SRF2013 - List of Keywords (cryogenics)

Paper	Title	Other Keywords	Page
MOP022	Preliminary Design of CEPC RF Superconducting System	cavity, HOM, impedance, storage-ring	140
	H.J. Zheng, J. Gao, S. Jin, Y. Liu, Z.C. Liu, J.Y. Zhai, T.X. Zhao IHEP, Beijing, People's Republic of China
	In order to study Higgs Boson, scientists proposed to construct a Higgs factory. Chinese scientists are also actively involved in research of the construction of Higgs factory. Construction of a circular collider and several construction solutions were proposed. Electron and positron are eventually accelerated to the center of mass energy 240GeV. RF superconducting acceleration system is indispensable to ensure the normal operation of machine. This article mainly introduces the RF parameters in the design of 700MHz China Higgs Factory (CHF) system. It mainly includes choose of cavity type, couplers and relevant parameters of cryogenic system.

MOP029	Cryo-Losses Measurements of the XFEL Prototype and Pre-Series Cryomodules	cryomodule, operation, electron, linac	162
	S. Barbanotti, J. Eschke, K. Jensch, W. Maschmann, O. Sawlanski DESY, Hamburg, Germany W. Gaj, L.M. Kolwicz-Chodak, W. Maciocha IFJ-PAN, Kraków, Poland X. Wang ESS, Lund, Sweden
	Cryo-losses measurements of the XFEL prototype and pre-series cryomodules are here presented and compared with the XFEL requirements. Cryo-losses at the 4.5 K, 80 K and 2K temperatures are calculated during the test period at CMTB (CryoModule Test Bench) at DESY to qualify the cryomodules before installation. This paper summarizes the test procedure for the different circuits (2K, 4.5K, 80K) and in different load conditions: static losses, losses due to the magnet and dynamic losses due to the RF power sent to the cavities at different MV/m levels.

MOP038	Series Production of EXFEL 1.3 GHz SRF Cavities at E. Zanon: Management, Infrastructures and Quality Control	cavity, SRF, controls, niobium	194
	G. Massaro Ettore Zanon S.p.A., Nuclear Division, Schio, Italy G. Corniani, M. Festa, M. Maule Ettore Zanon S.p.A., Schio, Italy
	In this paper we report on the capability of Ettore Zanon S.p.A. (EZ) to implement a EXFEL 1,3 GHz SRF cavities production system. In order to assure the series efficient repeatability of the product, this system is based on work team, composed of people with different skills, qualified infrastructures and technical procedures. A detailed study of the different work phases of the production cycle has been performed in advance, highlighting the technical difficulties and the production constraints. Based on this result, infrastructures and processes have been optimized to grant the specified quality and time/cost requirements and procedures and operating instructions, where the most complexes and delicate phases as well as the responsibilities and acceptance criteria are investigated, have been introduced. Qualification operations and eight pre-series cavities have proven EZ capability of fulfilling the imposed requirements. The above described manufacturing system allows nowadays a production rate of 4 cavities per week. EZ future developments involve minimizing time and costs while keeping the highest quality standard.

MOP044	Performance Characteristics of Jefferson Lab’s New SRF Infrastructure	SRF, cavity, cryomodule, vacuum	216
	C.E. Reece, P. Denny, A.V. Reilly JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In the past two years, Jefferson Lab has reconfigured and renovated its SRF support infrastructure as part of the Technology and Engineering Development Facility project, TEDF. The most significant changes are in the cleanroom and chemistry facilities. We report the initial characterization data on the new ultra-pure water systems, cleanroom facilities, describe the reconfiguration of existing facilities and also opportunities for flexible growth presented by the new arrangement.

MOP054	Tests of the Accelerating Cryomodules for the European X-Ray Free Electron Laser	cryomodule, cavity, operation, radiation	244
	M. Wiencek, B. Dzieza, W. Gaj, D. Karolczyk, K. Kasprzak, L.M. Kolwicz-Chodak, A. Kotarba, A. Krawczyk, K. Krzysik, W. Maciocha, A. Marendziak, K. Myalski, S. Myalski, T. Ostrowicz, B. Prochal, M. Sienkiewicz, M. Skiba, J. Świerbleski, J. Zbroja, A. Zwozniak IFJ-PAN, Kraków, Poland
	The European X-ray Free Electron Laser (XFEL) is currently under construction in Germany in Hamburg area. A 2.1 km long superconducting linear accelerator, part of the XFEL, consists of 101 accelerating cryomodules. The XFEL cryomodule is assembled with eight superconducting RF cavities, one cold magnet and Beam Position Monitor (BPM). The cryomodules are tested in dedicated test facility before installation in the XFEL tunnel. The testing procedures for the cryomodules were prepared with use of DESY expertise from TTF (Tesla Test Facility) Collaboration and FLASH (Freie-Elektronen-Laser in Hamburg). This paper describes the full set of testing procedure and incoming and outgoing inspections as well.

MOP057	Developments and Tests of a 700 MHz Cryomodule for the Superconducting Linac of MYRRHA	cavity, cryomodule, linac, vacuum	250
	F. Bouly CERN, Geneva, Switzerland S. Berthelot, J.-L. Biarrotte, M. El Yakoubi, C. Joly, J. Lesrel, E. Rampnoux IPN, Orsay, France A. Bosotti, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy
	Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project). The MYRRHA (“Multi-purpose Hybrid Research reactor for High-tech Applications”) project aims at the construction of a new flexible fast spectrum research reactor. This reactor will operate as an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux; produced thanks to a 600 MeV high intensity proton beam. This CW beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable the rapid mitigation of RF failures. To carry out “real scale” reliability-oriented experiments a prototype of cryomodule was developed by INFN Milano and installed at IPN Orsay. The module holds a 700 MHz 5-cell elliptical cavity (βg = 0.47) equipped with its blade frequency tuner. Several tests were carried out to commission the experimental set-up. We review here the obtained results and the lessons learnt by operating this module, as well as the on-going developments.

MOP063	Mature Operation of CESR-Type 500-MHz SRF Module at Taiwan Light Source	SRF, operation, vacuum, cavity	266
	Ch. Wang, L.-H. Chang, M.H. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, Y.-H. Lin, Z.K. Liu, C.H. Lo, M.H. Tsai, T.-T. Yang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	The Cornell-type 500-MHz SRF module has been routinely operated since the end of 2004 to power the 1.5 GeV Taiwan Light Source with 360 mA in top-up mode. A new record of SRF operation with mean time between failures (MTBF)up to 800 hr has been achieved in the 1st half of 2013 that is compatible with the best operational record of room temperature cavities ever made in the same machine. To meet the user’s strict requirements on highly operational reliability, developing in advanced diagnostic instrumentation together with user-friendly event logging software does never stop. Here, we review our SRF operational experience in last 9 years.

MOP064	Operational Experience with the SOLEIL Superconducting RF System	cavity, operation, HOM, vacuum	269
	P. Marchand, J.P. Baete, R.C. Cuoq, H.D. Dias, M. Diop, J.L. Labelle, R. Lopes, M. Louvet, C.M. Monnot, S. Petit, F. Ribeiro, T. Ruan, R. Sreedharan, K. Tavakoli SOLEIL, Gif-sur-Yvette, France
	In the SOLEIL storage ring, two cryomodules provide to the electron beam an accelerating voltage of 3-4 MV and a power of 575 kW at 352 MHz. Each cryomodule contains a pair of superconducting cavities, cooled with liquid Helium at 4K, which is supplied by a single 350 W cryogenic plant. The RF power is provided by 4 solid state amplifiers, each delivering up to 180 kW. The parasitic impedances of the high order modes are strongly mitigated by means of four coaxial couplers, located on the central pipe connecting the two cavities. Seven years of operational experience with this system as well as its upgrades are reported.

MOP068	NGLS Linac Design	cryomodule, linac, cavity, controls	286
	R.P. Wells, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, A. Ratti LBNL, Berkeley, California, USA C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA D. Arenius JLAB, Newport News, Virginia, USA C.M. Ginsburg, T.J. Peterson Fermilab, Batavia, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts for the cavity and cryostat design operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules, This leverages the extensive experience derived from R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given now to high loaded Q operation and microphonics control, as well as high reliability and expected up time. The work describes the design and configuration of the linac, including choice of gradient, possible modes of operation, cavity design and RF power, as well as the consequent requirements for the cryogenic system.

MOP074	Design and Construction of the Main Linac Cryomodule for the Energy Recovery Linac Project at Cornell	linac, cryomodule, vacuum, alignment	308
	R.G. Eichhorn, B. Bullock, J.V. Conway, Y. He, T.I. O'Connel, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R&D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities and high beam currents (2*100 mA)are targeted. We will present the design of the main linac module (MLC) being finalized recently, its cryogenic features and report on the status of the fabrication which started in late 2012

MOP079	Design and Test of a Cryogenic Seal for Rectangular Waveguide Using VATSEAL Technology	vacuum, superconducting-RF, detector, controls	325
	J.D. Fuerst, J.P. Holzbauer, J.A. Kaluzny, C.R. Montiel, Y. Shiroyanagi, B.K. Stillwell ANL, Argonne, USA
	Funding: This work was supported by the U. S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357. A commercially available rectangular metal seal from VAT Vacuum Valves AG has been evaluated and cold tested as a possible cryogenic seal for srf cavities. A program of analysis and cryogenic testing was undertaken to evaluate seal parameters and suitability. Seal line loads, bolt torque and resultant flange/seal deformation at low temperature and during thermal cycling were calculated both statically and via time-dependent numerical simulation to confirm the mechanical integrity of the flange/seal system. Cold testing of flange/waveguide assemblies included thermal shocks in liquid nitrogen and realistic cool-downs below the λ point. Acceptable seal performance has been demonstrated under all test conditions although seal joint assembly is sensitive to details including bolt torque, flange flatness, and surface finish.

MOP081	Preliminary Studies of the Cryogenic Refrigerator and Distribution Systems for the MYRRHA Proton Linac	linac, cryomodule, proton, operation	331
	T. Junquera, N.R. Chevalier, J.P. Thermeau Accelerators and Cryogenic Systems, Orsay, France L. Medeiros Romão, D. Vandeplassche SCK•CEN, Mol, Belgium H. Saugnac IPN, Orsay, France
	Funding: Work supported by the EU, FP7 MAX contract number 269565 In the framework of recent European programs (FP6-Eurotrans, FP7-MAX), the SC proton Linac for the MYRRHA project (associating an accelerator to a subcritical nuclear reactor, to be installed in the SCK•CEN at Mol-Belgium), has been extensively studied and optimized to reach strict requirements in beam power and reliability as needed for this ADS demonstrator. The linac, composed of 150 SC cavities (CH, spoke and elliptical) installed in 60 cryomodules, operates at 2K, delivering a beam power of 2.5 MW (600 MeV, 4 mA) in CW mode, will be installed in a tunnel of 240 m length. In this paper we present the evaluation of the cryogenic power requirements, a preliminary architecture of the cryogenic refrigerator system including all its major components, and preliminary proposals for the cryofluids distribution along the SC linac.

MOP083	Operational Experience With the SOLEIL Storage Ring RF Cryogenic Plant	controls, operation, cavity, HOM	337
	M. Louvet, H.D. Dias, M. Diop, P. Marchand SOLEIL, Gif-sur-Yvette, France
	In the Storage Ring of the Synchrotron SOLEIL light source, two cryomodules provide the required power of 575 kW at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. Each cryomodule contains a pair of 352 MHz superconducting cavities (Nb/Cu), cooled in a bath of liquid helium at 4.5 K. A single 350 W cryogenic system supplies the liquid helium for the two cryomodules. The seven years of operational experience with this cryogenic plant as well as its upgrades are reported.

MOP084	ESS Cryomodules for Elliptical Cavities	cryomodule, vacuum, cavity, operation	341
	G. Olivier, J.P. Thermeau IPN, Orsay, France P. Bosland CEA/IRFU, Gif-sur-Yvette, France C. Darve ESS, Lund, Sweden
	The European Spallation Source will be the world's most powerfull neutron source. IPN Orsay undertakes the development of the ESS linac cryomodules for both medium and high beta elliptical cavities which constitute the high energy section. A medium beta technical demonstrator will be built in a first time. The cryomodules are composed of 4 superconducting cavities cooled at 2K. The cold mass assembly is hanged in an intermediate structure located inside the vacuum vessel. A 50K fixed temperature is implemented by the mean of an aluminium shield. Each cryomodule is connected to the cryogenic distribution line. The vacuum vessel is 6.3m long and has a 1.2m diameter. The poster describes the general design,the solutions implemented, the characteristics of the main components and the mechanical/thermal calculations .

MOP085	Status of the Superconducting Proton Linac (SPL) Cryomodule	cavity, vacuum, operation, linac	345
	V. Parma, R. Bonomi, O. Capatina, J.K. Chambrillon, E. Montesinos, K.M. Schirm, A. Vande Craen, G. Vandoni, R. van Weelderen CERN, Geneva, Switzerland G. Devanz CEA/IRFU, Gif-sur-Yvette, France P. Duchesne, P. Duthil, S. Rousselot IPN, Orsay, France
	The Superconducting Proton Linac (SPL) is an R&D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art SRF technology. Such an accelerator would serve as a driver in new physics facilities for neutrinos and/or radioactive ion beams. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium β=1 elliptical cavities (operating at 2 K and providing an accelerating field of 25 MV/m) and the test of a string of cavities integrated in a machine-type cryo-module. In an initial phase, only four out of the eight cavities of the SPL cryo-module will be tested in a half- length cryo-module developed for this purpose, which nonetheless preserves the main features of the full size machine. This paper presents the final design of the cryo-module and the status of the construction of the main cryostat parts. Preliminary plans for the assembly and testing of the cryo-module at CERN are presented and discussed.

MOP086	Integration, Commissioning and Cryogenics Performance of the ERL Cryomodule Installed on ALICE-ERL Facility at STFC Daresbury Laboratory, UK	cryomodule, SRF, HOM, linac	349
	S.M. Pattalwar, R.K. Buckley, P.A. Corlett, P. Goudket, A.R. Goulden, A.J. May, P.A. McIntosh, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S.A. Belomestnykh BNL, Upton, Long Island, New York, USA A. Büchner, F.G. Gabriel, P. Michel HZDR, Dresden, Germany E.P. Chojnacki, J.V. Conway, R.G. Eichhorn, G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA M.A. Cordwell, T.J. Jones, L. Ma, A.J. Moss, J. Strachan STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom J.N. Corlett, D. Li, S.M. Lidia LBNL, Berkeley, California, USA T. Kimura Stanford University, Stanford, California, USA R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada J.K. Sekutowicz DESY, Hamburg, Germany T.J. Smith SLAC, Menlo Park, California, USA
	On successful assembly and preliminary testing of an optimised SRF cryomodule for application on ERL accelerators, which is being developed through an international collaboration the cryomodule has been installed on the 35 MeV ALICE (Accelerators and Lasers in Combined Experiments) Energy Recovery Linac (ERL) facility at STFC Daresbury Laboratory. Existing cryogenic infrastructure has a capacity to deliver approximately 120 W cooling power at 2 K, but the HOM (Higher Order Mode) absorbers, the thermal intercepts for the high power RF couplers and the radiation shield in the cryomodule are designed to be cooled (to 5 K and 80 K) with gaseous helium instead of liquid nitrogen. As a result the cryogenic infrastructure for ALICE had to be modified to meet these additional requirements. In this paper we describe our experience with the process of integration and the cryogenic commissioning, and present some initial results.

MOP087	Conceptual Design of a Cryomodule for Compact Crab Cavities for Hi-Lumi LHC	cryomodule, cavity, SRF, luminosity	353
	S.M. Pattalwar, P.A. McIntosh, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Warrington, Cheshire, United Kingdom G. Burt Lancaster University, Lancaster, United Kingdom O. Capatina CERN, Geneva, Switzerland B.D.S. Hall Cockcroft Institute, Lancaster University, Lancaster, United Kingdom T.J. Jones, N. Templeton STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom T.J. Peterson Fermilab, Batavia, USA
	A prototype Superconducting (RF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the “Hi-Lumi LHC”, a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the tests with SPS.

MOP089	Design of the ESS Spoke Cryomodule	vacuum, cryomodule, cavity, operation	357
	D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, E. Rampnoux IPN, Orsay, France
	The European Spallation Source (ESS) project brings together 17 European countries to develop the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the linear accelerator consists in 59 cryomodules housing different superconducting radiofrequency (SRF) resonators among which 28 paired β=0.5 352.2 MHz SRF niobium double Spoke cavities, held at 2K in a saturated helium bath. A prototype Spoke cryomodule with two cavities equipped with their 300kW RF power couplers is now being designed and will be constructed and tested at full power by the end of 2015 for the validation of all chosen technical solutions. It integrates all the interfaces necessary to be operational within a linac machine. Its assembly requires dedicated tooling and procedures in and out of a clean room. The design takes into account an industrial approach for the management of the fabrication costs. This prototype will have to guarantee an accelerating field of 8MV/m while optimizing the energy consumption and will aim at assessing the maintenance operations issues. We propose to present the design of this cryomodule and its related tooling.

TUP014	Fast Table Top Niobium Hydride Investigations Using Direct Imaging in a Cryo-Stage	niobium, cavity, laser, vacuum	447
	F.L. Barkov, A. Grassellino, A. Romanenko Fermilab, Batavia, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy. Performance of niobium SRF cavities can be strongly affected by hydrogen segregation into lossy niobium hydrides as known for "hydrogen Q disease" at higher concentration of dissolved H and may be a reason for the "high field Q slope" at lower concentrations. With the use of optical cryostat and laser confocal microscope we have developed a "table top technique" for direct observation of hydride precipitation, and studied formation, morphology, and time evolution of hydrides after different treatments used for cavities. Our results show that hydrides can form at the niobium surface at 90-180K depending mainly on H concentration and the cooldown rate. A lot of H is absorbed by bulk niobium during mechanical polishing, which leads to the formation of very large (>10 microns) hydrides. Both EP and BCP do not influence H concentration significantly provided that temperature during treatments is kept below 15C. 800C degassing reduces H concentration and precludes large hydride precipitation. 120C baking and mechanical deformation do not change H concentration but affect hydride precipitation through their influence on the number of nucleation centers and H binding defects.

TUP069	The Copper Substrate Developments for the HIE-ISOLDE High-Beta Quarter Wave Resonator	cavity, electron, operation, linac	596
	L. Alberty, G. Arnau-Izquierdo, I. Aviles Santillana, S. Calatroni, O. Capatina, A. D'Elia, G. Foffano, Y. Kadi, P. Moyret, K.M. Schirm, T. Tardy, W. Venturini Delsolaro CERN, Geneva, Switzerland A. D'Elia UMAN, Manchester, United Kingdom
	A new linac using superconducting quarter-wave resonators (QWR) is under construction at CERN in the framework of the HIE-ISOLDE project. The QWRs are made by Niobium sputtered on a bulk Copper substrate. The working frequency at 4.5 K is 101.28 MHz and they will provide 6 MV/m accelerating gradient on the beam axis with a total maximum power dissipation of 10 W. The properties of the cavity substrate have a direct impact on the final cavity performance. The Copper substrate has to ensure an optimum surface for the Niobium sputtered layer. It has also to fulfill the required geometrical tolerances, the mechanical stability during operation and the thermal performance to optimally extract the RF dissipated power on cavity walls. The paper presents the mechanical design of the high β cavities. The procurement process of the Copper raw material is detailed, including specifications and tests. The manufacture sequence of the complete cavity is then explained and the structural and thermo-mechanical behavior during the tests performed on a prototype cavity is discussed. The industrialization strategy is presented in view of final production of the cavities.

TUP082	Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities	cavity, SRF, HOM, ion	638
	X. Zhao, C.E. Reece JLab, Newport News, Virginia, USA G. Ciovati Jefferson Lab, Newport News, Virginia, USA I. Irfan, C. James, M. Krishnan AASC, San Leandro, California, USA A.D. Palczewski JLAB, Newport News, Virginia, USA
	Funding: This research is supported at AASC by DOE via Grant No. DE-FG02-08ER85162 and Grant No. DE-SC0004994 and by Jefferson Science Associates, LLC under U.S. DOE Contract No. DEAC05- 06OR23177 This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavity were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film at 2 K and low rf field, produced by CED, could be close to that of the pre-coated bulk Nb surface (being CBP'ed plus a light EP); but the quality drops rapidly for increasing rf field. We are investigating if the severe Q0-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

TUP083	Film Deposition, Cryogenic RF Testing and Materials Analysis of a Nb/Cu Single Cell SRF Cavity	cavity, niobium, SRF, plasma	642
	X. Zhao JLab, Newport News, Virginia, USA R.L. Geng, Y.M. Li, A.D. Palczewski JLAB, Newport News, Virginia, USA Y.M. Li PKU, Beijing, People's Republic of China
	Funding: The JLab effort was provided by Jefferson Science Associates, LLC under U.S. DOE Contract No. DEAC05- 06OR23177. In this study, we present preliminary results on using a cathodic-arc-discharge Nb plasma ion source to establish a Nb film-coated single-cell Cu cavity for SRF research. The polycrystalline Cu cavity was fabricated and mirror-surface-finished by a centrifugal barrel polishing (CBP) process at Jefferson Lab. Special pre-coating processes were conducted, in order to create a template-layer for follow-on Nb grain thickening. A sequence of cryogenic RF testing demonstrated that the Nb film does show superconductivity. But the quality factor of this Nb/Cu cavity is low as a result of high residual surface resistance. We are conducting a thorough materials characterization to explore if some microstructural defects or hydrogen impurities, led to such a low quality factor.

TUP103	Calibration and Characterization of Capacitive OST Quench Detectors in SRF Cavities at IPN Orsay	SRF, detector, cavity, diagnostics	714
	M. Fouaidy, F. Dubois, J.-M. Dufour, D. Longuevergne, A. Maroni, G. Michel, J.-F. Yaniche IPN, Orsay, France
	Funding: IPNO/IPN2P3/CNRS The maximum RF surface magnetic field (Bs) achieved with SRF bulk Nb cavities is often limited by anomalous losses due to Joule heating of normal-resistive defects embedded onto the RF surface. At high BS (e.g Bs>50 mT), the defect temperature increases strongly with BS, leading to a thermal runaway of the cavity or quench. The unloaded quality factor Q0 of the cavity decreases suddenly and strongly due to superconducting to normal state phase transition of the hot spot area. Quench detectors, called Oscillating Superleak Transducer (OST) and sensing 2nd sound events in He II, have been recently used to study quench of SRF cavities. IPN developed his prototypes of OST quench detectors and a test stand for their calibration and characterization in the temperature range T0=1.6 K-2.2 K. This device allows precise and controlled experimental simulation of SRF cavity quench using pulsed heat sources. Experimental runs were performed to study the dynamic response of OST detectors when the heat source is subjected to a time varying heat flux q(t) as function of several parameters (T0, q(t) time structure and density, heat source size) and first experimental data are presented.

TUP114	XT-map System for Locating SC Cavity Quench Position	cavity, survey, operation, accelerating-gradient	747
	H. Tongu, Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan H. Hayano, Y. Yamamoto KEK, Ibaraki, Japan
	XT-map system under development in collaboration between Kyoto University and KEK is a combined system of the temperature mapping (T-map) and X-ray mapping (X-map). High resolution T-map at quench detection will give more information for improving yield in production of high performance SC Cavities. The high-density sensor distribution of the XT-map gives the high resolution. Because the huge amount of sensor lines are multiplexed at a hi-speed scanning rate in the vicinity of the sensors, the small number of signal lines makes the installation process easy and reduces the system complexity. The scanning test of this XT-map system has been performed in the vertical test at KEK. The detected quench events will be reported.

WEIOD02	Magnetic Shielding: Our Experience with Various Shielding Materials	shielding, superconducting-RF, simulation, linac	808
	M. Masuzawa, A. Terashima, K. Tsuchiya KEK, Ibaraki, Japan A. Daël, O. Napoly, J. Plouin CEA/DSM/IRFU, France
	Magnetic shielding is a key technology for superconducting RF cavities. The tolerance of the ambient magnetic field depends on factors such as the operating RF frequency and acceleration gradient, but it can be as small as a few mG. Some high-Ni-content alloys, such as Cryperm 10 or Cryophy, which are claimed to maintain high permeability at cryogenic temperatures where superconducting cavities are operated, are commercially available at present and are used for magnetic shielding of superconducting cavities at many laboratories. Permeability measurements were made in order to understand the characteristics of such materials at both room and cryogenic temperatures, and the results will be used as a database for designing magnetic shields. It was found that the catalog performance of such materials was not always reproduced in the measurements. Some degradation was observed which depended on how the material was handled. The results of investigation into possible causes for the performance degradation of the shielding material at cryogenic temperature will be presented, along with permeability measurement results for various materials at different temperatures.
	Slides WEIOD02 [8.475 MB]

THIOA04	Low-Beta Cryomodule Design Optimized for Large-Scale Linac Installations	cryomodule, vacuum, alignment, solenoid	825
	S.J. Miller, B. Bird, N.K. Bultman, F. Casagrande, A.D. Fox, M.J. Johnson, M. Leitner, T. Nellis, J.P. Ozelis, X. Rao, R.J. Rose, M. Shuptar, K. Witgen, Y. Xu FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. This paper will present most recent design developments at FRIB to optimize low-beta cryomodules for large-scale linac installations. FRIB, which requires the fabrication of 53 cryomodules, has to emphasize ease of assembly and alignment plus low cost. This paper will present experimental results of a novel kinematic rail support system which significantly eases cryomodule assembly. Design choices for mass-production are presented. Results of vibration calculations and measurements on a FRIB prototype cryomodule will be reported.
	Slides THIOA04 [10.842 MB]

THIOA05	Optimization of SRF Linacs	cryomodule, cavity, linac, operation	830
	T. Powers JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project. The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so.
	Slides THIOA05 [2.712 MB]

THP043	Design and Vertical Test of Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade	cavity, simulation, pick-up, HOM	1002
	B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, C. Cullen, L.R. Hammons, J. Skaritka, S. Verdú-Andrés, Q. Wu BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi Stony Brook University, Stony Brook, USA
	Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404. A proof of principle Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. Vertical cryogenic test has been done in Brookhaven National Lab (BNL). We report the test results of this design.

THP046	Magnetic Material Characterization & SC Solenoid Coil Package Design for FRIB	solenoid, shielding, cavity, operation	1009
	K. Saito, S. Chouhan, C. Compton, J. DeKamp, M. Leitner, F. Marti, J.P. Ozelis, S. Shanab, G.J. Velianoff, X. Wu, Y. Yamazaki, A. Zeller, Y. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA S.K. Chandrasekaran MSU, East Lansing, USA K. Hosoyama KEK, Ibaraki, Japan
	To date SRF technology is extending to large scale heavy ion LINACs, where SRF cavities accelerate beams from very low energy to high energy. In this application, superconducting (SC) solenoids are installed inside the cryomodule to provide strong beam focusing with enhanced space efficiency. FRIB will use local magnetic shielding, where magnetic shielding by Cryoperm or A4K is located close to the cavity at 2K. In this scheme rather strong magnetic fringe fields from the SC solenoid expose the shielding material and will magnetize it. An efficient degaussing process is required as cure against such magnetization. Magnetic material characterization of magnetic shielding materials is very important to be able to plan effective degaussing procedures. The paper will also discuss the design of FRIB solenoids optimized for cost, reliability, and robust long-term operation. NbTi wire performance criteria are discussed in addition to solenoid operational margins.

THP058	Update on the European XFEL RF Power Input Coupler	simulation, superconductivity, linac, electron	1047
	D. Kostin, W.-D. Möller DESY, Hamburg, Germany W. Kaabi LAL, Orsay, France
	European XFEL project is being currently realized in Hamburg, Germany. The 1.5 km 17.5 GeV linear electron accelerator is based on the 1.3GHz 9-cell TESLA type SRF cavity. The RF power input coupler design for the E-XFEL is based on well known TTF3 coupler design, used in FLASH accelerator. Coupler design was adapted for the industrial production with some parameters optimisation revisited and simulations done. Results are presented and discussed.

FRIOC02	ESS Elliptical Cavities and Cryomodules	cavity, HOM, cryomodule, proton	1218
	G. Devanz, P. Bosland, M. Desmons, P. Hardy, F. Leseigneur, M. Luong, F. Peauger, J. Plouin, D. Roudier CEA/DSM/IRFU, France N. Bazin CEA/IRFU, Gif-sur-Yvette, France G. Costanza Lund University, Lund, Sweden G. Olivier IPN, Orsay, France
	The accelerator of the European Spallation Source (ESS) is a 5 MW proton linac to be built in Lund Sweden. Its superconducting section is composed of 3 cavity families: double spoke resonators, medium beta and high beta elliptical multicell cavities. This paper presents the electromagnetic and mechanical design of the 704.42 MHz elliptical cavities. Both elliptical famillies are housed in 4-cavity cryomodules which share a common design and set of components which will be described here.
	Slides FRIOC02 [3.475 MB]

Paper

Title

Other Keywords

Page

MOP022

Preliminary Design of CEPC RF Superconducting System

cavity, HOM, impedance, storage-ring

140

H.J. Zheng, J. Gao, S. Jin, Y. Liu, Z.C. Liu, J.Y. Zhai, T.X. Zhao
IHEP, Beijing, People's Republic of China

In order to study Higgs Boson, scientists proposed to construct a Higgs factory. Chinese scientists are also actively involved in research of the construction of Higgs factory. Construction of a circular collider and several construction solutions were proposed. Electron and positron are eventually accelerated to the center of mass energy 240GeV. RF superconducting acceleration system is indispensable to ensure the normal operation of machine. This article mainly introduces the RF parameters in the design of 700MHz China Higgs Factory (CHF) system. It mainly includes choose of cavity type, couplers and relevant parameters of cryogenic system.

MOP029

Cryo-Losses Measurements of the XFEL Prototype and Pre-Series Cryomodules

cryomodule, operation, electron, linac

162

S. Barbanotti, J. Eschke, K. Jensch, W. Maschmann, O. Sawlanski
DESY, Hamburg, Germany
W. Gaj, L.M. Kolwicz-Chodak, W. Maciocha
IFJ-PAN, Kraków, Poland
X. Wang
ESS, Lund, Sweden

Cryo-losses measurements of the XFEL prototype and pre-series cryomodules are here presented and compared with the XFEL requirements. Cryo-losses at the 4.5 K, 80 K and 2K temperatures are calculated during the test period at CMTB (CryoModule Test Bench) at DESY to qualify the cryomodules before installation. This paper summarizes the test procedure for the different circuits (2K, 4.5K, 80K) and in different load conditions: static losses, losses due to the magnet and dynamic losses due to the RF power sent to the cavities at different MV/m levels.

MOP038

Series Production of EXFEL 1.3 GHz SRF Cavities at E. Zanon: Management, Infrastructures and Quality Control

cavity, SRF, controls, niobium

194

G. Massaro
Ettore Zanon S.p.A., Nuclear Division, Schio, Italy
G. Corniani, M. Festa, M. Maule
Ettore Zanon S.p.A., Schio, Italy

In this paper we report on the capability of Ettore Zanon S.p.A. (EZ) to implement a EXFEL 1,3 GHz SRF cavities production system. In order to assure the series efficient repeatability of the product, this system is based on work team, composed of people with different skills, qualified infrastructures and technical procedures. A detailed study of the different work phases of the production cycle has been performed in advance, highlighting the technical difficulties and the production constraints. Based on this result, infrastructures and processes have been optimized to grant the specified quality and time/cost requirements and procedures and operating instructions, where the most complexes and delicate phases as well as the responsibilities and acceptance criteria are investigated, have been introduced. Qualification operations and eight pre-series cavities have proven EZ capability of fulfilling the imposed requirements. The above described manufacturing system allows nowadays a production rate of 4 cavities per week. EZ future developments involve minimizing time and costs while keeping the highest quality standard.

MOP044

Performance Characteristics of Jefferson Lab’s New SRF Infrastructure

SRF, cavity, cryomodule, vacuum

216

C.E. Reece, P. Denny, A.V. Reilly
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In the past two years, Jefferson Lab has reconfigured and renovated its SRF support infrastructure as part of the Technology and Engineering Development Facility project, TEDF. The most significant changes are in the cleanroom and chemistry facilities. We report the initial characterization data on the new ultra-pure water systems, cleanroom facilities, describe the reconfiguration of existing facilities and also opportunities for flexible growth presented by the new arrangement.

MOP054

Tests of the Accelerating Cryomodules for the European X-Ray Free Electron Laser

cryomodule, cavity, operation, radiation

244

M. Wiencek, B. Dzieza, W. Gaj, D. Karolczyk, K. Kasprzak, L.M. Kolwicz-Chodak, A. Kotarba, A. Krawczyk, K. Krzysik, W. Maciocha, A. Marendziak, K. Myalski, S. Myalski, T. Ostrowicz, B. Prochal, M. Sienkiewicz, M. Skiba, J. Świerbleski, J. Zbroja, A. Zwozniak
IFJ-PAN, Kraków, Poland

The European X-ray Free Electron Laser (XFEL) is currently under construction in Germany in Hamburg area. A 2.1 km long superconducting linear accelerator, part of the XFEL, consists of 101 accelerating cryomodules. The XFEL cryomodule is assembled with eight superconducting RF cavities, one cold magnet and Beam Position Monitor (BPM). The cryomodules are tested in dedicated test facility before installation in the XFEL tunnel. The testing procedures for the cryomodules were prepared with use of DESY expertise from TTF (Tesla Test Facility) Collaboration and FLASH (Freie-Elektronen-Laser in Hamburg). This paper describes the full set of testing procedure and incoming and outgoing inspections as well.

MOP057

Developments and Tests of a 700 MHz Cryomodule for the Superconducting Linac of MYRRHA

cavity, cryomodule, linac, vacuum

250

F. Bouly
CERN, Geneva, Switzerland
S. Berthelot, J.-L. Biarrotte, M. El Yakoubi, C. Joly, J. Lesrel, E. Rampnoux
IPN, Orsay, France
A. Bosotti, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy

Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project).
The MYRRHA (“Multi-purpose Hybrid Research reactor for High-tech Applications”) project aims at the construction of a new flexible fast spectrum research reactor. This reactor will operate as an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux; produced thanks to a 600 MeV high intensity proton beam. This CW beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable the rapid mitigation of RF failures. To carry out “real scale” reliability-oriented experiments a prototype of cryomodule was developed by INFN Milano and installed at IPN Orsay. The module holds a 700 MHz 5-cell elliptical cavity (βg = 0.47) equipped with its blade frequency tuner. Several tests were carried out to commission the experimental set-up. We review here the obtained results and the lessons learnt by operating this module, as well as the on-going developments.

MOP063

Mature Operation of CESR-Type 500-MHz SRF Module at Taiwan Light Source

SRF, operation, vacuum, cavity

266

Ch. Wang, L.-H. Chang, M.H. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, Y.-H. Lin, Z.K. Liu, C.H. Lo, M.H. Tsai, T.-T. Yang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

The Cornell-type 500-MHz SRF module has been routinely operated since the end of 2004 to power the 1.5 GeV Taiwan Light Source with 360 mA in top-up mode. A new record of SRF operation with mean time between failures (MTBF)up to 800 hr has been achieved in the 1st half of 2013 that is compatible with the best operational record of room temperature cavities ever made in the same machine. To meet the user’s strict requirements on highly operational reliability, developing in advanced diagnostic instrumentation together with user-friendly event logging software does never stop. Here, we review our SRF operational experience in last 9 years.

MOP064

Operational Experience with the SOLEIL Superconducting RF System

cavity, operation, HOM, vacuum

269

P. Marchand, J.P. Baete, R.C. Cuoq, H.D. Dias, M. Diop, J.L. Labelle, R. Lopes, M. Louvet, C.M. Monnot, S. Petit, F. Ribeiro, T. Ruan, R. Sreedharan, K. Tavakoli
SOLEIL, Gif-sur-Yvette, France

In the SOLEIL storage ring, two cryomodules provide to the electron beam an accelerating voltage of 3-4 MV and a power of 575 kW at 352 MHz. Each cryomodule contains a pair of superconducting cavities, cooled with liquid Helium at 4K, which is supplied by a single 350 W cryogenic plant. The RF power is provided by 4 solid state amplifiers, each delivering up to 180 kW. The parasitic impedances of the high order modes are strongly mitigated by means of four coaxial couplers, located on the central pipe connecting the two cavities. Seven years of operational experience with this system as well as its upgrades are reported.

MOP068

NGLS Linac Design

cryomodule, linac, cavity, controls

286

R.P. Wells, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, A. Ratti
LBNL, Berkeley, California, USA
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
D. Arenius
JLAB, Newport News, Virginia, USA
C.M. Ginsburg, T.J. Peterson
Fermilab, Batavia, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts for the cavity and cryostat design operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules, This leverages the extensive experience derived from R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given now to high loaded Q operation and microphonics control, as well as high reliability and expected up time. The work describes the design and configuration of the linac, including choice of gradient, possible modes of operation, cavity design and RF power, as well as the consequent requirements for the cryogenic system.

MOP074

Design and Construction of the Main Linac Cryomodule for the Energy Recovery Linac Project at Cornell

linac, cryomodule, vacuum, alignment

308

R.G. Eichhorn, B. Bullock, J.V. Conway, Y. He, T.I. O'Connel, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R&D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities and high beam currents (2*100 mA)are targeted. We will present the design of the main linac module (MLC) being finalized recently, its cryogenic features and report on the status of the fabrication which started in late 2012

MOP079

Design and Test of a Cryogenic Seal for Rectangular Waveguide Using VATSEAL Technology

vacuum, superconducting-RF, detector, controls

325

J.D. Fuerst, J.P. Holzbauer, J.A. Kaluzny, C.R. Montiel, Y. Shiroyanagi, B.K. Stillwell
ANL, Argonne, USA

Funding: This work was supported by the U. S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357.
A commercially available rectangular metal seal from VAT Vacuum Valves AG has been evaluated and cold tested as a possible cryogenic seal for srf cavities. A program of analysis and cryogenic testing was undertaken to evaluate seal parameters and suitability. Seal line loads, bolt torque and resultant flange/seal deformation at low temperature and during thermal cycling were calculated both statically and via time-dependent numerical simulation to confirm the mechanical integrity of the flange/seal system. Cold testing of flange/waveguide assemblies included thermal shocks in liquid nitrogen and realistic cool-downs below the λ point. Acceptable seal performance has been demonstrated under all test conditions although seal joint assembly is sensitive to details including bolt torque, flange flatness, and surface finish.

MOP081

Preliminary Studies of the Cryogenic Refrigerator and Distribution Systems for the MYRRHA Proton Linac

linac, cryomodule, proton, operation

331

T. Junquera, N.R. Chevalier, J.P. Thermeau
Accelerators and Cryogenic Systems, Orsay, France
L. Medeiros Romão, D. Vandeplassche
SCK•CEN, Mol, Belgium
H. Saugnac
IPN, Orsay, France

Funding: Work supported by the EU, FP7 MAX contract number 269565
In the framework of recent European programs (FP6-Eurotrans, FP7-MAX), the SC proton Linac for the MYRRHA project (associating an accelerator to a subcritical nuclear reactor, to be installed in the SCK•CEN at Mol-Belgium), has been extensively studied and optimized to reach strict requirements in beam power and reliability as needed for this ADS demonstrator. The linac, composed of 150 SC cavities (CH, spoke and elliptical) installed in 60 cryomodules, operates at 2K, delivering a beam power of 2.5 MW (600 MeV, 4 mA) in CW mode, will be installed in a tunnel of 240 m length. In this paper we present the evaluation of the cryogenic power requirements, a preliminary architecture of the cryogenic refrigerator system including all its major components, and preliminary proposals for the cryofluids distribution along the SC linac.

MOP083

Operational Experience With the SOLEIL Storage Ring RF Cryogenic Plant

controls, operation, cavity, HOM

337

M. Louvet, H.D. Dias, M. Diop, P. Marchand
SOLEIL, Gif-sur-Yvette, France

In the Storage Ring of the Synchrotron SOLEIL light source, two cryomodules provide the required power of 575 kW at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. Each cryomodule contains a pair of 352 MHz superconducting cavities (Nb/Cu), cooled in a bath of liquid helium at 4.5 K. A single 350 W cryogenic system supplies the liquid helium for the two cryomodules. The seven years of operational experience with this cryogenic plant as well as its upgrades are reported.

MOP084

ESS Cryomodules for Elliptical Cavities

cryomodule, vacuum, cavity, operation

341

G. Olivier, J.P. Thermeau
IPN, Orsay, France
P. Bosland
CEA/IRFU, Gif-sur-Yvette, France
C. Darve
ESS, Lund, Sweden

The European Spallation Source will be the world's most powerfull neutron source. IPN Orsay undertakes the development of the ESS linac cryomodules for both medium and high beta elliptical cavities which constitute the high energy section. A medium beta technical demonstrator will be built in a first time. The cryomodules are composed of 4 superconducting cavities cooled at 2K. The cold mass assembly is hanged in an intermediate structure located inside the vacuum vessel. A 50K fixed temperature is implemented by the mean of an aluminium shield. Each cryomodule is connected to the cryogenic distribution line. The vacuum vessel is 6.3m long and has a 1.2m diameter. The poster describes the general design,the solutions implemented, the characteristics of the main components and the mechanical/thermal calculations .

MOP085

Status of the Superconducting Proton Linac (SPL) Cryomodule

cavity, vacuum, operation, linac

345

V. Parma, R. Bonomi, O. Capatina, J.K. Chambrillon, E. Montesinos, K.M. Schirm, A. Vande Craen, G. Vandoni, R. van Weelderen
CERN, Geneva, Switzerland
G. Devanz
CEA/IRFU, Gif-sur-Yvette, France
P. Duchesne, P. Duthil, S. Rousselot
IPN, Orsay, France

The Superconducting Proton Linac (SPL) is an R&D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art SRF technology. Such an accelerator would serve as a driver in new physics facilities for neutrinos and/or radioactive ion beams. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium β=1 elliptical cavities (operating at 2 K and providing an accelerating field of 25 MV/m) and the test of a string of cavities integrated in a machine-type cryo-module. In an initial phase, only four out of the eight cavities of the SPL cryo-module will be tested in a half- length cryo-module developed for this purpose, which nonetheless preserves the main features of the full size machine. This paper presents the final design of the cryo-module and the status of the construction of the main cryostat parts. Preliminary plans for the assembly and testing of the cryo-module at CERN are presented and discussed.

MOP086

Integration, Commissioning and Cryogenics Performance of the ERL Cryomodule Installed on ALICE-ERL Facility at STFC Daresbury Laboratory, UK

cryomodule, SRF, HOM, linac

349

S.M. Pattalwar, R.K. Buckley, P.A. Corlett, P. Goudket, A.R. Goulden, A.J. May, P.A. McIntosh, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA
A. Büchner, F.G. Gabriel, P. Michel
HZDR, Dresden, Germany
E.P. Chojnacki, J.V. Conway, R.G. Eichhorn, G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
M.A. Cordwell, T.J. Jones, L. Ma, A.J. Moss, J. Strachan
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
J.N. Corlett, D. Li, S.M. Lidia
LBNL, Berkeley, California, USA
T. Kimura
Stanford University, Stanford, California, USA
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
J.K. Sekutowicz
DESY, Hamburg, Germany
T.J. Smith
SLAC, Menlo Park, California, USA

On successful assembly and preliminary testing of an optimised SRF cryomodule for application on ERL accelerators, which is being developed through an international collaboration the cryomodule has been installed on the 35 MeV ALICE (Accelerators and Lasers in Combined Experiments) Energy Recovery Linac (ERL) facility at STFC Daresbury Laboratory. Existing cryogenic infrastructure has a capacity to deliver approximately 120 W cooling power at 2 K, but the HOM (Higher Order Mode) absorbers, the thermal intercepts for the high power RF couplers and the radiation shield in the cryomodule are designed to be cooled (to 5 K and 80 K) with gaseous helium instead of liquid nitrogen. As a result the cryogenic infrastructure for ALICE had to be modified to meet these additional requirements. In this paper we describe our experience with the process of integration and the cryogenic commissioning, and present some initial results.

MOP087

Conceptual Design of a Cryomodule for Compact Crab Cavities for Hi-Lumi LHC

cryomodule, cavity, SRF, luminosity

353

S.M. Pattalwar, P.A. McIntosh, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G. Burt
Lancaster University, Lancaster, United Kingdom
O. Capatina
CERN, Geneva, Switzerland
B.D.S. Hall
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
T.J. Jones, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
T.J. Peterson
Fermilab, Batavia, USA

A prototype Superconducting (RF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the “Hi-Lumi LHC”, a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the tests with SPS.

MOP089

Design of the ESS Spoke Cryomodule

vacuum, cryomodule, cavity, operation

357

D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, E. Rampnoux
IPN, Orsay, France

The European Spallation Source (ESS) project brings together 17 European countries to develop the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the linear accelerator consists in 59 cryomodules housing different superconducting radiofrequency (SRF) resonators among which 28 paired β=0.5 352.2 MHz SRF niobium double Spoke cavities, held at 2K in a saturated helium bath. A prototype Spoke cryomodule with two cavities equipped with their 300kW RF power couplers is now being designed and will be constructed and tested at full power by the end of 2015 for the validation of all chosen technical solutions. It integrates all the interfaces necessary to be operational within a linac machine. Its assembly requires dedicated tooling and procedures in and out of a clean room. The design takes into account an industrial approach for the management of the fabrication costs. This prototype will have to guarantee an accelerating field of 8MV/m while optimizing the energy consumption and will aim at assessing the maintenance operations issues. We propose to present the design of this cryomodule and its related tooling.

TUP014

Fast Table Top Niobium Hydride Investigations Using Direct Imaging in a Cryo-Stage

niobium, cavity, laser, vacuum

447

F.L. Barkov, A. Grassellino, A. Romanenko
Fermilab, Batavia, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
Performance of niobium SRF cavities can be strongly affected by hydrogen segregation into lossy niobium hydrides as known for "hydrogen Q disease" at higher concentration of dissolved H and may be a reason for the "high field Q slope" at lower concentrations. With the use of optical cryostat and laser confocal microscope we have developed a "table top technique" for direct observation of hydride precipitation, and studied formation, morphology, and time evolution of hydrides after different treatments used for cavities. Our results show that hydrides can form at the niobium surface at 90-180K depending mainly on H concentration and the cooldown rate. A lot of H is absorbed by bulk niobium during mechanical polishing, which leads to the formation of very large (>10 microns) hydrides. Both EP and BCP do not influence H concentration significantly provided that temperature during treatments is kept below 15C. 800C degassing reduces H concentration and precludes large hydride precipitation. 120C baking and mechanical deformation do not change H concentration but affect hydride precipitation through their influence on the number of nucleation centers and H binding defects.

TUP069

The Copper Substrate Developments for the HIE-ISOLDE High-Beta Quarter Wave Resonator

cavity, electron, operation, linac

596

L. Alberty, G. Arnau-Izquierdo, I. Aviles Santillana, S. Calatroni, O. Capatina, A. D'Elia, G. Foffano, Y. Kadi, P. Moyret, K.M. Schirm, T. Tardy, W. Venturini Delsolaro
CERN, Geneva, Switzerland
A. D'Elia
UMAN, Manchester, United Kingdom

A new linac using superconducting quarter-wave resonators (QWR) is under construction at CERN in the framework of the HIE-ISOLDE project. The QWRs are made by Niobium sputtered on a bulk Copper substrate. The working frequency at 4.5 K is 101.28 MHz and they will provide 6 MV/m accelerating gradient on the beam axis with a total maximum power dissipation of 10 W. The properties of the cavity substrate have a direct impact on the final cavity performance. The Copper substrate has to ensure an optimum surface for the Niobium sputtered layer. It has also to fulfill the required geometrical tolerances, the mechanical stability during operation and the thermal performance to optimally extract the RF dissipated power on cavity walls. The paper presents the mechanical design of the high β cavities. The procurement process of the Copper raw material is detailed, including specifications and tests. The manufacture sequence of the complete cavity is then explained and the structural and thermo-mechanical behavior during the tests performed on a prototype cavity is discussed. The industrialization strategy is presented in view of final production of the cavities.

TUP082

Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities

cavity, SRF, HOM, ion

638

X. Zhao, C.E. Reece
JLab, Newport News, Virginia, USA
G. Ciovati
Jefferson Lab, Newport News, Virginia, USA
I. Irfan, C. James, M. Krishnan
AASC, San Leandro, California, USA
A.D. Palczewski
JLAB, Newport News, Virginia, USA

Funding: This research is supported at AASC by DOE via Grant No. DE-FG02-08ER85162 and Grant No. DE-SC0004994 and by Jefferson Science Associates, LLC under U.S. DOE Contract No. DEAC05- 06OR23177
This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavity were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film at 2 K and low rf field, produced by CED, could be close to that of the pre-coated bulk Nb surface (being CBP'ed plus a light EP); but the quality drops rapidly for increasing rf field. We are investigating if the severe Q0-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

TUP083

Film Deposition, Cryogenic RF Testing and Materials Analysis of a Nb/Cu Single Cell SRF Cavity

cavity, niobium, SRF, plasma

642

X. Zhao
JLab, Newport News, Virginia, USA
R.L. Geng, Y.M. Li, A.D. Palczewski
JLAB, Newport News, Virginia, USA
Y.M. Li
PKU, Beijing, People's Republic of China

Funding: The JLab effort was provided by Jefferson Science Associates, LLC under U.S. DOE Contract No. DEAC05- 06OR23177.
In this study, we present preliminary results on using a cathodic-arc-discharge Nb plasma ion source to establish a Nb film-coated single-cell Cu cavity for SRF research. The polycrystalline Cu cavity was fabricated and mirror-surface-finished by a centrifugal barrel polishing (CBP) process at Jefferson Lab. Special pre-coating processes were conducted, in order to create a template-layer for follow-on Nb grain thickening. A sequence of cryogenic RF testing demonstrated that the Nb film does show superconductivity. But the quality factor of this Nb/Cu cavity is low as a result of high residual surface resistance. We are conducting a thorough materials characterization to explore if some microstructural defects or hydrogen impurities, led to such a low quality factor.

TUP103

Calibration and Characterization of Capacitive OST Quench Detectors in SRF Cavities at IPN Orsay

SRF, detector, cavity, diagnostics

714

M. Fouaidy, F. Dubois, J.-M. Dufour, D. Longuevergne, A. Maroni, G. Michel, J.-F. Yaniche
IPN, Orsay, France

Funding: IPNO/IPN2P3/CNRS
The maximum RF surface magnetic field (Bs) achieved with SRF bulk Nb cavities is often limited by anomalous losses due to Joule heating of normal-resistive defects embedded onto the RF surface. At high BS (e.g Bs>50 mT), the defect temperature increases strongly with BS, leading to a thermal runaway of the cavity or quench. The unloaded quality factor Q0 of the cavity decreases suddenly and strongly due to superconducting to normal state phase transition of the hot spot area. Quench detectors, called Oscillating Superleak Transducer (OST) and sensing 2nd sound events in He II, have been recently used to study quench of SRF cavities. IPN developed his prototypes of OST quench detectors and a test stand for their calibration and characterization in the temperature range T0=1.6 K-2.2 K. This device allows precise and controlled experimental simulation of SRF cavity quench using pulsed heat sources. Experimental runs were performed to study the dynamic response of OST detectors when the heat source is subjected to a time varying heat flux q(t) as function of several parameters (T0, q(t) time structure and density, heat source size) and first experimental data are presented.

TUP114

XT-map System for Locating SC Cavity Quench Position

cavity, survey, operation, accelerating-gradient

747

H. Tongu, Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, Y. Yamamoto
KEK, Ibaraki, Japan

XT-map system under development in collaboration between Kyoto University and KEK is a combined system of the temperature mapping (T-map) and X-ray mapping (X-map). High resolution T-map at quench detection will give more information for improving yield in production of high performance SC Cavities. The high-density sensor distribution of the XT-map gives the high resolution. Because the huge amount of sensor lines are multiplexed at a hi-speed scanning rate in the vicinity of the sensors, the small number of signal lines makes the installation process easy and reduces the system complexity. The scanning test of this XT-map system has been performed in the vertical test at KEK. The detected quench events will be reported.

WEIOD02

Magnetic Shielding: Our Experience with Various Shielding Materials

shielding, superconducting-RF, simulation, linac

808

M. Masuzawa, A. Terashima, K. Tsuchiya
KEK, Ibaraki, Japan
A. Daël, O. Napoly, J. Plouin
CEA/DSM/IRFU, France

Magnetic shielding is a key technology for superconducting RF cavities. The tolerance of the ambient magnetic field depends on factors such as the operating RF frequency and acceleration gradient, but it can be as small as a few mG. Some high-Ni-content alloys, such as Cryperm 10 or Cryophy, which are claimed to maintain high permeability at cryogenic temperatures where superconducting cavities are operated, are commercially available at present and are used for magnetic shielding of superconducting cavities at many laboratories. Permeability measurements were made in order to understand the characteristics of such materials at both room and cryogenic temperatures, and the results will be used as a database for designing magnetic shields. It was found that the catalog performance of such materials was not always reproduced in the measurements. Some degradation was observed which depended on how the material was handled. The results of investigation into possible causes for the performance degradation of the shielding material at cryogenic temperature will be presented, along with permeability measurement results for various materials at different temperatures.

Slides WEIOD02 [8.475 MB]

THIOA04

Low-Beta Cryomodule Design Optimized for Large-Scale Linac Installations

cryomodule, vacuum, alignment, solenoid

825

S.J. Miller, B. Bird, N.K. Bultman, F. Casagrande, A.D. Fox, M.J. Johnson, M. Leitner, T. Nellis, J.P. Ozelis, X. Rao, R.J. Rose, M. Shuptar, K. Witgen, Y. Xu
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
This paper will present most recent design developments at FRIB to optimize low-beta cryomodules for large-scale linac installations. FRIB, which requires the fabrication of 53 cryomodules, has to emphasize ease of assembly and alignment plus low cost. This paper will present experimental results of a novel kinematic rail support system which significantly eases cryomodule assembly. Design choices for mass-production are presented. Results of vibration calculations and measurements on a FRIB prototype cryomodule will be reported.

Slides THIOA04 [10.842 MB]

THIOA05

Optimization of SRF Linacs

cryomodule, cavity, linac, operation

830

T. Powers
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S.
This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project. The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so.

Slides THIOA05 [2.712 MB]

THP043

Design and Vertical Test of Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade

cavity, simulation, pick-up, HOM

1002

B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, C. Cullen, L.R. Hammons, J. Skaritka, S. Verdú-Andrés, Q. Wu
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi
Stony Brook University, Stony Brook, USA

Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404.
A proof of principle Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. Vertical cryogenic test has been done in Brookhaven National Lab (BNL). We report the test results of this design.

THP046

Magnetic Material Characterization & SC Solenoid Coil Package Design for FRIB

solenoid, shielding, cavity, operation

1009

K. Saito, S. Chouhan, C. Compton, J. DeKamp, M. Leitner, F. Marti, J.P. Ozelis, S. Shanab, G.J. Velianoff, X. Wu, Y. Yamazaki, A. Zeller, Y. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA
S.K. Chandrasekaran
MSU, East Lansing, USA
K. Hosoyama
KEK, Ibaraki, Japan

To date SRF technology is extending to large scale heavy ion LINACs, where SRF cavities accelerate beams from very low energy to high energy. In this application, superconducting (SC) solenoids are installed inside the cryomodule to provide strong beam focusing with enhanced space efficiency. FRIB will use local magnetic shielding, where magnetic shielding by Cryoperm or A4K is located close to the cavity at 2K. In this scheme rather strong magnetic fringe fields from the SC solenoid expose the shielding material and will magnetize it. An efficient degaussing process is required as cure against such magnetization. Magnetic material characterization of magnetic shielding materials is very important to be able to plan effective degaussing procedures. The paper will also discuss the design of FRIB solenoids optimized for cost, reliability, and robust long-term operation. NbTi wire performance criteria are discussed in addition to solenoid operational margins.

THP058

Update on the European XFEL RF Power Input Coupler

simulation, superconductivity, linac, electron

1047

D. Kostin, W.-D. Möller
DESY, Hamburg, Germany
W. Kaabi
LAL, Orsay, France

European XFEL project is being currently realized in Hamburg, Germany. The 1.5 km 17.5 GeV linear electron accelerator is based on the 1.3GHz 9-cell TESLA type SRF cavity. The RF power input coupler design for the E-XFEL is based on well known TTF3 coupler design, used in FLASH accelerator. Coupler design was adapted for the industrial production with some parameters optimisation revisited and simulations done. Results are presented and discussed.

FRIOC02

ESS Elliptical Cavities and Cryomodules

cavity, HOM, cryomodule, proton

1218

G. Devanz, P. Bosland, M. Desmons, P. Hardy, F. Leseigneur, M. Luong, F. Peauger, J. Plouin, D. Roudier
CEA/DSM/IRFU, France
N. Bazin
CEA/IRFU, Gif-sur-Yvette, France
G. Costanza
Lund University, Lund, Sweden
G. Olivier
IPN, Orsay, France

The accelerator of the European Spallation Source (ESS) is a 5 MW proton linac to be built in Lund Sweden. Its superconducting section is composed of 3 cavity families: double spoke resonators, medium beta and high beta elliptical multicell cavities. This paper presents the electromagnetic and mechanical design of the 704.42 MHz elliptical cavities. Both elliptical famillies are housed in 4-cavity cryomodules which share a common design and set of components which will be described here.

Slides FRIOC02 [3.475 MB]