.3 GHz elliptical cavities in the other projects. This paper summarises main results obtained from fabrication to final testing, including frequency tuning strategy, performance, limitation in vertical cryostat, and identifies future direction of projects and R&D in the field of spoke cavities.  
slides icon Slides THIAA04 [4.623 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA04  
About • Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 19 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THCAA02 Commissioning of the UHH Quadrupole Resonator at DESY cavity, quadrupole, SRF, dipole 952
 
  • R. Monroy-Villa, W. Hillert, M. Wenskat
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • A. Gössel, D. Reschke, M. Röhling, M. Schmökel, J.H. Thie, M. Wiencek
    DESY, Hamburg, Germany
  • C. Martens
    University of Hamburg, Hamburg, Germany
  
  Funding: This work was supported by the BMBF under the research grants 05H18GURB1, 05K19GUB and 05H2021.
Pushing the limits of the accelerating field or quality factor of SRF cavities beyond pure Nb requires the implementation of specific inner surface treatments, which are yet to be studied and optimized. One of the fundamental challenges in exploring alternative materials is that only samples or cavity cuts can be fully characterized from a material point of view. On the other hand, complete cavities allow for the SRF characterization of the inner surface, while samples can usually only be analyzed using DC methods. To address this problem, a test resonator for samples, called "Quadrupole Resonator", was designed and operated at CERN and later at HZB. It allows for a full RF characterization of samples at frequencies of 0.42 GHz, 0.86 GHz, and 1.3 GHz, within a temperature range of 2-20 K and at magnetic fields up to 120 mT. This work presents the design process, which incorporated improvements motivated by mechanical and RF studies and experience, and the results from both warm and cold commissioning are discussed. More important, the results for the RF tests of a Nb sample after undergoing a series of heat treatments and an outlook of the further usage of the QPR is presented. 		 
slides icon Slides THCAA02 [6.677 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-THCAA02  
About • Received ※ 25 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 19 August 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THIXA03 Cryocooler Application for Accelerator and Development Status of Powerful Cryocooler at SHI Ltd. controls, SRF, cavity, interface 968
 
  • T. Ikeda, S. Sasazaki
    SHI, Tokyo, Japan
  
  Advances in recent Nb₃Sn cavity development makes possible to operate the cavities with Qo ~ 1xE10 at 4.3 K and to design SRF accelerator in which the cavities are cooled directly with small mechanical cryocoolers instead of using liquid helium. Conduction-cooling with cryocoolers greatly simplify the overall design and also contribute for cost saving of an SRF accelerator, making the SRF technology feasible for industrial accelerators. However, in the case of using current cryocooler systems (like Gifford-McMahon cryocooler, Pulse-Tube cryocooler, etc.) for the conduction-cooling, since the cooling capacity per unit is small, multiple units will be used in combination depending on the required cooling capacity, it will cause problems in terms of power consumption (efficiency), footprint, and maintenance costs. Therefore, SHI have been developing a large-capacity and high-efficiency 4KGM-JT (Gifford-McMahon-Joule-Thomson) cryocooler system in the 10 W class at 4.2 K. This contribution will report the overview of this cryocooler system and its status of development.  
slides icon Slides THIXA03 [1.638 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIXA03  
About • Received ※ 20 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 04 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THIXA05 Conduction-Cooled SRF Cavities: Opportunities and Challenges cavity, SRF, cryomodule, radio-frequency 973
 
  • N.A. Stilin, H. Conklin, T. Gruber, A.T. Holic, M. Liepe, T.I. O’Connell, P. Quigley, J. Sears, V.D. Shemelin, J. Turco
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Thanks to improvements in the performance of both commercial cryocoolers and Nb₃Sn-coated superconducting radio-frequency (SRF) cavities, it is now possible to design and build compact, SRF cryomodules without the need for liquid cryogenics. In addition, these systems offer robust, non-expert, turn-key operation, making SRF technology significantly more accessible for smaller-scale applications in fields such as industry, national security, medicine, environmental sustainability, etc. To fully realize these systems, many technical and operational challenges must be overcome. These include properly cooling the SRF cavity via thermal conduction and designing high-power (~ 100 kW continuous) RF couplers which dissipate minimal heat (~ 1 W) at 4.2 K. This presentation will discuss these challenges and the solutions which have been developed at Cornell University and elsewhere.  
slides icon Slides THIXA05 [7.219 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIXA05  
About • Received ※ 27 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 04 July 2023 — Issue date ※ 08 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRIBA04 Crab Cavities for ILC cavity, HOM, SRF, impedance 990
 
  • P.A. McIntosh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • S.A. Belomestnykh, I.V. Gonin, T.N. Khabiboulline, A. Lunin, Y.M. Orlov, V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
  • G. Burt
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • R. Calaga
    CERN, Meyrin, Switzerland
  • S.U. De Silva
    JLab, Newport News, Virginia, USA
  • J.R. Delayen
    ODU, Norfolk, Virginia, USA
  • T. Okugi, A. Yamamoto
    KEK, Ibaraki, Japan
  • S. Verdú-Andrés, B.P. Xiao
    BNL, Upton, New York, USA
  
  For the 14 mrad crossing angle proposed, crab cavity systems are fundamentally anticipated for the viable operation of the International Linear Collider (ILC), in order to maximise its luminosity performance. Since 2021, a specialist development team have been defining optimum crab cavity technologies which can fulfil the operational requirements for ILC, both for its baseline centre-of-mass energy of 250 GeV, but also extending those requirements out to higher beam collision intensities. Five design teams have established crab cavity technology solutions, which have the capability to also operate up to 1 TeV centre-of-mass. This presentation showcases the key performance capabilities of these designs and their associated benefits for both manufacture and integration into the ILC Interaction Region. The recommended outcome of the recently conducted crab cavity technology down-selection, will also be highlighted.  
slides icon Slides FRIBA04 [2.526 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2023-FRIBA04  
About • Received ※ 19 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 20 July 2023
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)