SRF2015 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOAA01	FRIB Project: Moving to Production Phase	cavity, SRF, solenoid, cryomodule	1
	K. Saito, H. Ao, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K.D. Davidson, K. Elliott, F. Feyzi, A.D. Fox, P.E. Gibson, L. Hodges, K. Holland, G. Kiupel, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, G.J. Velianoff, D.R. Victory, J. Wei, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng FRIB, East Lansing, Michigan, USA S.K. Chandrasekaran Fermilab, Batavia, Illinois, USA A. Facco INFN/LNL, Legnaro (PD), Italy K. Hosoyama, M. Masuzawa KEK, Ibaraki, Japan R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M.X. Xu IMP/CAS, Lanzhou, People's Republic of China
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Facility for Rare Isotope Beams (FRIB) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.
	Slides MOAA01 [2.754 MB]
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MOAA02	Recent Progress with EU-XFEL	cryomodule, cavity, operation, cryogenics	14
	D. Reschke DESY, Hamburg, Germany
	The superconducting accelerator of the European XFEL consists of the injector part and the main linac. The injector includes one 1.3 GHz accelerator module and one 3.9 GHz third-harmonic module, while the main linac will consist of 100 accelerator modules, operating at an average design gradient of 23.6 MV/m. The fabrication and surface treatment by industry as well as RF acceptance tests of the required 808 superconducting 1.3 GHz cavities are close to an end by the time of SRF15. The accelerator module assembly, testing and installation in the tunnel is in full swing. First steps of commissioning have been made. The status and results of cavity and module RF tests at 1.3 GHz and 3.9 GHz are presented.
	Slides MOAA02 [2.903 MB]
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MOAA04	Overview of Recent SRF Developments for ERLs	SRF, gun, cavity, cryomodule	24
	S.A. Belomestnykh BNL, Upton, Long Island, New York, USA S.A. Belomestnykh Stony Brook University, Stony Brook, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE. This talk reviews SRF technology for Energy Recovery Linacs (ERLs). In particular, recent developments and results reported at the ERL2015 Workshop are highlighted. The talk covers facilities under construction, commissioning or operation, such as cERL at KEK, BERLinPro at HZB and R&D ERL at BNL, as well as facilities in the development phase. Future perspectives will be discussed.
	Slides MOAA04 [5.376 MB]
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MOAA05	Status of the RISP Superconducting Heavy Ion Accelerator	cryomodule, ion, rfq, ECR	31
	D. Jeon IBS, Daejeon, Republic of Korea
	Funding: This work was supported by the the Institute for Basic Science funded by the Ministry of Science, ICT and Future Planning (MSIP) and the National Research Foundation (NRF) of Korea. Construction of the RISP heavy ion accelerator facility is in progress in Korea. The driver linac is a superconducting linac that can accelerate uranium to proton beams, delivering 400 kW beam power to various targets. Prototyping and test of the superconducting cavities and cryomodules are proceeding. Prototype superconducting cavities were fabricated through domestic vendors and their vertical tests were performed in collaboration with TRIUMF. Vertical tests showed good performance of the prototype cavities, which verified that there were no significant issues of the cavity design and fabrication. SRF Test Facility is under construction to be completed by early 2016. Progress report of the RAON accelerator systems is presented.
	Slides MOAA05 [5.587 MB]
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MOPB033	LCLS-II SRF Cavity Processing Protocol Development and Baseline Cavity Performance Demonstration	cavity, cryomodule, SRF, vacuum	159
	M. Liepe, P. Bishop, H. Conklin, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, T. Gruber, D.L. Hall, G.H. Hoffstaetter, J.J. Kaufman, G. Kulina, J.T. Maniscalco, T.I. O'Connell, P. Quigley, D.M. Sabol, J. Sears, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA M. Checchin, A.C. Crawford, A. Grassellino, C.J. Grimm, A. Hocker, M. Martinello, O.S. Melnychuk, J.P. Ozelis, A. Romanenko, A.M. Rowe, D.A. Sergatskov, W.M. Soyars, R.P. Stanek, G. Wu Fermilab, Batavia, Illinois, USA E. Daly, G.K. Davis, M.A. Drury, J.F. Fischer, A.D. Palczewski, C.E. Reece JLab, Newport News, Virginia, USA M.C. Ross SLAC, Menlo Park, California, USA
	Funding: Work supported, in part, by the US DOE and the LCLS-II Project under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-76SF00515. The ”Linac Coherent Light Source-II” Project will construct a 4 GeV CW superconducting RF linac in the first kilometer of the existing SLAC linac tunnel. The baseline design calls for 280 1.3 GHz nine-cell cavities with an average intrinsic quality factor Q0 of 2.7·10¹⁰ at 2K and 16 MV/m accelerating gradient. The LCLS-II high Q0 cavity treatment protocol utilizes the reduction in BCS surface resistance by nitrogen doping of the RF surface layer, which was discovered originally at FNAL. Cornell University, FNAL, and TJNAF conducted a joint high Q0 R&D program with the goal of (a) exploring the robustness of the N-doping technique and establishing the LCLS-II cavity high Q0 processing protocol suitable for production use, and (b) demonstrating that this process can reliably achieve LCLS-II cavity specification in a production acceptance testing setting. In this paper we describe the LCLS-II cavity protocol and analyze combined cavity performance data from both vertical and horizontal testing at the three partner labs, which clearly shows that LCLS-II specifications were met, and thus demonstrates readiness for LCLS-II cavity production.
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MOPB039	Analysis of BCS RF Loss Dependence on N-Doping Protocols	cavity, niobium, SRF, operation	174
	A.D. Palczewski, P. Dhakal, C.E. Reece JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 with supplemental funding from the LCLS-II Project U.S. DOE Contract No. DE-AC02-76SF00515. We present a study on two parallel-path SRF cavities (one large grain and one fine grain, 1.3 GHz) which seeks to explain the correlation between the amount of nitrogen on the inner surface of a “nitrogen doped” SRF cavity and the change in the temperature dependant (packaged into term BCS) RF losses. For each doping/EP, the cavities were tested at multiple temperatures (2.0 K to 1.5 K in 0.1 K steps) to create a Q0 vs. Eacc vs. T matrix which then could be used to extract temperature dependant and independent components. After each test, the cavities were thermally cycled to 120 K and then re-cooled and retested to assess if evidence of hydrogen migration might appear even at a small level. In addition, TD-5 was also tested at fixed low field (Q0 vs. T) to fit standard BCS theory. In parallel, SIMS data was taken on like-treated samples to correlate the amount of nitrogen within the RF surface to the change in the temperature dependant fitting parameter “A”.** [] H.Tian et al., contributed to SRF2015.
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MOPB040	Performance of Dressed Cavities for the Jefferson Laboratory LCLS-II Prototype Cryomodule - With Comparison to the Pre-Dressed Performance	cavity, HOM, cryomodule, hardware	178
	A.D. Palczewski, G.K. Davis JLab, Newport News, Virginia, USA F. Furuta, G.M. Ge, D. Gonnella, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 with supplemental funding from the LCLS-II Project U.S. DOE Contract No. DE-AC02-76SF00515. Initial vertical RF test results and quench studies for six of the eight undressed 9 cell cavities slated for use in the Jefferson laboratory LCLS-II prototype cryomodule were presented at IPAC2015. For the final string 2 more cavities AES029 and AES030 (work done at Cornell) are being processed and tested for qualification before helium vessel welding. In addition, AES034 (initial R&D treatment) is being reworked with the current production protocol after a surface reset to improve the overall performance. After final qualification all 8 cavities will be welded into helium vessels and equipped with HOM couplers. In this paper we will present the final undressed and dressed vertical RF data comparing the changes in the surface resistance before their installation in the cryomodule string. A.D. Palczewski et al. Quench Studies of Six High Temperature Nitrogen Doped 9 Cell Cavities for use in the LCLS-II Prototype Cryo-module at Jefferson Laboratory, Proc. IPAC2015, WEPWI019, 2015.
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MOPB041	Cryomodule Testing of Nitrogen-Doped Cavities	cavity, cryomodule, HOM, SRF	182
	D. Gonnella, B. Clasby, R.G. Eichhorn, B. Elmore, F. Furuta, G.M. Ge, D.L. Hall, Y. He, G.H. Hoffstaetter, J.J. Kaufman, P.N. Koufalis, M. Liepe, J.T. Maniscalco, T.I. O'Connell, P. Quigley, D.M. Sabol, E.N. Smith, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA A. Grassellino, C.J. Grimm, J.P. Holzbauer, O.S. Melnychuk, Y.M. Pischalnikov, A. Romanenko, W. Schappert, D.A. Sergatskov Fermilab, Batavia, Illinois, USA A.D. Palczewski, C.E. Reece JLab, Newport News, Virginia, USA
	Funding: DOE and the LCLS-II High Q Project The Linac Coherent Light Source-II (LCLS-II) is a new FEL x-ray source that is planned to be constructed in the existing SLAC tunnel. In order to meet the required high Q0 specification of 2.7x10¹⁰ at 2 K and 16 MV/m, nitrogen-doping has been proposed as a preparation method for the SRF cavities in the linac. In order to test the feasibility of these goals, four nitrogen-doped cavities have been tested at Cornell in the Horizontal Test Cryomodule (HTC) in five separate tests. The first three tests consisted of cavities assembled in the HTC with high Q input coupler. The fourth test used the same cavity as the third but with the prototype high power LCLS-II coupler installed. Finally, the fifth test used a high power LCLS-II coupler, cavity tuner, and HOM antennas. Here we report on the results from these tests along with a systematic analysis of change in performance due to the various steps in preparing and assembling LCLS-II cavities for cryomodule operation. These results represent one of the final steps to demonstrate readiness for full prototype cryomodule assembly for LCLS-II.
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MOPB063	Design of the Superconducting LINAC for SARAF	cryomodule, cavity, solenoid, cryogenics	250
	C. Madec CEA, Gif-sur-Yvette, France N. Bazin, L. Boudjaoui, R. Cubizolles, G. Ferrand, P. Hardy, C. Pes, N. Sellami CEA/IRFU, Gif-sur-Yvette, France P. Bertrand GANIL, Caen, France P. Brédy, B. Gastineau, N. Pichoff CEA/DSM/IRFU, France
	CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40.1 MeV. The SCL consists 4 cryomodules equipped with warm diagnostics. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.091), 176 MHz. As the last two identical welcome 7 HWR high-beta cavities (β = 0.181), 176 MHz. The beam is focused through the superconducting solenoids located between cavities housing steering coils. A Beam Position Monitor is placed upstream each solenoid. A diagnostic box containing a beam profiler, a bunch length monitor and a vacuum pump will be inserted between 2 consecutive cryomodules. The HWR cavities, the solenoid package and the cryomodules are being designed. These studies will be presented in this poster.
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MOPB065	Recent Measurements on the SC 325 MHz CH-Cavity	cavity, ion, heavy-ion, controls	255
	M. Busch, M. Amberg, M. Basten, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg HIM, Mainz, Germany
	Funding: Work supported by GSI, BMBF Contr. No. 06FY7102 At the Institute for Applied Physics (IAP), Frankfurt University, a sc 325 MHz CH-Cavity has been designed and fabricated. Successful tests at 4 K and 2 K with gradients up to 14.1 MV/m have been performed. The cavity is destined for a 11.4 AMeV 10 mA ion beam at the GSI UNILAC, Darmstadt. Consisting of 7 gaps and a geometrical beta of 0.16 this resonator is designed to provide a gradient of 5 MV/m. Novel features of this structure comprise a compact design, low electric peak fields, improved surface processing possibilities and power coupling. In addition a tuner system based on mechanically deformable bellow tuners attached inside the cavity and driven either by a stepping motor or a piezo actuator will keep the cavity on resonance. This contribution reports about the latest measurements on the cavity with the recently attached helium vessel and a renewed surface processing.
	Poster MOPB065 [1.270 MB]
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MOPB066	R&D Status of the New Superconducting CW Heavy Ion LINAC@GSI	cavity, simulation, ion, operation	258
	M. Basten, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech, M. Schwarz IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, M. Miski-Oglu HIM, Mainz, Germany W.A. Barth, V. Gettmann, M. Heilmann, S. Mickat GSI, Darmstadt, Germany
	To keep the ambitious Super Heavy Element (SHE) physics program at GSI competitive a superconducting (sc) continuous wave (cw) high intensity heavy ion LINAC is currently under progress as a multi-stage R&D program of GSI, HIM and IAP. The baseline linac design consists of a high performance ion source, a new low energy beam transport line, an (cw) upgraded High Charge State Injector (HLI), and a matching line (1.4 MeV/u) which is followed by the new sc-DTL LINAC for post acceleration up to 7.3 MeV/u. In the present design the new cw-heavy ion LINAC comprises constant-beta sc Crossbar-H-mode (CH) cavities operated at 217 MHz. The advantages of the proposed beam dynamics concept applying a constant beta profile are easy manufacturing with minimized costs as well as a straightforward energy variation. An important milestone will be the full performance test of the first CH cavity (Demonstrator), in a horizontal cryo module with beam. An advanced demonstrator setup comprising a string of cavities and focussing elements is proposed to build from 10 short CH-cavities with 8 gaps. The corresponding simulations and technical layout of the new cw heavy ion LINAC will be presented. W. Barth et al., Further R&D for a new Superconducting cw Heavy Ion LINAC@GSI, IPAC2014, THPME004 **M. Schwarz et al., Beam Dynamics for the sc cw Heavy Ion Linac at GSI, IPAC2015, THPF025
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MOPB067	Steps Towards Superconducting CW-LINAC for Heavy Ions at GSI	ion, heavy-ion, quadrupole, cavity	262
	M. Miski-Oglu, M. Amberg, K. Aulenbacher, V. Gettmann HIM, Mainz, Germany W.A. Barth, M. Heilmann, S. Mickat, S. Yaramyshev GSI, Darmstadt, Germany M. Basten, D. Bänsch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany
	Providing heavy ion beams for the ambitious experiment program at GSI, the Universal Linear Accelerator (UNILAC) serves as a powerful high duty factor (25%) accelerator. Beam time availability for SHE-research will be decreased due to the limitation of the UNILAC providing a proper beam for FAIR simultaneously. To keep the GSI-SHE program competitive on a high level, a standalone sc cw-LINAC in combination with the upgraded GSI High Charge State injector is planned to build. In preparation for this the first linac section (financed by HIM and partly by HGF-ARD-initiative) will be tested in 2015 as a demonstrator. After successful testing the construction of an extended cryomodule comprising two further, but shorter CH cavities is foreseen to test until end of 2017. In this contribution the measurement of the beam parameters at the entrance of CW-Demonstartor, the preliminary simulation of beam dynamics for the first stage of advanced demonstrator will be presented. As a final R&D step towards an entire linac an advanced cryo module comprising up to five CH cavities is envisaged for 2019 serving for first user experiments at the coulomb barrier.
	Poster MOPB067 [2.807 MB]
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MOPB068	Pulsed SC Ion Linac as an Injector to Booster of Electron Ion Collider	ion, operation, cavity, proton	265
	P.N. Ostroumov, Z.A. Conway, B. Mustapha ANL, Argonne, USA B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357. The electron-ion collider (EIC) being developed at JLAB requires a new ion accelerator complex (IAC). The IAC includes a new linac and a booster accelerator facility. The new facility is required for the acceleration of ions from protons to lead for colliding beam experiments with electrons in the EIC storage ring. Originally, we proposed a pulsed linac which is based upon a NC front end, < 5 MeV/u, with a SC section for energies > 5 MeV/u and capable of providing 285 MeV protons and ~100 MeV/u lead ions for injection into the IAC booster. A recent cost optimization study of the IAC suggested that lower injection energy into the booster may reduce the overall project cost with ~120 MeV protons and ~40 MeV/u lead ions. Stronger space charge effects in the booster caused by lower injection energy will be mitigated by the booster design. In this paper we discuss both linac options.
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MOPB069	Superconducting Linac Upgrade Plan for the Second Target Station Project at SNS	cryomodule, cavity, HOM, accelerating-gradient	268
	S.-H. Kim, M. Doleans, J. Galambos, M.P. Howell ORNL, Oak Ridge, Tennessee, USA J.D. Mammosser ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. The beam power of the Linac for the Second Target Station (STS) at the Spallation Neutron Source (SNS) will be doubled to 2.8 MW. For the energy upgrade seven additional cryomodules will be installed in the reserved space at the end of the linac tunnel to produce the linac output energy of 1.3 GeV. The cryomodules for STS will have some changes that do not require changes of overall layout based on the lessons learned from operational experience over the last 10 years and the high beta spare cryomodule developed in house. The average macro-pulse beam current for the STS will be 38 mA that is about 40 % increase from that for the present 1.4 MW operation. Plans for the existing cryomodules to support higher beam current for the STS is also presented in this paper.
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MOPB075	Experiences on Retreatment of EU-XFEL Series Cavities at DESY	cavity, controls, status, feedback	296
	A. Matheisen, N. Krupka, S. Saegebarth, P. Schilling, N. Steinhau-Kühl, B. van der Horst DESY, Hamburg, Germany
	For the European XFEL (EU-XFEL), two industrial companies are responsible for the manufacture and surface preparation of the eight hundred superconducting cavities. The companies had to strictly follow the XFEL specification and document all production and preparation steps. No performance guaranties were required. Each cavity delivered by industry to DESY is tested in a vertical test at 2K. Resonators not reaching the performances defined for application at the EU-XFEL linear accelerator modules or showing leakage during cold RF tests have undergone a subsequent retreatment at DESY. Nearly 20% of the cavity production required retreatment, most of them by an additional high pressure rinsing. Some cavities received additional chemical treatment by BCP flash after the initial HPR did not cure the problem. The analysis of retreatments and quality control data available from the retreatment sequences and the workflow of retreatment will be presented.
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MOPB078	Mode Sensitivity Analysis of 704.4 MHz Superconducting RF Cavities	HOM, cavity, operation, dipole	311
	K. Papke, F. Gerigk, S. Horvath-Mikulas, S. Papadopoulos, E. Pilicer, F. Pillon CERN, Geneva, Switzerland U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Due to the large variety of beam patterns considered for the superconducting proton linac (SPL) at CERN it is likely that the frequencies of some HOMs are close to machine lines during operation. Hence, in the interest of developing a method to shift HOM frequencies away from machine lines, we study the influence of cavity detuning and re-tuning (e.g. by Lorentz forces, field flatness tuning, frequency tuning during operation) on HOMs. The sensitivity of HOMs with respect to the fundamental mode was studied for a mono-cell and for 5-cell high-beta SPL cavities operating at 704.4 MHz. First, the variation of the HOMs during the flat-field tuning was measured. In this process, several detuning and re-tuning cycles were made to estimate the range of possible HOM frequency shifts. Secondly the effect of the frequency tuner on the HOMs is presented and finally the frequency shifts of all modes due to the cool down.
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MOPB080	Update and Status of Test Results of the XFEL Series Accelerator Modules	cryomodule, cavity, radiation, status	319
	M. Wiencek, K. Kasprzak, A. Zwozniak IFJ-PAN, Kraków, Poland D. Kostin, D. Reschke, N. Walker DESY, Hamburg, Germany
	The European X-ray Free Electron Laser is under construction at DESY, Hamburg. During preparation for tunnel installation 100 Cryomodules are tested in a dedicated facility on the DESY campus. Up to now around 50 cryomodules have been measured at 2K. This paper describes the current status of the measurements, especially single cavity limitations. In addition we present a comparison between the vertical test results of the individual cavities and the corresponding performance measurements of the cavities once assembled into the accelerator string inside the cryomodule.
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MOPB083	Cooling Front Measurement of a 9-Cell Cavity via the Multi-Cell Temperature-Mapping System at Cornell University	cavity, SRF, experiment, electronics	324
	G.M. Ge, R.G. Eichhorn, F. Furuta Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cooling speed significantly affects flux trapping of a SRF cavity, which will determine the residual resistance and the quality factor of the cavity. We measured the temperature distribution of a 9-cell cavity at different cooling speeds by the multi-cell T-map system of Cornell University. This paper proposed a method to evaluate the formation of a normal conducting island at different cooling speed. The fast cool-down and slow cool-down has been compared. We conclude that the slow cool-down freezes less normal conducting islands.
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MOPB084	Performance of Nitrogen-Doped 9-Cell SRF Cavities in Vertical Tests at Cornell University	cavity, SRF, superconducting-RF, HOM	328
	G.M. Ge, R.G. Eichhorn, B. Elmore, F. Furuta, D. Gonnella, T. Gruber, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, T.I. O'Connell, J. Sears, E.N. Smith Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cornell University treated five LCLS-II 9-cell cavities by nitrogen-doping recipe. In this paper, we reported the performance of these 9-cell cavities. In the treatments, the nitrogen recipes are slightly different. The cavities have been firstly doped under high nitrogen pressure; after the vertical tests some of the cavities has been reset the surface and re-doped under light nitrogen pressure. The detail of the cavity preparation and test results will be shown. The comparison of the different recipes will be discussed.
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MOPB086	Update and Status of Vertical Test Results of the European XFEL Series Cavities	cavity, status, cryomodule, niobium	337
	N. Walker, D. Reschke, J. Schaffran, L. Steder DESY, Hamburg, Germany L. Monaco INFN/LASA, Segrate (MI), Italy M. Wiencek IFJ-PAN, Kraków, Poland
	The series production by two industrial vendors of the 800 1.3-GHz superconducting cavities for the European XFEL has been on-going since the beginning of 2013 and will conclude towards the end of this year. As of publication some 740 cavities (~93%) have been produced at an average rate of 6 cavities per week. As part of the acceptance testing, all cavities have undergone at least one vertical RF test at 2K at the AMTF facility at DESY. The acceptance criterion for module assembly is based on the concept of a “usable gradient”, which is defined as the maximum field taking into account Q0 performance and allowed thresholds for field emission, as well as breakdown limits. Approximate 20% of the cavities have undergone further surface treatment in the DESY infrastructure to improve their usable gradient performance. In this paper we present the performance statistics of the vertical test results, as well as an analysis of the limiting criteria for the usable gradient, and finally the impact of the surface retreatment on both usable gradient and Q0.
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MOPB088	HOM Measurements on the ARIEL eLINAC Cryomodules	HOM, cavity, simulation, cryomodule	347
	P. Kolb, R.E. Laxdal, Y. Ma, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ARIEL eLINAC is a 50 MeV, 10 mA electron LINAC designed for the creation of rare isotopes via photo-fission. Future upgrade plans include the addition of a recirculating beam line to allow for either further energy increase of the beam beyond 50 MeV or to operate a free electron laser in an energy recovery mode. For both recirculating LINAC and ERL the higher order modes (HOM) have to be sufficiently suppressed to prevent beam-break-up. The design of the 1.3 GHz nine-cell cavity incorporated this requirement by including beam line absorbers on both ends of each cavity and an asymmetric beam pipe configuration on the cavity to allow trapped modes to propagate to the beam line absorbers. Measurements of the higher order modes on the completed injector cryomodule and the first cavity in the accelerating cryomodules will be shown and compared to simulations.
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MOPB095	SRF Cavity Processing and Chemical Etching Development for the FRIB Linac	cavity, SRF, controls, operation	373
	I.M. Malloch, E.S. Metzgar, L. Popielarski FRIB, East Lansing, Michigan, USA M.J. LaVere MSU, 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, the State of Michigan and Michigan State University. In preparation of a rigorous superconducting RF (SRF) cavity processing and test plan for the production of the Facility for Rare Isotope Beams (FRIB) driver linac, a state-of-the-art chemical etching tool has been installed in the FRIB coldmass production facility. This paper seeks to summarize the etching equipment design, installation, and validation program and subsequent etching results for a variety of SRF cavity types and etching configurations. Bulk etching, light etching, and custom (frequency tuning) etching results for different FRIB cavities are discussed. Special emphasis is placed on the etching removal uniformity and frequency tuning reliability of these processes.
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TUAA02	Commissioning of the SRF Linac for ARIEL	cavity, cryomodule, TRIUMF, electron	457
	V. Zvyagintsev, Z.T. Ang, T. Au, S. Calic, K. Fong, P.R. Harmer, B. Jakovljevic, J.J. Keir, D. Kishi, P. Kolb, S.R. Koscielniak, A. Koveshnikov, C. Laforge, D. Lang, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, N. Muller, R.R. Nagimov, W.R. Rawnsley, R.W. Shanks, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, Q. Zheng TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	This paper is reporting commissioning results for the SRF linac of ARIEL facility at TRIUMF. The paper is focused on the SRF challenges: cavity design and performance, ancillaries design and preparation, cryomodule design and performance, RF system and final beam test results.
	Slides TUAA02 [4.004 MB]
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TUAA04	Rapid Growth of SRF in India	cavity, niobium, SRF, electron	467
	D. Kanjilal IUAC, New Delhi, India
	Funding: Funding received from Ministry of Higher Education through University Grants Commission of India and from Department of Atomic Energy are gratefully acknowledged. The talk shall summarize the recent advances in the SRF program in various research centres in India. The SRF related activities at Inter-University Accelerator Centre (IUAC) at Delhi , Raja Ramanna Centre for Advanced Technology (RRCAT) at Indore, Bhabha Atomic Research Centre (BARC) and Tata Institute of Fundamental Research (TIFR) both at Mumbai, and Variable Energy Cyclotron Centre (VECC) at Kolkata shall be addressed. In particular indigenous niobium resonator fabrication and test facilities of IUAC operational for more than a decade which have been used extensively for development, fabrication and utilization of various types of resonators will be discussed. The results from the commissioning of the full three linac modules having eight niobium quarter wave resonators in each module of the heavy ion linac at IUAC for regular scheduled experiments will be presented. The technology and infrastructure developments at RRCAT, BARC, TIFR and VECC for fabrication, processing and tests of future cavities will be discussed.
	Slides TUAA04 [5.918 MB]
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TUAA06	Recent Progress of ESS Spoke and Elliptical Cryomodules	cryomodule, cavity, SRF, cryogenics	474
	G. Olry IPN, Orsay, France
	The ESS accelerator high level requirements are to provide a 2.86 ms long proton pulse at 2 GeV at repetition rate of 14 Hz. This represents 5 MW of average beam power with a 4% duty cycle on target. In a framework of collaboration between IPN Orsay, CEA Saclay and ESS, prototype spoke and medium and high beta elliptical cavities and cryomodules have been studied, constructed and tested. After a description of the ESS project and the accelerator layout, this paper will focus on the recent progress towards realization of the detailed design, the manufacturing of the first components of the prototype cryomodules and the first test results of some of the main critical elements such as SRF cavities and cold tuning systems.
	Slides TUAA06 [17.400 MB]
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TUPB007	Progress in the Elliptical Cavities and Cryomodule Demonstrators for the ESS LINAC	cryomodule, cavity, vacuum, cryogenics	544
	F. Peauger, C. Arcambal, S. Berry, N. Berton, P. Bosland, E. Cenni, J.-P. Charrier, G. Devanz, F. Éozénou, F. Gougnaud, A. Hamdi, X. Hanus, P. Hardy, V.M. Hennion, T. Joannem, F. Leseigneur, D. Loiseau, C. Madec, L. Maurice, O. Piquet, J. Plouin, J.P. Poupeau, B. Renard, D. Roudier, P. Sahuquet, C. Servouin CEA/DSM/IRFU, France C. Darve, N. Elias ESS, Lund, Sweden G. Olivier IPN, Orsay, France
	The European Spallation Source (ESS) accelerator is a large superconducting linac under construction in Lund, Sweden. A collaboration between CEA Saclay, IPN Orsay and ESS-AB is established to design the elliptical cavities cryomodule of the linac. It is foreseen to build and test two cryomodule demonstrators within the next two years. We present the design evolution and the fabrication status of the cryomodule components housing four cavities. The latest test results of two prototype cavities are shown. The cryomodule assembly process and the on-going testing infrastructures at CEA Saclay are also described.
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TUPB011	HPRF Transmission Componenets Study and Distribution in TRIUMF E-Linac	operation, klystron, simulation, TRIUMF	557
	Z.T. Ang TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF e-lianc was commissioning last September for the first stage. High power rf systems were in operation stable. Two 300 kW klystrons along with the key waveguide components were tested before feeding rf power into 1.3 GHz 9-cell superconducting cavities. The rf high power variable divider and 360 degree waveguide phase shifters are working successfully. The simulations on different waveguide structures for the power dividers, phase shifters have been studied. The comparisons of the calculation results are reported in the paper. The rf signal level tests of the components and waveguide distribution systems will also be present in this paper.
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TUPB012	LCLS-II High Power RF System Overview and Progress	cryomodule, LLRF, gun, radiation	562
	A.D. Yeremian, C. Adolphsen, J. Chan, G. DeContreras, K. Fant, C.D. Nantista SLAC, Menlo Park, California, USA
	Funding: Work supported by DoE, Contract No. DE-AC02-76SF00515 A second X-ray free electron laser facility, LCLS-II, will be constructed at SLAC. LCLS-II is based on a 1.3 GHz, 4 GeV, continuous-wave (CW) superconducting linear accelerator, to be installed in the first kilometer of the SLAC tunnel. Multiple types of high power RF (HPRF) sources will be used to power different systems on LCLS II. The main 1.3 GHz linac will be powered by 280 1.3 GHz, 3.8 kW solid state amplifier (SSA) sources. The normal conducting buncher in the injector will use four more such SSAs. Two 185.7 MHz, 60 kW sources will power the photocathode dual-feed RF gun. A third harmonic linac section, included for linearizing the bunch energy spread before the first bunch compressor, will require sixteen 3.9 GHz sources at about 1 kW CW. A diagnostic line at 94 MeV, for tuning and characterizing the beam prior to acceleration through the rest of the linac, will contain an S-band transverse deflection cavity (TCAV) to time-resolve the energy spread of the beam. A 2.856 GHZ model 5045 pulsed klystron already existing at SLAC will be used to power the TCAV. A description and an update on all the HPRF sources of LCLS-II and their implementation is the subject of this paper
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TUPB015	A New Cleanroom With Facilities for Cleaning and Assembly of Superconducting Cavities at Helmholtz-Institut Mainz	cavity, heavy-ion, status, ion	575
	F. Schlander, K. Aulenbacher, R.G. Heine IKP, Mainz, Germany K. Aulenbacher, W.A. Barth, V. Gettmann, M. Miski-Oglu HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	The Helmholtz-Institut Mainz HIM will operate a clean room facility for the assembly and possible re-treatment of superconducting cavities. This is mandatory for several SRF accelerator projects, like the advanced demonstrator for a dedicated sc heavy ion cw-linac at HIM or other projects pursued by research facilities or universities close by. While the installation of the clean room is in progress, the procurement of the appliances is ongoing. The present equipment planned and the current status of the installation will be presented.
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TUPB016	Progress on Superconducting Linac for the RAON Heavy Ion Accelerator	cavity, cryomodule, ion, electron	578
	H.J. Kim IBS, Daejeon, Republic of Korea
	The RISP (Rare Isotope Science Project) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from proton to uranium. Proton and uranium ions are accelerated upto 600 MeV and 200 MeV/u respectively. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the prototyping of superconducting cavity and cryomodule.
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TUPB020	Recent Status New Superconducting CW Heavy Ion LINAC@GSI	cavity, solenoid, heavy-ion, ion	589
	V. Gettmann, M. Amberg, K. Aulenbacher, W.A. Barth, M. Miski-Oglu HIM, Mainz, Germany M. Amberg, M. Basten, D. Bänsch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany K. Aulenbacher IKP, Mainz, Germany W.A. Barth, M. Heilmann, S. Mickat, S. Yaramyshev GSI, Darmstadt, Germany
	The demonstrator is a prototype of the first section of the proposed cw-LINAC@GSI, comprising a superconducting CH-cavity embedded by two superconducting solenoids. The sc CH-structure is the key component and offers a variety of research and development. The beam focusing solenoids provide maximum fields of 9.3 T at an overall length of 380 mm and a free beam aperture of 30 mm. The magnetic induction of the fringe is minimized to 50 mT at the inner NbTi-surface of the neighboring cavity. The fabrication of the key components is still in progress and is near to completion. After cold performance testing of the RF cavity, the helium jacket will be welded on. The cryostat is partly assembled and will be finished in the next weeks. The test environment is completely prepared. Advanced emittance measurement is foreseen to prepare for best matching of the heavy ion beam from the injector. Integration of the cryostat into the beam line, the first cool down of the module and commissioning of the RF elements will be performed as next steps towards a complete testing of the demonstrator.
	Poster TUPB020 [8.595 MB]
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TUPB021	Measurement of the Cavity Performances of Compact ERL Main Linac Cryomodule During Beam Operation	operation, cavity, radiation, cryomodule	592
	H. Sakai, M. Egi, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, K. Shinoe, K. Umemori KEK, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	We developed ERL main linac cryomodule for Compact ERL (cERL) in KEK. The module consists of two 9-cell 1.3 GHz superconducting cavities, two 20 kW high power coupler, two mechanical tuner and three HOM dampers. After construction of cERL recirculation loop, beam operation was started in 2013 Dec. First electron beam of 20 MeV successfully passed the main linac cavities. After adjusting beam optics, energy recovery operation was achieved. Main linac cavity was enough stable for ERL beam operation with digital LLRF system and energy recovery was successfully done with CW 80 uA beam. However, field emission was a problem for long term operation. In this paper, we express the measurement of the cavity performances of long term beam operation.
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TUPB024	Tuning the Linac With Superconducting Resonator Used as a Phase Detector	acceleration, detector, ion, bunching	602
	N.R. Lobanov, P. Linardakis, D. Tsifakis Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia
	The ANU Heavy Ion Facility is comprised of a 15 MV electrostatic accelerator and superconducting linac booster. The beam is double terminal stripped to provide high charge states at the entrance to the linac, which consists of twelve β=0.1 Split Loop Resonators (SLR). Each SLR needs to be individually tuned in phase and amplitude for optimum acceleration efficiency. The amplitude and phase of the superbuncher and time energy lens also have to be correctly set. The linac set up procedure developed at ANU utilises a beam profile monitor in the middle of a 180 degree achromat and a new technique based on a superconducting resonator operating in a beam bunch detection mode. Both techniques are used to derive a full set of phase distributions for quick and efficient setting up of the entire linac. Verification of the superconducting phase detector is accomplished during routine linac operations and is complemented by longitudinal phase space simulations. The new technique allows better resolution for setting the resonator acceleration phase and better sensitivity to accelerating current.
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TUPB025	Tuning the Superconducting Linac at Low Beam Intensities	ion, bunching, acceleration, operation	607
	N.R. Lobanov, P. Linardakis, D. Tsifakis Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia
	The ANU Heavy Ion Facility comprises a 15 MV electrostatic accelerator followed by a superconducting linac booster. The beam is foil stripped in the terminal and then stripped again to provide high charge states at the entrance to the linac. Employment of double terminal stripping allows the system to accelerate beams with mass up to 70 amu. The disadvantage of double terminal stripping is low beam intensity of few particle nA delivered to the linac. The linac encompasses twelve β=0.1 lead tin plated Split Loop Resonators (SLR) housed in four module cryostats. One of the linac set up procedures that developed at ANU utilises U-bend at the end of the linac. One special wide Beam Profile Monitor (BPM) is installed after 90 degrees magnet. The technique allows to set correct phase by observing the displacement of beam profile versus phase shift of the last phase locked resonator. In this paper a simple method has been proposed to improve sensitivity of commercially available BPM for efficient operation with low beam intensities. The system demonstrated very high stability, simplicity of operation and high reliability allowing sustained operation of the LINAC facility.
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TUPB071	Development and Testing of a 325 MHz beta0 = 0.82 Single-Spoke Cavity	cavity, vacuum, impedance, cryogenics	744
	C.S. Hopper, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen, H. Park JLab, Newport News, Virginia, USA
	A single-spoke cavity operating at 325 MHz with geometric beta of 0.82 has been developed and tested. Initial results* showed high levels of field emission which limited the achievable gradient. Several rounds of helium processing significantly improved the cavity performance. Here we discuss the development process and report on the improved results. *C.S. Hopper, HyeKyoung Park, and J.R. Delayen, “Cryogenic Testing of High-Velocity Spoke Cavities,” Proc. of the 27th Linear Accelerator Conference, Geneva, Switzerland, TUPP109, (2014).
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TUPB075	Measurements on the Superconducting 217 MHz CH Cavity During the Manufacturing Phase	cavity, simulation, operation, resonance	757
	F.D. Dziuba, M. Amberg, M. Basten, M. Busch, H. Podlech IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: GSI, HIM, BMBF Contr. No. 05P12RFRBL Since in future the existing UNILAC (Universal Linear Accelerator) will be used as an injector for the FAIR (Facility for Antiproton and Ion Research) project, a new superconducting (sc) continuous wave (cw) linac at GSI is proposed to keep the Super Heavy Element (SHE) program at a competitive high level. In this context, a sc 217 MHz crossbar-H-mode (CH) cavity has been designed at the Institute for Applied Physics (IAP), Frankfurt University, and was built at Research Instruments (RI) GmbH, Germany. The cavity serves as a first prototype to demonstrate the reliable operability under a realistic accelerator environment and its successful beam operation will be a milestone on the way to the new linac. In this contribution measurements during the production process of the cavity as well as corresponding simulations will be presented.
	Poster TUPB075 [2.476 MB]
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TUPB077	The Influence of Cooldown Conditions at Transition Temperature on the Quality Factor of Niobium Sputtered Quarter-Wave Resonators for HIE-ISOLDE	cavity, niobium, accelerating-gradient, cathode	765
	P. Zhang, G.J. Rosaz, A. Sublet, M. Therasse, W. Venturini Delsolaro CERN, Geneva, Switzerland
	Funding: This work has been supported partly by a Marie Curie Early Initial Training Network Fellowship of the European Community’s 7th Programme under contract number PITN-GA-2010-264330-CATHI. Superconducting quarter-wave resonators (QWRs) are to be used in the ongoing linac upgrade of the ISOLDE facility at CERN. The cavities are made of niobium sputtered on copper substrates. They will be operated at 101.28 MHz at 4.5 K providing 6 MV/m accelerating gradient with 10 W power dissipation. In recent measurements, we found the thermal gradient along the cavity during the niobium superconducting transition has an impact on the cavity quality factor. On the other hand, the speed of the cooling down through the superconducting transition turned out to have no influence on the cavity Q-factor.
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TUPB103	Cryomodule Protection for ARIEL e-Linac	cavity, cryomodule, beam-loading, vacuum	861
	Z.Y. Yao, R.E. Laxdal, W.R. Rawnsley, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The e-Linac cryomodules require high RF power, cryogenics, ultra-high vacuum, and precise mechanical adjustment. They require protection against of failures, like quench in the cavity, bad vacuum or multipacting in power couplers, low liquid helium level or high temperatures. The protection unit should stop RF power in the cryomodule in case of the listed failures. A Interlock Box is developed to implement protection function for the cryomodule. The paper will describe the design of Interlock Box for e-Linac cryomodule protection. As quench protection required, quench evolution analysis with RF transient analysis is investigated. The details of quench detection for e-Linac will also be reported.
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TUPB105	String Assembly for the EU-XFEL 3.9 GHz Module at DESY	cavity, alignment, vacuum, quadrupole	869
	M. Schmökel, R. Bandelmann, A. Daniel, A. Matheisen, P. Schilling, B. van der Horst DESY, Hamburg, Germany R. Paparella, P. Pierini, D. Sertore INFN/LASA, Segrate (MI), Italy
	For the injector of the EU- XFEL one so-called 3.9 GHz module is required. This special module houses eight 3.9 GHz s.c. cavities, a beam position monitor and a quadrupole package. The cavities were fabricated and vertically tested as an in-kind contribution to the EU-XFEL by INFN Milano collaborators. The power couplers have been fabricated and conditioned by FNAL. The string assembly took place inside the ISO 4 cleanroom at DESY. A seven meter long alignment and assembly girder for this special string assembly has been designed and fabricated at DESY. The girder facilitates the assembly of the 3.9 GHz resonators with alternating power coupler orientation in ISO 4 cleanrooms. For redundancy and fast action on problems during string assembly, the DESY high pressure rinsing system (HPR) has been modified on the basis of the INFN Milano design for this 3.9 GHz application. The HPR has been qualified by four 3.9 GHz resonators, tested at INFN Milano. The integration of the cavities into Helium vessels, power coupler coupling factor and the power coupler assembly at DESY is qualified by one cavity that has been equipped with Helium tank and a power coupler and tested horizontally.
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TUPB108	Connection of EU-XFEL Cryomodules, Caps, Boxes in EU-XFEL Main Linac and Injector: Welding of Cryo-Pipes and Assembly of Beam-Line Absorbers Under Requirements of PED Regulation	cryomodule, vacuum, cryogenics, operation	883
	S. Barbanotti, C. Buhr, H. Hintz, K. Jensch, L. Lilje, W. Maschmann, P. Pierini, A. Wagner DESY, Hamburg, Germany P. Pierini INFN/LASA, Segrate (MI), Italy
	The European X-ray Free Electron Laser (EU-XFEL) cold linac consists of 100 assembled cryomodules, 6 feed-/end-boxes and 6 string connection boxes fixed to the ceiling of the accelerator tunnel; the injector consists of a radio frequency gun, one 1.3 GHz and one 3.9 GHz cryomodule, one feed- and one end-cap lying on ground supports. The components are connected together in the tunnel, after cold testing, transport, final positioning and alignment. The cold linac is a pressure equipment and is therefore subjected to the requirements of the Pressure Equipment Directive (PED). This paper describes the welding and subsequent non-destructive testing of the cryo-pipes (with a deeper look at the technical solutions adopted to satisfy the PED requirements), the assembly of the beam line absorbers and the final steps before closing the connection with a DN1000 bellows. A special paragraph will be dedicated to the connection of the injector components, where the lack of space makes this installation a particularly challenging task.
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TUPB114	Transient Study of Beam Loading and Feed-Forward LLRF Control of ARIEL Superconducting RF e-LINAC	cavity, controls, beam-loading, feedback	902
	E. Thoeng UBC & TRIUMF, Vancouver, British Columbia, Canada R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	ARIEL e-LINAC is a ½ MW-class SRF accelerator operated at 10 mA of average current. In the initial commissioning, e-LINAC will be tested with increasing duty factors from 0.1% up to CW mode. During the pulsed mode operation, beam loading causes cavity gradient fluctuation and therefore transient behaviour of SRF Cavity gradient needs to be studied in order to determine how the Low-level RF (LLRF) should be implemented. Performance of LLRF control system with and without non-adaptive feed-forward are simulated to determine the resulting beam energy spread and experimental measurements are proposed to measure the increase of beam size due to beam loading.
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WEA2A01	High-Velocity Spoke Cavities	cavity, simulation, proton, ion	943
	C.S. Hopper ODU, Norfolk, Virginia, USA H. Park JLab, Newport News, Virginia, USA
	There are several current and recent projects which explore the feasibility of spoke-loaded cavities operating in the high-velocity region. Spoke cavities have a large number of geometric parameters which often influence multiple rf properties. Fabricating, handling, and processing these cavities presents some unique challenges, not unlike other TEM-class structures. This paper will summarize the current efforts toward the design, fabrication, and testing of spoke cavities with optimum beta greater than 0.8.
	Slides WEA2A01 [1.029 MB]
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WEBA02	RF Measurements for Quality Assurance During SC Cavity Mass Production	cavity, HOM, controls, GUI	955
	A.A. Sulimov DESY, Hamburg, Germany
	The publication will describe the comprehensive program and results of RF measurements taken during the mass production of superconducting cavities for the European XFEL.
	Slides WEBA02 [2.305 MB]
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WEBA03	Production Status of SRF Cavities for the Facility for Rare Isotope Beams (FRIB) Project	cavity, vacuum, niobium, controls	961
	C. Compton, A. Facco, S.J. Miller, J. Popielarski, L. Popielarski, A.P. Rauch, K. Saito, G.J. Velianoff, E.M. Wellman, K. Witgen, T. Xu FRIB, East Lansing, Michigan, USA
	As the Facility for Rare Isotope Beams (FRIB) project ramps into production, vendor relations, cavity quality, and schedule become critical to success. The driver linac will be constructed of 332 cavities housed in 48 cryomodules and designed with two cavity classes (quarter-wave and half-wave) and four different betas (0.041, 0.085, 0.29, and 0.53). The cavities will be supplied to FRIB from awarded industrial vendors. FRIB’s experience with SRF cavity fabrication will be presented including acceptance inspections, test results, technical issues, and mitigation strategies.
	Slides WEBA03 [1.672 MB]
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WEBA04	Performances of Spiral2 Low and High Beta Cryomodules	cryomodule, cavity, cryogenics, ion	967
	C. Marchand, P. Bosland, G. Devanz, O. Piquet CEA/IRFU, Gif-sur-Yvette, France P.-E. Bernaudin, R. Ferdinand GANIL, Caen, France Y. Gómez Martínez LPSC, Grenoble Cedex, France D. Longuevergne, G. Olry IPN, Orsay, France
	All SPIRAL2 cryomodules (twelve with one quarter wave resonator (QWR) at β=0.07 and seven with two QWRs at β=0.12) have been produced and qualified, and are now in installation phase on the LINAC at GANIL. After a general introduction on the LINAC, we will first remember and compare the different design choices taken for the two families of cryomodules. We will then present a summary of the techniques used for the preparation and integration of the cavities in the cryomodules, and compare the achieved performances with design parameters. At last, we describe the status of the LINAC installation as of end of August 2015.
	Slides WEBA04 [4.577 MB]
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WEBA06	Design Studies for Quarter-Wave Resonators and Cryomodules for the Riken SC-LINAC	cryomodule, beam-loading, simulation, ion	976
	N. Sakamoto, O. Kamigaito, H. Okuno, K. Ozeki, K. Suda, Y. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan H. Hara, K. Okihira, K. Sennyu, T. Yanagisawa MHI, Hiroshima, Japan E. Kako, H. Nakai, K. Umemori KEK, Ibaraki, Japan
	Recently we proposed a new project aimed at intensity upgrade of uranium beams of RIKEN RIBF. In this new project, construction of a superconducting linac is planned replacing the injector cyclotron so called RRC. The RIKEN superconducting linac consists of 14 cryomodules each of which contains four quarter-wave-resonators (QWRs) in each. The QWR operates at an rf frequency of 73 MHz in the continuous wave mode with beta as low as 0.055-1.008. A coaxial probe-type RF fundamental power-coupler which transmits RF power of several kW will be utilized for beam loading of 1.3 kW/resonator at the maximum with Qext of several x10⁶. Tuning of the resonant frequency will be realized with a mechanical tuner pressing the resonator wall in the direction parallel to the beam. This year, we started a development of a test cryomodule with SC-QWRs. In this paper, design studies for a SC-QWR and its cryomodule, e.g., QWR, coupler, and, tuner will be presented together with a construction schedule of the prototype. Prototyping of a superconducting cavity and its test cryomodule was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).
	Slides WEBA06 [17.564 MB]
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THAA06	Precise Studies on He-Processing and HPR for Recovery From Field Emission by Using X-Ray Mapping System	cavity, radiation, cryomodule, operation	1019
	H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori KEK, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	We usually met the degradation of superconducting RF cavity on the cryomodule test and beam operation even if the performance of this cavity is good on the vertical test (V.T). Field emission is the most severe problem for this degradation after reassembly work from vertical test. Not only high pressure rinsing (HPR) but also He-processing, which is more suitable method without the reassembly work for recovery, is recommended and tried to recover this degradation. However, we did not investigate the details of how field emission sources were processed and removed after HPR and He-processing. We deeply investigated the processing procedure during He-processing and how many field emission sources removed after HPR by using rotating X-ray mapping system* in V.T . *H.Sakai et.al., Proc. of IPAC10 p2950-2952.
	Slides THAA06 [4.347 MB]
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THBA05	Higher Order Mode Absorbers for High Current SRF Applications	HOM, cavity, higher-order-mode, operation	1036
	R.G. Eichhorn, J.V. Conway, T. Gruber, Y. He, G.H. Hoffstaetter, Y. Li, M. Liepe, T.I. O'Connell, P. Quigley, J. Sears, V.D. Shemelin, E.N. Smith, M. Tigner Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Efficient damping of the higher-order modes (HOMs) of the superconducting cavities is essential for any high current operation. The talk will provide an overview on the latest advances of HOM absorber development for high intensity SRF applications. As the ideal absorber does not exist, the different conceptual approaches will be presented and the associated issues are outlined. Design examples from various labs will be given that help explain the issues and resolutions. Some focus will be given to the Cornell HOM beamline absorber that was design for high current, short bunch operation with up to 400 W heating. The design will be reviewed and testing results will be reported.
	Slides THBA05 [4.022 MB]
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THBA06	Overview on Magnetic Field Management and Shielding in High Q Modules	cryomodule, cavity, cryogenics, shielding	1043
	G. Wu Fermilab, Batavia, Illinois, USA
	Funding: Work supported by FRA under DOE contract DE-AC02-07CH11359 Maintaining very high cavity Q0 in linac applications creates new challenges for cryomodule design. Magnetic shielding from both external fields and internal fields is required and its importance to thermal gradients during Tc transition is now emerging. This presentation will describe the design challenges and possible mitigation strategies with examples from various applications or laboratories including FRIB, LCLS-II, PIP-II, Cornell University and KEK.
	Slides THBA06 [1.839 MB]
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THPB002	Second Harmonic Cavity Design for Synchrotron Radiation Energy Compensator in eRHIC Project	cavity, HOM, impedance, radiation	1052
	C. Xu, S.A. Belomestnykh, I. Ben-Zvi, W. Xu BNL, Upton, Long Island, New York, USA
	Funding: DOE eRHIC project requires construction of a FFAG ring to accelerate electrons and connect to the existing ion ring of Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. This new ring will have the same radius as the RHIC ring. Synchrotron radiation lost in the electron ring should be compensated by a CW superconducting radio frequency (SRF) cavity. Here we propose an 845 MHz single cell harmonic cavity. This cavity will experience a high average current (∼0.7 A) passing through it. With this consideration, this cavity design requires optimization to reduce higher order mode power. On the other hand, the cavity will operate at relatively high gradient up to 18 MV/m. Current design requires fundamental couplers to handle 400 kW forward RF power and HOM couplers to extract 2.5 kW HOM power. This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
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THPB005	Simulations of 3.9 GHz CW Coupler for LCLS-II Project	cavity, simulation, operation, cryomodule	1066
	I.V. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak Fermilab, Batavia, Illinois, USA
	LCLS-II linac is based on XFEL/ILC superconducting technology. TTF-III fundamental power coupler for the 3.9 GHz 9-cell cavities has been modifies to satisfy requirements of LCLS-II, operating in CW regime. In this paper we discuss the results of COMSOL analysis of the possible modification of couplers, working at various operating regimes. We present also the results of mechanical study.
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THPB010	INFN Milano - LASA Activities for ESS	cavity, vacuum, niobium, cryomodule	1081
	P. Michelato, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, L. Monaco, M. Moretti, R. Paparella, P. Pierini, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy H.J. Zheng IHEP, Beijing, People's Republic of China
	INFN Milano – LASA is involved in the development and industrialization for the production of 704.4 MHz medium beta (β = 0.67) cavities for the ESS project. In this framework, we are designing a medium beta prototype cavity exploring both Large Grain and Fine Grain Niobium for its production as well as a high beta (β = 0.86) Large Grain cavity. In the meanwhile, an activity is ongoing for upgrading the LASA test facility to be able to test these kind of resonators.
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THPB015	Design of a Medium Beta Half-Wave SC Prototype Cavity at IMP	cavity, operation, electromagnetic-fields, accelerating-gradient	1097
	A.D. Wu, Y. He, T.C. Jiang, Y.M. Li, F.F. Wang, R.X. Wang, L.J. Wen, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China
	A superconducting half-wave resonator has been designed with frequency of 325 MHz and beta of 0.51. The geometry parameters and the three shapes of inner conductors (racetrack, ring-shape and elliptical-shape) were studied in details to decrease the peak electromagnetic fields to obtain higher accelerating gradients and minimize the dissipated power on the RF walls. To suppress the operation frequency shift caused by the helium pressure fluctuations and maximize the tuner ranges, the frequency shifts and mechanical characters were simulated in the electric and magnetic areas separately. At the end, the helium vessel was also designed to keep stability as possible. The fabrication and test of the prototype will be complete at the beginning of 2016.
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THPB025	Exchange and Repair of Titanium Service Pipes for the EXFEL Series Cavities	cavity, alignment, cryomodule, SRF	1122
	M. Schalwat, S. Barbanotti, A. Daniel, H. Hintz, K. Jensch, A. Matheisen, S. Saegebarth, P. Schilling DESY, Hamburg, Germany A. Schmidt XFEL. EU, Hamburg, Germany
	Longitudinally-welded 72 mm ID service pipes (HSP) made from titanium grade 2 is used by the two suppliers of the helium tanks for the EU-XFEL accelerator. From the perspective of the PED DESY is legally designated as the manufacturer and is responsible for conformity to all relevant codes. During module assemblies at CEA Saclay the orbital welds of the interconnection bellows between cavities showed pores with dimensions outside the specifications set by DESY. These welds needed to be redone which caused a project delay of several months. The X-ray examination of the HSP showed that the pipes already exhibited many out-of- DESY spec pores in the longitudinal welds and were most likely the main cause of the problems in the orbital welds. It was decided to replace the extremities of the service pipes with seamless titanium tubes both on “naked” helium tanks as well as on tanks with cavities already welded in. At DESY more than 750 service pipes were exchanged over a period of 2 years. The qualification of the repair line according to PED regulation and the prove with RF test at 2 K that the repairs do not influence the high performance of the s.c. cavities were done.
	Poster THPB025 [0.172 MB]
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THPB026	Update on SRF Cavity Design, Production and Testing for BERLinPro	cavity, gun, booster, HOM	1127
	A. Neumann, W. Anders, A. Burrill, A. Frahm, H.-W. Glock, J. Knobloch, O. Kugeler HZB, Berlin, Germany K. Brackebusch, T. Galek, J. Heller, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany G. Ciovati, W.A. Clemens, C. Dreyfuss, D. Forehand, T. Harris, P. Kneisel, R.B. Overton, L. Turlington JLab, Newport News, Virginia, USA E.N. Zaplatin FZJ, Jülich, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association. The BERLinPro Energy Recovery Linac (ERL) is currently being built at Helmholtz-Zentrum Berlin in order to study the accelerator physics of operating a high current, 100 mA, 50 MeV low emittance ERL utilizing all SRF cavity technology. For this machine three different types of SRF cavities are being developed. For the injector section, consisting of an SRF photoinjector and a three two cell booster cavity module, fabrication is completed. The cavities were designed at HZB and manufactured, processed and vertically tested at Jefferson Laboratory. In this paper we will review the design and production process of the two structures and show the latest horizontal acceptance tests at HZB prior to installation into the newly designed cryo-module. For the Linac cavity the latest cavity and module design studies are being shown.
	Poster THPB026 [1.535 MB]
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THPB028	ESS Medium Beta Cavity Prototypes Manufacturing	cavity, HOM, coupling, cryomodule	1136
	E. Cenni, C. Arcambal CEA/IRFU, Gif-sur-Yvette, France P. Bosland, G. Devanz, X. Hanus, P. Hardy, V.M. Hennion, F. Leseigneur, F. Peauger, J. Plouin, D. Roudier CEA/DSM/IRFU, France G. Costanza Lund University, Lund, Sweden C. Darve ESS, Lund, Sweden
	The ESS elliptical superconducting linac consists of two types of 704.42 MHz cavities, medium and high beta, to accelerate the beam from 216 MeV (spoke cavity linac) up to the full energy at 2 GeV. The last linac optimization, called Optimus+, has been carried out taking into account the limitations of SRF cavity performance (field emission). The medium and high-beta parts of the linac are composed of 36 and 84 elliptical cavities, with geometrical beta values of 0.67 and 0.86 respectively. We describe here the procedures and numerical analysis leading from half-cells to a complete medium cavity assembly, which take into account not only the frequency of the fundamental accelerating mode but also the higher order modes near the machine line. The half cell selection process to form dumb bells will be described, as well as the reshaping and trimming procedure.
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THPB032	Release Processes and Documentation Methods During Series Treatment of SRF Cavities for the European XFEL by Using an Engineering Data Management System	cavity, data-management, SRF, database	1154
	J. Iversen, J.A. Dammann, A. Matheisen, N. Steinhau-Kühl DESY, Hamburg, Germany
	For the European XFEL more than 800 superconducting cavities need to be treated. At least 65 quality documents per cavity have to be emitted and transferred to DESY by the vendor; two acceptance levels must be passed successfully to release a cavity for transportation to DESY. All quality documents, non-conformity reports and acceptance levels are automatically processed by using DESY’s Engineering Data Management System (EDMS). We summarize documentation methods, document transfer procedures, review and release processes; we describe the exchange of process information between customer and vendor; and report about experiences.
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THPB035	Fabrication of the 3.9 GHz SRF Structures for the European XFEL	cavity, controls, operation, status	1162
	P. Pierini, M. Bertucci, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, M. Moretti, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy A. Gresele Ettore Zanon S.p.A., Nuclear Division, Schio, Italy C.G. Maiano, P. Pierini, E. Vogel DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy M. Rizzi Ettore Zanon S.p.A., Schio, Italy
	One batch of 10 cavities has been completed and eight structures have been installed in the 3.9 GHz cryomodule for the European XFEL Injector operation. A second batch of 10 RF structures for a spare injector module is under fabrication. The fabrication has been performed according to the European Pressure Vessel regulations, as needed for the EXFEL operation. This paper describes the fabrication, quality control/assurance procedures and frequency preparation steps in order to achieve cavities at the correct frequency and length within the specifications.
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THPB038	XFEL Database Structure & Loading System	database, cavity, interface, status	1166
	S. Yasar, P.D. Gall, V. Gubarev DESY, Hamburg, Germany
	XFEL database was designed to store cavity production, preparation, and test data for the whole LINAC on the very detailed level: from half cells up to module tests. To load this amount of data (more than 140 files per cavity) in automatic regime the special Data Loading System was developed.
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THPB043	Alternative Fabrication Methods for the ARIEL e-Linac SRF Separator Cavity	cavity, niobium, SRF, induction	1185
	D.W. Storey Victoria University, Victoria, B.C., Canada R.E. Laxdal, N. Muller TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ARIEL e-Linac RF deflecting cavity is a 650 MHz superconducting deflecting mode cavity that will allow simultaneous beam delivery to both the Rare Isotope Beam program and an Energy Recovery Linac. The cavity will be operated at 4 K and with deflecting voltages of up 0.6 MV, resulting in a dissipated RF power of less than 1 W. Due to the modest performance requirements, alternative methods are being employed for the fabrication of this cavity. These include fabricating the entire cavity from reactor grade Niobium and welding the cavity using tungsten inert gas (TIG) welding in a high purity Argon environment. A post purification heat treatment will be performed in an RF induction oven to increase the cavity performance.
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THPB044	A Superconducting RF Deflecting Cavity for the ARIEL e-Linac Separator	cavity, HOM, electron, impedance	1187
	D.W. Storey Victoria University, Victoria, B.C., Canada R.E. Laxdal, L. Merminga, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A 650 MHz SRF deflecting mode cavity has been designed for the ARIEL e-Linac to separate interleaved beams heading towards either Rare Ion Beam production or a recirculation loop for energy recovery, allowing the e-Linac to provide beam delivery to multiple users simultaneously. The cavity geometry has been optimized for the ARIEL specifications, resulting in a very compact cavity with high shunt impedance and low dissipated power. Analyses have been performed on the susceptibility to multipacting, input coupling considering beam loading and microphonics, and extensive studies into the damping of transverse and longitudinal higher order modes. The pressure sensitivity, frequency tuning, and thermal behaviour have also been studied using ANSYS. The cavity design resulting from these considerations will be discussed here.
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THPB061	Performance of the Tuner Mechanism for SSR1 Resonators During Fully Integrated Tests at Fermilab	cavity, controls, niobium, resonance	1252
	D. Passarelli, J.P. Holzbauer, L. Ristori Fermilab, Batavia, Illinois, USA
	In the framework of the Proton Improvement Plan-II (PIPII) at Fermilab, a cavity tuner was developed to control the frequency of 325 MHz spoke resonators (SSR1). The behavior of the tuner mechanism and compliance with technical specifications were investigated through a campaign of experimental tests in operating conditions in the spoke test cryostat (STC) and at room temperature. Figures of merit for the tuner such as tuning range, stiffness, components hysteresis and overall performance were measured and are reported in this paper.
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THPB066	RF Analysis of Equator Welding Stability for the European XFEL Cavities	cavity, controls, HOM, factory	1272
	A.A. Sulimov DESY, Hamburg, Germany
	In order to guaranty a sufficient High Order Modes (HOM) damping in the European XFEL cavities, a detailed analysis of the mechanical cavity production was performed. The mechanical measurements are precise enough to control the shape of cavity parts, but cannot be used for a welded cavity. To estimate the shape deformation during equator welding, the eigenfrequencies of cavity cells are compared with frequencies of cavity parts. This simple RF analysis can indicate irregularity of 9 equator welds and was used in addition to control of mean values for longitudinal and transverse deformations.
	Poster THPB066 [0.148 MB]
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THPB074	High Current eRHIC Cavity Design and HOM Damping Scheme	cavity, HOM, damping, impedance	1297
	W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by LDRD program of Brookhaven Science Associates. A 422 MHz cavity was designed for high current FFAG lattice ERLs for high luminosity eRHIC. The cavity was optimized to be able to propagate all the HOMs out of the cavity for high BBU threshold current and low HOM power (loss factor). Coupling the full spectrum (up to 30 GHz) HOMs out of the cavity and delivering the HOM power (up to 8 kW) out of the cryomodule is a challenge. A damping scheme with 6 coaxial line HOM couplers for low frequency HOMs and 3 waveguide HOM dampers for high frequency (so that the waveguide is small) is proposed to damp the full spectrum and high power HOMs. This paper will present the cavity design and HOM damping scheme.
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THPB077	Modified TTF3 Couplers for LCLS-II	operation, vacuum, simulation, cavity	1306
	C. Adolphsen, K. Fant, Z. Li, C.D. Nantista, G. Stupakov, J. Tice, F.Y. Wang, L. Xiao SLAC, Menlo Park, California, USA I.V. Gonin, K. Premo, N. Solyak Fermilab, Batavia, Illinois, USA
	The LCLS-II 4 GeV SC electron linac will use 280 TESLA cavities and TTF3 couplers, modified for CW operation with input power up to about 7 kW. The coupler modifications include shortening the antenna to achieve higher Qext and thickening the copper plating on the warm section inner conductor to lower the peak temperature. Another change is the use a waveguide transition box that is machined out of a solid piece of aluminum, significantly reducing its cost and improving its fit to the warm coupler window section. This paper describes the changes, simulations of the coupler operation (heat loads and temperatures), rf processing results and CW tests with LCLS-II dressed cavities.
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THPB101	High Power Input Couplers for C-ADS	cavity, cryomodule, vacuum, proton	1383
	T.M. Huang, X. Chen, H.Y. Lin, Q. Ma, F. Meng, W.M. Pan, G.W. Wang, X.Y. Zhang IHEP, Beijing, People's Republic of China K.X. Gu Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	High power input couplers are key components of the superconducting system for China Accelerator Driven sub-critical System (C-ADS) project. For the first phase, C-ADS includes four types of superconducting cavities (SCCs) of two frequencies, 162.5 MHz HWR SCC and 325 MHz Spoke SCC up to the energy of 25 MeV. All input couplers for the SCCs are developed in IHEP. This paper will describe the development status of the high power input couplers for C-ADS.
	Poster THPB101 [0.430 MB]
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THPB103	High Power Coupler Test for ARIEL SC Cavities	vacuum, TRIUMF, cavity, cryomodule	1390
	Y. Ma, P.R. Harmer, D. Lang, R.E. Laxdal, B.S. Waraich, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF ARIEL[1](The Advanced Rare Isotope Laboratory) project employs five 1.3 GHz 9-cell superconducting elliptical cavities[2] for acceleration of 10 mA electron beam up to energy of 50 MeV. 100 kW CW RF power will be delivered into each cavity by means of pair of Power Couplers: 50 kW per each coupler. Before installing the power couplers with the cavities, they have to be assembled on Power Coupler Test Stand(PCTS) and conditioned with a 30 kW IOT. Six couplers have been conditioned at room temperature and four of them have been installed to the cavities and tested during beam commissioning. Test results of the power couplers will be described and discussed in this paper. #mayanyun@triumf.ca
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THPB109	ESS Spoke Cryomodule and Test Valve Box	cryomodule, cryogenics, vacuum, operation	1400
	D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, M. Pierens, E. Rampnoux IPN, Orsay, France C. Darve ESS, Lund, Sweden
	ESS project aims being the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the ESS linear accelerator includes 28 b=0.5 352.2 MHz SRF niobium double Spoke cavities. Paired in 13 cryomodules and held at 2K in a saturated helium bath those cavities will generate of an accelerating field of 9MV/m. The prototype Spoke cryomodule holds two cavities and their RF power couplers and integrates all the interfaces necessary to be operational within the linac machine. It is now being fabricated and its assembly will be performed with dedicated tooling and procedures in and out of the clean room. This prototype will be tested by the end of 2015 at IPNO site and then at full power at FREIA (Uppsala university) test stand. A valve box has thus been designed to take into account the specific features of this prototype cryomodule and of the cryogenic environments of both test sites. This valve box is also considered as a prototype of the cryogenic distribution of the linac Spoke section. This element will then be used for the tests of the series cryomodules. We propose to present this prototype Spoke cryomodule for ESS and the test valve box.
	Poster THPB109 [2.852 MB]
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THPB115	TRIUMF's Injector and Accelerator Cryomodules	cavity, cryomodule, TRIUMF, alignment	1409
	N. Muller, P.R. Harmer, J.J. Keir, D. Kishi, P. Kolb, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, A.K. Mitra, R.R. Nagimov, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF's ARIEL project includes a 50 MeV-10mA electron linear accelerator (e-Linac) using 1.3 GHz superconducting technology. The accelerator consists of three cryomodules; an injector cryomodule with one cavity and two accelerating cryomodules with two cavities each. One injector and one accelerator have been assembled and commissioned at TRIUMF with a second injector cryomodule being assembled for VECC in Kolkata. Both Injector and Accelerator cryomodules utilize a top-loaded cold mass design contained in a box-type cryomodule; design and early test results of both cryomodules are presented.
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FRAA01	Overview of Recent Tuner Development on Elliptical and Low-Beta Cavities	cavity, cryomodule, controls, operation	1425
	R. Paparella INFN/LASA, Segrate (MI), Italy
	The talk will provide an overview on the latest advances of tuner development for SRF applications. Issues and present approaches on how to resolve them will be emphasized for both TM and TEM cavities and examples from various labs and projects (XFEL, LCLS-II, ESS, SPL, ARIEL, SPIRAL2, FRIB, ANL, IFMIF) will be given in order to better explain issues and solutions. Details on author’s contributions to European-XFEL tuner activity for 1.3 GHz and 3.9 GHz cavities will be also shown.
	Slides FRAA01 [3.421 MB]
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FRAA04	Performance of the Cornell ERL Main Linac Prototype Cryomodule	cavity, HOM, cryomodule, operation	1437
	F. Furuta, B. Clasby, R.G. Eichhorn, B. Elmore, G.M. Ge, D. Gonnella, D.L. Hall, G.H. Hoffstaetter, R.P.K. Kaplan, J.J. Kaufman, M. Liepe, T.I. O'Connell, S. Posen, 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 has designed, fabricated, and tested (by the time of the conference) a high current (100 mA) CW SRF prototype cryomodule for the Cornell ERL. This talk will report on the design and performance of this very high Q0 CW cryomodule including design issues and mitigation strategies.
	Slides FRAA04 [4.614 MB]
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Paper

Title

Other Keywords

Page

MOAA01

FRIB Project: Moving to Production Phase

cavity, SRF, solenoid, cryomodule

1

K. Saito, H. Ao, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K.D. Davidson, K. Elliott, F. Feyzi, A.D. Fox, P.E. Gibson, L. Hodges, K. Holland, G. Kiupel, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, G.J. Velianoff, D.R. Victory, J. Wei, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng
FRIB, East Lansing, Michigan, USA
S.K. Chandrasekaran
Fermilab, Batavia, Illinois, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy
K. Hosoyama, M. Masuzawa
KEK, Ibaraki, Japan
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M.X. Xu
IMP/CAS, Lanzhou, People's Republic of China

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams (FRIB) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.

Slides MOAA01 [2.754 MB]

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MOAA02

Recent Progress with EU-XFEL

cryomodule, cavity, operation, cryogenics

14

D. Reschke
DESY, Hamburg, Germany

The superconducting accelerator of the European XFEL consists of the injector part and the main linac. The injector includes one 1.3 GHz accelerator module and one 3.9 GHz third-harmonic module, while the main linac will consist of 100 accelerator modules, operating at an average design gradient of 23.6 MV/m. The fabrication and surface treatment by industry as well as RF acceptance tests of the required 808 superconducting 1.3 GHz cavities are close to an end by the time of SRF15. The accelerator module assembly, testing and installation in the tunnel is in full swing. First steps of commissioning have been made. The status and results of cavity and module RF tests at 1.3 GHz and 3.9 GHz are presented.

Slides MOAA02 [2.903 MB]

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MOAA04

Overview of Recent SRF Developments for ERLs

SRF, gun, cavity, cryomodule

24

S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh
Stony Brook University, Stony Brook, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
This talk reviews SRF technology for Energy Recovery Linacs (ERLs). In particular, recent developments and results reported at the ERL2015 Workshop are highlighted. The talk covers facilities under construction, commissioning or operation, such as cERL at KEK, BERLinPro at HZB and R&D ERL at BNL, as well as facilities in the development phase. Future perspectives will be discussed.

Slides MOAA04 [5.376 MB]

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MOAA05

Status of the RISP Superconducting Heavy Ion Accelerator

cryomodule, ion, rfq, ECR

31

D. Jeon
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the the Institute for Basic Science funded by the Ministry of Science, ICT and Future Planning (MSIP) and the National Research Foundation (NRF) of Korea.
Construction of the RISP heavy ion accelerator facility is in progress in Korea. The driver linac is a superconducting linac that can accelerate uranium to proton beams, delivering 400 kW beam power to various targets. Prototyping and test of the superconducting cavities and cryomodules are proceeding. Prototype superconducting cavities were fabricated through domestic vendors and their vertical tests were performed in collaboration with TRIUMF. Vertical tests showed good performance of the prototype cavities, which verified that there were no significant issues of the cavity design and fabrication. SRF Test Facility is under construction to be completed by early 2016. Progress report of the RAON accelerator systems is presented.

Slides MOAA05 [5.587 MB]

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MOPB033

LCLS-II SRF Cavity Processing Protocol Development and Baseline Cavity Performance Demonstration

cavity, cryomodule, SRF, vacuum

159

M. Liepe, P. Bishop, H. Conklin, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, T. Gruber, D.L. Hall, G.H. Hoffstaetter, J.J. Kaufman, G. Kulina, J.T. Maniscalco, T.I. O'Connell, P. Quigley, D.M. Sabol, J. Sears, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
M. Checchin, A.C. Crawford, A. Grassellino, C.J. Grimm, A. Hocker, M. Martinello, O.S. Melnychuk, J.P. Ozelis, A. Romanenko, A.M. Rowe, D.A. Sergatskov, W.M. Soyars, R.P. Stanek, G. Wu
Fermilab, Batavia, Illinois, USA
E. Daly, G.K. Davis, M.A. Drury, J.F. Fischer, A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA
M.C. Ross
SLAC, Menlo Park, California, USA

Funding: Work supported, in part, by the US DOE and the LCLS-II Project under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-76SF00515.
The ”Linac Coherent Light Source-II” Project will construct a 4 GeV CW superconducting RF linac in the first kilometer of the existing SLAC linac tunnel. The baseline design calls for 280 1.3 GHz nine-cell cavities with an average intrinsic quality factor Q0 of 2.7·10¹⁰ at 2K and 16 MV/m accelerating gradient. The LCLS-II high Q0 cavity treatment protocol utilizes the reduction in BCS surface resistance by nitrogen doping of the RF surface layer, which was discovered originally at FNAL. Cornell University, FNAL, and TJNAF conducted a joint high Q0 R&D program with the goal of (a) exploring the robustness of the N-doping technique and establishing the LCLS-II cavity high Q0 processing protocol suitable for production use, and (b) demonstrating that this process can reliably achieve LCLS-II cavity specification in a production acceptance testing setting. In this paper we describe the LCLS-II cavity protocol and analyze combined cavity performance data from both vertical and horizontal testing at the three partner labs, which clearly shows that LCLS-II specifications were met, and thus demonstrates readiness for LCLS-II cavity production.

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MOPB039

Analysis of BCS RF Loss Dependence on N-Doping Protocols

cavity, niobium, SRF, operation

174

A.D. Palczewski, P. Dhakal, C.E. Reece
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 with supplemental funding from the LCLS-II Project U.S. DOE Contract No. DE-AC02-76SF00515.
We present a study on two parallel-path SRF cavities (one large grain and one fine grain, 1.3 GHz) which seeks to explain the correlation between the amount of nitrogen on the inner surface of a “nitrogen doped” SRF cavity and the change in the temperature dependant (packaged into term BCS) RF losses. For each doping/EP, the cavities were tested at multiple temperatures (2.0 K to 1.5 K in 0.1 K steps) to create a Q0 vs. Eacc vs. T matrix which then could be used to extract temperature dependant and independent components. After each test, the cavities were thermally cycled to 120 K and then re-cooled and retested to assess if evidence of hydrogen migration might appear even at a small level. In addition, TD-5 was also tested at fixed low field (Q0 vs. T) to fit standard BCS theory. In parallel, SIMS data was taken on like-treated samples to correlate the amount of nitrogen within the RF surface to the change in the temperature dependant fitting parameter “A”.**
[**] H.Tian et al., contributed to SRF2015.

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MOPB040

Performance of Dressed Cavities for the Jefferson Laboratory LCLS-II Prototype Cryomodule - With Comparison to the Pre-Dressed Performance

cavity, HOM, cryomodule, hardware

178

A.D. Palczewski, G.K. Davis
JLab, Newport News, Virginia, USA
F. Furuta, G.M. Ge, D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 with supplemental funding from the LCLS-II Project U.S. DOE Contract No. DE-AC02-76SF00515.
Initial vertical RF test results and quench studies for six of the eight undressed 9 cell cavities slated for use in the Jefferson laboratory LCLS-II prototype cryomodule were presented at IPAC2015*. For the final string 2 more cavities AES029 and AES030 (work done at Cornell) are being processed and tested for qualification before helium vessel welding. In addition, AES034 (initial R&D treatment) is being reworked with the current production protocol after a surface reset to improve the overall performance. After final qualification all 8 cavities will be welded into helium vessels and equipped with HOM couplers. In this paper we will present the final undressed and dressed vertical RF data comparing the changes in the surface resistance before their installation in the cryomodule string.
*A.D. Palczewski et al. Quench Studies of Six High Temperature Nitrogen Doped 9 Cell Cavities for use in the LCLS-II Prototype Cryo-module at Jefferson Laboratory, Proc. IPAC2015, WEPWI019, 2015.

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MOPB041

Cryomodule Testing of Nitrogen-Doped Cavities

cavity, cryomodule, HOM, SRF

182

D. Gonnella, B. Clasby, R.G. Eichhorn, B. Elmore, F. Furuta, G.M. Ge, D.L. Hall, Y. He, G.H. Hoffstaetter, J.J. Kaufman, P.N. Koufalis, M. Liepe, J.T. Maniscalco, T.I. O'Connell, P. Quigley, D.M. Sabol, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
A. Grassellino, C.J. Grimm, J.P. Holzbauer, O.S. Melnychuk, Y.M. Pischalnikov, A. Romanenko, W. Schappert, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA
A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA

Funding: DOE and the LCLS-II High Q Project
The Linac Coherent Light Source-II (LCLS-II) is a new FEL x-ray source that is planned to be constructed in the existing SLAC tunnel. In order to meet the required high Q0 specification of 2.7x10¹⁰ at 2 K and 16 MV/m, nitrogen-doping has been proposed as a preparation method for the SRF cavities in the linac. In order to test the feasibility of these goals, four nitrogen-doped cavities have been tested at Cornell in the Horizontal Test Cryomodule (HTC) in five separate tests. The first three tests consisted of cavities assembled in the HTC with high Q input coupler. The fourth test used the same cavity as the third but with the prototype high power LCLS-II coupler installed. Finally, the fifth test used a high power LCLS-II coupler, cavity tuner, and HOM antennas. Here we report on the results from these tests along with a systematic analysis of change in performance due to the various steps in preparing and assembling LCLS-II cavities for cryomodule operation. These results represent one of the final steps to demonstrate readiness for full prototype cryomodule assembly for LCLS-II.

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MOPB063

Design of the Superconducting LINAC for SARAF

cryomodule, cavity, solenoid, cryogenics

250

C. Madec
CEA, Gif-sur-Yvette, France
N. Bazin, L. Boudjaoui, R. Cubizolles, G. Ferrand, P. Hardy, C. Pes, N. Sellami
CEA/IRFU, Gif-sur-Yvette, France
P. Bertrand
GANIL, Caen, France
P. Brédy, B. Gastineau, N. Pichoff
CEA/DSM/IRFU, France

CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40.1 MeV. The SCL consists 4 cryomodules equipped with warm diagnostics. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.091), 176 MHz. As the last two identical welcome 7 HWR high-beta cavities (β = 0.181), 176 MHz. The beam is focused through the superconducting solenoids located between cavities housing steering coils. A Beam Position Monitor is placed upstream each solenoid. A diagnostic box containing a beam profiler, a bunch length monitor and a vacuum pump will be inserted between 2 consecutive cryomodules. The HWR cavities, the solenoid package and the cryomodules are being designed. These studies will be presented in this poster.

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MOPB065

Recent Measurements on the SC 325 MHz CH-Cavity

cavity, ion, heavy-ion, controls

255

M. Busch, M. Amberg, M. Basten, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany

Funding: Work supported by GSI, BMBF Contr. No. 06FY7102
At the Institute for Applied Physics (IAP), Frankfurt University, a sc 325 MHz CH-Cavity has been designed and fabricated. Successful tests at 4 K and 2 K with gradients up to 14.1 MV/m have been performed. The cavity is destined for a 11.4 AMeV 10 mA ion beam at the GSI UNILAC, Darmstadt. Consisting of 7 gaps and a geometrical beta of 0.16 this resonator is designed to provide a gradient of 5 MV/m. Novel features of this structure comprise a compact design, low electric peak fields, improved surface processing possibilities and power coupling. In addition a tuner system based on mechanically deformable bellow tuners attached inside the cavity and driven either by a stepping motor or a piezo actuator will keep the cavity on resonance. This contribution reports about the latest measurements on the cavity with the recently attached helium vessel and a renewed surface processing.

Poster MOPB065 [1.270 MB]

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MOPB066

R&D Status of the New Superconducting CW Heavy Ion LINAC@GSI

cavity, simulation, ion, operation

258

M. Basten, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech, M. Schwarz
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, M. Miski-Oglu
HIM, Mainz, Germany
W.A. Barth, V. Gettmann, M. Heilmann, S. Mickat
GSI, Darmstadt, Germany

To keep the ambitious Super Heavy Element (SHE) physics program at GSI competitive a superconducting (sc) continuous wave (cw) high intensity heavy ion LINAC is currently under progress as a multi-stage R&D program of GSI, HIM and IAP*. The baseline linac design consists of a high performance ion source, a new low energy beam transport line, an (cw) upgraded High Charge State Injector (HLI), and a matching line (1.4 MeV/u) which is followed by the new sc-DTL LINAC for post acceleration up to 7.3 MeV/u. In the present design the new cw-heavy ion LINAC comprises constant-beta sc Crossbar-H-mode (CH) cavities operated at 217 MHz. The advantages of the proposed beam dynamics concept applying a constant beta profile are easy manufacturing with minimized costs as well as a straightforward energy variation**. An important milestone will be the full performance test of the first CH cavity (Demonstrator), in a horizontal cryo module with beam. An advanced demonstrator setup comprising a string of cavities and focussing elements is proposed to build from 10 short CH-cavities with 8 gaps. The corresponding simulations and technical layout of the new cw heavy ion LINAC will be presented.
* W. Barth et al., Further R&D for a new Superconducting cw Heavy Ion LINAC@GSI, IPAC2014, THPME004
**M. Schwarz et al., Beam Dynamics for the sc cw Heavy Ion Linac at GSI, IPAC2015, THPF025

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MOPB067

Steps Towards Superconducting CW-LINAC for Heavy Ions at GSI

ion, heavy-ion, quadrupole, cavity

262

M. Miski-Oglu, M. Amberg, K. Aulenbacher, V. Gettmann
HIM, Mainz, Germany
W.A. Barth, M. Heilmann, S. Mickat, S. Yaramyshev
GSI, Darmstadt, Germany
M. Basten, D. Bänsch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany

Providing heavy ion beams for the ambitious experiment program at GSI, the Universal Linear Accelerator (UNILAC) serves as a powerful high duty factor (25%) accelerator. Beam time availability for SHE-research will be decreased due to the limitation of the UNILAC providing a proper beam for FAIR simultaneously. To keep the GSI-SHE program competitive on a high level, a standalone sc cw-LINAC in combination with the upgraded GSI High Charge State injector is planned to build. In preparation for this the first linac section (financed by HIM and partly by HGF-ARD-initiative) will be tested in 2015 as a demonstrator. After successful testing the construction of an extended cryomodule comprising two further, but shorter CH cavities is foreseen to test until end of 2017. In this contribution the measurement of the beam parameters at the entrance of CW-Demonstartor, the preliminary simulation of beam dynamics for the first stage of advanced demonstrator will be presented. As a final R&D step towards an entire linac an advanced cryo module comprising up to five CH cavities is envisaged for 2019 serving for first user experiments at the coulomb barrier.

Poster MOPB067 [2.807 MB]

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MOPB068

Pulsed SC Ion Linac as an Injector to Booster of Electron Ion Collider

ion, operation, cavity, proton

265

P.N. Ostroumov, Z.A. Conway, B. Mustapha
ANL, Argonne, USA
B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
The electron-ion collider (EIC) being developed at JLAB requires a new ion accelerator complex (IAC). The IAC includes a new linac and a booster accelerator facility. The new facility is required for the acceleration of ions from protons to lead for colliding beam experiments with electrons in the EIC storage ring. Originally, we proposed a pulsed linac which is based upon a NC front end, < 5 MeV/u, with a SC section for energies > 5 MeV/u and capable of providing 285 MeV protons and ~100 MeV/u lead ions for injection into the IAC booster. A recent cost optimization study of the IAC suggested that lower injection energy into the booster may reduce the overall project cost with ~120 MeV protons and ~40 MeV/u lead ions. Stronger space charge effects in the booster caused by lower injection energy will be mitigated by the booster design. In this paper we discuss both linac options.

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MOPB069

Superconducting Linac Upgrade Plan for the Second Target Station Project at SNS

cryomodule, cavity, HOM, accelerating-gradient

268

S.-H. Kim, M. Doleans, J. Galambos, M.P. Howell
ORNL, Oak Ridge, Tennessee, USA
J.D. Mammosser
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
The beam power of the Linac for the Second Target Station (STS) at the Spallation Neutron Source (SNS) will be doubled to 2.8 MW. For the energy upgrade seven additional cryomodules will be installed in the reserved space at the end of the linac tunnel to produce the linac output energy of 1.3 GeV. The cryomodules for STS will have some changes that do not require changes of overall layout based on the lessons learned from operational experience over the last 10 years and the high beta spare cryomodule developed in house. The average macro-pulse beam current for the STS will be 38 mA that is about 40 % increase from that for the present 1.4 MW operation. Plans for the existing cryomodules to support higher beam current for the STS is also presented in this paper.

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MOPB075

Experiences on Retreatment of EU-XFEL Series Cavities at DESY

cavity, controls, status, feedback

296

A. Matheisen, N. Krupka, S. Saegebarth, P. Schilling, N. Steinhau-Kühl, B. van der Horst
DESY, Hamburg, Germany

For the European XFEL (EU-XFEL), two industrial companies are responsible for the manufacture and surface preparation of the eight hundred superconducting cavities. The companies had to strictly follow the XFEL specification and document all production and preparation steps. No performance guaranties were required. Each cavity delivered by industry to DESY is tested in a vertical test at 2K. Resonators not reaching the performances defined for application at the EU-XFEL linear accelerator modules or showing leakage during cold RF tests have undergone a subsequent retreatment at DESY. Nearly 20% of the cavity production required retreatment, most of them by an additional high pressure rinsing. Some cavities received additional chemical treatment by BCP flash after the initial HPR did not cure the problem. The analysis of retreatments and quality control data available from the retreatment sequences and the workflow of retreatment will be presented.

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MOPB078

Mode Sensitivity Analysis of 704.4 MHz Superconducting RF Cavities

HOM, cavity, operation, dipole

311

K. Papke, F. Gerigk, S. Horvath-Mikulas, S. Papadopoulos, E. Pilicer, F. Pillon
CERN, Geneva, Switzerland
U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Due to the large variety of beam patterns considered for the superconducting proton linac (SPL) at CERN it is likely that the frequencies of some HOMs are close to machine lines during operation. Hence, in the interest of developing a method to shift HOM frequencies away from machine lines, we study the influence of cavity detuning and re-tuning (e.g. by Lorentz forces, field flatness tuning, frequency tuning during operation) on HOMs. The sensitivity of HOMs with respect to the fundamental mode was studied for a mono-cell and for 5-cell high-beta SPL cavities operating at 704.4 MHz. First, the variation of the HOMs during the flat-field tuning was measured. In this process, several detuning and re-tuning cycles were made to estimate the range of possible HOM frequency shifts. Secondly the effect of the frequency tuner on the HOMs is presented and finally the frequency shifts of all modes due to the cool down.

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MOPB080

Update and Status of Test Results of the XFEL Series Accelerator Modules

cryomodule, cavity, radiation, status

319

M. Wiencek, K. Kasprzak, A. Zwozniak
IFJ-PAN, Kraków, Poland
D. Kostin, D. Reschke, N. Walker
DESY, Hamburg, Germany

The European X-ray Free Electron Laser is under construction at DESY, Hamburg. During preparation for tunnel installation 100 Cryomodules are tested in a dedicated facility on the DESY campus. Up to now around 50 cryomodules have been measured at 2K. This paper describes the current status of the measurements, especially single cavity limitations. In addition we present a comparison between the vertical test results of the individual cavities and the corresponding performance measurements of the cavities once assembled into the accelerator string inside the cryomodule.

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MOPB083

Cooling Front Measurement of a 9-Cell Cavity via the Multi-Cell Temperature-Mapping System at Cornell University

cavity, SRF, experiment, electronics

324

G.M. Ge, R.G. Eichhorn, F. Furuta
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cooling speed significantly affects flux trapping of a SRF cavity, which will determine the residual resistance and the quality factor of the cavity. We measured the temperature distribution of a 9-cell cavity at different cooling speeds by the multi-cell T-map system of Cornell University. This paper proposed a method to evaluate the formation of a normal conducting island at different cooling speed. The fast cool-down and slow cool-down has been compared. We conclude that the slow cool-down freezes less normal conducting islands.

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MOPB084

Performance of Nitrogen-Doped 9-Cell SRF Cavities in Vertical Tests at Cornell University

cavity, SRF, superconducting-RF, HOM

328

G.M. Ge, R.G. Eichhorn, B. Elmore, F. Furuta, D. Gonnella, T. Gruber, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, T.I. O'Connell, J. Sears, E.N. Smith
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University treated five LCLS-II 9-cell cavities by nitrogen-doping recipe. In this paper, we reported the performance of these 9-cell cavities. In the treatments, the nitrogen recipes are slightly different. The cavities have been firstly doped under high nitrogen pressure; after the vertical tests some of the cavities has been reset the surface and re-doped under light nitrogen pressure. The detail of the cavity preparation and test results will be shown. The comparison of the different recipes will be discussed.

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MOPB086

Update and Status of Vertical Test Results of the European XFEL Series Cavities

cavity, status, cryomodule, niobium

337

N. Walker, D. Reschke, J. Schaffran, L. Steder
DESY, Hamburg, Germany
L. Monaco
INFN/LASA, Segrate (MI), Italy
M. Wiencek
IFJ-PAN, Kraków, Poland

The series production by two industrial vendors of the 800 1.3-GHz superconducting cavities for the European XFEL has been on-going since the beginning of 2013 and will conclude towards the end of this year. As of publication some 740 cavities (~93%) have been produced at an average rate of 6 cavities per week. As part of the acceptance testing, all cavities have undergone at least one vertical RF test at 2K at the AMTF facility at DESY. The acceptance criterion for module assembly is based on the concept of a “usable gradient”, which is defined as the maximum field taking into account Q0 performance and allowed thresholds for field emission, as well as breakdown limits. Approximate 20% of the cavities have undergone further surface treatment in the DESY infrastructure to improve their usable gradient performance. In this paper we present the performance statistics of the vertical test results, as well as an analysis of the limiting criteria for the usable gradient, and finally the impact of the surface retreatment on both usable gradient and Q0.

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MOPB088

HOM Measurements on the ARIEL eLINAC Cryomodules

HOM, cavity, simulation, cryomodule

347

P. Kolb, R.E. Laxdal, Y. Ma, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ARIEL eLINAC is a 50 MeV, 10 mA electron LINAC designed for the creation of rare isotopes via photo-fission. Future upgrade plans include the addition of a recirculating beam line to allow for either further energy increase of the beam beyond 50 MeV or to operate a free electron laser in an energy recovery mode. For both recirculating LINAC and ERL the higher order modes (HOM) have to be sufficiently suppressed to prevent beam-break-up. The design of the 1.3 GHz nine-cell cavity incorporated this requirement by including beam line absorbers on both ends of each cavity and an asymmetric beam pipe configuration on the cavity to allow trapped modes to propagate to the beam line absorbers. Measurements of the higher order modes on the completed injector cryomodule and the first cavity in the accelerating cryomodules will be shown and compared to simulations.

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MOPB095

SRF Cavity Processing and Chemical Etching Development for the FRIB Linac

cavity, SRF, controls, operation

373

I.M. Malloch, E.S. Metzgar, L. Popielarski
FRIB, East Lansing, Michigan, USA
M.J. LaVere
MSU, 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, the State of Michigan and Michigan State University.
In preparation of a rigorous superconducting RF (SRF) cavity processing and test plan for the production of the Facility for Rare Isotope Beams (FRIB) driver linac, a state-of-the-art chemical etching tool has been installed in the FRIB coldmass production facility. This paper seeks to summarize the etching equipment design, installation, and validation program and subsequent etching results for a variety of SRF cavity types and etching configurations. Bulk etching, light etching, and custom (frequency tuning) etching results for different FRIB cavities are discussed. Special emphasis is placed on the etching removal uniformity and frequency tuning reliability of these processes.

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TUAA02

Commissioning of the SRF Linac for ARIEL

cavity, cryomodule, TRIUMF, electron

457

V. Zvyagintsev, Z.T. Ang, T. Au, S. Calic, K. Fong, P.R. Harmer, B. Jakovljevic, J.J. Keir, D. Kishi, P. Kolb, S.R. Koscielniak, A. Koveshnikov, C. Laforge, D. Lang, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, N. Muller, R.R. Nagimov, W.R. Rawnsley, R.W. Shanks, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, Q. Zheng
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

This paper is reporting commissioning results for the SRF linac of ARIEL facility at TRIUMF. The paper is focused on the SRF challenges: cavity design and performance, ancillaries design and preparation, cryomodule design and performance, RF system and final beam test results.

Slides TUAA02 [4.004 MB]

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TUAA04

Rapid Growth of SRF in India

cavity, niobium, SRF, electron

467

D. Kanjilal
IUAC, New Delhi, India

Funding: Funding received from Ministry of Higher Education through University Grants Commission of India and from Department of Atomic Energy are gratefully acknowledged.
The talk shall summarize the recent advances in the SRF program in various research centres in India. The SRF related activities at Inter-University Accelerator Centre (IUAC) at Delhi , Raja Ramanna Centre for Advanced Technology (RRCAT) at Indore, Bhabha Atomic Research Centre (BARC) and Tata Institute of Fundamental Research (TIFR) both at Mumbai, and Variable Energy Cyclotron Centre (VECC) at Kolkata shall be addressed. In particular indigenous niobium resonator fabrication and test facilities of IUAC operational for more than a decade which have been used extensively for development, fabrication and utilization of various types of resonators will be discussed. The results from the commissioning of the full three linac modules having eight niobium quarter wave resonators in each module of the heavy ion linac at IUAC for regular scheduled experiments will be presented. The technology and infrastructure developments at RRCAT, BARC, TIFR and VECC for fabrication, processing and tests of future cavities will be discussed.

Slides TUAA04 [5.918 MB]

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TUAA06

Recent Progress of ESS Spoke and Elliptical Cryomodules

cryomodule, cavity, SRF, cryogenics

474

G. Olry
IPN, Orsay, France

The ESS accelerator high level requirements are to provide a 2.86 ms long proton pulse at 2 GeV at repetition rate of 14 Hz. This represents 5 MW of average beam power with a 4% duty cycle on target. In a framework of collaboration between IPN Orsay, CEA Saclay and ESS, prototype spoke and medium and high beta elliptical cavities and cryomodules have been studied, constructed and tested. After a description of the ESS project and the accelerator layout, this paper will focus on the recent progress towards realization of the detailed design, the manufacturing of the first components of the prototype cryomodules and the first test results of some of the main critical elements such as SRF cavities and cold tuning systems.

Slides TUAA06 [17.400 MB]

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TUPB007

Progress in the Elliptical Cavities and Cryomodule Demonstrators for the ESS LINAC

cryomodule, cavity, vacuum, cryogenics

544

F. Peauger, C. Arcambal, S. Berry, N. Berton, P. Bosland, E. Cenni, J.-P. Charrier, G. Devanz, F. Éozénou, F. Gougnaud, A. Hamdi, X. Hanus, P. Hardy, V.M. Hennion, T. Joannem, F. Leseigneur, D. Loiseau, C. Madec, L. Maurice, O. Piquet, J. Plouin, J.P. Poupeau, B. Renard, D. Roudier, P. Sahuquet, C. Servouin
CEA/DSM/IRFU, France
C. Darve, N. Elias
ESS, Lund, Sweden
G. Olivier
IPN, Orsay, France

The European Spallation Source (ESS) accelerator is a large superconducting linac under construction in Lund, Sweden. A collaboration between CEA Saclay, IPN Orsay and ESS-AB is established to design the elliptical cavities cryomodule of the linac. It is foreseen to build and test two cryomodule demonstrators within the next two years. We present the design evolution and the fabrication status of the cryomodule components housing four cavities. The latest test results of two prototype cavities are shown. The cryomodule assembly process and the on-going testing infrastructures at CEA Saclay are also described.

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TUPB011

HPRF Transmission Componenets Study and Distribution in TRIUMF E-Linac

operation, klystron, simulation, TRIUMF

557

Z.T. Ang
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF e-lianc was commissioning last September for the first stage. High power rf systems were in operation stable. Two 300 kW klystrons along with the key waveguide components were tested before feeding rf power into 1.3 GHz 9-cell superconducting cavities. The rf high power variable divider and 360 degree waveguide phase shifters are working successfully. The simulations on different waveguide structures for the power dividers, phase shifters have been studied. The comparisons of the calculation results are reported in the paper. The rf signal level tests of the components and waveguide distribution systems will also be present in this paper.

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TUPB012

LCLS-II High Power RF System Overview and Progress

cryomodule, LLRF, gun, radiation

562

A.D. Yeremian, C. Adolphsen, J. Chan, G. DeContreras, K. Fant, C.D. Nantista
SLAC, Menlo Park, California, USA

Funding: Work supported by DoE, Contract No. DE-AC02-76SF00515
A second X-ray free electron laser facility, LCLS-II, will be constructed at SLAC. LCLS-II is based on a 1.3 GHz, 4 GeV, continuous-wave (CW) superconducting linear accelerator, to be installed in the first kilometer of the SLAC tunnel. Multiple types of high power RF (HPRF) sources will be used to power different systems on LCLS II. The main 1.3 GHz linac will be powered by 280 1.3 GHz, 3.8 kW solid state amplifier (SSA) sources. The normal conducting buncher in the injector will use four more such SSAs. Two 185.7 MHz, 60 kW sources will power the photocathode dual-feed RF gun. A third harmonic linac section, included for linearizing the bunch energy spread before the first bunch compressor, will require sixteen 3.9 GHz sources at about 1 kW CW. A diagnostic line at 94 MeV, for tuning and characterizing the beam prior to acceleration through the rest of the linac, will contain an S-band transverse deflection cavity (TCAV) to time-resolve the energy spread of the beam. A 2.856 GHZ model 5045 pulsed klystron already existing at SLAC will be used to power the TCAV. A description and an update on all the HPRF sources of LCLS-II and their implementation is the subject of this paper

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TUPB015

A New Cleanroom With Facilities for Cleaning and Assembly of Superconducting Cavities at Helmholtz-Institut Mainz

cavity, heavy-ion, status, ion

575

F. Schlander, K. Aulenbacher, R.G. Heine
IKP, Mainz, Germany
K. Aulenbacher, W.A. Barth, V. Gettmann, M. Miski-Oglu
HIM, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

The Helmholtz-Institut Mainz HIM will operate a clean room facility for the assembly and possible re-treatment of superconducting cavities. This is mandatory for several SRF accelerator projects, like the advanced demonstrator for a dedicated sc heavy ion cw-linac at HIM or other projects pursued by research facilities or universities close by. While the installation of the clean room is in progress, the procurement of the appliances is ongoing. The present equipment planned and the current status of the installation will be presented.

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TUPB016

Progress on Superconducting Linac for the RAON Heavy Ion Accelerator

cavity, cryomodule, ion, electron

578

H.J. Kim
IBS, Daejeon, Republic of Korea

The RISP (Rare Isotope Science Project) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from proton to uranium. Proton and uranium ions are accelerated upto 600 MeV and 200 MeV/u respectively. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the prototyping of superconducting cavity and cryomodule.

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TUPB020

Recent Status New Superconducting CW Heavy Ion LINAC@GSI

cavity, solenoid, heavy-ion, ion

589

V. Gettmann, M. Amberg, K. Aulenbacher, W.A. Barth, M. Miski-Oglu
HIM, Mainz, Germany
M. Amberg, M. Basten, D. Bänsch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
K. Aulenbacher
IKP, Mainz, Germany
W.A. Barth, M. Heilmann, S. Mickat, S. Yaramyshev
GSI, Darmstadt, Germany

The demonstrator is a prototype of the first section of the proposed cw-LINAC@GSI, comprising a superconducting CH-cavity embedded by two superconducting solenoids. The sc CH-structure is the key component and offers a variety of research and development. The beam focusing solenoids provide maximum fields of 9.3 T at an overall length of 380 mm and a free beam aperture of 30 mm. The magnetic induction of the fringe is minimized to 50 mT at the inner NbTi-surface of the neighboring cavity. The fabrication of the key components is still in progress and is near to completion. After cold performance testing of the RF cavity, the helium jacket will be welded on. The cryostat is partly assembled and will be finished in the next weeks. The test environment is completely prepared. Advanced emittance measurement is foreseen to prepare for best matching of the heavy ion beam from the injector. Integration of the cryostat into the beam line, the first cool down of the module and commissioning of the RF elements will be performed as next steps towards a complete testing of the demonstrator.

Poster TUPB020 [8.595 MB]

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TUPB021

Measurement of the Cavity Performances of Compact ERL Main Linac Cryomodule During Beam Operation

operation, cavity, radiation, cryomodule

592

H. Sakai, M. Egi, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

We developed ERL main linac cryomodule for Compact ERL (cERL) in KEK. The module consists of two 9-cell 1.3 GHz superconducting cavities, two 20 kW high power coupler, two mechanical tuner and three HOM dampers. After construction of cERL recirculation loop, beam operation was started in 2013 Dec. First electron beam of 20 MeV successfully passed the main linac cavities. After adjusting beam optics, energy recovery operation was achieved. Main linac cavity was enough stable for ERL beam operation with digital LLRF system and energy recovery was successfully done with CW 80 uA beam. However, field emission was a problem for long term operation. In this paper, we express the measurement of the cavity performances of long term beam operation.

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TUPB024

Tuning the Linac With Superconducting Resonator Used as a Phase Detector

acceleration, detector, ion, bunching

602

N.R. Lobanov, P. Linardakis, D. Tsifakis
Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia

The ANU Heavy Ion Facility is comprised of a 15 MV electrostatic accelerator and superconducting linac booster. The beam is double terminal stripped to provide high charge states at the entrance to the linac, which consists of twelve β=0.1 Split Loop Resonators (SLR). Each SLR needs to be individually tuned in phase and amplitude for optimum acceleration efficiency. The amplitude and phase of the superbuncher and time energy lens also have to be correctly set. The linac set up procedure developed at ANU utilises a beam profile monitor in the middle of a 180 degree achromat and a new technique based on a superconducting resonator operating in a beam bunch detection mode. Both techniques are used to derive a full set of phase distributions for quick and efficient setting up of the entire linac. Verification of the superconducting phase detector is accomplished during routine linac operations and is complemented by longitudinal phase space simulations. The new technique allows better resolution for setting the resonator acceleration phase and better sensitivity to accelerating current.

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TUPB025

Tuning the Superconducting Linac at Low Beam Intensities

ion, bunching, acceleration, operation

607

N.R. Lobanov, P. Linardakis, D. Tsifakis
Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia

The ANU Heavy Ion Facility comprises a 15 MV electrostatic accelerator followed by a superconducting linac booster. The beam is foil stripped in the terminal and then stripped again to provide high charge states at the entrance to the linac. Employment of double terminal stripping allows the system to accelerate beams with mass up to 70 amu. The disadvantage of double terminal stripping is low beam intensity of few particle nA delivered to the linac. The linac encompasses twelve β=0.1 lead tin plated Split Loop Resonators (SLR) housed in four module cryostats. One of the linac set up procedures that developed at ANU utilises U-bend at the end of the linac. One special wide Beam Profile Monitor (BPM) is installed after 90 degrees magnet. The technique allows to set correct phase by observing the displacement of beam profile versus phase shift of the last phase locked resonator. In this paper a simple method has been proposed to improve sensitivity of commercially available BPM for efficient operation with low beam intensities. The system demonstrated very high stability, simplicity of operation and high reliability allowing sustained operation of the LINAC facility.

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TUPB071

Development and Testing of a 325 MHz beta0 = 0.82 Single-Spoke Cavity

cavity, vacuum, impedance, cryogenics

744

C.S. Hopper, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
J.R. Delayen, H. Park
JLab, Newport News, Virginia, USA

A single-spoke cavity operating at 325 MHz with geometric beta of 0.82 has been developed and tested. Initial results* showed high levels of field emission which limited the achievable gradient. Several rounds of helium processing significantly improved the cavity performance. Here we discuss the development process and report on the improved results.
*C.S. Hopper, HyeKyoung Park, and J.R. Delayen, “Cryogenic Testing of High-Velocity Spoke Cavities,” Proc. of the 27th Linear Accelerator Conference, Geneva, Switzerland, TUPP109, (2014).

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TUPB075

Measurements on the Superconducting 217 MHz CH Cavity During the Manufacturing Phase

cavity, simulation, operation, resonance

757

F.D. Dziuba, M. Amberg, M. Basten, M. Busch, H. Podlech
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

Funding: GSI, HIM, BMBF Contr. No. 05P12RFRBL
Since in future the existing UNILAC (Universal Linear Accelerator) will be used as an injector for the FAIR (Facility for Antiproton and Ion Research) project, a new superconducting (sc) continuous wave (cw) linac at GSI is proposed to keep the Super Heavy Element (SHE) program at a competitive high level. In this context, a sc 217 MHz crossbar-H-mode (CH) cavity has been designed at the Institute for Applied Physics (IAP), Frankfurt University, and was built at Research Instruments (RI) GmbH, Germany. The cavity serves as a first prototype to demonstrate the reliable operability under a realistic accelerator environment and its successful beam operation will be a milestone on the way to the new linac. In this contribution measurements during the production process of the cavity as well as corresponding simulations will be presented.

Poster TUPB075 [2.476 MB]

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TUPB077

The Influence of Cooldown Conditions at Transition Temperature on the Quality Factor of Niobium Sputtered Quarter-Wave Resonators for HIE-ISOLDE

cavity, niobium, accelerating-gradient, cathode

765

P. Zhang, G.J. Rosaz, A. Sublet, M. Therasse, W. Venturini Delsolaro
CERN, Geneva, Switzerland

Funding: This work has been supported partly by a Marie Curie Early Initial Training Network Fellowship of the European Community’s 7th Programme under contract number PITN-GA-2010-264330-CATHI.
Superconducting quarter-wave resonators (QWRs) are to be used in the ongoing linac upgrade of the ISOLDE facility at CERN. The cavities are made of niobium sputtered on copper substrates. They will be operated at 101.28 MHz at 4.5 K providing 6 MV/m accelerating gradient with 10 W power dissipation. In recent measurements, we found the thermal gradient along the cavity during the niobium superconducting transition has an impact on the cavity quality factor. On the other hand, the speed of the cooling down through the superconducting transition turned out to have no influence on the cavity Q-factor.

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TUPB103

Cryomodule Protection for ARIEL e-Linac

cavity, cryomodule, beam-loading, vacuum

861

Z.Y. Yao, R.E. Laxdal, W.R. Rawnsley, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The e-Linac cryomodules require high RF power, cryogenics, ultra-high vacuum, and precise mechanical adjustment. They require protection against of failures, like quench in the cavity, bad vacuum or multipacting in power couplers, low liquid helium level or high temperatures. The protection unit should stop RF power in the cryomodule in case of the listed failures. A Interlock Box is developed to implement protection function for the cryomodule. The paper will describe the design of Interlock Box for e-Linac cryomodule protection. As quench protection required, quench evolution analysis with RF transient analysis is investigated. The details of quench detection for e-Linac will also be reported.

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TUPB105

String Assembly for the EU-XFEL 3.9 GHz Module at DESY

cavity, alignment, vacuum, quadrupole

869

M. Schmökel, R. Bandelmann, A. Daniel, A. Matheisen, P. Schilling, B. van der Horst
DESY, Hamburg, Germany
R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy

For the injector of the EU- XFEL one so-called 3.9 GHz module is required. This special module houses eight 3.9 GHz s.c. cavities, a beam position monitor and a quadrupole package. The cavities were fabricated and vertically tested as an in-kind contribution to the EU-XFEL by INFN Milano collaborators. The power couplers have been fabricated and conditioned by FNAL. The string assembly took place inside the ISO 4 cleanroom at DESY. A seven meter long alignment and assembly girder for this special string assembly has been designed and fabricated at DESY. The girder facilitates the assembly of the 3.9 GHz resonators with alternating power coupler orientation in ISO 4 cleanrooms. For redundancy and fast action on problems during string assembly, the DESY high pressure rinsing system (HPR) has been modified on the basis of the INFN Milano design for this 3.9 GHz application. The HPR has been qualified by four 3.9 GHz resonators, tested at INFN Milano. The integration of the cavities into Helium vessels, power coupler coupling factor and the power coupler assembly at DESY is qualified by one cavity that has been equipped with Helium tank and a power coupler and tested horizontally.

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TUPB108

Connection of EU-XFEL Cryomodules, Caps, Boxes in EU-XFEL Main Linac and Injector: Welding of Cryo-Pipes and Assembly of Beam-Line Absorbers Under Requirements of PED Regulation

cryomodule, vacuum, cryogenics, operation

883

S. Barbanotti, C. Buhr, H. Hintz, K. Jensch, L. Lilje, W. Maschmann, P. Pierini, A. Wagner
DESY, Hamburg, Germany
P. Pierini
INFN/LASA, Segrate (MI), Italy

The European X-ray Free Electron Laser (EU-XFEL) cold linac consists of 100 assembled cryomodules, 6 feed-/end-boxes and 6 string connection boxes fixed to the ceiling of the accelerator tunnel; the injector consists of a radio frequency gun, one 1.3 GHz and one 3.9 GHz cryomodule, one feed- and one end-cap lying on ground supports. The components are connected together in the tunnel, after cold testing, transport, final positioning and alignment. The cold linac is a pressure equipment and is therefore subjected to the requirements of the Pressure Equipment Directive (PED). This paper describes the welding and subsequent non-destructive testing of the cryo-pipes (with a deeper look at the technical solutions adopted to satisfy the PED requirements), the assembly of the beam line absorbers and the final steps before closing the connection with a DN1000 bellows. A special paragraph will be dedicated to the connection of the injector components, where the lack of space makes this installation a particularly challenging task.

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TUPB114

Transient Study of Beam Loading and Feed-Forward LLRF Control of ARIEL Superconducting RF e-LINAC

cavity, controls, beam-loading, feedback

902

E. Thoeng
UBC & TRIUMF, Vancouver, British Columbia, Canada
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

ARIEL e-LINAC is a ½ MW-class SRF accelerator operated at 10 mA of average current. In the initial commissioning, e-LINAC will be tested with increasing duty factors from 0.1% up to CW mode. During the pulsed mode operation, beam loading causes cavity gradient fluctuation and therefore transient behaviour of SRF Cavity gradient needs to be studied in order to determine how the Low-level RF (LLRF) should be implemented. Performance of LLRF control system with and without non-adaptive feed-forward are simulated to determine the resulting beam energy spread and experimental measurements are proposed to measure the increase of beam size due to beam loading.

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WEA2A01

High-Velocity Spoke Cavities

cavity, simulation, proton, ion

943

C.S. Hopper
ODU, Norfolk, Virginia, USA
H. Park
JLab, Newport News, Virginia, USA

There are several current and recent projects which explore the feasibility of spoke-loaded cavities operating in the high-velocity region. Spoke cavities have a large number of geometric parameters which often influence multiple rf properties. Fabricating, handling, and processing these cavities presents some unique challenges, not unlike other TEM-class structures. This paper will summarize the current efforts toward the design, fabrication, and testing of spoke cavities with optimum beta greater than 0.8.

Slides WEA2A01 [1.029 MB]

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WEBA02

RF Measurements for Quality Assurance During SC Cavity Mass Production

cavity, HOM, controls, GUI

955

A.A. Sulimov
DESY, Hamburg, Germany

The publication will describe the comprehensive program and results of RF measurements taken during the mass production of superconducting cavities for the European XFEL.

Slides WEBA02 [2.305 MB]

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WEBA03

Production Status of SRF Cavities for the Facility for Rare Isotope Beams (FRIB) Project

cavity, vacuum, niobium, controls

961

C. Compton, A. Facco, S.J. Miller, J. Popielarski, L. Popielarski, A.P. Rauch, K. Saito, G.J. Velianoff, E.M. Wellman, K. Witgen, T. Xu
FRIB, East Lansing, Michigan, USA

As the Facility for Rare Isotope Beams (FRIB) project ramps into production, vendor relations, cavity quality, and schedule become critical to success. The driver linac will be constructed of 332 cavities housed in 48 cryomodules and designed with two cavity classes (quarter-wave and half-wave) and four different betas (0.041, 0.085, 0.29, and 0.53). The cavities will be supplied to FRIB from awarded industrial vendors. FRIB’s experience with SRF cavity fabrication will be presented including acceptance inspections, test results, technical issues, and mitigation strategies.

Slides WEBA03 [1.672 MB]

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WEBA04

Performances of Spiral2 Low and High Beta Cryomodules

cryomodule, cavity, cryogenics, ion

967

C. Marchand, P. Bosland, G. Devanz, O. Piquet
CEA/IRFU, Gif-sur-Yvette, France
P.-E. Bernaudin, R. Ferdinand
GANIL, Caen, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
D. Longuevergne, G. Olry
IPN, Orsay, France

All SPIRAL2 cryomodules (twelve with one quarter wave resonator (QWR) at β=0.07 and seven with two QWRs at β=0.12) have been produced and qualified, and are now in installation phase on the LINAC at GANIL. After a general introduction on the LINAC, we will first remember and compare the different design choices taken for the two families of cryomodules. We will then present a summary of the techniques used for the preparation and integration of the cavities in the cryomodules, and compare the achieved performances with design parameters. At last, we describe the status of the LINAC installation as of end of August 2015.

Slides WEBA04 [4.577 MB]

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WEBA06

Design Studies for Quarter-Wave Resonators and Cryomodules for the Riken SC-LINAC

cryomodule, beam-loading, simulation, ion

976

N. Sakamoto, O. Kamigaito, H. Okuno, K. Ozeki, K. Suda, Y. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan
H. Hara, K. Okihira, K. Sennyu, T. Yanagisawa
MHI, Hiroshima, Japan
E. Kako, H. Nakai, K. Umemori
KEK, Ibaraki, Japan

Recently we proposed a new project aimed at intensity upgrade of uranium beams of RIKEN RIBF. In this new project, construction of a superconducting linac is planned replacing the injector cyclotron so called RRC. The RIKEN superconducting linac consists of 14 cryomodules each of which contains four quarter-wave-resonators (QWRs) in each. The QWR operates at an rf frequency of 73 MHz in the continuous wave mode with beta as low as 0.055-1.008. A coaxial probe-type RF fundamental power-coupler which transmits RF power of several kW will be utilized for beam loading of 1.3 kW/resonator at the maximum with Qext of several x10⁶. Tuning of the resonant frequency will be realized with a mechanical tuner pressing the resonator wall in the direction parallel to the beam. This year, we started a development of a test cryomodule with SC-QWRs. In this paper, design studies for a SC-QWR and its cryomodule, e.g., QWR, coupler, and, tuner will be presented together with a construction schedule of the prototype. Prototyping of a superconducting cavity and its test cryomodule was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).

Slides WEBA06 [17.564 MB]

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THAA06

Precise Studies on He-Processing and HPR for Recovery From Field Emission by Using X-Ray Mapping System

cavity, radiation, cryomodule, operation

1019

H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

We usually met the degradation of superconducting RF cavity on the cryomodule test and beam operation even if the performance of this cavity is good on the vertical test (V.T). Field emission is the most severe problem for this degradation after reassembly work from vertical test. Not only high pressure rinsing (HPR) but also He-processing, which is more suitable method without the reassembly work for recovery, is recommended and tried to recover this degradation. However, we did not investigate the details of how field emission sources were processed and removed after HPR and He-processing. We deeply investigated the processing procedure during He-processing and how many field emission sources removed after HPR by using rotating X-ray mapping system* in V.T .
*H.Sakai et.al., Proc. of IPAC10 p2950-2952.

Slides THAA06 [4.347 MB]

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THBA05

Higher Order Mode Absorbers for High Current SRF Applications

HOM, cavity, higher-order-mode, operation

1036

R.G. Eichhorn, J.V. Conway, T. Gruber, Y. He, G.H. Hoffstaetter, Y. Li, M. Liepe, T.I. O'Connell, P. Quigley, J. Sears, V.D. Shemelin, E.N. Smith, M. Tigner
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Efficient damping of the higher-order modes (HOMs) of the superconducting cavities is essential for any high current operation. The talk will provide an overview on the latest advances of HOM absorber development for high intensity SRF applications. As the ideal absorber does not exist, the different conceptual approaches will be presented and the associated issues are outlined. Design examples from various labs will be given that help explain the issues and resolutions. Some focus will be given to the Cornell HOM beamline absorber that was design for high current, short bunch operation with up to 400 W heating. The design will be reviewed and testing results will be reported.

Slides THBA05 [4.022 MB]

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THBA06

Overview on Magnetic Field Management and Shielding in High Q Modules

cryomodule, cavity, cryogenics, shielding

1043

G. Wu
Fermilab, Batavia, Illinois, USA

Funding: Work supported by FRA under DOE contract DE-AC02-07CH11359
Maintaining very high cavity Q0 in linac applications creates new challenges for cryomodule design. Magnetic shielding from both external fields and internal fields is required and its importance to thermal gradients during Tc transition is now emerging. This presentation will describe the design challenges and possible mitigation strategies with examples from various applications or laboratories including FRIB, LCLS-II, PIP-II, Cornell University and KEK.

Slides THBA06 [1.839 MB]

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THPB002

Second Harmonic Cavity Design for Synchrotron Radiation Energy Compensator in eRHIC Project

cavity, HOM, impedance, radiation

1052

C. Xu, S.A. Belomestnykh, I. Ben-Zvi, W. Xu
BNL, Upton, Long Island, New York, USA

Funding: DOE
eRHIC project requires construction of a FFAG ring to accelerate electrons and connect to the existing ion ring of Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. This new ring will have the same radius as the RHIC ring. Synchrotron radiation lost in the electron ring should be compensated by a CW superconducting radio frequency (SRF) cavity. Here we propose an 845 MHz single cell harmonic cavity. This cavity will experience a high average current (∼0.7 A) passing through it. With this consideration, this cavity design requires optimization to reduce higher order mode power. On the other hand, the cavity will operate at relatively high gradient up to 18 MV/m. Current design requires fundamental couplers to handle 400 kW forward RF power and HOM couplers to extract 2.5 kW HOM power.
This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.

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THPB005

Simulations of 3.9 GHz CW Coupler for LCLS-II Project

cavity, simulation, operation, cryomodule

1066

I.V. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak
Fermilab, Batavia, Illinois, USA

LCLS-II linac is based on XFEL/ILC superconducting technology. TTF-III fundamental power coupler for the 3.9 GHz 9-cell cavities has been modifies to satisfy requirements of LCLS-II, operating in CW regime. In this paper we discuss the results of COMSOL analysis of the possible modification of couplers, working at various operating regimes. We present also the results of mechanical study.

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THPB010

INFN Milano - LASA Activities for ESS

cavity, vacuum, niobium, cryomodule

1081

P. Michelato, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, L. Monaco, M. Moretti, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
H.J. Zheng
IHEP, Beijing, People's Republic of China

INFN Milano – LASA is involved in the development and industrialization for the production of 704.4 MHz medium beta (β = 0.67) cavities for the ESS project. In this framework, we are designing a medium beta prototype cavity exploring both Large Grain and Fine Grain Niobium for its production as well as a high beta (β = 0.86) Large Grain cavity. In the meanwhile, an activity is ongoing for upgrading the LASA test facility to be able to test these kind of resonators.

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THPB015

Design of a Medium Beta Half-Wave SC Prototype Cavity at IMP

cavity, operation, electromagnetic-fields, accelerating-gradient

1097

A.D. Wu, Y. He, T.C. Jiang, Y.M. Li, F.F. Wang, R.X. Wang, L.J. Wen, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China

A superconducting half-wave resonator has been designed with frequency of 325 MHz and beta of 0.51. The geometry parameters and the three shapes of inner conductors (racetrack, ring-shape and elliptical-shape) were studied in details to decrease the peak electromagnetic fields to obtain higher accelerating gradients and minimize the dissipated power on the RF walls. To suppress the operation frequency shift caused by the helium pressure fluctuations and maximize the tuner ranges, the frequency shifts and mechanical characters were simulated in the electric and magnetic areas separately. At the end, the helium vessel was also designed to keep stability as possible. The fabrication and test of the prototype will be complete at the beginning of 2016.

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THPB025

Exchange and Repair of Titanium Service Pipes for the EXFEL Series Cavities

cavity, alignment, cryomodule, SRF

1122

M. Schalwat, S. Barbanotti, A. Daniel, H. Hintz, K. Jensch, A. Matheisen, S. Saegebarth, P. Schilling
DESY, Hamburg, Germany
A. Schmidt
XFEL. EU, Hamburg, Germany

Longitudinally-welded 72 mm ID service pipes (HSP) made from titanium grade 2 is used by the two suppliers of the helium tanks for the EU-XFEL accelerator. From the perspective of the PED DESY is legally designated as the manufacturer and is responsible for conformity to all relevant codes. During module assemblies at CEA Saclay the orbital welds of the interconnection bellows between cavities showed pores with dimensions outside the specifications set by DESY. These welds needed to be redone which caused a project delay of several months. The X-ray examination of the HSP showed that the pipes already exhibited many out-of- DESY spec pores in the longitudinal welds and were most likely the main cause of the problems in the orbital welds. It was decided to replace the extremities of the service pipes with seamless titanium tubes both on “naked” helium tanks as well as on tanks with cavities already welded in. At DESY more than 750 service pipes were exchanged over a period of 2 years. The qualification of the repair line according to PED regulation and the prove with RF test at 2 K that the repairs do not influence the high performance of the s.c. cavities were done.

Poster THPB025 [0.172 MB]

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THPB026

Update on SRF Cavity Design, Production and Testing for BERLinPro

cavity, gun, booster, HOM

1127

A. Neumann, W. Anders, A. Burrill, A. Frahm, H.-W. Glock, J. Knobloch, O. Kugeler
HZB, Berlin, Germany
K. Brackebusch, T. Galek, J. Heller, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
G. Ciovati, W.A. Clemens, C. Dreyfuss, D. Forehand, T. Harris, P. Kneisel, R.B. Overton, L. Turlington
JLab, Newport News, Virginia, USA
E.N. Zaplatin
FZJ, Jülich, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association.
The BERLinPro Energy Recovery Linac (ERL) is currently being built at Helmholtz-Zentrum Berlin in order to study the accelerator physics of operating a high current, 100 mA, 50 MeV low emittance ERL utilizing all SRF cavity technology. For this machine three different types of SRF cavities are being developed. For the injector section, consisting of an SRF photoinjector and a three two cell booster cavity module, fabrication is completed. The cavities were designed at HZB and manufactured, processed and vertically tested at Jefferson Laboratory. In this paper we will review the design and production process of the two structures and show the latest horizontal acceptance tests at HZB prior to installation into the newly designed cryo-module. For the Linac cavity the latest cavity and module design studies are being shown.

Poster THPB026 [1.535 MB]

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THPB028

ESS Medium Beta Cavity Prototypes Manufacturing

cavity, HOM, coupling, cryomodule

1136

E. Cenni, C. Arcambal
CEA/IRFU, Gif-sur-Yvette, France
P. Bosland, G. Devanz, X. Hanus, P. Hardy, V.M. Hennion, F. Leseigneur, F. Peauger, J. Plouin, D. Roudier
CEA/DSM/IRFU, France
G. Costanza
Lund University, Lund, Sweden
C. Darve
ESS, Lund, Sweden

The ESS elliptical superconducting linac consists of two types of 704.42 MHz cavities, medium and high beta, to accelerate the beam from 216 MeV (spoke cavity linac) up to the full energy at 2 GeV. The last linac optimization, called Optimus+, has been carried out taking into account the limitations of SRF cavity performance (field emission). The medium and high-beta parts of the linac are composed of 36 and 84 elliptical cavities, with geometrical beta values of 0.67 and 0.86 respectively. We describe here the procedures and numerical analysis leading from half-cells to a complete medium cavity assembly, which take into account not only the frequency of the fundamental accelerating mode but also the higher order modes near the machine line. The half cell selection process to form dumb bells will be described, as well as the reshaping and trimming procedure.

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THPB032

Release Processes and Documentation Methods During Series Treatment of SRF Cavities for the European XFEL by Using an Engineering Data Management System

cavity, data-management, SRF, database

1154

J. Iversen, J.A. Dammann, A. Matheisen, N. Steinhau-Kühl
DESY, Hamburg, Germany

For the European XFEL more than 800 superconducting cavities need to be treated. At least 65 quality documents per cavity have to be emitted and transferred to DESY by the vendor; two acceptance levels must be passed successfully to release a cavity for transportation to DESY. All quality documents, non-conformity reports and acceptance levels are automatically processed by using DESY’s Engineering Data Management System (EDMS). We summarize documentation methods, document transfer procedures, review and release processes; we describe the exchange of process information between customer and vendor; and report about experiences.

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THPB035

Fabrication of the 3.9 GHz SRF Structures for the European XFEL

cavity, controls, operation, status

1162

P. Pierini, M. Bertucci, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, M. Moretti, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
A. Gresele
Ettore Zanon S.p.A., Nuclear Division, Schio, Italy
C.G. Maiano, P. Pierini, E. Vogel
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
M. Rizzi
Ettore Zanon S.p.A., Schio, Italy

One batch of 10 cavities has been completed and eight structures have been installed in the 3.9 GHz cryomodule for the European XFEL Injector operation. A second batch of 10 RF structures for a spare injector module is under fabrication. The fabrication has been performed according to the European Pressure Vessel regulations, as needed for the EXFEL operation. This paper describes the fabrication, quality control/assurance procedures and frequency preparation steps in order to achieve cavities at the correct frequency and length within the specifications.

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THPB038

XFEL Database Structure & Loading System

database, cavity, interface, status

1166

S. Yasar, P.D. Gall, V. Gubarev
DESY, Hamburg, Germany

XFEL database was designed to store cavity production, preparation, and test data for the whole LINAC on the very detailed level: from half cells up to module tests. To load this amount of data (more than 140 files per cavity) in automatic regime the special Data Loading System was developed.

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THPB043

Alternative Fabrication Methods for the ARIEL e-Linac SRF Separator Cavity

cavity, niobium, SRF, induction

1185

D.W. Storey
Victoria University, Victoria, B.C., Canada
R.E. Laxdal, N. Muller
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ARIEL e-Linac RF deflecting cavity is a 650 MHz superconducting deflecting mode cavity that will allow simultaneous beam delivery to both the Rare Isotope Beam program and an Energy Recovery Linac. The cavity will be operated at 4 K and with deflecting voltages of up 0.6 MV, resulting in a dissipated RF power of less than 1 W. Due to the modest performance requirements, alternative methods are being employed for the fabrication of this cavity. These include fabricating the entire cavity from reactor grade Niobium and welding the cavity using tungsten inert gas (TIG) welding in a high purity Argon environment. A post purification heat treatment will be performed in an RF induction oven to increase the cavity performance.

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THPB044

A Superconducting RF Deflecting Cavity for the ARIEL e-Linac Separator

cavity, HOM, electron, impedance

1187

D.W. Storey
Victoria University, Victoria, B.C., Canada
R.E. Laxdal, L. Merminga, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A 650 MHz SRF deflecting mode cavity has been designed for the ARIEL e-Linac to separate interleaved beams heading towards either Rare Ion Beam production or a recirculation loop for energy recovery, allowing the e-Linac to provide beam delivery to multiple users simultaneously. The cavity geometry has been optimized for the ARIEL specifications, resulting in a very compact cavity with high shunt impedance and low dissipated power. Analyses have been performed on the susceptibility to multipacting, input coupling considering beam loading and microphonics, and extensive studies into the damping of transverse and longitudinal higher order modes. The pressure sensitivity, frequency tuning, and thermal behaviour have also been studied using ANSYS. The cavity design resulting from these considerations will be discussed here.

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THPB061

Performance of the Tuner Mechanism for SSR1 Resonators During Fully Integrated Tests at Fermilab

cavity, controls, niobium, resonance

1252

D. Passarelli, J.P. Holzbauer, L. Ristori
Fermilab, Batavia, Illinois, USA

In the framework of the Proton Improvement Plan-II (PIPII) at Fermilab, a cavity tuner was developed to control the frequency of 325 MHz spoke resonators (SSR1). The behavior of the tuner mechanism and compliance with technical specifications were investigated through a campaign of experimental tests in operating conditions in the spoke test cryostat (STC) and at room temperature. Figures of merit for the tuner such as tuning range, stiffness, components hysteresis and overall performance were measured and are reported in this paper.

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THPB066

RF Analysis of Equator Welding Stability for the European XFEL Cavities

cavity, controls, HOM, factory

1272

A.A. Sulimov
DESY, Hamburg, Germany

In order to guaranty a sufficient High Order Modes (HOM) damping in the European XFEL cavities, a detailed analysis of the mechanical cavity production was performed. The mechanical measurements are precise enough to control the shape of cavity parts, but cannot be used for a welded cavity. To estimate the shape deformation during equator welding, the eigenfrequencies of cavity cells are compared with frequencies of cavity parts. This simple RF analysis can indicate irregularity of 9 equator welds and was used in addition to control of mean values for longitudinal and transverse deformations.

Poster THPB066 [0.148 MB]

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THPB074

High Current eRHIC Cavity Design and HOM Damping Scheme

cavity, HOM, damping, impedance

1297

W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by LDRD program of Brookhaven Science Associates.
A 422 MHz cavity was designed for high current FFAG lattice ERLs for high luminosity eRHIC. The cavity was optimized to be able to propagate all the HOMs out of the cavity for high BBU threshold current and low HOM power (loss factor). Coupling the full spectrum (up to 30 GHz) HOMs out of the cavity and delivering the HOM power (up to 8 kW) out of the cryomodule is a challenge. A damping scheme with 6 coaxial line HOM couplers for low frequency HOMs and 3 waveguide HOM dampers for high frequency (so that the waveguide is small) is proposed to damp the full spectrum and high power HOMs. This paper will present the cavity design and HOM damping scheme.

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THPB077

Modified TTF3 Couplers for LCLS-II

operation, vacuum, simulation, cavity

1306

C. Adolphsen, K. Fant, Z. Li, C.D. Nantista, G. Stupakov, J. Tice, F.Y. Wang, L. Xiao
SLAC, Menlo Park, California, USA
I.V. Gonin, K. Premo, N. Solyak
Fermilab, Batavia, Illinois, USA

The LCLS-II 4 GeV SC electron linac will use 280 TESLA cavities and TTF3 couplers, modified for CW operation with input power up to about 7 kW. The coupler modifications include shortening the antenna to achieve higher Qext and thickening the copper plating on the warm section inner conductor to lower the peak temperature. Another change is the use a waveguide transition box that is machined out of a solid piece of aluminum, significantly reducing its cost and improving its fit to the warm coupler window section. This paper describes the changes, simulations of the coupler operation (heat loads and temperatures), rf processing results and CW tests with LCLS-II dressed cavities.

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THPB101

High Power Input Couplers for C-ADS

cavity, cryomodule, vacuum, proton

1383

T.M. Huang, X. Chen, H.Y. Lin, Q. Ma, F. Meng, W.M. Pan, G.W. Wang, X.Y. Zhang
IHEP, Beijing, People's Republic of China
K.X. Gu
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

High power input couplers are key components of the superconducting system for China Accelerator Driven sub-critical System (C-ADS) project. For the first phase, C-ADS includes four types of superconducting cavities (SCCs) of two frequencies, 162.5 MHz HWR SCC and 325 MHz Spoke SCC up to the energy of 25 MeV. All input couplers for the SCCs are developed in IHEP. This paper will describe the development status of the high power input couplers for C-ADS.

Poster THPB101 [0.430 MB]

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THPB103

High Power Coupler Test for ARIEL SC Cavities

vacuum, TRIUMF, cavity, cryomodule

1390

Y. Ma, P.R. Harmer, D. Lang, R.E. Laxdal, B.S. Waraich, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF ARIEL[1](The Advanced Rare Isotope Laboratory) project employs five 1.3 GHz 9-cell superconducting elliptical cavities[2] for acceleration of 10 mA electron beam up to energy of 50 MeV. 100 kW CW RF power will be delivered into each cavity by means of pair of Power Couplers: 50 kW per each coupler. Before installing the power couplers with the cavities, they have to be assembled on Power Coupler Test Stand(PCTS) and conditioned with a 30 kW IOT. Six couplers have been conditioned at room temperature and four of them have been installed to the cavities and tested during beam commissioning. Test results of the power couplers will be described and discussed in this paper.
#mayanyun@triumf.ca

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THPB109

ESS Spoke Cryomodule and Test Valve Box

cryomodule, cryogenics, vacuum, operation

1400

D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, M. Pierens, E. Rampnoux
IPN, Orsay, France
C. Darve
ESS, Lund, Sweden

ESS project aims being the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the ESS linear accelerator includes 28 b=0.5 352.2 MHz SRF niobium double Spoke cavities. Paired in 13 cryomodules and held at 2K in a saturated helium bath those cavities will generate of an accelerating field of 9MV/m. The prototype Spoke cryomodule holds two cavities and their RF power couplers and integrates all the interfaces necessary to be operational within the linac machine. It is now being fabricated and its assembly will be performed with dedicated tooling and procedures in and out of the clean room. This prototype will be tested by the end of 2015 at IPNO site and then at full power at FREIA (Uppsala university) test stand. A valve box has thus been designed to take into account the specific features of this prototype cryomodule and of the cryogenic environments of both test sites. This valve box is also considered as a prototype of the cryogenic distribution of the linac Spoke section. This element will then be used for the tests of the series cryomodules. We propose to present this prototype Spoke cryomodule for ESS and the test valve box.

Poster THPB109 [2.852 MB]

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THPB115

TRIUMF's Injector and Accelerator Cryomodules

cavity, cryomodule, TRIUMF, alignment

1409

N. Muller, P.R. Harmer, J.J. Keir, D. Kishi, P. Kolb, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, A.K. Mitra, R.R. Nagimov, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF's ARIEL project includes a 50 MeV-10mA electron linear accelerator (e-Linac) using 1.3 GHz superconducting technology. The accelerator consists of three cryomodules; an injector cryomodule with one cavity and two accelerating cryomodules with two cavities each. One injector and one accelerator have been assembled and commissioned at TRIUMF with a second injector cryomodule being assembled for VECC in Kolkata. Both Injector and Accelerator cryomodules utilize a top-loaded cold mass design contained in a box-type cryomodule; design and early test results of both cryomodules are presented.

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FRAA01

Overview of Recent Tuner Development on Elliptical and Low-Beta Cavities

cavity, cryomodule, controls, operation

1425

R. Paparella
INFN/LASA, Segrate (MI), Italy

The talk will provide an overview on the latest advances of tuner development for SRF applications. Issues and present approaches on how to resolve them will be emphasized for both TM and TEM cavities and examples from various labs and projects (XFEL, LCLS-II, ESS, SPL, ARIEL, SPIRAL2, FRIB, ANL, IFMIF) will be given in order to better explain issues and solutions. Details on author’s contributions to European-XFEL tuner activity for 1.3 GHz and 3.9 GHz cavities will be also shown.

Slides FRAA01 [3.421 MB]

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FRAA04

Performance of the Cornell ERL Main Linac Prototype Cryomodule

cavity, HOM, cryomodule, operation

1437

F. Furuta, B. Clasby, R.G. Eichhorn, B. Elmore, G.M. Ge, D. Gonnella, D.L. Hall, G.H. Hoffstaetter, R.P.K. Kaplan, J.J. Kaufman, M. Liepe, T.I. O'Connell, S. Posen, 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 has designed, fabricated, and tested (by the time of the conference) a high current (100 mA) CW SRF prototype cryomodule for the Cornell ERL. This talk will report on the design and performance of this very high Q0 CW cryomodule including design issues and mitigation strategies.

Slides FRAA04 [4.614 MB]

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