SRF2015 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
MOPB065	Recent Measurements on the SC 325 MHz CH-Cavity	cavity, ion, linac, heavy-ion	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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MOPB075	Experiences on Retreatment of EU-XFEL Series Cavities at DESY	cavity, status, feedback, linac	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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MOPB076	Horizontal RF Test of a Fully Equipped 3.9 GHz Cavity for the European XFEL in the DESY AMTF	cavity, HOM, operation, cryomodule	301
	C.G. Maiano, C. Albrecht, R. Bospflug, J. Branlard, L. Butkowski, T. Delfs, J. Eschke, A. Gössel, F. Hoffmann, M. Hüning, K. Jensch, R. Jonas, R. Klos, D. Kostin, W. Maschmann, A. Matheisen, U. Mavrič, W.-D. Möller, C. Müller, K. Mueller, B. Petersen, P. Pierini, J. Rothenburg, O. Sawlanski, M. Schmökel, A.A. Sulimov, E. Vogel DESY, Hamburg, Germany A. Bosotti, M. Moretti, R. Paparella, P. Pierini, D. Sertore INFN/LASA, Segrate (MI), Italy E.R. Harms Fermilab, Batavia, Illinois, USA C.R. Montiel ANL, Argonne, Illinois, USA S. Pivovarov BINP SB RAS, Novosibirsk, Russia
	In order to validate the cavity package concept before the module preparation for the European XFEL Injector, one 3.9 GHz cavity, complete with magnetic shielding, power coupler and frequency tuner was tested in a specially designed single cavity cryomodule in one of the caves of the DESY Accelerator Module Test Facility (AMTF). The cavity was tested in high power pulsed operation up to the quench limit of 24 MV/m, above the vertical test qualifications and all subsystems under test (coupler, tuner, waveguide tuners, LLRF system) were qualified to design performances.
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MOPB094	Inspection and Repair Techniques for the EXFEL Superconducting 1.3 GHz Cavities at Ettore Zanon S.p.A: Methods and Results	cavity, operation, accelerating-gradient, electron	368
	G. Massaro, G. Corniani, N. Maragno Ettore Zanon S.p.A., Schio, Italy A. Matheisen, A. Navitski DESY, Hamburg, Germany P. Michelato, L. Monaco INFN/LASA, Segrate (MI), Italy
	The quality control of the inner surface of superconducting RF cavities is essential in order to assure high accelerating gradient and quality factor. Ettore Zanon S.p.A. (EZ) has implemented in the serial production an optical system that use an high-resolution camera, in order to detect various types of defects. This system is added to a grinding machine, that was specifically designed and built to repair imperfections of the cavities inner surface. This inspection and repair system is applied to recover performance limited cavities of the 1.3 GHz European XFEL project, where surface irregularities are detected, either by the Obacht inspection system at Desy or the optical system at EZ. The optical system and the grinding procedure are qualified using two series cavities limited in gradient and showing different types of surface defects. The performances of these cavities have been recovered to reach the specifications of the project. Until now, all the series XFEL cavities built by EZ, repaired with this technique, have shown an accelerating gradient well above the EXFEL goal.
	Poster MOPB094 [0.795 MB]
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MOPB095	SRF Cavity Processing and Chemical Etching Development for the FRIB Linac	cavity, SRF, linac, 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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MOPB098	Improvement of Temperature Control During Nb 9-Cell SRF Cavity Vertical Electro-Polishing (VEP) and Progress of VEP Quality	cavity, experiment, cathode, SRF	381
	K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi MGH, Hyogo-ken, Japan H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe KEK, Ibaraki, Japan K. Ishimi MGI, Chiba, Japan
	Marui Galvanizing Co.,Ltd. has been developing Nb 9-cell SRF cavity vertical electro-polishing (VEP) facility and technique for mass production in collaboration with KEK. Our first 9-cell cavity VEP facility was not enough to control temperature during VEP, so the polishing quality was not so high. In this article, we will report the progress of temperature distribution and polishing quality due to the improvement of temperature control system of electrolyte and cavity during VEP.
	Poster MOPB098 [0.988 MB]
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MOPB102	Comments on Electropolishing at Ettore Zanon SpA at the End of EXFEL Production	cavity, niobium, cathode, acceleration	394
	M. Rizzi, G. Corniani Ettore Zanon S.p.A., Schio, Italy A. Matheisen DESY, Hamburg, Germany P. Michelato INFN/LASA, Segrate (MI), Italy
	In 2013 a new horizontal Electropolishing facility was developed and implemented by Ettore Zanon SpA (EZ) for the treatment of cavities for the European XFEL series production. More than 300 cavities have been treated. Electropolishing has been used for two applications: bulk removal and recovering of cavities with surface defects. Treatment settings have been analysed and compared with cavities performances to verify possible influences of the various parameters. Main parameters considered are treatment time, voltage and current, that together define average thickness removal. We present here the results of these investigation. The facility and process in use are also presented, together with possible next upgrade of the system, facing the new production of cavities for the LCLSII project.
	Poster MOPB102 [1.535 MB]
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MOPB110	The Transfer of Improved Cavity Processing Protocols to Industry for LCLS-II: N-Doping and Electropolishing	cavity, cathode, niobium, superconductivity	418
	C.E. Reece, F. Marhauser, A.D. Palczewski 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. Based on the R&D efforts of colleagues at FNAL, Cornell, and JLab, the LCLS-II project adopted a modification to the rather standard niobium SRF cavity surface processing protocol that incorporates a high temperature diffusion doping with nitrogen gas. This change was motivated by the resulting higher Q0 and the prospect of significantly lower cryogenic heat load for LCLS-II. JLab is responsible for managing the cavity procurement for the LCLS-II project. The first phase of the procurement action is to transfer the nitrogen-doping protocol to the industrial vendors. We also seek to exploit improvements in understanding of the niobium electropolishing process as part of the production processing of the TESLA-style LCLS-II cavities. We report on the technology transfer activities and progress toward the envisaged performance demonstration of vendor-processed cavities.
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MOPB111	Furnace N2 Doping Treatments at Fermilab	vacuum, cavity, SRF, PLC	423
	M. Merio, M. Checchin, A.C. Crawford, A. Grassellino, M. Martinello, A.M. Rowe, M. Wong Fermilab, Batavia, Illinois, USA M. Checchin, M. Martinello Illinois Institute of Technology, Chicago, Illlinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy. The Fermilab SRF group regularly performs Nitrogen (N2) doping heat treatments on superconducting cavities in order to improve their Radio Frequency (RF) performances. This paper describes the set up and operations of the Fermilab vacuum furnaces, with a major focus on the implementation and execution of the N2 doping recipe. The cavity preparation will be presented, N2 doping recipes will be analyzed and heat treatment data will be reported in the form of plot showing temperature, total pressure and partial pressures over time. Finally possible upgrades and improvements of the furnace and the N2 doping process are discussed.
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MOPB113	Study of the Evolution of Artificial Defects on the Surface of Niobium During Electrochemical and Chemical Polishing	SRF, laser, cavity, operation	433
	L. Monaco, P. Michelato INFN/LASA, Segrate (MI), Italy A. Navitski, J. Schaffran, W. Singer DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy A.L. Prudnikava, Y. Tamashevich University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	The presence of defects on the inner surface of Nb superconducting RF structures might limit its final performance. For this reason, strict requirements are imposed during mechanical production of the cavities, specifically on the quality control of the inner surface of components, to avoid the presence of defects or scratches. Nevertheless, some defects may remain also after control or can arise from the following production steps. Understanding the evolution of the defect might shine new insight on its origin and help in defining possible repair techniques. This paper reports the topographical evolution of defects on a Nb sample polished with the standard recipe used for the 1.3 GHz cavities of the EXFEL project. Various artificial defects of different shape, dimensions, and thicknesses/depths, with geometrical characteristics similar to the one that may occur during the machining and handling of cavities, have been “ad hoc” produced on the sample of the same material used for the cell fabrication. Analysis shows the evolution of the shape and profile of the defects at the different polishing steps.
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MOPB118	Cleanliness and Vacuum Acceptance Tests for the UHV Cavity String of the XFEL Linac	cavity, vacuum, operation, cryomodule	452
	S. Berry, O. Napoly, B. Visentin CEA/DSM/IRFU, France C. Boulch, C. Cloué, C. Madec, T. Trublet CEA/IRFU, Gif-sur-Yvette, France D. Henning, L. Lilje, A. Matheisen, M. Schmökel DESY, Hamburg, Germany
	The main linac of the European XFEL will consist of 100 accelerator modules, i.e. 800 superconducting accelerator cavities operated at a design gradient of 23.6MV/m. In this context CEA-Saclay built an assembly facility designed to produce one module per week, ready to be tested at DESY. The facility overcame the foreseen production rate. We would like to highlight and discuss the critical fields: cleanliness and vacuum. A new assembly method to protect final assembly against particulates contamination has been implemented on the production line. Impact on cryomodule RF test is presented. Particle transport measurements on components used for the European XFEL accelerator module are presented. The results indicate that the nominal operation of the automated pumping and venting units will not lead to particle transport. Vacuum acceptance tests are of major interest: leak tests and residual gas analysis (RGA) are used to control the absence of air leak and contamination. The RGA specifications have been slightly relaxed to ensure the production rate.
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TUPB002	Elimination of High Frequency Noise From the Beam in the Diamond Light Source Storage Ring	storage-ring, operation, synchrotron, power-supply	525
	C. Christou, A. Bogusz, P.J. Marten DLS, Oxfordshire, United Kingdom
	High frequency beam motion has been identified as a source of noise in infrared beamlines in a number of synchrotron light sources. Diamond is a third generation synchrotron light source with storage ring current maintained by two superconducting CESR-B cavities powered by IOT-driven RF amplifiers. In our case, undesirable beam motion in the kilohertz range is predominantly driven by spectral content in the voltage across the IOTs arising from the switched mode nature of the high voltage power supply. Spectral noise on the amplifiers and beam has been identified and characterised and efforts to eliminate this noise are described. Care has been taken to maintain the overall stability of the RF at Diamond and tests have been carried out on an infrared beamline to investigate the degree to which beam noise impacts beamline operation in its different operating configurations.
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TUPB003	Cavity Procurement and Qualification Plan for LCLS-II	cavity, hardware, site, cathode	529
	F. Marhauser, E. Daly, J.A. Fitzpatrick 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. The LCLS-II project aims to build 35 accelerating cryomodules, which are based on the European XFEL design but modified for operation in CW mode. Each cryomodule houses eight TESLA-style nine-cell superconducting radio-frequency cavities. The activities to assemble the first two prototype cryomodules are ongoing at FNAL and JLab. 264 cavities worth of cavities for the remaining 33 cryomodules will be procured from two industrial vendors in similar quantity considering the option to produce spares. The assembly of cavities into the production cryomodules will be distributed among FNAL (16 cryomodules) and JLab (17 cryomodules). In this paper the cavity procurement and qualification plan for the LCLS-II project is detailed.
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TUPB004	Vertical Cavity Test Facility at Fermilab	cavity, instrumentation, experiment, SRF	534
	O.S. Melnychuk, A. Grassellino, F.L. Lewis, J.P. Ozelis, R.V. Pilipenko, Y.M. Pischalnikov, O.V. Pronitchev, A. Romanenko, D.A. Sergatskov, B. Squires Fermilab, Batavia, Illinois, USA
	After a recent upgrade, the vertical test facility for SRF cavities at Fermilab features a low level RF system capable of testing 325MHz, 650MHz, 1.3GHz, and 3.9GHz cavities, helium liquefying plant, three test cryostats, and the interlock safety system. The cryostats can accommodate measurements of multiple cavities in a given cryogenic cycle in the range of temperatures from 4.2K to 1.4K. We present a description of the components of the vertical test facility. We also discuss cavity instrumentation that is used for diagnostics of cavity ambient conditions and quench characterization.
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TUPB008	A New Cryogenic Control System for the Vertical Test Area at Jefferson Lab	PLC, cryogenics, SRF, operation	549
	G.K. Davis, T. Goodman, P. Kushnick, T. Powers, C.M. Wilson JLab, Newport News, Virginia, USA
	Funding: DOE The Vertical Test Area at Jefferson Lab, consisting of eight vertical dewars, recently received a major upgrade by replacing the original (1995) cryogenic control system. A new, state-of-the-art, distributed control system (DC S) based on Programmable Logic Controllers (PLCs) was installed and commissioned. The new system increases facility throughput, reliability and cryogenic efficiency, while improving safety. The system employs a touchscreen graphical user interface and a highly redundant architecture on an Ethernet backbone.
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TUPB013	Fermilab Cryomodule Test Stand Design and Plans	cryomodule, cryogenics, cavity, SRF	566
	E.R. Harms, C.M. Baffes, K. Carlson, B.E. Chase, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, M.W. McGee, P.S. Prieto, J. Reid, R.P. Stanek, D. Sun, M.J. White Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. A facility dedicated to SRF cryomodule testing is under construction at Fermilab. The test stand has been designed to be flexible enough to cool down and power test full length TESLA-style 8-cavity cryomodules as well cryomodules for low-β acceleration. We describe the design considerations, status, and near future plans for utilization of the test stand.
	Poster TUPB013 [5.146 MB]
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TUPB022	Low-Beta SRF Cavity Processing and Testing Facility for the Facility for Rare Isotope Beams at Michigan State University	cavity, SRF, vacuum, cryomodule	597
	L. Popielarski NSCL, East Lansing, Michigan, USA B.W. Barker, C. Compton, K. Elliott, I.M. Malloch, E.S. Metzgar, J. Popielarski, K. Saito, G.J. Velianoff, D.R. Victory, T. Xu FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661, the State of Michigan and Michigan State University Major work centers of the new SRF Highbay are fully installed and in use for FRIB pre-production SRF quarter-wave and half-wave resonators, including inspection area, high temperature vacuum furnace for cavity degassing, chemical etching facility and processing and assembly cleanrooms. Pre-production activities focus on optimizing workflow by reducing process time, tracking part status and related data, and identifying bottlenecks. Topics discussed may include; buffered chemical polish (BCP) etching for cavity frequency control, degassing time reduction, automated high pressure rinse, particle control against field emission, pre-production cavity test results and implementation of workflow status programs
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TUPB026	Cryogenic Performance of the HNOSS Test Facility at Uppsala University	cavity, cryogenics, operation, vacuum	612
	R. Santiago Kern, K.J. Gajewski, L. Hermansson, R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden P. Bujard, T. Junquera, J.P. Thermeau Accelerators and Cryogenic Systems, Orsay, France
	Funding: Knut and Alice Wallenbergs foundation The FREIA Laboratory at Uppsala University, Sweden, is developing part of the RF system and testing the superconducting double spoke cavitites for ESS. During 2014 it was equipped with HNOSS, a versatile horizontal cryostat system for testing superconducting cavities. HNOSS is designed for high power RF testing of up to two superconducting accelerating cavities equipped with helium tank, fundamental power coupler and tuning system. In particular it will be used to characterise the performance of spoke cavities like used in the accelerator for the ESS project. HNOSS is connected to a cryogenic plant providing liquid helium and a sub-atmospheric pumping system enabling operation in the range 1.8 to 4.5~K. We present a brief description of the major components, installation and results from the recent operation and tests.
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TUPB081	Multi-Cell Temperature Mapping and Conclusions	cavity, SRF, monitoring, cryogenics	783
	F. Furuta, R.G. Eichhorn, G.M. Ge, D. Gonnella, D.L. Hartill, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, E.N. Smith Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Multi-cell temperature mapping (T-map) system has been developed and applied on SRF Nb cavities vertical tests (VT) at Cornell. It has nearly two thousand thermometers and achieved a 1mK resolution of niobium surface temperature rinsing in superfluid helium . We have upgraded the system to be capable of monitoring the temperature profiles of quench spot on cavity. The recent results of T-map during cavity tests and details will be reported.
	Poster TUPB081 [4.421 MB]
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TUPB093	Initial Commissioning Experience with the Spallation Neutron Source Vertical Test Area RF System	cavity, operation, software, hardware	819
	M.T. Crofford, J.A. Ball, M. Doleans, S.-H. Kim, S.W. Lee, J.D. Mammosser, J. Saunders ORNL, Oak Ridge, Tennessee, USA T.L. Davidson, S. Whaley ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. The Spallation Neutron Source (SNS) has developed a vertical test area (VTA) for the testing and qualification of superconducting radio frequency cavities. The associated RF System successfully supported the initial commissioning of the VTA system and has been utilized for cavity testing at both 4 and 2 K. As operational experience was gained, improvements to the RF system were implemented to better utilize the dynamic range of the system, and software updates and additions were made to meet the operational needs. The system continues to evolve as we gain better understanding of the testing needs.
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TUPB094	Jefferson Lab Vertical Test Area RF System Improvement	cavity, network, software, low-level-rf	823
	T. Powers, M.L. Morrone 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. RF systems for testing critically coupled SRF cavities require the ability to track the cavity frequency excursions while making accurate measurements of the radio frequency (RF) signals associated with the cavity. Two types of systems are being used at Jefferson Lab. The first, the traditional approach, is to use a voltage controlled oscillator configured as a phase locked loop such that it will track the cavity frequency. The more recently developed approach is to use a digital low level RF (LLRF) system in self excited loop (SEL) mode to track the cavity frequency. Using a digital LLRF system in SEL mode has the advantage that it is much easier to lock to the cavity’s resonant frequencies and they tend to have a wider capture range. This paper will report on the system designs used to implement the 12 GeV digital LLRF system in the JLAB vertical test area. Additionally, it will report on the system modifications which are being implemented so that the RF infrastructure in the VTA will be ready to support the LCLS II cryomodule production effort, which is scheduled to begin in calendar year 2016.
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TUPB113	JLab Cryomodule Assembly Infrastructure Modifications for LCLS-II	cavity, cryomodule, vacuum, cryogenics	898
	E. Daly, J. Armstrong, G. Cheng, M.A. Drury, J.F. Fischer, D. Forehand, K. Harding, J. Henry, K. Macha, J.P. Preble, A.V. Reilly, K.M. Wilson JLab, Newport News, Virginia, USA
	Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515. The Thomas Jefferson National Accelerator Facility is currently engaged, along with several other DOE national laboratories, in the Linac Coherent Light Source II project (LCLS II). The SRF Institute at Jefferson Lab will be building 1 prototype and 17 production cryomodules based on the TESLA / ILC / XFEL design. Each cryomodule will contain eight nine cell cavities with coaxial power couplers operating at 1.3 GHz. New and modified infrastructure and assembly tooling is required to construct cryomodules in accordance with LCLS-II requirements. The approach for modifying assembly infrastructure included evaluating the existing assembly infrastructure implemented at laboratories world-wide in support of ILC and XFEL production activities and considered compatibility with existing infrastructure at JLab employed for previous cryomodule production projects. These modifications include capabilities to test cavities, construct cavity strings in a class 10 cleanroom environment, assemble cavity strings into cryostats, and prepare cryomodules for cryogenic performance testing. This paper will give a detailed description of these modifications.
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TUPB114	Transient Study of Beam Loading and Feed-Forward LLRF Control of ARIEL Superconducting RF e-LINAC	cavity, linac, 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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WEBA02	RF Measurements for Quality Assurance During SC Cavity Mass Production	cavity, HOM, GUI, linac	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, linac	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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THPB023	The Statistics of Industrial XFEL Cavities Fabrication at E.ZANON	cavity, target, niobium, accelerating-gradient	1119
	A. Gresele, M. Giaretta, A. Visentin Ettore Zanon S.p.A., Nuclear Division, Schio, Italy A.A. Sulimov, J.H. Thie DESY, Hamburg, Germany
	Serial production of superconducting cavities for European-XFEL will be completed at E.ZANON by the end of 2015. For that reason we can summarize the results and present the statistics of industrial cavity fabrication. Many parameters have been traced during different steps of cavity production. The most interesting of them, as cavity length, frequency, field flatness and eccentricity, are presented and discussed.
	Poster THPB023 [3.227 MB]
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THPB031	Operation Experience with Half Cell Measurement Machine and Cavity Tuning Machine in 3 Years of European XFEL Cavity Series Production	cavity, operation, SRF, HOM	1149
	J.H. Thie, A. Gössel, J. Iversen, D. Klinke, C. Müller, A.A. Sulimov, D. Tischhauser DESY, Hamburg, Germany
	For the European XFEL superconducting Cavity series production at both cavity vendors’ four manufacturing machines for production key functions, HAZEMEMA and CTM, are supplied by DESY. Among three years of cavity production in two companies a lot of experience is gathered about influence of surroundings and production quality on cycle times, machine drop outs, general stability time of machines and parts subject to wear. Significant factors on cycle time for tuning operation like temperature stability and drift during tuning and measurements, precision of cell trimming before welding and tuning and generally geometrical factors are shown. RF aspects of tuning and production quality control as additional measurements for TM011-mode to estimate quality of its damping is presented. Performed full Cavity RF measurements exceeds XFEL specifications gives a possibility for additional quality control on welding shrinkage stability and it’s homogeneously distribution. The use of HAZEMEMA and CTM to assess the impact of asymmetric trimming, including calculation of it’s influence on the higher-order modes, is shown.
	Poster THPB031 [0.201 MB]
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THPB035	Fabrication of the 3.9 GHz SRF Structures for the European XFEL	cavity, operation, linac, 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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THPB039	XFEL Database User Interface	cavity, database, GUI, interface	1168
	S. Yasar, P.D. Gall, V. Gubarev, D. Reschke, A.A. Sulimov, J.H. Thie DESY, Hamburg, Germany
	The XFEL database plays an important role for an effective part of the quality control system for the whole cavity production and preparation process for the European XFEL on a very detailed level. Database has the Graphical User Interface based on the web-technologies, and it can be accessed via low level Oracle SQL.
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THPB045	Progress in IFMIF Half Wave Resonators Manufacturing and Test Preparation	cavity, simulation, cryomodule, vacuum	1191
	G. Devanz, N. Bazin, G. Disset, P. Hardy, O. Piquet, J. Plouin CEA/DSM/IRFU, France H. Dzitko, H. Jenhani, J. Neyret, N. Sellami CEA/IRFU, Gif-sur-Yvette, France
	The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux to test samples as possible candidate materials to a full lifetime of fusion energy reactors. The first phase of the project aims at validating the technical options for the construction of an accelerator prototype, called LIPAc (Linear IFMIF Prototype Accelerator). A cryomodule hosting 8 Half Wave Resonators (HWR) at 175 MHz will provide the acceleration from 5 to 9 MeV. We report on the progress of the HWR manufacturing. A pre-series cavity will be used to assess and optimize the tuning procedure of the HWR, as well as the processing steps and related tooling. A new horizontal test cryostat (SATHORI) is also being set up at Saclay in the existing SRF test area. The SATHORI is dedicated to the IFMIF HWR performance check, fully equipped with its power coupler and cold tuning system. A 30kW-RF power will be available for these tests.
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THPB061	Performance of the Tuner Mechanism for SSR1 Resonators During Fully Integrated Tests at Fermilab	cavity, niobium, resonance, linac	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, linac, 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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THPB067	HOM Coupler Notch Filter Tuning for the European XFEL Cavities	HOM, cavity, resonance, database	1274
	A.A. Sulimov DESY, Hamburg, Germany
	The notch filter (NF) tuning prevents the extraction of fundamental mode (1.3 GHz) RF power through Higher Order Modes (HOM) couplers. The procedure of NF tuning was optimized at the beginning of serial European XFEL cavities production. It allows keeping the filter more stable against temperature and pressure changes during cavity cool down. Some statistics of NF condition during cavities and modules cold tests is presented.
	Poster THPB067 [0.404 MB]
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THPB076	Quality Control of Welding, Brazing Joints and Cu Deposition on EU-XFEL Coupler Parts	interface, electron, Windows, vacuum	1301
	A. Ermakov, D. Kostin, W.-D. Möller DESY, Hamburg, Germany
	In frames of EU-XFEL Project the quality control of fundamental 1.3GHz power couplers is very important task. The power coupler consists of a several number of parts including itself the different types of welding and brazing joints between ceramic, copper and stainless steel components. The quality of these joints is subject to be investigated and controlled according to EU-XFEL Coupler specification taking into account the different coupler manufacturers involved. The quality of Cu deposition on some EU-XFEL coupler parts is also the issue to be qualified according to specs. The number of microscope images of different types of joints and Cu deposition on some EU-XFEL 1.3GHz coupler parts are presented.
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THPB095	Automatic RF Conditioning Test Bench of Fundamental Power Couplers for the European XFEL Accelerator	vacuum, SRF, interface, data-acquisition	1367
	S. Sierra, C. Lievin, P. Rouillon TED, Velizy, France H. Guler, W. Kaabi, A. Verguet LAL, Orsay, France
	In order to perform the RF conditioning of the fundamental coupler for the XFEL accelerator, Thales and LAL developed together a test bench being able to make the automatic RF conditioning. The capability of this test bench is of 4 pairs of coupler at the same time with automatic sequences of increasing the RF power. The test bench is composed of the overall RF station providing up to 5 MW peak power at 1.3 GHz. The waveguide distribution allows 4 individual RF lines for conditionning,and the automatic sequence applied to the couplers in respect with all signals monitored and controlled during the RF process. The paper will also provide some examples of such process.
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THPB096	Lesson Learned on the Manufacturing of Fundamental Power Couplers for the European XFEL Accelerator	status, FEL, cryomodule, SRF	1370
	S. Sierra, G. Garcin, C. Lievin, G. Vignette TED, Velizy, France M. Knaak, M. Pekeler RI Research Instruments GmbH, Bergisch Gladbach, Germany
	In this paper we described lesson learned during the production of Fundamental Power Couplerfor the European XFEL accelerator and different steps necessaries for obtaining a rate of 8 couplers a week. From the manufacturing of individual components up to the RF conditioning. This paper also propose some possible ways to be optimized for a future mass production of such components. With comparison of processes and adaptation which could benefit to an increase rate or a more secure program. Some of them which could be studies from the coupler definition to the manufacturing process in order to obtain a stable and possible increased rate or lower cost of production by decreasing the risks on programs. This analysis is based on a current production of more than 500 couplers
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THPB102	RF Conditioning of the XFEL Power Couplers at the Industrial Scale	vacuum, pick-up, electron, monitoring	1387
	H. Guler, A. Gallas, W. Kaabi, D.J.M. Le Pinvidic, C. Magueur, M. Oublaid, A. Thiebault, A. Verguet LAL, Orsay, France
	LAL has in charge the production monitoring and the RF conditioning of 800 power couplers to equip 100 XFEL cryomodules. The conditioning process and all the preceding preparation steps are performed in a 70m2 clean room. This infrastructure, its equipment and the RF station are designed to allow the treatment of 8 couplers in the same time, after a ramp-up phase. Clean room process and conditioning results are presented and discussed.
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THPB120	Status of LCLS-II QA Systems Collaboration for Cyromodule Construction at TJNAF and FNAL	cryomodule, database, status, cavity	1422
	E.A. McEwen, V. Bookwalter, J. Leung JLab, Newport News, Virgina, USA J.N. Blowers, J.B. Szal Fermilab, Batavia, Illinois, USA
	At the Thomas Jefferson National Accelerator Facility (JLab), we are supporting the LCLS-II Project at SLAC. The plan is to build thirty-five 1.3 GHz continuous wave cryomodules, production to be split between JLab and FNAL (Fermilab). This has required a close collaboration between the partner labs, including enhancing our existing quality systems to include this collaboration. This over view describes the current status of the Quality System development as of August 2015, when the partner labs start the assembly of the prototype cryomodules.
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FRAA01	Overview of Recent Tuner Development on Elliptical and Low-Beta Cavities	cavity, linac, cryomodule, 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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Paper

Title

Other Keywords

Page

MOPB065

Recent Measurements on the SC 325 MHz CH-Cavity

cavity, ion, linac, heavy-ion

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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MOPB075

Experiences on Retreatment of EU-XFEL Series Cavities at DESY

cavity, status, feedback, linac

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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MOPB076

Horizontal RF Test of a Fully Equipped 3.9 GHz Cavity for the European XFEL in the DESY AMTF

cavity, HOM, operation, cryomodule

301

C.G. Maiano, C. Albrecht, R. Bospflug, J. Branlard, L. Butkowski, T. Delfs, J. Eschke, A. Gössel, F. Hoffmann, M. Hüning, K. Jensch, R. Jonas, R. Klos, D. Kostin, W. Maschmann, A. Matheisen, U. Mavrič, W.-D. Möller, C. Müller, K. Mueller, B. Petersen, P. Pierini, J. Rothenburg, O. Sawlanski, M. Schmökel, A.A. Sulimov, E. Vogel
DESY, Hamburg, Germany
A. Bosotti, M. Moretti, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy
E.R. Harms
Fermilab, Batavia, Illinois, USA
C.R. Montiel
ANL, Argonne, Illinois, USA
S. Pivovarov
BINP SB RAS, Novosibirsk, Russia

In order to validate the cavity package concept before the module preparation for the European XFEL Injector, one 3.9 GHz cavity, complete with magnetic shielding, power coupler and frequency tuner was tested in a specially designed single cavity cryomodule in one of the caves of the DESY Accelerator Module Test Facility (AMTF). The cavity was tested in high power pulsed operation up to the quench limit of 24 MV/m, above the vertical test qualifications and all subsystems under test (coupler, tuner, waveguide tuners, LLRF system) were qualified to design performances.

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MOPB094

Inspection and Repair Techniques for the EXFEL Superconducting 1.3 GHz Cavities at Ettore Zanon S.p.A: Methods and Results

cavity, operation, accelerating-gradient, electron

368

G. Massaro, G. Corniani, N. Maragno
Ettore Zanon S.p.A., Schio, Italy
A. Matheisen, A. Navitski
DESY, Hamburg, Germany
P. Michelato, L. Monaco
INFN/LASA, Segrate (MI), Italy

The quality control of the inner surface of superconducting RF cavities is essential in order to assure high accelerating gradient and quality factor. Ettore Zanon S.p.A. (EZ) has implemented in the serial production an optical system that use an high-resolution camera, in order to detect various types of defects. This system is added to a grinding machine, that was specifically designed and built to repair imperfections of the cavities inner surface. This inspection and repair system is applied to recover performance limited cavities of the 1.3 GHz European XFEL project, where surface irregularities are detected, either by the Obacht inspection system at Desy or the optical system at EZ. The optical system and the grinding procedure are qualified using two series cavities limited in gradient and showing different types of surface defects. The performances of these cavities have been recovered to reach the specifications of the project. Until now, all the series XFEL cavities built by EZ, repaired with this technique, have shown an accelerating gradient well above the EXFEL goal.

Poster MOPB094 [0.795 MB]

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MOPB095

SRF Cavity Processing and Chemical Etching Development for the FRIB Linac

cavity, SRF, linac, 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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MOPB098

Improvement of Temperature Control During Nb 9-Cell SRF Cavity Vertical Electro-Polishing (VEP) and Progress of VEP Quality

cavity, experiment, cathode, SRF

381

K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan
K. Ishimi
MGI, Chiba, Japan

Marui Galvanizing Co.,Ltd. has been developing Nb 9-cell SRF cavity vertical electro-polishing (VEP) facility and technique for mass production in collaboration with KEK. Our first 9-cell cavity VEP facility was not enough to control temperature during VEP, so the polishing quality was not so high. In this article, we will report the progress of temperature distribution and polishing quality due to the improvement of temperature control system of electrolyte and cavity during VEP.

Poster MOPB098 [0.988 MB]

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MOPB102

Comments on Electropolishing at Ettore Zanon SpA at the End of EXFEL Production

cavity, niobium, cathode, acceleration

394

M. Rizzi, G. Corniani
Ettore Zanon S.p.A., Schio, Italy
A. Matheisen
DESY, Hamburg, Germany
P. Michelato
INFN/LASA, Segrate (MI), Italy

In 2013 a new horizontal Electropolishing facility was developed and implemented by Ettore Zanon SpA (EZ) for the treatment of cavities for the European XFEL series production. More than 300 cavities have been treated. Electropolishing has been used for two applications: bulk removal and recovering of cavities with surface defects. Treatment settings have been analysed and compared with cavities performances to verify possible influences of the various parameters. Main parameters considered are treatment time, voltage and current, that together define average thickness removal. We present here the results of these investigation. The facility and process in use are also presented, together with possible next upgrade of the system, facing the new production of cavities for the LCLSII project.

Poster MOPB102 [1.535 MB]

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MOPB110

The Transfer of Improved Cavity Processing Protocols to Industry for LCLS-II: N-Doping and Electropolishing

cavity, cathode, niobium, superconductivity

418

C.E. Reece, F. Marhauser, A.D. Palczewski
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.
Based on the R&D efforts of colleagues at FNAL, Cornell, and JLab, the LCLS-II project adopted a modification to the rather standard niobium SRF cavity surface processing protocol that incorporates a high temperature diffusion doping with nitrogen gas. This change was motivated by the resulting higher Q0 and the prospect of significantly lower cryogenic heat load for LCLS-II. JLab is responsible for managing the cavity procurement for the LCLS-II project. The first phase of the procurement action is to transfer the nitrogen-doping protocol to the industrial vendors. We also seek to exploit improvements in understanding of the niobium electropolishing process as part of the production processing of the TESLA-style LCLS-II cavities. We report on the technology transfer activities and progress toward the envisaged performance demonstration of vendor-processed cavities.

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MOPB111

Furnace N2 Doping Treatments at Fermilab

vacuum, cavity, SRF, PLC

423

M. Merio, M. Checchin, A.C. Crawford, A. Grassellino, M. Martinello, A.M. Rowe, M. Wong
Fermilab, Batavia, Illinois, USA
M. Checchin, M. Martinello
Illinois Institute of Technology, Chicago, Illlinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
The Fermilab SRF group regularly performs Nitrogen (N2) doping heat treatments on superconducting cavities in order to improve their Radio Frequency (RF) performances. This paper describes the set up and operations of the Fermilab vacuum furnaces, with a major focus on the implementation and execution of the N2 doping recipe. The cavity preparation will be presented, N2 doping recipes will be analyzed and heat treatment data will be reported in the form of plot showing temperature, total pressure and partial pressures over time. Finally possible upgrades and improvements of the furnace and the N2 doping process are discussed.

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MOPB113

Study of the Evolution of Artificial Defects on the Surface of Niobium During Electrochemical and Chemical Polishing

SRF, laser, cavity, operation

433

L. Monaco, P. Michelato
INFN/LASA, Segrate (MI), Italy
A. Navitski, J. Schaffran, W. Singer
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
A.L. Prudnikava, Y. Tamashevich
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

The presence of defects on the inner surface of Nb superconducting RF structures might limit its final performance. For this reason, strict requirements are imposed during mechanical production of the cavities, specifically on the quality control of the inner surface of components, to avoid the presence of defects or scratches. Nevertheless, some defects may remain also after control or can arise from the following production steps. Understanding the evolution of the defect might shine new insight on its origin and help in defining possible repair techniques. This paper reports the topographical evolution of defects on a Nb sample polished with the standard recipe used for the 1.3 GHz cavities of the EXFEL project. Various artificial defects of different shape, dimensions, and thicknesses/depths, with geometrical characteristics similar to the one that may occur during the machining and handling of cavities, have been “ad hoc” produced on the sample of the same material used for the cell fabrication. Analysis shows the evolution of the shape and profile of the defects at the different polishing steps.

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MOPB118

Cleanliness and Vacuum Acceptance Tests for the UHV Cavity String of the XFEL Linac

cavity, vacuum, operation, cryomodule

452

S. Berry, O. Napoly, B. Visentin
CEA/DSM/IRFU, France
C. Boulch, C. Cloué, C. Madec, T. Trublet
CEA/IRFU, Gif-sur-Yvette, France
D. Henning, L. Lilje, A. Matheisen, M. Schmökel
DESY, Hamburg, Germany

The main linac of the European XFEL will consist of 100 accelerator modules, i.e. 800 superconducting accelerator cavities operated at a design gradient of 23.6MV/m. In this context CEA-Saclay built an assembly facility designed to produce one module per week, ready to be tested at DESY. The facility overcame the foreseen production rate. We would like to highlight and discuss the critical fields: cleanliness and vacuum. A new assembly method to protect final assembly against particulates contamination has been implemented on the production line. Impact on cryomodule RF test is presented. Particle transport measurements on components used for the European XFEL accelerator module are presented. The results indicate that the nominal operation of the automated pumping and venting units will not lead to particle transport. Vacuum acceptance tests are of major interest: leak tests and residual gas analysis (RGA) are used to control the absence of air leak and contamination. The RGA specifications have been slightly relaxed to ensure the production rate.

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TUPB002

Elimination of High Frequency Noise From the Beam in the Diamond Light Source Storage Ring

storage-ring, operation, synchrotron, power-supply

525

C. Christou, A. Bogusz, P.J. Marten
DLS, Oxfordshire, United Kingdom

High frequency beam motion has been identified as a source of noise in infrared beamlines in a number of synchrotron light sources. Diamond is a third generation synchrotron light source with storage ring current maintained by two superconducting CESR-B cavities powered by IOT-driven RF amplifiers. In our case, undesirable beam motion in the kilohertz range is predominantly driven by spectral content in the voltage across the IOTs arising from the switched mode nature of the high voltage power supply. Spectral noise on the amplifiers and beam has been identified and characterised and efforts to eliminate this noise are described. Care has been taken to maintain the overall stability of the RF at Diamond and tests have been carried out on an infrared beamline to investigate the degree to which beam noise impacts beamline operation in its different operating configurations.

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TUPB003

Cavity Procurement and Qualification Plan for LCLS-II

cavity, hardware, site, cathode

529

F. Marhauser, E. Daly, J.A. Fitzpatrick
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.
The LCLS-II project aims to build 35 accelerating cryomodules, which are based on the European XFEL design but modified for operation in CW mode. Each cryomodule houses eight TESLA-style nine-cell superconducting radio-frequency cavities. The activities to assemble the first two prototype cryomodules are ongoing at FNAL and JLab. 264 cavities worth of cavities for the remaining 33 cryomodules will be procured from two industrial vendors in similar quantity considering the option to produce spares. The assembly of cavities into the production cryomodules will be distributed among FNAL (16 cryomodules) and JLab (17 cryomodules). In this paper the cavity procurement and qualification plan for the LCLS-II project is detailed.

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TUPB004

Vertical Cavity Test Facility at Fermilab

cavity, instrumentation, experiment, SRF

534

O.S. Melnychuk, A. Grassellino, F.L. Lewis, J.P. Ozelis, R.V. Pilipenko, Y.M. Pischalnikov, O.V. Pronitchev, A. Romanenko, D.A. Sergatskov, B. Squires
Fermilab, Batavia, Illinois, USA

After a recent upgrade, the vertical test facility for SRF cavities at Fermilab features a low level RF system capable of testing 325MHz, 650MHz, 1.3GHz, and 3.9GHz cavities, helium liquefying plant, three test cryostats, and the interlock safety system. The cryostats can accommodate measurements of multiple cavities in a given cryogenic cycle in the range of temperatures from 4.2K to 1.4K. We present a description of the components of the vertical test facility. We also discuss cavity instrumentation that is used for diagnostics of cavity ambient conditions and quench characterization.

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TUPB008

A New Cryogenic Control System for the Vertical Test Area at Jefferson Lab

PLC, cryogenics, SRF, operation

549

G.K. Davis, T. Goodman, P. Kushnick, T. Powers, C.M. Wilson
JLab, Newport News, Virginia, USA

Funding: DOE
The Vertical Test Area at Jefferson Lab, consisting of eight vertical dewars, recently received a major upgrade by replacing the original (1995) cryogenic control system. A new, state-of-the-art, distributed control system (DC S) based on Programmable Logic Controllers (PLCs) was installed and commissioned. The new system increases facility throughput, reliability and cryogenic efficiency, while improving safety. The system employs a touchscreen graphical user interface and a highly redundant architecture on an Ethernet backbone.

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TUPB013

Fermilab Cryomodule Test Stand Design and Plans

cryomodule, cryogenics, cavity, SRF

566

E.R. Harms, C.M. Baffes, K. Carlson, B.E. Chase, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, M.W. McGee, P.S. Prieto, J. Reid, R.P. Stanek, D. Sun, M.J. White
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
A facility dedicated to SRF cryomodule testing is under construction at Fermilab. The test stand has been designed to be flexible enough to cool down and power test full length TESLA-style 8-cavity cryomodules as well cryomodules for low-β acceleration. We describe the design considerations, status, and near future plans for utilization of the test stand.

Poster TUPB013 [5.146 MB]

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TUPB022

Low-Beta SRF Cavity Processing and Testing Facility for the Facility for Rare Isotope Beams at Michigan State University

cavity, SRF, vacuum, cryomodule

597

L. Popielarski
NSCL, East Lansing, Michigan, USA
B.W. Barker, C. Compton, K. Elliott, I.M. Malloch, E.S. Metzgar, J. Popielarski, K. Saito, G.J. Velianoff, D.R. Victory, T. Xu
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661, the State of Michigan and Michigan State University
Major work centers of the new SRF Highbay are fully installed and in use for FRIB pre-production SRF quarter-wave and half-wave resonators, including inspection area, high temperature vacuum furnace for cavity degassing, chemical etching facility and processing and assembly cleanrooms. Pre-production activities focus on optimizing workflow by reducing process time, tracking part status and related data, and identifying bottlenecks. Topics discussed may include; buffered chemical polish (BCP) etching for cavity frequency control, degassing time reduction, automated high pressure rinse, particle control against field emission, pre-production cavity test results and implementation of workflow status programs

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TUPB026

Cryogenic Performance of the HNOSS Test Facility at Uppsala University

cavity, cryogenics, operation, vacuum

612

R. Santiago Kern, K.J. Gajewski, L. Hermansson, R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
P. Bujard, T. Junquera, J.P. Thermeau
Accelerators and Cryogenic Systems, Orsay, France

Funding: Knut and Alice Wallenbergs foundation
The FREIA Laboratory at Uppsala University, Sweden, is developing part of the RF system and testing the superconducting double spoke cavitites for ESS. During 2014 it was equipped with HNOSS, a versatile horizontal cryostat system for testing superconducting cavities. HNOSS is designed for high power RF testing of up to two superconducting accelerating cavities equipped with helium tank, fundamental power coupler and tuning system. In particular it will be used to characterise the performance of spoke cavities like used in the accelerator for the ESS project. HNOSS is connected to a cryogenic plant providing liquid helium and a sub-atmospheric pumping system enabling operation in the range 1.8 to 4.5~K. We present a brief description of the major components, installation and results from the recent operation and tests.

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TUPB081

Multi-Cell Temperature Mapping and Conclusions

cavity, SRF, monitoring, cryogenics

783

F. Furuta, R.G. Eichhorn, G.M. Ge, D. Gonnella, D.L. Hartill, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, E.N. Smith
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Multi-cell temperature mapping (T-map) system has been developed and applied on SRF Nb cavities vertical tests (VT) at Cornell. It has nearly two thousand thermometers and achieved a 1mK resolution of niobium surface temperature rinsing in superfluid helium . We have upgraded the system to be capable of monitoring the temperature profiles of quench spot on cavity. The recent results of T-map during cavity tests and details will be reported.

Poster TUPB081 [4.421 MB]

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TUPB093

Initial Commissioning Experience with the Spallation Neutron Source Vertical Test Area RF System

cavity, operation, software, hardware

819

M.T. Crofford, J.A. Ball, M. Doleans, S.-H. Kim, S.W. Lee, J.D. Mammosser, J. Saunders
ORNL, Oak Ridge, Tennessee, USA
T.L. Davidson, S. Whaley
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
The Spallation Neutron Source (SNS) has developed a vertical test area (VTA) for the testing and qualification of superconducting radio frequency cavities. The associated RF System successfully supported the initial commissioning of the VTA system and has been utilized for cavity testing at both 4 and 2 K. As operational experience was gained, improvements to the RF system were implemented to better utilize the dynamic range of the system, and software updates and additions were made to meet the operational needs. The system continues to evolve as we gain better understanding of the testing needs.

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TUPB094

Jefferson Lab Vertical Test Area RF System Improvement

cavity, network, software, low-level-rf

823

T. Powers, M.L. Morrone
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.
RF systems for testing critically coupled SRF cavities require the ability to track the cavity frequency excursions while making accurate measurements of the radio frequency (RF) signals associated with the cavity. Two types of systems are being used at Jefferson Lab. The first, the traditional approach, is to use a voltage controlled oscillator configured as a phase locked loop such that it will track the cavity frequency. The more recently developed approach is to use a digital low level RF (LLRF) system in self excited loop (SEL) mode to track the cavity frequency. Using a digital LLRF system in SEL mode has the advantage that it is much easier to lock to the cavity’s resonant frequencies and they tend to have a wider capture range. This paper will report on the system designs used to implement the 12 GeV digital LLRF system in the JLAB vertical test area. Additionally, it will report on the system modifications which are being implemented so that the RF infrastructure in the VTA will be ready to support the LCLS II cryomodule production effort, which is scheduled to begin in calendar year 2016.

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TUPB113

JLab Cryomodule Assembly Infrastructure Modifications for LCLS-II

cavity, cryomodule, vacuum, cryogenics

898

E. Daly, J. Armstrong, G. Cheng, M.A. Drury, J.F. Fischer, D. Forehand, K. Harding, J. Henry, K. Macha, J.P. Preble, A.V. Reilly, K.M. Wilson
JLab, Newport News, Virginia, USA

Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515.
The Thomas Jefferson National Accelerator Facility is currently engaged, along with several other DOE national laboratories, in the Linac Coherent Light Source II project (LCLS II). The SRF Institute at Jefferson Lab will be building 1 prototype and 17 production cryomodules based on the TESLA / ILC / XFEL design. Each cryomodule will contain eight nine cell cavities with coaxial power couplers operating at 1.3 GHz. New and modified infrastructure and assembly tooling is required to construct cryomodules in accordance with LCLS-II requirements. The approach for modifying assembly infrastructure included evaluating the existing assembly infrastructure implemented at laboratories world-wide in support of ILC and XFEL production activities and considered compatibility with existing infrastructure at JLab employed for previous cryomodule production projects. These modifications include capabilities to test cavities, construct cavity strings in a class 10 cleanroom environment, assemble cavity strings into cryostats, and prepare cryomodules for cryogenic performance testing. This paper will give a detailed description of these modifications.

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TUPB114

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

cavity, linac, 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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WEBA02

RF Measurements for Quality Assurance During SC Cavity Mass Production

cavity, HOM, GUI, linac

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, linac

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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THPB023

The Statistics of Industrial XFEL Cavities Fabrication at E.ZANON

cavity, target, niobium, accelerating-gradient

1119

A. Gresele, M. Giaretta, A. Visentin
Ettore Zanon S.p.A., Nuclear Division, Schio, Italy
A.A. Sulimov, J.H. Thie
DESY, Hamburg, Germany

Serial production of superconducting cavities for European-XFEL will be completed at E.ZANON by the end of 2015. For that reason we can summarize the results and present the statistics of industrial cavity fabrication. Many parameters have been traced during different steps of cavity production. The most interesting of them, as cavity length, frequency, field flatness and eccentricity, are presented and discussed.

Poster THPB023 [3.227 MB]

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THPB031

Operation Experience with Half Cell Measurement Machine and Cavity Tuning Machine in 3 Years of European XFEL Cavity Series Production

cavity, operation, SRF, HOM

1149

J.H. Thie, A. Gössel, J. Iversen, D. Klinke, C. Müller, A.A. Sulimov, D. Tischhauser
DESY, Hamburg, Germany

For the European XFEL superconducting Cavity series production at both cavity vendors’ four manufacturing machines for production key functions, HAZEMEMA and CTM, are supplied by DESY. Among three years of cavity production in two companies a lot of experience is gathered about influence of surroundings and production quality on cycle times, machine drop outs, general stability time of machines and parts subject to wear. Significant factors on cycle time for tuning operation like temperature stability and drift during tuning and measurements, precision of cell trimming before welding and tuning and generally geometrical factors are shown. RF aspects of tuning and production quality control as additional measurements for TM011-mode to estimate quality of its damping is presented. Performed full Cavity RF measurements exceeds XFEL specifications gives a possibility for additional quality control on welding shrinkage stability and it’s homogeneously distribution. The use of HAZEMEMA and CTM to assess the impact of asymmetric trimming, including calculation of it’s influence on the higher-order modes, is shown.

Poster THPB031 [0.201 MB]

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THPB035

Fabrication of the 3.9 GHz SRF Structures for the European XFEL

cavity, operation, linac, 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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THPB039

XFEL Database User Interface

cavity, database, GUI, interface

1168

S. Yasar, P.D. Gall, V. Gubarev, D. Reschke, A.A. Sulimov, J.H. Thie
DESY, Hamburg, Germany

The XFEL database plays an important role for an effective part of the quality control system for the whole cavity production and preparation process for the European XFEL on a very detailed level. Database has the Graphical User Interface based on the web-technologies, and it can be accessed via low level Oracle SQL.

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THPB045

Progress in IFMIF Half Wave Resonators Manufacturing and Test Preparation

cavity, simulation, cryomodule, vacuum

1191

G. Devanz, N. Bazin, G. Disset, P. Hardy, O. Piquet, J. Plouin
CEA/DSM/IRFU, France
H. Dzitko, H. Jenhani, J. Neyret, N. Sellami
CEA/IRFU, Gif-sur-Yvette, France

The IFMIF accelerator aims to provide an accelerator-based D-Li neutron source to produce high intensity high energy neutron flux to test samples as possible candidate materials to a full lifetime of fusion energy reactors. The first phase of the project aims at validating the technical options for the construction of an accelerator prototype, called LIPAc (Linear IFMIF Prototype Accelerator). A cryomodule hosting 8 Half Wave Resonators (HWR) at 175 MHz will provide the acceleration from 5 to 9 MeV. We report on the progress of the HWR manufacturing. A pre-series cavity will be used to assess and optimize the tuning procedure of the HWR, as well as the processing steps and related tooling. A new horizontal test cryostat (SATHORI) is also being set up at Saclay in the existing SRF test area. The SATHORI is dedicated to the IFMIF HWR performance check, fully equipped with its power coupler and cold tuning system. A 30kW-RF power will be available for these tests.

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THPB061

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

cavity, niobium, resonance, linac

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, linac, 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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THPB067

HOM Coupler Notch Filter Tuning for the European XFEL Cavities

HOM, cavity, resonance, database

1274

A.A. Sulimov
DESY, Hamburg, Germany

The notch filter (NF) tuning prevents the extraction of fundamental mode (1.3 GHz) RF power through Higher Order Modes (HOM) couplers. The procedure of NF tuning was optimized at the beginning of serial European XFEL cavities production. It allows keeping the filter more stable against temperature and pressure changes during cavity cool down. Some statistics of NF condition during cavities and modules cold tests is presented.

Poster THPB067 [0.404 MB]

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THPB076

Quality Control of Welding, Brazing Joints and Cu Deposition on EU-XFEL Coupler Parts

interface, electron, Windows, vacuum

1301

A. Ermakov, D. Kostin, W.-D. Möller
DESY, Hamburg, Germany

In frames of EU-XFEL Project the quality control of fundamental 1.3GHz power couplers is very important task. The power coupler consists of a several number of parts including itself the different types of welding and brazing joints between ceramic, copper and stainless steel components. The quality of these joints is subject to be investigated and controlled according to EU-XFEL Coupler specification taking into account the different coupler manufacturers involved. The quality of Cu deposition on some EU-XFEL coupler parts is also the issue to be qualified according to specs. The number of microscope images of different types of joints and Cu deposition on some EU-XFEL 1.3GHz coupler parts are presented.

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THPB095

Automatic RF Conditioning Test Bench of Fundamental Power Couplers for the European XFEL Accelerator

vacuum, SRF, interface, data-acquisition

1367

S. Sierra, C. Lievin, P. Rouillon
TED, Velizy, France
H. Guler, W. Kaabi, A. Verguet
LAL, Orsay, France

In order to perform the RF conditioning of the fundamental coupler for the XFEL accelerator, Thales and LAL developed together a test bench being able to make the automatic RF conditioning. The capability of this test bench is of 4 pairs of coupler at the same time with automatic sequences of increasing the RF power. The test bench is composed of the overall RF station providing up to 5 MW peak power at 1.3 GHz. The waveguide distribution allows 4 individual RF lines for conditionning,and the automatic sequence applied to the couplers in respect with all signals monitored and controlled during the RF process. The paper will also provide some examples of such process.

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THPB096

Lesson Learned on the Manufacturing of Fundamental Power Couplers for the European XFEL Accelerator

status, FEL, cryomodule, SRF

1370

S. Sierra, G. Garcin, C. Lievin, G. Vignette
TED, Velizy, France
M. Knaak, M. Pekeler
RI Research Instruments GmbH, Bergisch Gladbach, Germany

In this paper we described lesson learned during the production of Fundamental Power Couplerfor the European XFEL accelerator and different steps necessaries for obtaining a rate of 8 couplers a week. From the manufacturing of individual components up to the RF conditioning. This paper also propose some possible ways to be optimized for a future mass production of such components. With comparison of processes and adaptation which could benefit to an increase rate or a more secure program. Some of them which could be studies from the coupler definition to the manufacturing process in order to obtain a stable and possible increased rate or lower cost of production by decreasing the risks on programs. This analysis is based on a current production of more than 500 couplers

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THPB102

RF Conditioning of the XFEL Power Couplers at the Industrial Scale

vacuum, pick-up, electron, monitoring

1387

H. Guler, A. Gallas, W. Kaabi, D.J.M. Le Pinvidic, C. Magueur, M. Oublaid, A. Thiebault, A. Verguet
LAL, Orsay, France

LAL has in charge the production monitoring and the RF conditioning of 800 power couplers to equip 100 XFEL cryomodules. The conditioning process and all the preceding preparation steps are performed in a 70m2 clean room. This infrastructure, its equipment and the RF station are designed to allow the treatment of 8 couplers in the same time, after a ramp-up phase. Clean room process and conditioning results are presented and discussed.

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THPB120

Status of LCLS-II QA Systems Collaboration for Cyromodule Construction at TJNAF and FNAL

cryomodule, database, status, cavity

1422

E.A. McEwen, V. Bookwalter, J. Leung
JLab, Newport News, Virgina, USA
J.N. Blowers, J.B. Szal
Fermilab, Batavia, Illinois, USA

At the Thomas Jefferson National Accelerator Facility (JLab), we are supporting the LCLS-II Project at SLAC. The plan is to build thirty-five 1.3 GHz continuous wave cryomodules, production to be split between JLab and FNAL (Fermilab). This has required a close collaboration between the partner labs, including enhancing our existing quality systems to include this collaboration. This over view describes the current status of the Quality System development as of August 2015, when the partner labs start the assembly of the prototype cryomodules.

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FRAA01

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

cavity, linac, cryomodule, 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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