Keyword: operation
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MOFAA2 Operation of the European XFEL Towards the Maximum Energy electron, FEL, cavity, MMI 9
 
  • M. Omet, V. Ayvazyan, J. Branlard, S. Choroba, W. Decking, V.V. Katalev, D. Kostin, L. Lilje, P. Morozov, Y. Nachtigal, H. Schlarb, V. Vogel, N. Walker, B. Yildirim
    DESY, Hamburg, Germany
 
  After the initial commissioning of the available 25 radio frequency (RF) stations of the European XFEL (RF gun, A1, AH1 and stations A2 through A23) a maximum electron beam energy of 14.5 GeV was achieved, 3 GeV short of the design energy of 17.5 GeV. In order to tackle this problem, the Maximum Gradient Task Force (MGTF) was formed. In the scope of the work of the MGTF, RF stations A6 through A25 (linac L3) were systematically investigated and voltage-limiting factors of the SRF accelerating modules and their RF distribution system were identified and improved. As a result, the design electron beam energy was exceeded at 17.6 GeV on the 18.7.2018. Beside this an overview over the regular RF operation at the European XFEL is given.  
slides icon Slides MOFAA2 [5.695 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOFAA2  
About • paper received ※ 21 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP019 Surface Preparation and Optimization of SC CH Cavities cavity, linac, coupling, ECR 71
 
  • P. Müller, M. Basten, M. Busch, T. Conrad, H. Podlech
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher, F.D. Dziuba, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth
    GSI, Darmstadt, Germany
 
  The Institute of Applied Physics (IAP) introduced the superconducting multi-gap CH-structure, which is mainly designed for low beta hadron acceleration. In 2017, a 217 MHz sc CH-structure was successfully tested with beam at GSI and multiple CH-structures are currently under development for the GSI cw linac. RF performance of all sc cavities are limited by the surface properties of the used material. Therefore, sufficient surface preparation and optimization is necessary to achieve optimal performance. Presently as standard procedure BCP and HPR is used for CH-cavities. Several surface treatments will be applied to the very first CH-prototype, a 360 MHz, 19-cell cavity. Prior to the first treatment, the status of the cavity was examined, including leak tests and performance tests at 4 and 2 K. This paper presents the performance development of a sc CH cavity depending on different preparation methods.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP019  
About • paper received ※ 23 June 2019       paper accepted ※ 05 July 2019       issue date ※ 14 August 2019  
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MOP034 European XFEL: Accelerating Module Repair at DESY cavity, FEL, linac, SRF 127
 
  • D. Kostin, J. Eschke, K. Jensch, N. Krupka, D. Reschke, S. Saegebarth, J. Schaffran, M. Schalwat, P. Schilling, M. Schmökel, S. Sievers, N. Steinhau-Kühl, E. Vogel, H. Weise, M. Wiencek, B. van der Horst
    DESY, Hamburg, Germany
 
  The European XFEL is in operation since 2017. The design projected energy of 17.5 GeV was reached, even with the last 4 main linac accelerating modules not yet installed. 2 out of 4 not installed modules did suffer from strong cavity performance degradation, namely increased field emission, and required surface processing. The first of two modules is reassembled and tested. The module test results confirm a successful repair action. The module repair and test steps are described together with cavities performance evolution.  
poster icon Poster MOP034 [1.863 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP034  
About • paper received ※ 17 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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MOP055 Fabrication and Performance of Superconducting Quarter-Wavelength Resonators for SRILAC cavity, linac, cryomodule, acceleration 182
 
  • K. Suda, O. Kamigaito, K. Ozeki, N. Sakamoto, Y. Watanabe, K. Yamada
    RIKEN Nishina Center, Wako, Japan
  • H. Hara, A. Miyamoto, K. Sennyu, T. Yanagisawa
    MHI-MS, Kobe, Japan
  • E. Kako, H. Nakai, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
 
  A new superconducting booster linac (SRILAC) at the RIKEN heavy-ion linac is under construction. Ten 73-MHz low-beta quarter-wavelength resonators (QWRs) that operate at 4 K have been fabricated from pure niobium sheets. The cavity parts were assembled by electron beam welding. The resonant frequency for each cavity was adjusted by changing the lengths of the straight sections before welding. The performance and frequency were evaluated by vertical tests. All the cavities exceeded the design specifications of Q0 = 1x109 and Eacc = 6.8 MV/m. Details of the fabrication and frequency tuning as well as the performance of the cavities are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP055  
About • paper received ※ 17 July 2019       paper accepted ※ 13 August 2019       issue date ※ 14 August 2019  
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MOP063 Beam Loading in the BESSY VSR SRF Cavities cavity, beam-loading, SRF, storage-ring 217
 
  • A.V. Tsakanian, H.-W. Glock, J. Knobloch, A.V. Vélez
    HZB, Berlin, Germany
 
  The BESSY VSR upgrade of the BESSY II light source represents a novel approach to simultaneously store long (ca. 15 ps) and short (ca. 1.7 ps) bunches in the storage ring at currents up to 300 mA. This challenging goal requires installation of four new 4-cell SRF cavities (2x1.5 GHz and 2x1.75 GHz) in one module for installation in a single straight. As far as we are aware of, this is the first installation of multi-cell L-Band cavities in a high-current storage ring. These cavities are equipped with newly developed waveguide HOM dampers necessary for stable operation. Up to 2 kW of HOM power must be absorbed. Operating two SRF cavities for each frequency will also enable transparent parking of the cavities for the beam. Based on wakefield theory, a technique for beam loading calculation will be presented. The expected beam loading both at 2 K and at room temperature has been analyzed to evaluate transparent parking for both situations. The presented study is performed for various BESSY II and VSR bunch filling patterns with 300 mA beam current.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP063  
About • paper received ※ 22 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP072 FRIB Solenoid Package in Cryomodule and Local Magnetic Shield solenoid, cavity, cryomodule, dipole 235
 
  • K. Saito, H. Ao, B. Bird, R. Bliton, N.K. Bultman, F. Casagrande, C. Compton, J. Curtin, K. Elliott, A. Ganshyn, W. Hartung, L. Hodges, K. Holland, S.H. Kim, S.M. Lidia, D. Luo, S.J. Miller, D.G. Morris, L. Nguyen, D. Norton, J.T. Popielarski, L. Popielarski, T. Russo, J.F. Schwartz, S.M. Shanab, M. Shuptar, D.R. Victory, C. Wei, J. Wei, M. Xu, T. Xu, Y. Yamazaki, C. Zhang, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  • A. Facco
    INFN/LNL, Legnaro (PD), Italy
  • K. Hosoyama, M. Masuzawa
    KEK, Ibaraki, Japan
  • R.E. Laxdal
    TRIUMF, Vancouver, Canada
 
  Funding: U.S. Department of Energy Office of Science under Cooperative Agreement DE -SC0000661
FRIB cryomodule design has a feature: solenoid package(s) and local magnetic shields in the cryomodule. In this design, exposing SRF cavities to a very strong fringe field from the solenoid is concerned. A tangled issue between solenoid package design and magnetic shield one has to be resolved. FRIB made intensive studies, designed, prototyped, validated the solenoid packages and magnetic shields, and finally certified them in the bunker test. This paper reports activity results, and LS1 commissioning results in FRIB tunnel. This is a FRIB success story.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP072  
About • paper received ※ 24 June 2019       paper accepted ※ 14 August 2019       issue date ※ 14 August 2019  
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MOP073 The Study of High Power Couplers for CIADS status, multipactoring, experiment, simulation 241
 
  • Z.Q. Lin, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, C.L. Li, Y.M. Li, M. Lu, F. Pan, T. Tan, R.X. Wang, Z. Xue, Z.Q. Yang, S.X. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  High power couplers with high operation reliability are needed for the superconducting cavities used in the Linac of CiADS project at IMP. This paper will report two works on high power coupler. The DC bias structure of the coupler was optimized to suppress the multipacting effect, where the series resistors were introduced to the wire of the DC bias to reduce the field propagating along the DC bias’s wire. For the purpose of significantly decreasing the power needed to condition the coupler, we designed a new RF conditioning scheme, in which the coupler served as a standing wave resonator, and the positions of the crests and troughs of the wave were tunable. The details of the design mentioned above will be depicted.  
poster icon Poster MOP073 [14.677 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP073  
About • paper received ※ 25 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP077 Ceramic Study on RF Windows for Power Coupler, Waveguide, and Klystron in Particle Accelerator electron, GUI, klystron, multipactoring 255
 
  • Y. Yamamoto, S. Michizono
    KEK, Ibaraki, Japan
 
  R&Ds on different types of ceramic used in power coupler, waveguide, and klystron for particle accelerators are under progress in Center of Innovation (COI) at KEK, and at some outside companies. There are five important parameters on the properties of ceramics; that is, relative permittivity, dielectric loss tangent, surface and volume resistivity, and secondary electron emission coefficient. For measurements of these parameters, eight kinds of ceramic samples supplied from five vendors have been measured using three different measurement systems since 2017. In this report, the recent results for these studies will be presented in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP077  
About • paper received ※ 22 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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MOP098 Spoke Cryomodule Prototyping for the MINERVA Project cryomodule, cavity, cryogenics, controls 315
 
  • H. Saugnac, S. Blivet, N. Gandolfo, C. Joly, J. Lesrel, D. Longuevergne, G. Olivier, M. Pierens
    IPN, Orsay, France
  • M.A. Baylac, D. Bondoux, F. Bouly, P.-O. Dumont, Y. Gómez Martínez
    LPSC, Grenoble Cedex, France
  • W. Kaabi
    LAL, Orsay, France
  • W. Sarlin
    IPNO, Orsay, France
 
  In the framework of the MINERVA (MYRRHA 100 MeV) project, a prototyping period started at the end of 2017, has been planned. During this period a prototype cryomodule fully equipped (Spoke Cavities, Cryomodule Vessel, Cold Tuning System, Magnetic shielding, Power Couplers’) as well as its operating and controlling components (LLRF, RF amplifiers’) will be studied and manufactured. The aim of this prototyping period is first to complete the study of all the components and to validate the manufacturing and the assembling procedure in order to freeze the specifications for the serial construction. On the other hand the prototypes will serve as a test stand allowing to study and adjust the "Fault Tolerance" strategy parameters , which is a challenging operating concept specific to the MYRRHA LINAC This poster presents the various tasks related to this Spoke Cryomodule prototyping and their status.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP098  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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MOP099 Design of Crab Cavity Cryomodule for HL-LHC cryomodule, cavity, vacuum, cryogenics 320
 
  • T. Capelli, K. Artoos, A.B. Boucherie, K. Brodzinski, R. Calaga, S.J. Calvo, E. Cano-Pleite, O. Capatina, F. Carra, L. Dassa, F. Eriksson, M. Garlasché, A. Krawczyk, R. Leuxe, P. Minginette, E. Montesinos, B. Prochal, M. Sosin, M. Therasse
    CERN, Geneva, Switzerland
  • T.J. Jones, N. Templeton
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • A. Krawczyk, B. Prochal
    IFJ-PAN, Kraków, Poland
  • S.M. Pattalwar
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Funding: Research supported by the HL-LHC project
Crab cavities are a key element to achieve the HL-LHC performance goals. There are two types of cavities Double Quarter Wave (DQW) for vertical crabbing, and Radiofrequency Dipole (RFD) for horizontal crabbing. Cavities are hosted in a cryomodule to provide optimal conditions for their operation at 2K while minimizing the external thermal loads and stray magnetic fields. One crab cryomodule contains more than thirteen thousand components and the assembly procedure for the first DQW prototype was carefully planned and executed. It was installed in the SPS accelerator at CERN in 2018 and successfully tested with proton beams. A review has thus been performed right after completion of the assembly in order to gather all the experience acquired and improve accordingly the design of the next generation of crab cryomodules. A second cryomodule with two RFD cavities is currently under production. This paper presents the lessons learnt from the first assembly and their implementation to the design of the future crab cryomodules.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP099  
About • paper received ※ 21 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP105 A Superconducting Magnetic Shield for the Photoelectron Injector of BERLinPro solenoid, cavity, gun, shielding 335
 
  • J. Völker, A. Frahm, A. Jankowiak, S. Keckert, J. Knobloch, G. Kourkafas, O. Kugeler, A. Neumann, H. Plötz
    HZB, Berlin, Germany
 
  Magnetic fields are a big issue for SRF cavities, especially in areas with strong electromagnets or ferromagnetic materials. Magnetic shieldings consisting of metal alloys with high magnetic permeability are often used to reroute the external magnetic flux from the cavity region. Those Mu metal shields are typically designed for weak magnetic fields like Earth’s magnetic field. Next to strong magnetic field sources like superconducting (SC) solenoids, those shields can be easily saturated resulting in a degradation of the shielding efficiency and a permanent magnetization. For the photoinjector of BERLinPro a new SC solenoid will be installed inside the cryomodule next to the SRF gun cavity. Calculations show that the fringe fields of the solenoid during operation can saturate the cavity Mu-metal shields. Therefore we designed an SC magnetic shield placed between solenoid and cavity shield to protect the latter during magnet operation. In this paper we will present the design and first measurements of this SC magnetic shield.  
poster icon Poster MOP105 [2.011 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP105  
About • paper received ※ 04 July 2019       paper accepted ※ 14 August 2019       issue date ※ 14 August 2019  
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TUP013 Non-Evaporative Getter-Based Differential Pumping System for SRILAC at RIBF vacuum, SRF, linac, cavity 419
 
  • H. Imao
    RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan
  • O. Kamigaito, N. Sakamoto, T. Watanabe, Y. Watanabe, K. Yamada
    RIKEN Nishina Center, Wako, Japan
  • K. Oyamada
    SHI Accelerator Service Ltd., Tokyo, Japan
 
  Upgrades of the RIKEN heavy-ion linac (RILAC) involving a new superconducting linac (SRILAC) are undergoing to promote super-heavy element searches at the RIKEN radioactive isotope beam factory (RIBF). Stable ultra-high vacuum (<10-8 Pa) and particulate-free conditions are strictly necessary for keeping the performance of the superconductive radio frequency (SRF) cavities of the SRILAC. It is crucially important to develop neighboring warm sections to prevent contamination from the existing old RILAC and beamlines built almost four decades ago. In the present study, non-evaporative getter-based differential pumping systems were newly developed to achieve the pressure reduction from the existing beamline vacuum (10-5–10-6 Pa ) to the ultra-high vacuum within very limited length (<80 cm) ensuring the large beam aperture of more than 40 mm. They are also equipped with compact electrostatic particle removers. We will describe and discuss details of the design, construction and performance of the system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP013  
About • paper received ※ 03 July 2019       paper accepted ※ 14 August 2019       issue date ※ 14 August 2019  
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TUP084 Testing of the Piezo-actuators at High Dynamic Rate Operational Conditions SRF, cavity, vacuum, linac 656
 
  • Y.M. Pischalnikov, J.C. Yun
    Fermilab, Batavia, Illinois, USA
  • C. Contreras-Martinez
    FRIB, East Lansing, Michigan, USA
 
  Reliability of the piezo-actuators that deployed into SRF cavity tuner and operated at high dynamic rate operational conditions made significant impact on the overall performance of the SRF linacs. We tested at FNAL piezo-actuators P-P-844K075 that were developed at Physik Instrumente for LCLS II project. Even these actuators were developed for CW linac we tested them at high dynamic rate inside cryogenic/insulated vacuum environment. Results of the tests will be presented. Different modes of the piezo-actuators failure will be discussed.  
poster icon Poster TUP084 [3.168 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP084  
About • paper received ※ 23 June 2019       paper accepted ※ 04 July 2019       issue date ※ 14 August 2019  
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TUP085 Operation of an SRF Cavity Tuner Submerged into Liquid He cavity, experiment, SRF, resonance 660
 
  • Y.M. Pischalnikov, D.J. Bice, A. Grassellino, T.N. Khabiboulline, O.S. Melnychuk, R.V. Pilipenko, S. Posen, O.V. Pronitchev, A.S. Romanenko
    Fermilab, Batavia, Illinois, USA
 
  To precisely control the resonance of 1.3 GHz SRF cavities during testing at the FNAL’s Vertical Test Facility, we install for the first time a double lever tuner and operate it when submerged into the liquid He bath. Both active components of the tuner: electromechanical actuator (stepper motor) and piezo-actuators are operated inside superfluid helium. Accuracy in controlling the SRF cavity resonance frequency will be presented. Specifics of the tuner operation when submerged into liquid He will be discussed.  
poster icon Poster TUP085 [2.164 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP085  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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TUP087 Development and Performances of Spoke Cavity Tuner for MYRRHA Linac Project cavity, controls, linac, simulation 667
 
  • N. Gandolfo, S. Blivet, P. Duchesne, D. Le Dréan
    IPN, Orsay, France
 
  In the framework of the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) 100 MeV linac construction, a fully equipped prototype cryomodule is being developed. In order to control the resonance frequency of the cavities during operation, a tuner has been studied with the specific requirements: high degree of reliability and high tuning speed. This paper reports the design consideration and the first performances measurement in vertical cryostat test at an early stage of the prototyping phase.  
poster icon Poster TUP087 [2.367 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP087  
About • paper received ※ 01 July 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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TUP102 Superconducting Harmonic Cavity for Bunch Lengthening in the APS Upgrade cavity, HOM, cryomodule, photon 715
 
  • M.P. Kelly, Z.A. Conway, M. Kedzie, S.W.T. MacDonald, T. Reid, U. Wienands, G.P. Zinkann
    ANL, Lemont, Illinois, USA
 
  A superconducting cavity based Bunch Lengthening System is under construction for the Argonne’s Advanced Photon Source (APS) Upgrade. The system will reduce the undesirable effects of Touschek scattering on the beam lifetime by providing bunch lengthening in the longitudinal direction by 2-4 times. The major technical components for the beam-driven 1.4 GHz fourth harmonic superconducting cryomodule are in hand and have been tested. These include a superconducting cavity, cw rf power couplers, a pneumatic cavity slow tuner and beamline higher-order mode absorbers. Initial assembly and engineering testing of the cryomodule is underway. Final integrated testing will be complete in 2021. Transportation to and commissioning in the APS is planned for 2022-23.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP102  
About • paper received ※ 08 July 2019       paper accepted ※ 12 July 2019       issue date ※ 14 August 2019  
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TUP105 Preparation of the Cryomodule Assembly for the Linear IFMIF Prototype Accelerator (LIPAc) in Rokkasho cryomodule, vacuum, cavity, SRF 726
 
  • T. Ebisawa, A. Kasugai, K. Kondo, S. Maebara, K. Sakamoto
    QST, Aomori, Japan
  • N. Bazin, S. Berry
    CEA-DRF-IRFU, France
  • P. Cara
    IFMIF/EVEDA, Rokkasho, Japan
  • H. Dzitko, G. Phillips
    F4E, Germany
  • E. Kako, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
 
  The staged installation and commissioning of LIPAc is ongoing at Rokkasho Fusion Institute of QST, Japan for validating the low energy section of the IFMIF deuteron accelerator up to 9 MeV. The LIPAc Superconducting Radio Frequency accelerator (SRF) cryomodule is assembled under the responsibility of the EU Home Team, and the assembly work recently started at Rokkasho in March 2019. To fulfil the cleanliness requirements for the assembly process, QST took the responsibility to prepare the infrastructure of a cleanroom and associated devices. In this present paper, the details of the preparation work for the cryomodule assembly made by QST will be presented.  
poster icon Poster TUP105 [2.116 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP105  
About • paper received ※ 17 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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TUP106 Mechanical Tuner for a 325 MHz Balloon Single Spoke Resonator cavity, cryomodule, linac, simulation 730
 
  • R.E. Laxdal, J.J. Keir, B. Matheson, N. Muller, Z.Y. Yao
    TRIUMF, Vancouver, Canada
 
  TRIUMF has designed, fabricated and tested the first balloon variant of the single spoke resonator at 325 MHz and β=0.3. TRIUMF has also designed and built a mechanical tuner as part of the development. The tuner employs a nutcracker lever pressing at the beam ports driven by a scissor jack. The scissor is actuated through a tube coupling to a warm ball-screw and servo-motor located outside the cryostat. The design and warm tests of the tuner will be presented.  
poster icon Poster TUP106 [1.089 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP106  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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WETEB3 CEBAF C100 Fault Classification based on Time Domain RF Signals cavity, cryomodule, controls, vacuum 763
 
  • T. Powers, A.D. Solopova
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
The CEBAF 12 GeV upgrade project, which was completed and commissioned in 2014, included the construction and installation of 80 new 7-cell superconducting cavities that were configured in 10 cryomodules. In 2018, the software and hardware in the digital low level RF systems were configured such that a fault would trigger an acquisition process which records waveform records of 17 of the RF signals for each of the 8 cavities within the cryomodule for subsequent analysis. These waveforms are especially useful in C100 cryomodules as there is a 10% mechanical coupling between adjacent cavities. When one cavity has a fault and the gradient is reduced quickly, it will mechanically deform due relaxation of the Lorentz force effects. This deformation change causes perturbations in the adjacent cavities which, in turn, causes a cascade of cavity faults that are difficult to understand without the time domain data. This contribution will describe the types of faults encountered during operation and their signatures in the time domain data, as well as how is being used to modify the setup of the machine and implement improvements to the cryomodules.
 
slides icon Slides WETEB3 [3.169 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB3  
About • paper received ※ 21 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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WETEB9 Design Development for the 1.5 GHz Couplers for BESSY VSR cavity, coupling, diagnostics, GUI 795
 
  • E. Sharples, M. Dirsat, J. Knobloch, Z. Muza, A.V. Vélez
    HZB, Berlin, Germany
 
  The Variable pulse length Storage Ring (BESSY VSR) is a superconducting radio frequency (SRF) upgrade to the existing BESSY II storage ring at Helmholtz-Zentrum Berlin (HZB). BESSY VSR uses the RF beating of superconducting cavities at 1.5 GHz and 1.75 GHz to produce simultaneously long and short bunches. Higher power couplers capable of handling 13 kW peak power at standing wave operation, are required to provide an average power of 1.5 kW for both the 1.5 GHz and 1.75 GHz cavities. These couplers must also provide variable coupling with a range of Qext from 6x106 to 6x107 to allow flexibility to adjust to operating conditions of BESSY VSR. Here the full design development process for the 1.5 GHZ BESSY VSR coupler is presented including the design for a diagnostic prototype to ensure comprehensive monitoring of critical components during testing and cool-down.  
slides icon Slides WETEB9 [8.085 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB9  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP012 Assessment of the Mechanical Properties of Ultra-High Purity Niobium After Cold Work and Heat Treatment With the HL-LHC Crab Cavities as Benchmark cavity, ECR, niobium, simulation 860
 
  • A. Gallifa Terricabras, A. Amorim Carvalho, I. Aviles Santillana, S. Barrière, R. Calaga, E. Cano-Pleite, O. Capatina, M.D. Crouvizier, L. Dassa, M.S. Meyer, N. Valverde Alonso
    CERN, Geneva, Switzerland
  • M. Benke, A.B. Palotas, G. Szabó, M. Szűcs
    University of Miskolc, Faculty of Materials Science and Engineering, Miskolc-Egyetemváros, Hungary
  • A. Hlavács, G.J. Krallics, V. Mertinger, M. Sepsi
    University of Miskolc, Miskolc, Hungary
 
  The High Luminosity Large Hadron Collider (HL-LHC) is the upgrade of the world’s largest particle collider; it will allow the full exploitation of the LHC potential and its operation beyond 2025. An essential part of the HL-LHC project are the Crab Cavities, that are particle deflecting SRF cavities of non-axisymmetric shape made of bulk ultra-high purity Nb. Since the cavities are produced by complex metal sheet forming processes, followed by a heat treatment (HT) for H outgassing (650 °C, 24 h), there is uncertainty on their mechanical properties after manufacturing and in service conditions (2 K). Mechanical tests at room temperature have been conducted on RRR300 pure Nb samples. The samples were previously submitted, by cold cross-rolling, to different levels of plastic deformation representative of the effective plastic strain seen by the Nb sheets during forming operations. Moreover, a comparison of the mechanical properties of cold cross-rolled samples before and after HT has been established. Results of evolution of the microstructure and hardness are also presented. This study can be of interest for Nb cavities to be sub-mitted to HT at 650 °C, and may help to push the design of novel SRF cavities.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP012  
About • paper received ※ 22 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP023 RF Commissioning of the CBETA Main Linac Cryomodule cavity, linac, LLRF, controls 881
 
  • N. Banerjee, J. Dobbins, G.H. Hoffstaetter, R.P.K. Kaplan, M. Liepe, C.W. Miller, P. Quigley, E.N. Smith, V. Veshcherevich
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: This work was performed through the support of New York State Energy Research and Development Agency (NYSERDA).
The Cornell BNL ERL Test Accelerator (CBETA) employs a superconducting Main Linac Cryomodule in order to perform multi-turn energy recovery operation. Optimizing the field stability of the low bandwidth SRF cavities in the presence of microphonics with limited available RF power is a challenging task. Despite of this, the Main Linac Cryomodule has been successfully used in CBETA to impart a maximum energy gain of 54 MeV, well above the energy gain requirement of CBETA. In this paper, we present an overview of our RF commissioning procedure including automatic coarse tuning, measurement of DAC and phase offsets. We further detail our microphonics measurements from our most recent run period.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP023  
About • paper received ※ 23 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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THP025 Overview of Superconducting RF Cavity Reliability at Diamond Light Source cavity, vacuum, GUI, storage-ring 885
 
  • C. Christou, P. Gu, P.J. Marten, S.A. Pande, A.F. Rankin, D. Spink, L.T. Stant, A. Tropp
    DLS, Oxfordshire, United Kingdom
 
  Diamond Light Source has been providing beam for users since January 2007. The electron beam in the storage ring is normally driven by two superconducting CESR-B cavities, with two similar cavities available as spares. Day-to-day reliability of the cavities, measured by storage ring MTBF, has improved enormously over the years. A full analysis of how this improvement has been achieved is given, with particular attention paid to cavity voltage and vacuum pressure management, and the scheduling and procedure of cavity conditioning. The benefits and risks of full and partial warm-ups of the cavities are discussed, and details and impacts of cavity failure and repair are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP025  
About • paper received ※ 21 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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THP026 Initial Operation of the LCLS-II Electron Source gun, cavity, vacuum, cathode 891
 
  • C. Adolphsen, A.L. Benwell, G.W. Brown, M.P. Dunning, S. Gilevich, K. Grouev, X. Liu, J.F. Schmerge, T. Vecchione, F.Y. Wang, F. Zhou
    SLAC, Menlo Park, California, USA
  • G. Huang, M.J. Johnson, T.H. Luo, F. Sannibale, S.P. Virostek
    LBNL, Berkeley, California, USA
 
  Funding: This work supported under DOE Contract DE-AC02-76SF00515
The Early Injector Commissioning program for LCLS-II aims to demonstrate CW electron beam production this year in the first two meters of the injector that includes the room-temperature 185.7 MHz single-cell gun and the 1.3 GHz two-cell buncher cavity. These cavities were designed and built by LBNL based on their experience with similar ones for their Advanced Photo-Injector Experiment (APEX) program. With the 258 nm laser system and Cs2Te cathodes, bunches of up to 300 pC are expected at rates as high as 1 MHz. The paper presents results from this program including the vacuum levels achieved, RF processing and field control experience, dark current measurements and laser and beam characterization.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP026  
About • paper received ※ 26 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP027 Cryogenics Performance of the Vertical Cryostat for Qualifying ESS-SRF High Beta Cavities cavity, SRF, cryogenics, MMI 895
 
  • S.M. Pattalwar, R.K. Buckley, P.C. Hornickel, K.J. Middleman, M.D. Pendleton, P. Pizzol, P.A. Smith, T.M. Weston, A.E. Wheelhouse, S. Wilde
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.J. May, A. Oates, J.T.G. Wilson
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  An innovative vertical cryostat has been developed and commissioned at STFC Daresbury Laboratory for qualifying the high-beta SRF cavities for the ESS (European Spallation Source). The cryostat is designed to test 3 dressed cavities in horizontal configuration in one cold run at 2K. The cavities are cooled to 2K with superfluid liquid helium filled into individual helium jackets of the cavities. This reduces the liquid helium consumption by more than 70% in comparison with the conventional vertical tests. The paper describes the cryogenic system and its performance with detail discussions on the initial results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP027  
About • paper received ※ 22 June 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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THP031 Operation Experience with the LHC ACS RF System cavity, cryomodule, injection, MMI 911
 
  • K. Turaj, L. Arnaudon, P. Baudrenghien, O. Brunner, A.C. Butterworth, F. Gerigk, M. Karppinen, P. Maesen, E. Montesinos, F. Peauger, G.J. Rosaz, E.N. Shaposhnikova, D. Smekens, M. Taborelli, M. Therasse, H. Timko, D. Valuch, N. Valverde Alonso, W. Venturini Delsolaro
    CERN, Meyrin, Switzerland
 
  The LHC accelerating RF system consists of two cryomodules per beam, each containing four single-cell niobium sputtered 400.8 MHz superconducting cavities working at 4.5 K and an average accelerating voltage of 2 MV. The paper summarises the experience, availability and evolution of the system within 10 years of operation. The lessons learned from the successful replacement and re-commissioning of one cryomodule with a spare module, and the recent re-test of the originally installed module on the test stand are also included. Finally, a review of currently launched spare cavity production and long-term developments are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP031  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP034 The First Tests on Vertical Cryostat GERSEMI at FREIA Facility controls, cryogenics, MMI, vacuum 921
 
  • J.P. Thermeau
    Laboratoire APC, Paris, France
  • K.J. Gajewski, L. Hermansson, R.J.M.Y. Ruber, R. Santiago Kern
    Uppsala University, Uppsala, Sweden
  • T. Junquera, O. Kochebina
    Accelerators and Cryogenic Systems, Orsay, France
 
  A new vertical cryostat, called Gersemi, installed at FREIA Laboratory at Uppsala University, Sweden, is designed to test superconducting magnets and radio-frequency cavities and operates at temperatures between 1.8 K and 4.2 K. Two different inserts can be used to test different superconducting equipment: a helium saturated bath insert for cavities without a helium vessel and a λ-plate insert for magnet testing in superfluid helium pressurized bath. The cold vessel cryostat has an internal diameter of 1.1 m and a useful height of 3.5 m. A valve box supplies the cryostat with the cryogens (LN2, LHe, SHe) and is linked to a gas reheater. The last one is connected to a helium recovery circuit and to a helium pumping system (4.5 g/s at 16 mbar). The Gersemi vertical cryostat is a part of FREIA cryogenic facility which also contains a helium liquefier and a horizontal cryostat inside of a bunker allowing the test of superconducting cavity cryomodules. The first results of the cryogenic tests on this equipment are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP034  
About • paper received ※ 23 June 2019       paper accepted ※ 04 July 2019       issue date ※ 14 August 2019  
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THP051 Upgrades to Cryogenic Capabilities for Cryomodule Testing at JLab cryomodule, cavity, cryogenics, HOM 983
 
  • N.A. Huque, E. Daly, T. Wijeratne
    JLab, Newport News, Virginia, USA
 
  The cryogenic facilities for cryomodule testing at Jefferson Lab (JLab) have been modified and to enable testing of Linear Coherent Light Source-II (LCLS-II) cryomodules. Temporary changes in u-tube connections at the Cryogenic Test Facility (CTF) has enabled rates of cavity cooling that are a factor of 10 higher than previously achieved. Cryogenic connections at JLab’s Low Energy Recirculator Facility (LERF) have been repurposed to enable two LCLS-II cryomodules to be tested in series. This testing shares the helium space with the Central Helium Liquefier (CHL) that is also used by the Continuous Electron Beam Accelerator Facility (CEBAF). Cryomodule testing can occur while beam operation is ongoing at CEBAF. Improvements to these facilities have allowed the testing of the JLab’s highest ever performing cryomodules.  
poster icon Poster THP051 [0.722 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP051  
About • paper received ※ 20 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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THP054 Cryogenic Installations for Module Tests at Mainz cryogenics, cryomodule, SRF, cavity 997
 
  • F. Hug, K. Aulenbacher, E. Schilling, D. Simon, T. Stengler, S.D.W. Thomas
    KPH, Mainz, Germany
  • K. Aulenbacher, T. Kürzeder
    HIM, Mainz, Germany
  • A. Skora
    IKP, Mainz, Germany
 
  Funding: This work is supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019
At Helmholtz Institute Mainz a cryomodule test bunker has been set up for testing dressed modules at 2 K. In a first measurement campaign the high power rf tests of two 1.3 GHz cryomodules for the future MESA accelerator have been performed. We will report on the performance of the test setup, the present and upcom-ing cryogenic installations at the Institute for Nuclear Physics at Mainz, and in particular on the Helium re-frigeration and transport system comprising of a 220 m transport line for liquified gases.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP054  
About • paper received ※ 29 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP056 Current Results From Acceptance Testing of LCLS-II Cryomodules at Jefferson Lab cryomodule, cavity, HOM, controls 1007
 
  • M.A. Drury, E. Daly, N.A. Huque, L.K. King, A.D. Solopova
    JLab, Newport News, Virginia, USA
  • J. Nelson, B.H. Ripman, L.M. Zacarias
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515.
The Thomas Jefferson National Accelerator Facility is currently engaged, along with several other Department of Energy (DOE) national laboratories, in the Linac Co-herent Light Source II project (LCLS-II). The SRF Insti-tute at Jefferson Lab is currently building 21 cryomod-ules for this project. The cryomodules are based on the XFEL design and have been modified for continuous wave (CW) operation and to comply with other LCLS-II specifications. Each cryomodule contains eight 9-cell cavities with coaxial power couplers operating at 1.3 GHz. The cryomodule also contain a magnet package that consists of a quadrupole and two correctors. Most of these cryomodules will be tested in the Cryomodule Test Facility (CMTF) at Jefferson Lab before shipment to SLAC. Up to three of these cryomodules will be tested in a test stand set up in the Low Energy Recovery Facility (LERF) at Jefferson Lab. Acceptance testing of the LCLS-II cryomodules began in December 2016. Twelve cryomodules have currently completed Acceptance Test-ing. This paper will summarize the results of those tests.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP056  
About • paper received ※ 22 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP058 Conditioning Experience of the ESS Spoke Cryomodule Prototype cavity, cryomodule, vacuum, hardware 1011
 
  • A. Miyazaki, K. Fransson, K.J. Gajewski, L. Hermansson, H. Li, R.J.M.Y. Ruber, R. Santiago Kern, R. Wedberg
    Uppsala University, Uppsala, Sweden
 
  The prototype cryomodule for the ESS double spoke cavities is tested in the FREIA laboratory at Uppsala University. One of the goals of this test is to establish an efficient way to assess one series cryomodule within a due time (about one month). In 2017, the dedicated high-power test for dressed cavities in the horizontal cryostat (HNOSS) revealed that one of the possible challenges is a conditioning process of the coupler and cavity multipacting. Each process should not damage any components of the cryomodule but at the same time it should be finished in a reasonable time scale. More importantly, unlike the previous tests in the vertical or horizontal cryostat, conditioning two cavities in one cryomodule in due time may require parallel processing in some part of the procedure. This study will be the first practical experience of double spoke cavity conditioning in a cryomodule, and will lead to a standard conditioning recipe for future projects containing superconducting spoke cavities. In this presentation, a preliminary result of cryomodule testing will be shown with a special focus on the conditioning processes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP058  
About • paper received ※ 01 July 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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THP060 Experience With LCLS-II Cryomodule Testing at Fermilab cryomodule, cavity, detector, SRF 1018
 
  • E.R. Harms, E. Cullerton, C.M. Ginsburg, B.J. Hansen, B.D. Hartsell, J.P. Holzbauer, J. Hurd, V.S. Kashikhin, M.J. Kucera, F.L. Lewis, A. Lunin, D.L. Newhart, D.J. Nicklaus, P.S. Prieto, O.V. Prokofiev, J. Reid, N. Solyak, R.P. Stanek, M.A. Tartaglia, G. Wu
    Fermilab, Batavia, Illinois, USA
  • C. Contreras-Martinez
    FRIB, East Lansing, Michigan, USA
  • J. Einstein-Curtis
    Private Address, Naperville, 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 Cryomodule Test Stand (CMTS1) at Fermilab has been engaged with testing 8-cavity 1.3 GHz cryomodules designed and assembled for the LCLS-II project at SLAC National Accelerator Laboratory since 2016. Over these three years twenty cryomodules have been cooled to 2K and power tested in continuous wave mode on a roughly once per month cycle. Test stand layout and testing procedures are presented together with results from the cryomodules tested to date. Lessons learned and future plans will also be shared.
 
poster icon Poster THP060 [2.774 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP060  
About • paper received ※ 22 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP062 Progress in FRIB Cryomodule Bunker Tests cavity, cryomodule, solenoid, SRF 1029
 
  • W. Chang, S. Caton, A. Ganshyn, W. Hartung, S.H. Kim, B. Laumer, H. Maniar, J.T. Popielarski, K. Saito, M. Xu, T. Xu, C. Zhang, S. Zhao
    FRIB, East Lansing, Michigan, USA
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams (FRIB) is under construction at Michigan State University (MSU). The FRIB superconducting driver linac will accelerate ion beams to 200 MeV per nucleon. The driver linac requires 104 quarter-wave resonators (QWRs, β = 0.041 and 0.085) and 220 half-wave resonators (HWRs, β = 0.29 and 0.54). The jacketed resonators are Dewar tested at MSU before installation into cryomodules. The cryomodules for β = 0.041, 0.085, and 0.29 have been completed and certified; 32 out of 49 cryomodules are certified via bunker test (as of March 2019). FRIB cryomodule needs 74 solenoid packages: 8-25 cm packages for 0.041 QWR CMs, 36-50 cm for 0.085 CMs, 12-50 cm for 0.29 CMs, and 18-50 cm for 0.53 CMs. The bunker certification completed 58 packages. All the magnets energized at FRIB goal (90 A/8 T for solenoid and 19 A/0.064 Tm for dipoles), all cavities tested at or above specified operating gradient. In this paper, we report the bunker test result.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP062  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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THP076 Simulation Analysis of Lorentz Force Induced Oscillations in RF Cavities in Vector Sum and Cw Operation cavity, controls, simulation, alignment 1078
 
  • R. Leewe, K. Fong
    TRIUMF, Vancouver, Canada
 
  Within TRIUMFs electron LINAC, two TESLA type cavities are operated with a single klystron in CW mode. Vector sum control is applied for field stabilization and the resonance frequencies are individually tuned with a proportional feedback controller. First operational experiences showed that amplitude oscillations can start in both cavities, while the vector sum is perfectly stable. These instabilities occur at high operating fields and are driven by Lorentz force changes. This paper presents a simulation study of multiple cavities in vector sum operation with respect to Lorentz force oscillations. It will be shown that all cavities in operation have to be damped to guarantee system stability.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP076  
About • paper received ※ 22 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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THP078 CERN’s SRF Test Stand for Cavity Performance Measurements cavity, controls, LLRF, interface 1082
 
  • N. Stapley, J. Bastard, M.R. Coly, A.E. Ivanov, A. Macpherson, N.C. Shipman, K. Turaj
    CERN, Geneva, Switzerland
  • I. Ben-Zvi
    BNL, Upton, New York, USA
  • A. Castilla
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • K. Hernandez-Chahin
    Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
  • M. Wartak, A. Zwozniak
    IFJ-PAN, Kraków, Poland
 
  Recent deployment of a digital LLRF system within the cavity testing framework of CERN’s vertical test cryostats has permitted a full revamp of cavity performance validation. With both full continuous and pulse mode operation, steady state a transient RF behaviour can be effectively probed. Due to direct and integrated control and monitoring of environmental test conditions, standard and novel RF measurement procedures have been developed and integrated into the testing infrastructure, along with a coherent data flow of high granularity measurement data. We present an overview of this cavity measurement system and address the underlying architectural structure, data handling and integration of user interfaces. In addition we highlight the benefits of variety of RF cavity measurements that can now be accommodated in our large 2 K cryostats.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP078  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP092 Status of Cryomodule Testing at CMTB for CW R&D cavity, cryomodule, FEL, linac 1129
 
  • J. Branlard, V. Ayvazyan, A. Bellandi, J. Eschke, C. Gümüş, D. Kostin, K.P. Przygoda, H. Schlarb, J.K. Sekutowicz
    DESY, Hamburg, Germany
 
  Cryo Module Test Bench (CMTB) is a facility to perform tests on European XFEL like superconducting accelerating modules. The 120 kW Inductive Output Tube (IOT) installed in the facility allows driving the eight superconducting cavities inside the module under test in a vector-sum or single cavity control fashion with average Continuous Wave (CW) gradients higher than 20 MV/m. The scope of these tests is to evaluate the feasibility of upgrading European XFEL to CW operation mode. Following the successful tests done on a prototype module XM-3 the initial performance results on the production module XM50 will be presented in this paper. Because of European XFEL requirements, XM50 is equipped with modified couplers that allow a variable Loaded Quality factor(QL) to values higher than 4x107. A cost relevant open question is the maximum QL that can be reached while maintaining the system within the European XFEL field stability specifications of 0.01 % in amplitude and 0.01 deg in phase. Because of this, the LLRF system capability of rejecting microphonic and RF disturbances, as well as Lorentz Force Detuning (LFD) related effects in open and closed loop is of prime interest.  
poster icon Poster THP092 [1.514 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP092  
About • paper received ※ 25 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP101 Commissioning of a Cleanroom for SRF Activities at the Helmholtz Institute Mainz cavity, vacuum, SRF, heavy-ion 1162
 
  • T. Kürzeder, K. Aulenbacher, W.A. Barth, C. Burandt, F.D. Dziuba, V. Gettmann, R.G. Heine, S. Lauber, J. List, M. Miski-Oglu
    HIM, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, C. Burandt, F.D. Dziuba, V. Gettmann, S. Lauber, J. List, M. Miski-Oglu, S. Yaramyshev
    GSI, Darmstadt, Germany
  • K. Aulenbacher, F.D. Dziuba, S. Lauber
    IKP, Mainz, Germany
  • J. Conrad
    TU Darmstadt, Darmstadt, Germany
  • R.G. Heine, F. Hug, J. List, T. Stengler
    KPH, Mainz, Germany
 
  A newly built cleanroom is under commissioning at the Helmholtz-Institute Mainz (HIM). In its ISO-class 6 area vacuum components and cavities can be cleaned in different ultrasonic baths and in a dedicated conductance rinsing bath. In the ISO-class 4 area a large vacuum oven offers the possibility for comprehensive drying. A high pressure rinsing cabinet (HPR) has been installed between the two cleanroom areas to be loaded and unloaded from both sides. Complete cold-strings have to be mounted in the ISO-class 4 area and to be rolled out of the cleanroom on a rail system installed on the floor. All installations and tools have been integrated to treat and assemble superconducting 217 MHz multigap crossbar cavities for the Helmholtz Linear Accelerator (HELIAC), which is under development by HIM and GSI. Those crossbar cavities have a diameter of 650 mm and a weight of up to 100 kg. The cleanroom will be also used for the Mainz Energy-Recovering Superconducting Accelerator (MESA) project, processing the TESLA/XFEL type 9-cell cavities and other beamline components. This paper reports on the commissioning of the cleanroom and shows the features of the different installations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP101  
About • paper received ※ 23 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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