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MOP013 Reducing Surface Roughness of Nb3Sn Through Chemical Polishing Treatments cavity, niobium, superconductivity, SRF 48
 
  • H. Hu, M. Liepe, R.D. Porter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Niobium-3 tin (Nb3Sn) is a promising alternative material for SRF cavities, with theoretical limits for critical temperatures and superheating fields reaching twice that of conventional Nb cavities. However, currently achievable accelerating gradients in Nb3Sn cavities are much lower than their theoretical limit. One limitation to the maximum accelerating gradient is surface magnetic field enhancement caused by the surface roughness of Nb3Sn. However, there are currently no standard techniques used to reduce Nb3Sn surface roughness. Since Nb3Sn is only 2-3 microns thick, it is difficult to selectively polish Nb3Sn without removing the entire layer. Here, we investigate reducing the surface roughness of Nb3Sn through applying chemical polishing treatments, including modified versions of standard techniques such as Buffered Chemical Polishing (BCP) and Electropolishing (EP). Through data acquired from Atomic Force Microscope (AFM) scans, SEM scans, and SEM-EDS analysis, we show the effects of these chemical treatments in reducing surface roughness and consider the changes in the chemical composition of Nb3Sn that may occur through the etching process. We find that BCP with a 1:1:8 solution is ineffective while EP halves the surface roughness of Nb3Sn.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP013  
About • paper received ※ 01 July 2019       paper accepted ※ 04 July 2019       issue date ※ 14 August 2019  
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MOP030 Analysis of Surface Nitrides Created During "Doping" Heat Treatments of Niobium niobium, cavity, SRF, lattice 106
 
  • J.K. Spradlin, A.D. Palczewski, C.E. Reece, H. Tian
    JLab, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The benefits of reduced RF losses from interstitial "doping" of niobium are well established. Many of the details involved in the process remain yet to be elucidated. The niobium surface reacted with low-pressure nitrogen at 800°C presents a surface with chemical reactivity different than standard niobium. While standard "recipes" are being used to produce cavities, we seek additional insight into the chemical processes that may be used to remove the "undesirable" as-formed surface layer. This may lead to new processing routes or quality assurance methods to build confidence that all surface "nitrides" have been removed. We report a series of alternate chemistry treatments and subsequent morphological examinations and interpret the results. We also introduce a new standardized Nb sample system in use for efficient characterization of varying doping protocols and cross-laboratory calibration. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP030  
About • paper received ※ 23 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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MOP040 Low Temperature Thermal Conductivity of Niobium and Materials for SRF Cavities niobium, SRF, cavity, experiment 144
 
  • M. Fouaidy
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  A test facility, allowing the test of 4 samples simultaneously during each run, was developed for measuring at low temperature (T= 1.5 K - 10 K) the thermal conductivity k(T) of niobium and other materials used for the fabrication of SRF cavities. The measurements are performed using steady-state axial heat flow method with a careful control of heat leaks to the surrounding. Several samples of different materials (industrial Nb sheets, Ti¿) were either tested as received or/and subjected to various Heat Treatment (H.T) prior to the experiment then tested. The resulting experimental data are presented and compared to the experimental results previously reported by other groups. As expected, H.T @ 1200°C with Ti gettering improves the Nb RRR by a factor of 3 and consequently k(T). Finally, the correlation between the Niobium RRR and the thermal conductivity. at T=4.2 K is confirmed in good agreement with the Wiedemann-Franz law.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP040  
About • paper received ※ 04 July 2019       paper accepted ※ 05 July 2019       issue date ※ 14 August 2019  
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MOP058 ESS Medium Beta Activity at INFN LASA cavity, HOM, status, SRF 199
 
  • D. Sertore, M. Bertucci, A. Bignami, A. Bosotti, M. Chiodini, A. D’Ambros, G. Fornasier, P. Michelato, L. Monaco, R. Paparella
    INFN/LASA, Segrate (MI), Italy
  • S. Aurnia, O. Leonardi, A. Miraglia, G. Vecchio
    INFN/LNS, Catania, Italy
  • A. Gresele, A. Visentin
    Ettore Zanon S.p.A., Nuclear Division, Schio, Italy
  • C. Pagani
    Università degli Studi di Milano & INFN, Segrate, Italy
  • D. Reschke, A. Sulimov, M. Wiencek
    DESY, Hamburg, Germany
  • D. Rizzetto, M. Rizzi
    Ettore Zanon S.p.A., Schio, Italy
  • L. Sagliano
    ESS, Lund, Sweden
  
  The industrial production of the 36 resonators (plus 2 spares) for the ESS linac started and it is steadily progressing. Cavities are delivered by industry as fully surface-treated and dressed to AMTF facility at DESY for their qualification via vertical cold-test. This paper reports the current status of the manufacturing process from sub-components to processing of the complete cavity inner surface. It also reviews the documental control strategy deployed to preserve the fulfillment of ESS requirements as well as the cavity performances demonstrated so far.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP058  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP092 Overview of LCLS-II Project Status at Fermilab cryomodule, SRF, cavity, cryogenics 302
 
  • R.P. Stanek, T.T. Arkan, J.N. Blowers, C.M. Ginsburg, A. Grassellino, C.J. Grimm, B.J. Hansen, E.R. Harms, B.D. Hartsell, J.P. Holzbauer, J.A. Kaluzny, A.L. Klebaner, A. Martinez, T.H. Nicol, Y.O. Orlov, K.S. Premo, N. Solyak, J. Theilacker, G. Wu
    Fermilab, Batavia, Illinois, USA
  
  The superconducting RF Continuous-Wave (CW) Linac for the LCLS-II consists of thirty-five 1.3 GHz and two 3.9 GHz cryomodules that Fermilab and Jefferson Lab are jointly producing in collaboration with SLAC. Fermilab¿s scope of work is to build, test, and deliver half the 1.3 GHz and all the 3.9 GHz cryomodules and to design and procure components for the cryogenic distribution system. Fermilab has primary responsibility for delivering a working design. The cryomodule design basis was the European XFEL but several elements evolved to meet CW operation requirements and specifics of the SLAC tunnel. There have been several challenges faced during the design, assembly, testing and transportation of the cryomodules which have required design updates. Success in overcoming these challenges is attributable to the strength of the LCLS-II SRF Collaboration (Fermilab, Jefferson Lab and SLAC with extensive help from DESY and CEA/Saclay). The cryogenic distribution system has progressed relatively well and there are valuable Lessons Learned. An overview of the status, accomplishments, problems encountered, solutions developed, and a summary of Lessons Learned will be presented.  
poster icon Poster MOP092 [0.393 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP092  
About • paper received ※ 20 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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MOP098 Spoke Cryomodule Prototyping for the MINERVA Project cryomodule, cavity, cryogenics, operation 315
 
  • H. Saugnac, S. Blivet, N. Gandolfo, C. Joly, W. Kaabi, J. Lesrel, D. Longuevergne, G. Olivier, M. Pierens, W. Sarlin
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • M.A. Baylac, D. Bondoux, F. Bouly, P.-O. Dumont, Y. Gómez Martínez
    LPSC, Grenoble Cedex, 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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TUP022 Fermilab EP Facility Improvement cavity, niobium, target, SRF 453
 
  • F. Furuta, D.J. Bice, A.C. Crawford, T.J. Ring
    Fermilab, Batavia, Illinois, USA
  
  Electro-chemical Polishing (EP) is one of the key technologies of surface treatments for niobium superconducting cavities. We have established a single-cell scale horizontal electro-polishing facility at Fermilab and routinely processed the niobium cavities with the frequencies of 1.3 GHz to 3.9 GHz. The precise control of EP parameters, especially the temperatures of cavity outside wall, allows the uniform removal over the cell with the variation of ±15%. Here we report the details of our EP process and recent improvements on our EP facility at Fermilab.  
poster icon Poster TUP022 [1.711 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP022  
About • paper received ※ 10 July 2019       paper accepted ※ 17 August 2019       issue date ※ 14 August 2019  
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TUP028 Development of Vertical Electropolishing Facility for Nb 9-Cell Cavity (3) cavity, scattering, cathode, linac 470
 
  • Y.I. Ida, V. Chouhan, K.N. Nii
    MGH, Hyogo-ken, Japan
  • T. Akabori, G. Mitoya, K. Miyano
    HKK, Morioka, Japan
  • Y. Anetai, F. Takahashi
    WING. Co.Ltd, Iwate-ken, Japan
  • H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
    KEK, Ibaraki, Japan
  
  The 1st report was delivered in May, 2018 at the IPAC 18 in Vancouver, Canada. The 2nd report was delivered in September, 2018 at the LINAC 18 in Beijing, China. We will make our 3rd report in July, 2019 at the SRF-19 in Dresden, Germany. There will be two main points this time. The first is that by using our improved Ninja Electrode Premium, we can out-perform our number one and number two competitors in terms of uniform electropolishing of the interior of the 9-cell cavity. The second point is that we can remove hydrogen gas, reacted during electropolishing, from the cavity chambers in a manner that has not been successfully achieved by 1st report, May 2018 and 2nd report, September 2018. We will report our 9-cell vertical polishing revolver-type unit that solves the above two problems.  
poster icon Poster TUP028 [0.444 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP028  
About • paper received ※ 24 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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TUP030 Automation of Particulate Characterization cavity, software, SRF, electron 477
 
  • J.K. Spradlin, C.E. Reece, O. Trofimova, A-M. Valente-Feliciano
    JLab, Newport News, Virginia, USA
  
  Funding: Notice: This manuscript has been authored by Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 with the U.S. Department of Energy.
Foreign particles residing on the field carrying surface of accelerator cavities are a known mechanism for field emission. Developing the methods and tools for collecting and characterizing particles found in an accelerator enables process development towards field emission free SRF cavities. Methods are presented for sampling assemblies, components, processes, and environmental conditions utilizing forensic techniques with specialized tooling. Sampling activities to date have produced an inventory of over 850 GSR spindles. Traditional SEM + EDS analysis of this volume of spindles is challenged by labor investment, spindle sampling methods, and the subsequent data pipeline which ultimately results in a statically inadequate dataset for any particulate distribution characterization. A complete systematic analysis of the spindles is enabled by third party software controlling SEM automation for EDS data acquisition. Details of spindle creation, collection equipment, component sampling, automating particle assessment, and data analysis used to characterize samples from beamline elements in CEBAF are presented. 		 
poster icon Poster TUP030 [3.257 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP030  
About • paper received ※ 21 June 2019       paper accepted ※ 14 August 2019       issue date ※ 14 August 2019  
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TUP032 Modal Analysis and Vibration Test for Quarter Wave Resonator for RAON cavity, cryomodule, SRF, resonance 485
 
  • M.O. Hyun, H.C. Jung, Y. Kim, M. Lee
    IBS, Daejeon, Republic of Korea
  
  Funding: This paper was supported by the Rare Isotope Science Project (RISP), which is funded by the Ministry of Science and ICT (MSIT) and National Research Foundation (NRF) of the Republic of Korea.
The Rare Isotope Science Project (RISP) in the Institute of Basic Science (IBS), Korea, is developing and con-structing the multi-purpose linear accelerator at the north side of Daejeon, South Korea. RISP accelerator (RAON) is composed with low-energy region (SCL3) and high-energy region (SCL2), and low-energy region is made with quarter-wave resonator (QWR) and half-wave resonator (HWR) when high-energy region is made with single spoke resonator type-1 (SSR1) and type-2 (SSR2). This paper shows about the initial resonance issues of QWR superconducting (SC) cavity during cold test and SRF disturbance measurement. Afterwards, this paper shows the modal analysis and vibration test of QWR SC cavity. 		 
poster icon Poster TUP032 [0.584 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP032  
About • paper received ※ 23 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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TUP037 Construction of Superconducting Linac Booster for Heavy-Ion Linac at RIKEN Nishina Center cryomodule, linac, vacuum, booster 502
 
  • K. Yamada, T. Dantsuka, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe
    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
  
  At RIKEN Nishina Center, the RIKEN Heavy-Ion Linac (RILAC) is undergoing an upgrade of its acceleration voltage in order to allow it further investigation of new super-heavy elements. In this project, a new superconducting (SC) booster linac, so-called SRILAC, is being developed and constructed. The SRILAC consists of 10 TEM quarter-wavelength resonators made of pure niobium sheets which operate at 4 K. The target performance of each cavity is set as Q0 of 1×109 with its accelerating gradient of 6.8 MV/m. Recently we succeeded to develop high performance SC-cavities which satisfies the requirement with a wide margin. The cryomodule assembly is under way, and installation of cryomodules and He liquefaction system will be completed by the end of FY2018. The cooling-down test is scheduled in the Q1 of FY2019. This contribution makes a report on the construction status of the SRILAC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP037  
About • paper received ※ 02 July 2019       paper accepted ※ 04 July 2019       issue date ※ 14 August 2019  
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TUP041 SRF testing for Mainz Energy Recovering Superconducting Accelerator MESA cavity, cryomodule, SRF, radiation 508
 
  • T. Stengler, K. Aulenbacher, F. Hug, S.D.W. Thomas
    KPH, Mainz, Germany
  • K. Aulenbacher
    GSI, Darmstadt, Germany
  • K. Aulenbacher
    HIM, Mainz, Germany
  
  Funding: This work is supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019
The two superconducting radio frequency acceleration cryomodules for the new multiturn ERL ’Mainz Energy Recovering Superconducting Accelerator’ MESA at Johannes Gutenberg-Universität Mainz have been fabricated and are currently under testing at the Helmholtz Institut Mainz. These modules are based on the ELBE modules of the Helmholtz Center Dresden-Rossendorf but are modified to suit the high current and energy-recovering operation at MESA. The energy gain per module per turn should be 25 MeV, provided by two TESLA cavities, which were vertically tested at DESY, Hamburg, Germany. These tests showed an excellent performance of the quench limit and quality factor for three out of the four cavities. The fourth cavity has a lower but still acceptable quench limit and quality factor. In order to validate the performance of the fully assembled cryomodules after delivery to Mainz a test stand has been set up at the Helmholtz Institut Mainz. The test stand is described in detail and the status of the module testing is reported. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP041  
About • paper received ※ 21 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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TUP053 Optimal Thermal Gradient for Flux Expulsion in 600°C Heat-treated CEBAF 12 GeV Upgrade Cavities cavity, HOM, niobium, experiment 550
 
  • R.L. Geng, F. Marhauser, P.D. Owen
    JLab, Newport News, Virginia, USA
  
  We will present results on measurement of flux expulsion in CEBAF 12 GeV upgrade cavities and original CEBAF cavities and the search for optimal thermal gradient for reducing the trapped flux in cavities installed in CEBAF linacs. Preliminary measurements of one C100 cavities has shown that a nearly perfect flux expulsion can be achieved at an optimal thermal gradient - a surprising result contrary to the expectation of zero flux expulsion for 600°C heat treated niobium cavities. These results could lead to a cost-effective path for improving the quality factor of cavities installed in CEBAF and ultimately saving accelerator operation cost.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP053  
About • paper received ※ 24 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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TUP058 Characterization of Small AMR Sensors in Liquid Helium to Measure Residual Magnetic Field on Superconducting Samples SRF, cavity, experiment, site 576
 
  • G. Martinet
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  
  Trapped residual magnetic flux is responsible of residual resistance degradation on superconducting materials used in SRF technologies. To characterize this effect on superconducting samples, compact sensors are required to mount on sample characterization devices. In this paper, we present results on AMR sensors supplied from different manufacturers in the temperature range from 4.2 K up to 300 K.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP058  
About • paper received ※ 23 June 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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TUP060 Development of Temperature and Magnetic Field Mapping System for Superconducting Cavities at KEK cavity, solenoid, site, radio-frequency 583
 
  • T. Okada, E. Kako, T. Konomi, H. Sakai, K. Umemori
    Sokendai, Ibaraki, Japan
  • E. Kako, T. Konomi, M. Masuzawa, H. Sakai, K. Tsuchiya, R. Ueki, K. Umemori
    KEK, Ibaraki, Japan
  • A. Poudel, T. Tajima
    LANL, Los Alamos, New Mexico, USA
  
  A temperature and magnetic field mapping system for a single cell superconducting cavity is being developed at KEK. The mapping system is used to observe the temperature distribution and the ambient magnetic field distribution around the outer surface of the cavity. A total of 36 boards at every 10 degrees are attached on the cavity. Each board consists of 15 carbon resistors of 100 Ω at room temperature and 3 AMR sensors of X, Y and Z directions at the equator. The calibration of the resisters and AMR sensors were carefully and precisely carried out at low temperature. The data logging system using NI loggers is enabled to measure within 1 ms in the whole cavity surface. The initial test results in the vertical test of the single-cell cavity will be reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP060  
About • paper received ※ 05 July 2019       paper accepted ※ 05 July 2019       issue date ※ 14 August 2019  
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TUP070 The SRF Thin Film Test Facility in LHe-Free Cryostat cavity, cryogenics, SRF, vacuum 610
 
  • O.B. Malyshev, J.A. Conlon, P. Goudket, N. Pattalwar, S.M. Pattalwar
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • G. Burt
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • G. Burt
    Lancaster University, Lancaster, United Kingdom
  
  An ongoing programme of development superconducting thin film coating for SRF cavities requires a facility for a quick sample evaluation at the RF conditions. One of the key specifications is a simplicity of the testing procedure, allowing an easy installation and quick turnover of the testing samples. Choked test cavities operating at 7.8 GHz with three RF chokes have been designed and tested at DL in a LHe cryostat verifying that the system could perform as required. Having a sample and a cavity physically separate reduces the complexity involved in changing samples (major causes of low throughput rate and high running costs for other test cavities) and also allows direct measurement of the RF power dissipated in the sample via power calorimetry. However, changing a sample and preparation for a test requires about two-week effort per sample. In order to simplify the measurements and achieve a faster turnaround, a new cryostat cooled with a closed-cycle refrigerator has been designed, built and tested. Changing a sample, cooling down and testing can be reduced to 2-3 days per sample. Detailed design and results of testing of this facility will be reported at the conference.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP070  
About • paper received ※ 21 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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TUP076 Electrochemical Deposition of Nb3Sn on the Surface of Cu Substrates niobium, cavity, site, SRF 624
 
  • M. Lu, Q.W. Chu, Y. He, Z.Q. Lin, F. Pan, T. Tan, Z.Q. Yang
    IMP/CAS, Lanzhou, People’s Republic of China
  
  Coating superconducting Nb3Sn thin film on the inner surface of a superconducting RF cavity is one of the most promising approaches to improve the performance of the accelerating cavity. Compared with traditional evaporation and sputtering, electrochemical coating has the advantages on process simplicity, low cost and mass production. However, the conventional electroplating, because of its low growth temperature and aqueous reaction environment, tends to produce porous, loosely bonded, and often contaminated film. All these properties result in excessive pinning center and deteriorate the superconducting radio frequency cavities performance. In this paper, a new method including multi-layer electroplating and heat treatment is used to deposit Nb3Sn thin film on top of copper substrates. Important growth parameters, e.g. electrical current density, layer thickness ratio, and annealing temperature are studied. The morphology of the film surfaces was observed by scanning electron microscope (SEM) and the structure of the film was analyzed by X-ray diffraction (XRD). The results showed that a flat and uniform Nb3Sn layer on copper can be obtained, and the thickness is about 7 micron.  
poster icon Poster TUP076 [0.716 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP076  
About • paper received ※ 23 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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TUP087 Development and Performances of Spoke Cavity Tuner for MYRRHA Linac Project cavity, linac, simulation, operation 667
 
  • N. Gandolfo, S. Blivet, P. Duchesne, D. Le Dréan
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, 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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TUP089 FRIB LS1 Cryomodule’s Solenoid Commissioning solenoid, cryomodule, MMI, linac 671
 
  • M. Xu, H. Ao, B. Bird, R. Bliton, C. Compton, J. Curtin, L. Hodges, K. Holland, S.J. Miller, K. Saito, T. Xu, C. Zhang
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 and the National Science Foundation under Cooperative Agreement PHY-1102511.
The Facility for Rare Isotope Beams (FRIB) is a heavy ion accelerator that produces rare isotopes for science. To achieve the high beam quality of FRIB¿s linear accelera-tor (linac), the superconducting solenoid packages are employed for beam focusing and steering in the cry-omodule. The solenoid packages will generate a maxi-mum 8T focusing field along beam direction and 0.124 T bending field for beam steering. A total 74 solenoid packages have been produced and the first segment linac (LS1) of FRIB have completed commissioning and beam acceleration. In this paper, the cryomodule¿s solenoid commissioning and the performance of the LS1 linac are introduced. The lessons learned during the testing will also be presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP089  
About • paper received ※ 24 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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TUP093 Summary of FRIB Cavity Processing in the SRF Coldmass Processing Facility and Lessons Learned cavity, niobium, SRF, linac 680
 
  • E.S. Metzgar, B.W. Barker, K. Elliott, W. Hartung, L. Popielarski, G.V. Simpson, D.R. Victory, J.D. Whaley
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 and the National Science Foundation under Cooperative Agreement PHY-1102511.
Baseline coldmass production for the linear particle accelerator at the Facility for Rare Isotope Beams (FRIB) is nearing completion. This paper will review the processing of cavities through the FRIB superconducting radio frequency (SRF) coldmass production facility focusing on chemical processing and high-pressure rinsing. Key processing data will be compiled and correlations between processing variables and cavity RF testing results will be examined. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP093  
About • paper received ※ 22 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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TUP104 Improvement of a Clean Assembly Work for Superconducting RF Cryomodule and Its Application to the KEK-STF Cryomodule cryomodule, cavity, vacuum, SRF 721
 
  • H. Sakai, E. Kako, T. Konomi, K. Umemori, Y. Yamamoto
    KEK, Ibaraki, Japan
  • T. Ebisawa, A. Kasugai
    QST, Aomori, Japan
  
  We usually encountered the degradation of the superconducting RF cavities on the cryomodule test even though the performance of these cavities was good on the vertical test. In reality, the degradation of Q-values of two cavities of cERL main-linac were observed after cryomodule assembly in KEK [1] and STF cryomodule also met the degradation after the cryomodule assembly [2]. Some dusts and invisible particles might enter the cavity and generate field emission during the assembly work. Field emission is the most important cause of this degradation. In this paper, first we introduce some trials for the improved clean assembly work to SRF cavity by re-examining our clean assembly work and vacuum work. For example, slow pumping system with vacuum particle monitor was developed to know and control the particle movement during slow pumping and venting. Next we show the application of this improved work to the STF re-assemble cryomodule work in KEK.
[1} H. Sakai et al., SRF’13, Paris, France, p.855, 2013.
[2] Y. Yamamoto et al., IPAC’16, Busan, Korea, p.2158, 2016. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP104  
About • paper received ※ 20 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, vacuum, operation 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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WETEB4 Virtual SRF Cavity: Testing SRF Cavity Support Systems Without the Hassle of Liquid Helium and Klystrons cavity, LLRF, FPGA, SRF 770
 
  • P. Echevarria, J. Knobloch, A. Neumann, A. Ushakov
    HZB, Berlin, Germany
  • E. Aldekoa, J. Jugo
    University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
  
  Setting up and debugging SRF support systems, such as LLRF control, quench detection, microphonics and Lorentz-force detuning control, etc., often requires extensive time spent operating the cavities. This results in time consuming and costly operation. Early into the development stages the actual cavity system may not even be available. It is therefore highly desirable to pre-evaluate these systems under realistic conditions prior to final testing with the SRF cavities. We devised an FPGA-based "virtual cavity" that takes a regular low-level RF input and generates the signals for RF-power reflection, transmission and detuning that mimic the response of a real cavity system. As far as the user is concerned, the response is the same as for a real cavity. This "black-box" model includes mechanical modes, Lorentz force detuning, a field depended quality factor, quenches and variable input coupling and is currently being expanded. We present the model and show some applications for operating the quench detection, LLRF and microphonics control for 1.3 GHz BERLinPro cavities. The same system can be used for other cavity types, including normal conducting cavities.  
slides icon Slides WETEB4 [9.784 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB4  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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WETEB6 Active Suppression of Microphonics Detuning in High QL Cavities cavity, linac, resonance, SRF 776
 
  • N. Banerjee, G.H. Hoffstaetter, M. Liepe, P. Quigley
    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). SRF 2019 provided travel support in the form of a student grant.
Accelerators operating with low beam loading such as Energy Recovery Linacs (ERL) greatly benefit from using SRF cavities operated at high loaded quality factors, since it leads to lower RF power requirements. However, large microphonics detuning several times the operating bandwidth of the cavities severely limit the maximum accelerating fields which can be sustained in a stable manner. In this talk, I will describe an active microphonics control technique based on the narrow band Active noise Control (ANC) algorithm which we have used in CBETA, a multi-turn SRF ERL being commissioned at Cornell University. I will describe its stability and performance during beam operations of CBETA with consistent reduction of peak detuning by almost a factor of 2 on multiple cavities. 		 
slides icon Slides WETEB6 [10.296 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB6  
About • paper received ※ 23 June 2019       paper accepted ※ 29 June 2019       issue date ※ 14 August 2019  
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WETEB7 A Ferroelectric Fast Reactive Tuner for Superconducting Cavities cavity, linac, experiment, superconducting-cavity 781
 
  • N.C. Shipman, J. Bastard, M.R. Coly, F. Gerigk, A. Macpherson, N. Stapley
    CERN, Geneva, Switzerland
  • I. Ben-Zvi
    BNL, Upton, New York, USA
  • G. Burt, A. Castilla
    Lancaster University, Lancaster, United Kingdom
  • C.-J. Jing, A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • S. Kazakov
    Fermilab, Batavia, Illinois, USA
  • E. Nenasheva
    Ceramics Ltd., St. Petersburg, Russia
  
  A prototype FerroElectric Fast Reactive Tuner (FE-FRT) for superconducting cavities has been developed, which allows the frequency to be controlled by application of a potential difference across a ferroelectric residing within the tuner. This technique has now become practically feasible due to the recent development of a new extremely low loss ferroelectric material. In a world first, CERN has tested the prototype FE-FRT with a superconducting cavity, and frequency tuning has been successfully demonstrated. This is a significant first step in the development of an entirely new class of tuner. These will allow electronic control of cavity frequencies, by a device operating at room temperature, within timescales that will allow active compensation of microphonics. For many applications this could eliminate the need to use over-coupled fundamental power couplers, thus significantly reducing RF amplifier power.  
slides icon Slides WETEB7 [21.570 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB7  
About • paper received ※ 23 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, operation, linac, LLRF 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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THP034 The First Tests on Vertical Cryostat GERSEMI at FREIA Facility cryogenics, operation, 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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THP035 Design of LHC Crab Cavities Based on DQW Cryomodule Test Experience cavity, pick-up, coupling, HOM 925
 
  • S. Verdú-Andrés
    BNL, Upton, New York, USA
  • R. Calaga, E. Cano-Pleite, R. Leuxe
    CERN, Geneva, Switzerland
  • J.A. Mitchell
    Lancaster University, Lancaster, United Kingdom
  
  Funding: Work supported by US DOE through Brookhaven Science Associates LLC under contract No. DE-SC0012704, contract No. DE-FOA-0001848 and by the European Union HL-LHC Project.
A cryomodule with two Double-Quarter Wave (DQW) cavities was designed, built and tested with the SPS beam in 2018. Each cavity was equipped with an rf pickup antenna to monitor field amplitude and phase. The pickup antenna also included a section expressly designed to couple and extract one of the Higher-Order Modes (HOM) at 1.754 GHz. The SPS beam tests evidenced direct coupling of the beam to this pickup antenna, in a similar way that a beam position monitor pickup couples to the passing beam. This undesired coupling had an impact on the RF feedback system responsible to regulate the cavity field and frequency. The present paper proposes a new DQW cavity design with improved antennae which provides adequate fundamental mode extraction while providing a reduction of both direct coupling to the beam and heat dissipation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP035  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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THP049 Commissioning the JLab LERF Cryomodule Test Facility cryomodule, cavity, LLRF, MMI 973
 
  • C. Hovater, R. Bachimanchi, E. Daly, M.A. Drury, L.E. Farrish, J. Gubeli, N.A. Huque, K. Jordan, M.E. Joyce, L.K. King, M. Marchlik, W. Moore, T.E. Plawski, A.D. Solopova, C.M. Wilson
    JLab, Newport News, Virginia, USA
  • A.L. Benwell, C. Bianchini, D. Gonnella, S.L. Hoobler, K.J. Mattison, J. Nelson, A. Ratti, B.H. Ripman, S. Saraf, L.M. Zacarias
    SLAC, Menlo Park, California, USA
  • L.R. Doolittle, S. Paiagua, C. Serrano
    LBNL, Berkeley, California, USA
  
  The JLab Low Energy Recirculating Facility, LERF, has been modified to support concurrent testing of two LCLS-II cryomodules. The cryomodules are installed in a similar fashion as they would be in the L1 section of the LCLS-II linac, including the floor slope and using all of the LCLS-II hardware and controls for cryomodule cryogenics, vacuum, and RF (SSA and LLRF). From the start, it was intended to use LCLS-II electronics and EPICS software controls for cryomodule testing. In affect the LERF test facility becomes the first opportunity to commission and operate the LCLS-II LINAC hardware and software controls. Support for specific cryomodule high level test applications like Q0 and HOMs measurements, are being developed from the basic cryomodule control suite. To support the testing, 2 K He is supplied from the CEBAF south linac cryogenic system, where care must be taken when using the LERF test facility to not upset the CEBAF cryogenics plant. This paper discusses the commissioning of the hardware and software development for testing the first two LCLS-II cryomodules.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP049  
About • paper received ※ 22 June 2019       paper accepted ※ 02 July 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, operation 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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THP059 RF Incoming Inspection of 1.3 GHz Cryomodules for LCLS-II at SLAC National Accelerator Laboratory cryomodule, cavity, HOM, linac 1014
 
  • S. Aderhold, C. Adolphsen, A. Burrill, D. Gonnella, J. Nelson
    SLAC, Menlo Park, California, USA
  
  Funding: This work was supported by the US DOE and the LCLS-II Project.
The main part of the SRF linac for the Linac Coherent Light Source II (LCLS-II) at SLAC National Accelerator Laboratory will consist of 35 cryomodules with superconducting RF cavities operating at 1.3 GHz. The cryomodules are assembled and tested at Fermi National Accelerator Laboratory and Thomas Jefferson National Accelerator Facility. Following the transport to SLAC, the cryomodules undergo several incoming inspection steps before ultimately being moved to the tunnel for installation in the linac. The RF part of the incoming inspection covers measurements of a number of parameters like cavity frequency spectrum, notch filter frequency of the higher order mode couplers and external quality factor Qext of the input coupler. The inspection results are compared to measurements at the partner labs prior to shipping and the nominal values in order to verify that the cryomodules have not been damaged during the transport and are ready for installation. We present an overview and analysis of the inspections for the cryomodules received to date. 		 
poster icon Poster THP059 [1.223 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP059  
About • paper received ※ 02 July 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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THP073 Advanced LLRF System Setup Tool for RF Field Regulation of SRF Cavities cavity, feedback, FEL, electron 1063
 
  • S. Pfeiffer, J. Branlard, M. Hoffmann, Ch. Schmidt
    DESY, Hamburg, Germany
  
  Feedback operation at the European XFEL ensures an amplitude and phase stability of 0.01% and 0.01 deg, respectively. To reach such high RF field stability, model-based approaches for RF field system characterization and RF field controller design are in use. High demand on this system modelling is set especially to the characterization of additional passband modes for small bandwidth SRF cavities operated in pulsed mode and vector-sum regulation. This contribution discusses the developed "Advanced system setup tool" using a graphical user implementation in Matlab® for the RF field system characterization and the multiple-input-multiple-output feedback controller setup. Examples and current limitations will be presented.  
poster icon Poster THP073 [0.873 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP073  
About • paper received ※ 19 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP074 Microphonics Noise Suppression with Observer Based Feedback cavity, SRF, resonance, linac 1068
 
  • M. Keikha, K. Fong
    TRIUMF, Vancouver, Canada
  • M. Moallem
    SFU, Surrey, Canada
  
  Funding: TRIUMF
Detuning of superconducting radio frequency (SRF) cavities is mainly caused by the Lorentz force, which is the radiation pressure induced by a high radio frequency (RF) field, and environmental mechanical vibrations that induce undesirable interference signals referred to as microphonics. Both of these influences can be described by a second order differential equation of the mechanical vibration modes of the cavity. In this paper we consider three dominant mechanical modes of the system and develop a control scheme based on input-output linearization. It is shown through simulation studies that the proposed control technique can successfully the suppress microphonic noise due to the SRF cavity¿s dynamics. 		 
poster icon Poster THP074 [0.610 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP074  
About • paper received ※ 22 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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THP075 Development of a 166.6 MHz Digital LLRF System for HEPS-TF Project cavity, LLRF, low-level-rf, superconducting-cavity 1073
 
  • Q.Y. Wang, J.P. Dai, T.M. Huang, D.B. Li, H.Y. Lin, Z.H. Mi, P. Zhang
    IHEP, Beijing, People’s Republic of China
  
  A 166.6 MHz superconducting RF system has been proposed for the High Energy Photon Source (HEPS), a 6 GeV kilometer-scale light source. A 166.6MHz digital low-level RF system for HEPS-TF project has been developed firstly. And the digital low-level RF system has been successfully applied to the horizontal high power test of 166.6MHz superconducting cavity. The cavity field stability has been successfully achieved about ±0.03% (pk-pk) in amplitude and ±0.02 degree (pk-pk) in phase while the cavity field voltage is up to 1.2MV. It can meet the field stability requirements towards ±0.1% in ampli-tude and ±0.1 degree in phase of HEPS project. Further study and optimization of the system is under way.  
poster icon Poster THP075 [1.612 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP075  
About • paper received ※ 29 June 2019       paper accepted ※ 30 June 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, operation, 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, LLRF, operation, 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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THP086 Preliminary Design of Superconducting Cavity Test Platform in CSNS Campus cavity, superconducting-cavity, cryomodule, SRF 1104
 
  • S.H. Liu, X. Li, W. Long, H. Sun, S. Wang, C.L. Zhang, J.Y. Zhu
    IHEP, People’s Republic of China
  • S.Y. Chen, Y. Liu, C. Shi
    DNSC, Dongguan, People’s Republic of China
  • P.C. Wang, B. Wu
    IHEP CSNS, Guangdong Province, People’s Republic of China
  
  For the beam power upgrade of CSNS (China Spallation Neutron Source) and the construction of the high performance photon source in South China in the near future, the superconducting cavity test platform which includes vertical test stand, single cavity horizontal test stand, cryomodule horizontal test stand and coupler test stand will be built. This paper will generally introduce the preliminary design of the test platform and corresponding test parameters.  
poster icon Poster THP086 [0.171 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP086  
About • paper received ※ 21 June 2019       paper accepted ※ 01 July 2019       issue date ※ 14 August 2019  
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THP088 Updates on the Inspection System for SRF Cavities cavity, superconducting-cavity, GUI, interface 1111
 
  • Y. Iwashita, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Hayano
    KEK, Ibaraki, Japan
  • Y. Kuriyama
    Kyoto University, Research Reactor Institute, Osaka, Japan
  
  Optical inspections on superconducting cavities are familiar to those who are involved in the cavity fabrications. Further improvements on the Kyoto Camera have been carried out these years together with further processing technique developments, such as removing found defects by local grinding techniques. Improvements on Kyoto Camera includes implementation of color LEDs for illumination system, which improves the inspection efficiency. These progresses will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP088  
About • paper received ※ 02 July 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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THP100 Insight into DESY’s Test Laboratory for Niobium Raw Material and Semi-finished Products cavity, niobium, FEL, SRF 1157
 
  • J.I. Iversen, A. Brinkmann, A. Ermakov, A. Muhs, J. Ziegler
    DESY, Hamburg, Germany
  
  DESY has started setting up a test laboratory for niobium more than 20 years ago. The initial application was to assure required surface quality of niobium sheets before its forming to half cells for the 1.3 GHz SRF Tesla shape cavities. As a first test equipment DESY developed a basic eddy current test device which was refined continuously. Since that time the laboratory grew with the requirements on R&D activities for niobium raw material and its semi-finished products. To be able to assure the Quality of niobium products needed for the European XFEL series cavity production, the Lab¿s infrastructure was updated significantly. Now the capabilities of the test laboratory cover the investigation of the fundamental physical properties of various materials including for example mechanical properties, surface, microstructure and chemical composition analysis. The Quality Assurance for the European XFEL was performed successfully on an outstanding level and in the meantime the laboratory was used for several other projects like LCLS-II and ESS. We present DESY’s test infrastructure as well as applied methods for the Quality Assurance and R&D activities and we report about experiences.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP100  
About • paper received ※ 25 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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FRCAB3 The Design of an Automated High-Pressure Rinsing System for SRF Cavity and the Outlook for Future Automated Cleanroom on Strings Assembly cavity, SRF, linac, alignment 1216
 
  • H. Guo, Q.W. Chu, Y. He, C.L. Li, Y.K. Song, T. Tan, Z.M. You
    IMP/CAS, Lanzhou, People’s Republic of China
  
  High-pressure rinsing (HPR) and cavity assembly are two critical steps in cavity post-processing. Traditionally, high-pressure rinsing processing is based on ultra pure water system, pump, rinsing wand and simple-functional control system; cavity assembly processing is based on simple fixtures, wrenches, bolts and nuts. Beside the equipments, at least two operators are required in either of these two processing. Operators and their actions could bring mistakes and cause extra airborne particle contamination in cleanroom. To avoid the risk from labors, a robot has been introduced in IMP cleanroom for HPR assisting and assembly assisting. Labor cost and cavity RF test results are compared between the circumstances with and without robot assisting. In this work, an automated HPR system that has been designed and will be installed in IMP cleanroom will be presented. In addition, a future automated cleanroom on strings assembly will be discussed as well.  
slides icon Slides FRCAB3 [6.203 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-FRCAB3  
About • paper received ※ 03 July 2019       paper accepted ※ 12 July 2019       issue date ※ 14 August 2019  
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