2011 Particle Accelerator Conference - List of Keywords (cryomodule)

Paper	Title	Other Keywords	Page
MOP009	Status and Plans for a SRF Accelerator Test Facility at Fermilab	SRF, cryogenics, electron, gun	118
	J.R. Leibfritz, R. Andrews, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, S.L. Lackey, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln Fermilab, Batavia, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy A superconducting RF accelerator test facility is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 810 MeV electron beam with ILC beam intensity. Expansion plans of the facility are underway that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. In addition to testing accelerator components, this facility will be used to test RF power equipment, instrumentation, LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

MOP145	Physics Design of the Project X CW Linac	linac, lattice, simulation, focusing	364
	N. Solyak, J.-P. Carneiro, J.S. Kerby, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, A. Vostrikov, V.P. Yakovlev Fermilab, Batavia, USA
	The general design of the 3 GeV superconducting CW linac of the Project X is presented. Different physical and technical issues and limitations that determine the linac concept are discussed. The results of the RF system optimization are presented as well as the lattice design and beam dynamics analysis.

MOP184	Beam Instrumentation for the European Spallation Source	linac, diagnostics, target, rfq	432
	A. Jansson, H. Danared, M. Eshraqi, L. Tchelidze ESS, Lund, Sweden
	The European Spallation Source, which will be built in the south of Sweden, is a neutron source based on a 5MW, 2.5GeV proton linac. The project is currently in the design update phase, and will deliver a Technical Design Report at the end of 2012. Construction is expected to begin in 2013. This paper discusses the initial beam diagnostics specifications, along with some possible instrument design options.

MOP257	High Power RF Distribution and Control for Multi-Cavity Cryomodule Testing	controls, cavity, linac, klystron	591
	Y.W. Kang, M. Broyles, M.T. Crofford, X. Geng, S.-H. Kim, S.W. Lee, C.L. Phibbs, K.R. Shin, W.H. Strong ORNL, 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 SNS has been successfully operating 81 superconducting six-cell cavities in 23 cryomodules in its linac to achieve the goals in beam power and energy. For near-term production of spare cryomodules and the upcoming power upgrade project that will need 36 additional cavities in 9 cryomodules, high RF power testing and qualification of the cavities is required in the RF test facility. Simultaneously powering all the cavities in a cryomodule is considered desirable for robust conditioning and studying of cavity field emission since certain cavities exhibit field emissions that could be mutually coupled. A four-way variable output power waveguide splitting system is being prepared for testing cryomodules with up to four cavities. The splitting system is fed by an 805 MHz, 5 MW peak power pulsed klystron. The power output at each arm can be adjusted in both amplitude and phase to wide ranges of values using two mechanical waveguide phase shifters that form a vector modulator. The system control is implemented in the EPICS environment similar to the main accelerator controls. The work performed on the design, integration, operation, and test of the system are presented.

TUP031	Project X Elliptical Cavity Structural Analyses	cavity, simulation, vacuum, linac	868
	E.N. Zaplatin FZJ, Jülich, Germany
	Project X is proposed at Fermi National Accelerator Laboratory high-intensity proton accelerator complex that could provide beam for a variety of physics projects. Superconducting resonators will be used for beam acceleration. Here we report a structural design of elliptical cavities with resonance frequency 650 MHz and β=0.91 and 0.61. Since there is a concern that the pressure in the helium plumbing will not be stable when the cryomodules are connected to the liquid helium supply and helium gas returns it is necessary to provide the cavity stiffening with requirements of 15 Hz amplitude frequency shift. The cavity RF and mechanical properties are investigated. The calculations of the cavity frequency shift with pressure for different schemes of cavity stiffening were provided. The criterion for the optimization was the minimization of a resonant frequency dependence on an external pressure. Based on the results of these simulations several options on cavity stiffening have been proposed. Additionally, the cavity stiffening structural scheme for self-compensation of resonator detuning caused by external pressure fluctuation have been investigated.

TUP044	A Comparison of Superconducting RF Structures Optimized for β = 0.285	cavity, ion, simulation, SRF	889
	Z.A. Conway, R.L. Fischer, M.P. Kelly, A. Kolomiets, B. Mustapha, P.N. Ostroumov ANL, Argonne, USA
	Recent advances in low-beta superconducting RF technology have enabled the proposal and construction of ever-increasing-intensity ion accelerators, e.g. The Facility for Rare Isotope Beams (FRIB) at Michigan State University and Project-X at Fermilab. Superconducting TEM-class structures are required for these accelerators and beam quality preservation and cost efficiency are of the highest importance. This paper presents a comparison of the superconducting TEM-class cavities available for the acceleration of ions in the energy range of 16 to 55 MeV/u in order to guide their selection in future ion accelerator projects.

TUP051	Design and First Cold Test of BNL Superconducting 112 MHz QWR for Electron Gun Applications	cavity, gun, electron, cathode	898
	S.A. Belomestnykh, I. Ben-Zvi, X. Chang, R. Than BNL, Upton, Long Island, New York, USA C.H. Boulware, T.L. Grimm, B. Siegel, M.J. Winowski Niowave, Inc., Lansing, Michigan, USA
	Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments. Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The work at Niowave is supported by the U.S. DOE under SBIR contract No. DE-FG02-07ER84861

TUP055	Design and Preliminary Test of the 1500 MHz NSLS-II Passive Superconducting RF Cavity	cavity, HOM, vacuum, niobium	910
	J. Rose, W.K. Gash, B.N. Kosciuk, V. Ravindranath, S.K. Sharma, R. Sikora, N.A. Towne BNL, Upton, Long Island, New York, USA C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski Niowave, Inc., Lansing, Michigan, USA
	NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed.

TUP063	HOM Measurements with Beam at the Cornell Injector Cryomodule	HOM, simulation, laser, pick-up	934
	S. Posen, M. Liepe CLASSE, Ithaca, New York, USA
	Funding: NSF The Cornell ERL injector prototype is undergoing commissioning and testing for running unprecedented currents in an electron cw injector. This paper discusses preliminary measurements of HOMs in the injector prototype’s superconducting RF cryomodule. These include HOM spectra up to 30 GHz measured via small antennae located at the HOM beam line absorbers between the SRF cavities. The spectra are compared at different beam currents and repetition rates. The shape of the spectra are compared to ABCI simulations of the loss factor spectrum of the cryomodule beam line. The total HOM power dissipated in the HOM loads was also measured with beam on, which allowed for an estimate of the loss factor. This measurement was accomplished via temperature sensors on the loads, calibrated to input power by heaters on the loads.

TUP071	High Power Tests of Dressed Superconducting 1.3 GHz RF Cavities	cavity, resonance, higher-order-mode, shielding	949
	A. Hocker, E.R. Harms, A. Lunin, A.I. Sukhanov Fermilab, Batavia, USA
	Funding: U.S. Department of Energy, Contract No. DE-AC02-07CH11359 A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted (“dressed”) with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

TUP072	High Power Couplers for Project X Linac	coupling, linac, cavity, vacuum	952
	S. Kazakov, M.S. Champion, M. Kramp, Y. Orlov, O. Pronitchev, V.P. Yakovlev Fermilab, Batavia, USA
	Project X, a multi-megawatt proton sources is under development in Fermi National Accelerator Laboratory. The key element of the project is a superconducting (SC) 3GV CW proton liner accelerator (linac). The linac includes 5 types of SC accelerating cavities of three 325 and 650 MHz frequencies. The cavities consumes up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. New cost effective schemes of the couplers are described. Results of electrodynamics and thermal simulations are presented.

TUP075	Cavity Loss Factors of Non-relativistic Beams for Project X	cavity, linac, simulation, factory	961
	A. Lunin, S. Kazakov, V.P. Yakovlev Fermilab, Batavia, USA
	Cavity loss factor calculation is an important part of total cryolosses estimation for the super conductive (SC) accelerating structures. There are two approaches how to calculate cavity loss factors, the integration of a wake potential over the bunch profile and the combining of loss factors for individual cavity modes. We applied both methods in order to get reliable results for non-relativistic beam. The time domain CST solver was used for a wake potential calculation and the frequency domain HFSS code was used for the cavity eigenmodes spectrum findings. Finally we present the results of cavity loss factors simulations for a non-relativistic part of the ProjectX and analyze it for various beam parameters.

TUP077	Vibrational Measurements for Commissioning SRF Accelerator Test Facility at Fermilab	cavity, cryogenics, vacuum, quadrupole	967
	M.W. McGee, J.R. Leibfritz, A. Martinez, Y.M. Pischalnikov, W. Schappert Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy. The commissioning of two cryomodule components is underway at Fermilab’s Superconducting Radio Frequency (SRF) Accelerator Test Facility. The research at this facility supports the next generation high intensity linear accelerators such as the International Linear Collider (ILC), a new high intensity injector (Project X) and other future machines. These components, Cryomodule #1 (CM1) and Capture Cavity II (CC2) which contain 1.3 GHz cavities are connected in series in the beamline and through cryogenic plumbing. Studies regarding characterization of ground motion, technical and cultural noise continue. Mechanical transfer functions between the foundation and critical beamline components have been measured and overall system displacement characterized. Baseline motion measurements given initial operation of cryogenic, vacuum systems and other utilities are considered.

TUP079	Cryomodule Design for 325 MHz Superconducting Single Spoke Cavities and Solenoids	cavity, vacuum, solenoid, cryogenics	970
	T.H. Nicol, S. Cheban, R.L. Madrak, F. McConologue, T.J. Peterson, V. Poloubotko, L. Ristori, W. Schappert, I. Terechkine, B.A. Vosmek Fermilab, Batavia, USA
	Funding: U.S. Department of Energy The low-beta section of the linac being considered for Project X at Fermilab contains several styles of 325 MHz superconducting single spoke cavities and solenoid based focusing lenses, all operating at 2 K. Each type of cavity and focusing lens will eventually be incorporated into the design of cryomodules unique to various sections of the linac front end. This paper describes the design of a multiple-cavity and solenoid cryomodule being developed to test the function of each of the main cryomodule systems – cryogenic systems and instrumentation, cavity and lens positioning and alignment, conduction-cooled current leads, magnetic shielding, cold-to-warm beam tube transitions, interfaces to interconnecting equipment and adjacent modules, as well as evaluation of overall assembly procedures.

TUP082	Test of a Coaxial Blade Tuner at HTS/FNAL	cavity, SRF, resonance, controls	976
	Y.M. Pischalnikov, S. Barbanotti, E.R. Harms, A. Hocker, T.N. Khabiboulline, W. Schappert Fermilab, Batavia, USA A. Bosotti, C. Pagani, R. Paparella INFN/LASA, Segrate (MI), Italy
	Funding: Work is supported by the U.S. Department of Energy Fermilab is building Cryomodule 2 for ILCTA facility at NML. A coaxial blade tuner has been chosen for the CM2 1.3GHz SRF cavities. A summary of results from cold test of the tuners in the Fermilab Horizontal Test Stand will be presented.

TUP086	Microphonics control for Project X	cavity, controls, linac, SRF	988
	W. Schappert, S. Barbanotti, J. Branlard, G.I. Cancelo, R.H. Carcagno, M.S. Champion, B. Chase, I.G. Gonin, A.L. Klebaner, D.F. Orris, T.J. Peterson, Y.M. Pischalnikov, L. Ristori, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Work is supported by the U.S. Department of Energy The proposed multi-MW Project X facility at Fermilab will employ cavities with bandwidths as narrow as 20 Hz. This combination of high RF power with narrow bandwidths combined requires careful attention to detuning control if these cavities are to be operated successfully. Detuning control for Projects X will require a coordinated effort between the groups responsible for various machine subsystems. Considerable progress in this area has been made over the past year.

TUP089	Concept EM Design of the 650 MHz Cavities for the Project X	cavity, linac, HOM, resonance	994
	V.P. Yakovlev, M.S. Champion, I.G. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak Fermilab, Batavia, USA A. Saini University of Delhi, Delhi, India
	Concept of the 650 MHz cavities for the Project X is presented. Choice of the basic parameters, i.e, number of cells, geometrical β, apertures, coupling coefficients, etc, is discussed. The cavities optimization criteria are formulated. Results of the RF design are presented for the cavities of both low-energy and high energy sections.

TUP090	Design of a β = 0.29 Half-wave Resonator for the FRIB Driver Linac	cavity, linac, simulation, ion	997
	J.P. Holzbauer, W. Hartung, J. Popielarski NSCL, East Lansing, Michigan, USA
	The driver linac for the Facility for Rare Isotope Beams will produce primary beams of ions at 200 MeV per nucleon for nuclear physics research. The driver linac will require 344 superconducting cavities, consisting of two types of Quarter-Wave Resonators (QWRs, β = 0.041 and 0.085) and two types of Half-Wave Resonators (HWRs, β = 0.29 and 0.53). A first-generation β = 0.29 HWR has been designed, prototyped, and tested. Second-generation versions of the other cavities are being developed, with one or more prototype having been tested. A second-generation β = 0.29 HWR design has been developed, making use of the experience with the first-generation β = 0.29 HWR and second-generation β = 0.53 HWR. In the second-generation design, the inner conductor is tapered to reduce the peak surface magnetic field. The outer conductor is a straight tube to increase the mechanical stiffness and reduce the sensitivity of the resonant frequency to bath pressure fluctuations. Optimization was employed to minimize the peak surface electric field. The second-generation β = 0.29 HWR design will be presented, including the RF design and mechanical analysis.

TUP107	RF-thermal Combined Simulations of a Superconducting HOM Coaxial Coupler	HOM, cavity, simulation, SRF	1041
	G. Cheng, H. Wang JLAB, Newport News, Virginia, USA D.N. Smithe Tech-X, Boulder, Colorado, USA
	Funding: This work is supported by Jefferson LAB and Tech-X CRADA #2009S005 on “Simulations of Electromagnetic and Thermal Characteristics of SRF Structures”. To benchmark a multi-physics code VORPAL developed by Tech-X, the High Order Mode (HOM) coaxial coupler design implemented in Jefferson Lab’s 12GeV upgrade cryomodules is analyzed by use of commercial codes, such as ANSYS, HFSS and Microwave Studio. Testing data from a Horizontal Test Bed (HTB) experiment on a dual-cavity prototype are also utilized in the verification of simulation results. The work includes two stages: first, the HOM feedthrough that has a high RRR niobium probe and sapphire insulator is analyzed for the RF-thermal response when there is traveling wave passing through; second, the HTB testing condition is simulated and results from simulation are compared to thermal measurements from HTB tests. The analyses are of coupled-field nature and involve highly nonlinear temperature dependent thermal conductivities and electric resistivities for the eight types of materials used in the design. Accuracy and efficiency are the main factors in evaluation of the performance of the codes.

TUP108	Summary Report for the C50 Cryomodule Project	cavity, vacuum, accelerating-gradient, electron	1044
	M.A. Drury, G.K. Davis, J.F. Fischer, C. Grenoble, J. Hogan, L.K. King, K. Macha, J.D. Mammosser, C.E. Reece, A.V. Reilly, J. Saunders, H. Wang JLAB, Newport News, Virginia, USA E. Daly, J.P. Preble ITER Organization, St. Paul lez Durance, France
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177. The Thomas Jefferson National Accelerator Facility has recently completed the C50 cryomodule refurbishment project. The goal of this project was to enable robust 6 GeV, 5 pass operation of the Continuous Electron Beam Accelerator Facility (CEBAF). The scope of the project included removal, refurbishment and reinstallation of ten CEBAF cryomodules at a rate of three per year. The refurbishment process included reprocessing of SRF cavities to eliminate field emission and to increase the nominal gradient from the original 5 MV/m to 12.5 MV/m. New “dogleg“ couplers were installed between the cavity and helium vessel flanges to intercept secondary electrons that produce arcing in the fundamental Power Coupler (FPC). Other changes included new ceramic RF windows for the air to vacuum interface of the FPC and improvements to the mechanical tuner. Damaged or worn components were replaced as well. All ten of the refurbished cryomodules are now installed in CEBAF and are currently operational. This paper will summarize the performance of the cryomodules. This paper will also look at problems that must be addressed by future refurbishment projects. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUP223	Cryogenic System for the Energy Recovery Linac and Vertical Test Facility at BNL	cryogenics, cavity, vacuum, controls	1235
	R. Than, D.L. Lederle, L. Masi, P. Orfin, R. Porqueddu, V. Soria, T.N. Tallerico, P. Talty, Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A small cryogenic system and warm helium vacuum pumping system provides cooling to the Energy Recovery Linac's (ERL) cryomodules, a 5-cell cavity and an SRF gun, and a large Vertical Test Dewar. The system consist of a model 1660S PSI (KPS) plant, a 4000 liter storage dewar, subcooler, wet expander, 50 g/s main helium compressor and 170 m³ storage tank. A system description and operating plan is given of the cryogenic plant and cryomodules

TUP270	RF and Structural Analysis of the 72.75 MHz QWR for the ATLAS Upgrade	cavity, niobium, coupling, cryogenics	1325
	T. Schultheiss, J. Rathke AES, Medford, NY, USA J.D. Fuerst, M.P. Kelly, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by Argonne National Lab under contract # 0F-32381 & 0F32422 An energy upgrade to the heavy-ion accelerator ATLAS at Argonne Lab is progressing,. The plans include replacing split-ring cavities with high performance quarter wave resonators. The new 72.75 MHz resonators are designed for optimum ion velocity β=.077 and a record high accelerating voltage of 2.5 MV by modifying the top geometry and reducing the peak surface fields. This new cavity has a longer center conductor than the 10⁹ MHz cavities previously built by ANL with AES assistance, this and the other geometry changes add new engineering requirements to the design. This paper presents the engineering studies that were performed to resolve new issues. These studies include determining structural frequencies of the center conductor and stiffening methods, resonator frequency sensitivity to helium pressure fluctuations, and determining stress levels due to pressure and slow tuning. Evaluation of fast piezoelectric tuner frequency shift to tuner load was also performed and the local cavity shape was optimized based on these results. P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016 ** P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045

TUP271	CESR-type SRF Cavity - Meeting the ASME Pressure Vessel Criteria by Analysis	niobium, cavity, SRF, factory	1328
	T. Schultheiss, J. Rathke AES, Medford, NY, USA V. Ravindranath, J. Rose, S.K. Sharma BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by BNL under contract #147322 Over a dozen CESR-B Type SRF cryomodules have been implemented in advanced accelerators around the world. The cryomodule incorporates a niobium cavity operating in liquid helium at approximately 1.2 bar and at 4.5 K, and therefore, is subjected to a differential pressure of 1.2 bar to the beam vacuum. Over the past few decades niobium RRR values have increased, as manufacturing processes have improved, resulting in higher purity niobium and improved thermal properties. Along with these increases may come a decrease of yield strength, therefore, prior designs such as CESR-B, must be evaluated at the newer strength levels when using the newer high purity niobium. In addition to this the DOE directive 10CFR851 requires all DOE laboratories to provide a level of safety equivalent to that of the ASME Boiler and Pressure Vessel codes. The goal of this work was to analyze the CESR-B Type cavity and compare the results to ASME pressure vessel criteria and where necessary modify the design to meet the code criteria.

TUP272	Analysis and Comparison to Test of AlMg3 Seals Near a SRF Cavity	cavity, niobium, SRF, linac	1331
	T. Schultheiss, C.M. Astefanous, M.D. Cole, D. Holmes, J. Rathke AES, Medford, NY, USA I. Ben-Zvi, D. Kayran, G.T. McIntyre, B. Sheehy, R. Than BNL, Upton, Long Island, New York, USA A. Burrill JLAB, Newport News, Virginia, USA
	The Energy Recovery Linac (ERL) presently under construction at Brookhaven National Laboratory is being developed as research and development towards eRHIC, an Electron-Heavy Ion Collider. The experimental 5-cell 703.75 MHz (ECX) cavity was recently evaluated at continuous field levels greater than 10 MV/m. These tests indicated stored energy limits of the cavity on the order of 75 joules. During design of the cavity the cold flange on one side was moved closer to the cavity to allow the cavity to fit into the available chemical processing chamber at Jefferson Laboratory. RF and thermal analysis of the AlMg3 seal region of the closer side indicate this to be the prime candidate limiting the fields. This work presents the analysis results and compares these results to test data.

WEOBS5	Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)	cavity, feedback, emittance, impedance	1427
	R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents ANL, Argonne, USA J.M. Byrd, L.R. Doolittle, G. Huang LBNL, Berkeley, California, USA G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang JLAB, Newport News, Virginia, USA
	Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future. *A. Zholents et al., NIM A 425, 385 (1999).
	Slides WEOBS5 [1.730 MB]

WEOCS6	The Injector Cryomodule for e-Linac at TRIUMF	linac, ISAC, TRIUMF, cavity	1469
	R.E. Laxdal, C.D. Beard, S.R. Koscielniak, A. Koveshnikov, A.K. Mitra, T.C. Ries, I. Sekachev, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M. Mondal, V. Naik DAE/VECC, Calcutta, India
	The e-Linac project at TRIUMF, now funded, is specified to accelerate 10mA of electrons to 50MeV using 1.3GHz multi-cell superconducting cavities. The linac consists of three cryomodules; an injector cryomodule with one cavity and two accelerating modules with two cavities each. The injector module is being designed and constructed in collaboration with VECC in Kolkata. The design utilizes a unique box cryomodule with a top-loading cold mass. A 4K phase separator, 2K-4K heat exchanger and Joule-Thompson valve are installed within each module to produce 2K liquid. The design and status of the development will be presented.
	Slides WEOCS6 [13.002 MB]

WEOCS7	Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source	cavity, HOM, coupling, alignment	1472
	H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington JLAB, Newport News, Virginia, USA R. Nassiri, G.J. Waldschmidt, G. Wu ANL, Argonne, USA
	Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.
	Slides WEOCS7 [7.008 MB]

WEP174	Simulations and Calculations of Cavity-to-cavity Coupling for Elliptical SCRF Cavities in ESS	cavity, coupling, simulation, linac	1813
	R. Ainsworth, S. Molloy Royal Holloway, University of London, Surrey, United Kingdom
	The proton linac of the European Spallation Source (ESS) will rely on two families of superconducting cavities for the medium and high beta regions. Presented here are simulations of various cavity designs for different betas. The simulations are performed using the ACE3P codes developed at SLAC National Accelerator Laboratory, and the simulated eigenmode and R/Q spectrum will be shown for each design. Dangerous modes are identified. Of particular importance is the investigations of multiple cavity (cryomodule) configurations. From this, the simulated cavity-to-cavity coupling within a cryomodule is extracted. A theoretical model of this coupling based on the calculated cutoff frequencies, decay lengths, and resonance conditions, has also been developed, and a comparison made with the results of the simulation.

WEP226	Commissioning Results of the ReA RFQ at MSU*	rfq, ion, emittance, acceleration	1912
	D. Leitner, C. Benatti, S.W. Krause, D. Morris, S. Nash, J. Ottarson, G. Perdikakis, M. Portillo, R. Rencsok, T. Ropponen, L. Tobos, N.R. Usher, D. Wang NSCL, East Lansing, Michigan, USA J. Haeuser Kress GmbH, Biebergemuend, Germany O.K. Kester GSI, Darmstadt, Germany F. Marti, E. Tanke, X. Wu, Q. Zhao FRIB, East Lansing, Michigan, USA A. Schempp, J.S. Schmidt, H. Zimmermann IAP, Frankfurt am Main, Germany
	Funding: Project funded by Michigan State University The Facility for Rare Isotope Beams (FRIB) is currently in the preliminary design phase at Michigan State University (MSU). FRIB consists of a driver LINAC for the acceleration of heavy ion beams, followed by a fragmentation target station and a ReAccelerator facility (ReA3). ReA3 comprises gas stopper systems, an Electron Beam Ion Trap (EBIT) charge state booster, a room temperature radio frequency quadrupole (RFQ), a LINAC using superconducting quarter wave resonators and an achromatic beam transport and distribution line to the new experimental area. Beams from ReA3 will range from 3 MeV/u for heavy ions to about 6 MeV/u for light ions. The ReA3 RFQ, which is of the 4 rod type, is designed to accelerate ions with an Q/A of 0.2 to 0.5 from 12 keV/u to 600 keV/u. The RFQ operates at a frequency of 80.5 MHz and power levels up to 120 kW at 10% duty factor. In this paper we will report on commissioning results from the ReA3 RFQ using a H²⁺ and He⁺ beam from an auxiliary ion source.

THOCN5	ATLAS Upgrade	cavity, rfq, ion, linac	2110
	P.N. Ostroumov, A. Barcikowski, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.W.T. MacDonald, B. Mustapha, R.C. Pardo, S.I. Sharamentov ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. ATLAS (Argonne Tandem Linac Accelerator System) upgrade requires several substantial developments in accelerator technologies, such as CW heavy ion RFQ and high-performance cryomodule with low-beta cavities. The upgrade project is well advanced. The physics and engineering design of the RFQ are complete and fabrication of OFE copper parts is in progress. The 3.9-meter length RFQ is composed from 5 strongly coupled segments. High-temperature furnace brazing of the segments is planned for the summer of 2011. The RFQ design includes several innovative features such as trapezoidal vane tip modulation, compact output radial matcher to form an axially symmetric beam. The upgrade project also includes development and construction of a cryomodule containing seven 72.75 MHz SC quarter wave cavities designed for the geometrical β= 0.077 and four SC solenoids. The cavity is designed to obtain an accelerating voltage higher than 2.5 MV. The prototype cavity together with high-power capacitive coupler and piezoelectric tuner has been developed, fabricated and is being tested. This paper reports innovative design features of both RFQ and SRF linac and current status of the project.
	Slides THOCN5 [3.070 MB]

THOCS3	R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source	plasma, cavity, SRF, ion	2124
	S.-H. Kim, M.T. Crofford ORNL, Oak Ridge, Tennessee, USA M. Doleans NSCL, East Lansing, Michigan, USA J.D. Mammosser JLAB, Newport News, Virginia, USA J. Saunders 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 SNS SCL is reliably operating at 0.93 GeV output energy with an energy reserve of 10MeV with high availability. Most of the cavities exhibit field emission, which directly or indirectly (through heating of end groups) limits the gradients achievable in the high beta cavities in normal operation with the beam. One of the field emission sources would be surface contaminations during surface processing for which mild surface cleaning, if any, will help in reducing field emission. An R&D effort is in progress to develop in-situ surface processing for the cryomodules in the tunnel without disassembly. As the first attempt, in-situ plasma processing has been applied to the CM12 in the SNS SRF facility after the repair work with a promising result. This paper will report the R&D status of plasma processing in the SNS.
	Slides THOCS3 [3.294 MB]

THOCS4	RF Power Upgrade for CEBAF at Jefferson Laboratory	klystron, solenoid, controls, cavity	2127
	A.J. Kimber, R.M. Nelson JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed.
	Slides THOCS4 [3.364 MB]

THOCS6	Progress in Cavity and Cryomodule Design for the Project X Linac	cavity, linac, solenoid, lattice	2133
	M.S. Champion, S. Barbanotti, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, J.S. Kerby, S. Nagaitsev, T.H. Nicol, T.J. Peterson, L. Ristori, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	The continuous wave 3 GeV Project X Linac requires the development of two families of cavities and cryomodules at 325 and 650 MHz. The baseline design calls for three types of superconducting single-spoke resonators at 325 MHz having betas of 0.11, 0.22, and 0.42 and two types of superconducting five-cell elliptical cavities having betas of 0.61 and 0.9. These cavities shall accelerate a 1 mA H⁻ beam initially and must support eventual operation at 4 mA. The electromagnetic and mechanical designs of the cavities are in progress and acquisition of prototypes is planned. The heat load to the cryogenic system is up to 25 W per cavity in the 650 MHz section, thus segmentation of the cryogenic system is a major issue in the cryomodule design. Designs for the two families of cryomodules are underway.
	Slides THOCS6 [2.241 MB]

THP077	SC Quadrupole for Cryomodule for ERL/ILC	quadrupole, dipole, focusing, linac	2276
	A.A. Mikhailichenko CLASSE, Ithaca, New York, USA
	Funding: NSF We are considering the SC quadrupole where the field formed not only by the current distributions, but with the poles also. This delivers a good quality field in all aperture allowing compact and inexpensive design. This type of quadrupole designed for Cornell ERL could be recommended for ILC also.

THP212	Superconducting Cavity Design for Short-Pulse X-Rays at the Advanced Photon Source	cavity, damping, HOM, coupling	2516
	G.J. Waldschmidt, B. Brajuskovic, R. Nassiri ANL, Argonne, USA G. Cheng, J. Henry, J.D. Mammosser, R.A. Rimmer, H. Wang JLAB, Newport News, Virginia, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Superconducting cavities have been analyzed for the short-pulse x-ray (SPX) project at the Advanced Photon Source (APS). Due to the strong damping requirements in the APS storage ring, single-cell superconducting cavities have been designed. The geometry has been optimized for lower-order and higher-order mode damping, reduced peak surface magnetic fields, and compact size. The integration of the cavity assembly, with dampers and waveguide input coupler, into a cryomodule will be discussed.

FROAN1	The European Spallation Source	linac, target, neutron, proton	2549
	S. Peggs, H. Danared, M. Eshraqi, H. Hahn, A. Jansson, M. Lindroos, A. Ponton, K. Rathsman, G. Trahern ESS, Lund, Sweden S. Bousson IPN, Orsay, France R. Calaga BNL, Upton, Long Island, New York, USA G. Devanz, R.D. Duperrier CEA/DSM/IRFU, France J. Eguia Fundación TEKNIKER, Eibar (Gipuzkoa), Spain S. Gammino INFN/LNS, Catania, Italy S.P. Møller ISA, Aarhus, Denmark C. Oyon SPRI, Bilbao, Spain R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden T. Satogata JLAB, Newport News, Virginia, USA
	The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.
	Slides FROAN1 [1.650 MB]

FROBN2	Technical Challenges in Design and Construction of FRIB	linac, ion, target, acceleration	2561
	R.C. York, G. Machicoane NSCL, East Lansing, Michigan, USA S. Assadi, G. Bollen, T . Glasmacher, W. Hartung, M.J. Johnson, F. Marti, E. Pozdeyev, M.J. Syphers, E. Tanke, J. Wei, X. Wu, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: Work supported by DOE CA DE-SC0000661 and Michigan State University. The Facility for Rare Isotope Beams (FRIB) will be a world-leading, DOE national users facility for the study of nuclear structure, reactions and astrophysics on the campus of Michigan State University. A superconducting, heavy-ion, driver linac will be used to provide stable beams of >200 MeV/u at beam powers up to 400 kW (~650 electrical micro-amps for uranium) that will be used to produce rare isotopes by in flight fragment separation. The selected rare isotopes will be used at velocity (~0.5 c), stopped, or reaccelerated. FRIB is a challenging technical project. An overview of the project, project challenges, and mitigating strategies will be presented.
	Slides FROBN2 [14.690 MB]

FROBS1	World-wide Experience with SRF Facilities	SRF, survey, vacuum, cavity	2575
	A. Hutton, A. Carpenter JLAB, Newport News, Virginia, USA
	The speaker will review and analyze the performance of existing SRF facilities in the world, addressing issues of usage and availability for different customers (HEP research, material sciences, ADS). Lessons learned should be summarized for proposed future facilities (ILC, ProjectX, Muon Collider).
	Slides FROBS1 [5.473 MB]

FROBS3	Progress on Superconducting RF for the Cornell Energy-Recovery-Linac	cavity, HOM, SRF, linac	2580
	M. Liepe, G.H. Hoffstaetter, S. Posen, J. Sears, V.D. Shemelin, M. Tigner, N.R.A. Valles, V. Veshcherevich CLASSE, Ithaca, New York, USA
	Cornell University is developing the superconducting RF technology required for the construction of a 5 GeV, 100 mA light source driven by an energy-recovery linac. Currently, a 100 mA injector cryomodule is under extensive testing and prototypes of the components of the SRF main linac cryomodule are under development, fabrication and testing. In this paper we give an overview of these recent activities at Cornell.
	Slides FROBS3 [10.577 MB]

FROBS5	1.3 GHz Superconducting RF Cavity Program at Fermilab	cavity, SRF, vacuum, diagnostics	2586
	C.M. Ginsburg, T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, L.D. Cooley, C.A. Cooper, M.H. Foley, M. Ge, C.J. Grimm, E.R. Harms, A. Hocker, R.D. Kephart, T.N. Khabiboulline, J.R. Leibfritz, A. Lunin, J.P. Ozelis, Y.M. Pischalnikov, A.M. Rowe, W. Schappert, D.A. Sergatskov, A.I. Sukhanov, G. Wu Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC under contract DE-AC02-07CH11359 with the U.S. Department of Energy. At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules, for Project X, an International Linear Collider, or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.
	Slides FROBS5 [3.749 MB]

Paper

Title

Other Keywords

Page

MOP009

Status and Plans for a SRF Accelerator Test Facility at Fermilab

SRF, cryogenics, electron, gun

118

J.R. Leibfritz, R. Andrews, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, S.L. Lackey, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln
Fermilab, Batavia, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
A superconducting RF accelerator test facility is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 810 MeV electron beam with ILC beam intensity. Expansion plans of the facility are underway that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. In addition to testing accelerator components, this facility will be used to test RF power equipment, instrumentation, LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

MOP145

Physics Design of the Project X CW Linac

linac, lattice, simulation, focusing

364

N. Solyak, J.-P. Carneiro, J.S. Kerby, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, A. Vostrikov, V.P. Yakovlev
Fermilab, Batavia, USA

The general design of the 3 GeV superconducting CW linac of the Project X is presented. Different physical and technical issues and limitations that determine the linac concept are discussed. The results of the RF system optimization are presented as well as the lattice design and beam dynamics analysis.

MOP184

Beam Instrumentation for the European Spallation Source

linac, diagnostics, target, rfq

432

A. Jansson, H. Danared, M. Eshraqi, L. Tchelidze
ESS, Lund, Sweden

The European Spallation Source, which will be built in the south of Sweden, is a neutron source based on a 5MW, 2.5GeV proton linac. The project is currently in the design update phase, and will deliver a Technical Design Report at the end of 2012. Construction is expected to begin in 2013. This paper discusses the initial beam diagnostics specifications, along with some possible instrument design options.

MOP257

High Power RF Distribution and Control for Multi-Cavity Cryomodule Testing

controls, cavity, linac, klystron

591

Y.W. Kang, M. Broyles, M.T. Crofford, X. Geng, S.-H. Kim, S.W. Lee, C.L. Phibbs, K.R. Shin, W.H. Strong
ORNL, 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 SNS has been successfully operating 81 superconducting six-cell cavities in 23 cryomodules in its linac to achieve the goals in beam power and energy. For near-term production of spare cryomodules and the upcoming power upgrade project that will need 36 additional cavities in 9 cryomodules, high RF power testing and qualification of the cavities is required in the RF test facility. Simultaneously powering all the cavities in a cryomodule is considered desirable for robust conditioning and studying of cavity field emission since certain cavities exhibit field emissions that could be mutually coupled. A four-way variable output power waveguide splitting system is being prepared for testing cryomodules with up to four cavities. The splitting system is fed by an 805 MHz, 5 MW peak power pulsed klystron. The power output at each arm can be adjusted in both amplitude and phase to wide ranges of values using two mechanical waveguide phase shifters that form a vector modulator. The system control is implemented in the EPICS environment similar to the main accelerator controls. The work performed on the design, integration, operation, and test of the system are presented.

TUP031

Project X Elliptical Cavity Structural Analyses

cavity, simulation, vacuum, linac

868

E.N. Zaplatin
FZJ, Jülich, Germany

Project X is proposed at Fermi National Accelerator Laboratory high-intensity proton accelerator complex that could provide beam for a variety of physics projects. Superconducting resonators will be used for beam acceleration. Here we report a structural design of elliptical cavities with resonance frequency 650 MHz and β=0.91 and 0.61. Since there is a concern that the pressure in the helium plumbing will not be stable when the cryomodules are connected to the liquid helium supply and helium gas returns it is necessary to provide the cavity stiffening with requirements of 15 Hz amplitude frequency shift. The cavity RF and mechanical properties are investigated. The calculations of the cavity frequency shift with pressure for different schemes of cavity stiffening were provided. The criterion for the optimization was the minimization of a resonant frequency dependence on an external pressure. Based on the results of these simulations several options on cavity stiffening have been proposed. Additionally, the cavity stiffening structural scheme for self-compensation of resonator detuning caused by external pressure fluctuation have been investigated.

TUP044

A Comparison of Superconducting RF Structures Optimized for β = 0.285

cavity, ion, simulation, SRF

889

Z.A. Conway, R.L. Fischer, M.P. Kelly, A. Kolomiets, B. Mustapha, P.N. Ostroumov
ANL, Argonne, USA

Recent advances in low-beta superconducting RF technology have enabled the proposal and construction of ever-increasing-intensity ion accelerators, e.g. The Facility for Rare Isotope Beams (FRIB) at Michigan State University and Project-X at Fermilab. Superconducting TEM-class structures are required for these accelerators and beam quality preservation and cost efficiency are of the highest importance. This paper presents a comparison of the superconducting TEM-class cavities available for the acceleration of ions in the energy range of 16 to 55 MeV/u in order to guide their selection in future ion accelerator projects.

TUP051

Design and First Cold Test of BNL Superconducting 112 MHz QWR for Electron Gun Applications

cavity, gun, electron, cathode

898

S.A. Belomestnykh, I. Ben-Zvi, X. Chang, R. Than
BNL, Upton, Long Island, New York, USA
C.H. Boulware, T.L. Grimm, B. Siegel, M.J. Winowski
Niowave, Inc., Lansing, Michigan, USA

Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments.
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The work at Niowave is supported by the U.S. DOE under SBIR contract No. DE-FG02-07ER84861

TUP055

Design and Preliminary Test of the 1500 MHz NSLS-II Passive Superconducting RF Cavity

cavity, HOM, vacuum, niobium

910

J. Rose, W.K. Gash, B.N. Kosciuk, V. Ravindranath, S.K. Sharma, R. Sikora, N.A. Towne
BNL, Upton, Long Island, New York, USA
C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski
Niowave, Inc., Lansing, Michigan, USA

NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed.

TUP063

HOM Measurements with Beam at the Cornell Injector Cryomodule

HOM, simulation, laser, pick-up

934

S. Posen, M. Liepe
CLASSE, Ithaca, New York, USA

Funding: NSF
The Cornell ERL injector prototype is undergoing commissioning and testing for running unprecedented currents in an electron cw injector. This paper discusses preliminary measurements of HOMs in the injector prototype’s superconducting RF cryomodule. These include HOM spectra up to 30 GHz measured via small antennae located at the HOM beam line absorbers between the SRF cavities. The spectra are compared at different beam currents and repetition rates. The shape of the spectra are compared to ABCI simulations of the loss factor spectrum of the cryomodule beam line. The total HOM power dissipated in the HOM loads was also measured with beam on, which allowed for an estimate of the loss factor. This measurement was accomplished via temperature sensors on the loads, calibrated to input power by heaters on the loads.

TUP071

High Power Tests of Dressed Superconducting 1.3 GHz RF Cavities

cavity, resonance, higher-order-mode, shielding

949

A. Hocker, E.R. Harms, A. Lunin, A.I. Sukhanov
Fermilab, Batavia, USA

Funding: U.S. Department of Energy, Contract No. DE-AC02-07CH11359
A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted (“dressed”) with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

TUP072

High Power Couplers for Project X Linac

coupling, linac, cavity, vacuum

952

S. Kazakov, M.S. Champion, M. Kramp, Y. Orlov, O. Pronitchev, V.P. Yakovlev
Fermilab, Batavia, USA

Project X, a multi-megawatt proton sources is under development in Fermi National Accelerator Laboratory. The key element of the project is a superconducting (SC) 3GV CW proton liner accelerator (linac). The linac includes 5 types of SC accelerating cavities of three 325 and 650 MHz frequencies. The cavities consumes up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. New cost effective schemes of the couplers are described. Results of electrodynamics and thermal simulations are presented.

TUP075

Cavity Loss Factors of Non-relativistic Beams for Project X

cavity, linac, simulation, factory

961

A. Lunin, S. Kazakov, V.P. Yakovlev
Fermilab, Batavia, USA

Cavity loss factor calculation is an important part of total cryolosses estimation for the super conductive (SC) accelerating structures. There are two approaches how to calculate cavity loss factors, the integration of a wake potential over the bunch profile and the combining of loss factors for individual cavity modes. We applied both methods in order to get reliable results for non-relativistic beam. The time domain CST solver was used for a wake potential calculation and the frequency domain HFSS code was used for the cavity eigenmodes spectrum findings. Finally we present the results of cavity loss factors simulations for a non-relativistic part of the ProjectX and analyze it for various beam parameters.

TUP077

Vibrational Measurements for Commissioning SRF Accelerator Test Facility at Fermilab

cavity, cryogenics, vacuum, quadrupole

967

M.W. McGee, J.R. Leibfritz, A. Martinez, Y.M. Pischalnikov, W. Schappert
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.
The commissioning of two cryomodule components is underway at Fermilab’s Superconducting Radio Frequency (SRF) Accelerator Test Facility. The research at this facility supports the next generation high intensity linear accelerators such as the International Linear Collider (ILC), a new high intensity injector (Project X) and other future machines. These components, Cryomodule #1 (CM1) and Capture Cavity II (CC2) which contain 1.3 GHz cavities are connected in series in the beamline and through cryogenic plumbing. Studies regarding characterization of ground motion, technical and cultural noise continue. Mechanical transfer functions between the foundation and critical beamline components have been measured and overall system displacement characterized. Baseline motion measurements given initial operation of cryogenic, vacuum systems and other utilities are considered.

TUP079

Cryomodule Design for 325 MHz Superconducting Single Spoke Cavities and Solenoids

cavity, vacuum, solenoid, cryogenics

970

T.H. Nicol, S. Cheban, R.L. Madrak, F. McConologue, T.J. Peterson, V. Poloubotko, L. Ristori, W. Schappert, I. Terechkine, B.A. Vosmek
Fermilab, Batavia, USA

Funding: U.S. Department of Energy
The low-beta section of the linac being considered for Project X at Fermilab contains several styles of 325 MHz superconducting single spoke cavities and solenoid based focusing lenses, all operating at 2 K. Each type of cavity and focusing lens will eventually be incorporated into the design of cryomodules unique to various sections of the linac front end. This paper describes the design of a multiple-cavity and solenoid cryomodule being developed to test the function of each of the main cryomodule systems – cryogenic systems and instrumentation, cavity and lens positioning and alignment, conduction-cooled current leads, magnetic shielding, cold-to-warm beam tube transitions, interfaces to interconnecting equipment and adjacent modules, as well as evaluation of overall assembly procedures.

TUP082

Test of a Coaxial Blade Tuner at HTS/FNAL

cavity, SRF, resonance, controls

976

Y.M. Pischalnikov, S. Barbanotti, E.R. Harms, A. Hocker, T.N. Khabiboulline, W. Schappert
Fermilab, Batavia, USA
A. Bosotti, C. Pagani, R. Paparella
INFN/LASA, Segrate (MI), Italy

Funding: Work is supported by the U.S. Department of Energy
Fermilab is building Cryomodule 2 for ILCTA facility at NML. A coaxial blade tuner has been chosen for the CM2 1.3GHz SRF cavities. A summary of results from cold test of the tuners in the Fermilab Horizontal Test Stand will be presented.

TUP086

Microphonics control for Project X

cavity, controls, linac, SRF

988

W. Schappert, S. Barbanotti, J. Branlard, G.I. Cancelo, R.H. Carcagno, M.S. Champion, B. Chase, I.G. Gonin, A.L. Klebaner, D.F. Orris, T.J. Peterson, Y.M. Pischalnikov, L. Ristori, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Work is supported by the U.S. Department of Energy
The proposed multi-MW Project X facility at Fermilab will employ cavities with bandwidths as narrow as 20 Hz. This combination of high RF power with narrow bandwidths combined requires careful attention to detuning control if these cavities are to be operated successfully. Detuning control for Projects X will require a coordinated effort between the groups responsible for various machine subsystems. Considerable progress in this area has been made over the past year.

TUP089

Concept EM Design of the 650 MHz Cavities for the Project X

cavity, linac, HOM, resonance

994

V.P. Yakovlev, M.S. Champion, I.G. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak
Fermilab, Batavia, USA
A. Saini
University of Delhi, Delhi, India

Concept of the 650 MHz cavities for the Project X is presented. Choice of the basic parameters, i.e, number of cells, geometrical β, apertures, coupling coefficients, etc, is discussed. The cavities optimization criteria are formulated. Results of the RF design are presented for the cavities of both low-energy and high energy sections.

TUP090

Design of a β = 0.29 Half-wave Resonator for the FRIB Driver Linac

cavity, linac, simulation, ion

997

J.P. Holzbauer, W. Hartung, J. Popielarski
NSCL, East Lansing, Michigan, USA

The driver linac for the Facility for Rare Isotope Beams will produce primary beams of ions at 200 MeV per nucleon for nuclear physics research. The driver linac will require 344 superconducting cavities, consisting of two types of Quarter-Wave Resonators (QWRs, β = 0.041 and 0.085) and two types of Half-Wave Resonators (HWRs, β = 0.29 and 0.53). A first-generation β = 0.29 HWR has been designed, prototyped, and tested. Second-generation versions of the other cavities are being developed, with one or more prototype having been tested. A second-generation β = 0.29 HWR design has been developed, making use of the experience with the first-generation β = 0.29 HWR and second-generation β = 0.53 HWR. In the second-generation design, the inner conductor is tapered to reduce the peak surface magnetic field. The outer conductor is a straight tube to increase the mechanical stiffness and reduce the sensitivity of the resonant frequency to bath pressure fluctuations. Optimization was employed to minimize the peak surface electric field. The second-generation β = 0.29 HWR design will be presented, including the RF design and mechanical analysis.

TUP107

RF-thermal Combined Simulations of a Superconducting HOM Coaxial Coupler

HOM, cavity, simulation, SRF

1041

G. Cheng, H. Wang
JLAB, Newport News, Virginia, USA
D.N. Smithe
Tech-X, Boulder, Colorado, USA

Funding: This work is supported by Jefferson LAB and Tech-X CRADA #2009S005 on “Simulations of Electromagnetic and Thermal Characteristics of SRF Structures”.
To benchmark a multi-physics code VORPAL developed by Tech-X, the High Order Mode (HOM) coaxial coupler design implemented in Jefferson Lab’s 12GeV upgrade cryomodules is analyzed by use of commercial codes, such as ANSYS, HFSS and Microwave Studio. Testing data from a Horizontal Test Bed (HTB) experiment on a dual-cavity prototype are also utilized in the verification of simulation results. The work includes two stages: first, the HOM feedthrough that has a high RRR niobium probe and sapphire insulator is analyzed for the RF-thermal response when there is traveling wave passing through; second, the HTB testing condition is simulated and results from simulation are compared to thermal measurements from HTB tests. The analyses are of coupled-field nature and involve highly nonlinear temperature dependent thermal conductivities and electric resistivities for the eight types of materials used in the design. Accuracy and efficiency are the main factors in evaluation of the performance of the codes.

TUP108

Summary Report for the C50 Cryomodule Project

cavity, vacuum, accelerating-gradient, electron

1044

M.A. Drury, G.K. Davis, J.F. Fischer, C. Grenoble, J. Hogan, L.K. King, K. Macha, J.D. Mammosser, C.E. Reece, A.V. Reilly, J. Saunders, H. Wang
JLAB, Newport News, Virginia, USA
E. Daly, J.P. Preble
ITER Organization, St. Paul lez Durance, France

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177.
The Thomas Jefferson National Accelerator Facility has recently completed the C50 cryomodule refurbishment project. The goal of this project was to enable robust 6 GeV, 5 pass operation of the Continuous Electron Beam Accelerator Facility (CEBAF). The scope of the project included removal, refurbishment and reinstallation of ten CEBAF cryomodules at a rate of three per year. The refurbishment process included reprocessing of SRF cavities to eliminate field emission and to increase the nominal gradient from the original 5 MV/m to 12.5 MV/m. New “dogleg“ couplers were installed between the cavity and helium vessel flanges to intercept secondary electrons that produce arcing in the fundamental Power Coupler (FPC). Other changes included new ceramic RF windows for the air to vacuum interface of the FPC and improvements to the mechanical tuner. Damaged or worn components were replaced as well. All ten of the refurbished cryomodules are now installed in CEBAF and are currently operational. This paper will summarize the performance of the cryomodules. This paper will also look at problems that must be addressed by future refurbishment projects.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUP223

Cryogenic System for the Energy Recovery Linac and Vertical Test Facility at BNL

cryogenics, cavity, vacuum, controls

1235

R. Than, D.L. Lederle, L. Masi, P. Orfin, R. Porqueddu, V. Soria, T.N. Tallerico, P. Talty, Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A small cryogenic system and warm helium vacuum pumping system provides cooling to the Energy Recovery Linac's (ERL) cryomodules, a 5-cell cavity and an SRF gun, and a large Vertical Test Dewar. The system consist of a model 1660S PSI (KPS) plant, a 4000 liter storage dewar, subcooler, wet expander, 50 g/s main helium compressor and 170 m³ storage tank. A system description and operating plan is given of the cryogenic plant and cryomodules

TUP270

RF and Structural Analysis of the 72.75 MHz QWR for the ATLAS Upgrade

cavity, niobium, coupling, cryogenics

1325

T. Schultheiss, J. Rathke
AES, Medford, NY, USA
J.D. Fuerst, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by Argonne National Lab under contract # 0F-32381 & 0F32422
An energy upgrade to the heavy-ion accelerator ATLAS at Argonne Lab is progressing*,**. The plans include replacing split-ring cavities with high performance quarter wave resonators. The new 72.75 MHz resonators are designed for optimum ion velocity β=.077 and a record high accelerating voltage of 2.5 MV by modifying the top geometry and reducing the peak surface fields. This new cavity has a longer center conductor than the 10⁹ MHz cavities previously built by ANL with AES assistance, this and the other geometry changes add new engineering requirements to the design. This paper presents the engineering studies that were performed to resolve new issues. These studies include determining structural frequencies of the center conductor and stiffening methods, resonator frequency sensitivity to helium pressure fluctuations, and determining stress levels due to pressure and slow tuning. Evaluation of fast piezoelectric tuner frequency shift to tuner load was also performed and the local cavity shape was optimized based on these results.
* P.N. Ostroumov, et.al, “A New Atlas Efficiency and Intensity Upgrade Project,” SRF2009, tuppo016
** P.N. Ostroumov, et.al., “Efficiency and Intensity Upgrade of the Atlas Facility,” LINAC 2010, MOP045

TUP271

CESR-type SRF Cavity - Meeting the ASME Pressure Vessel Criteria by Analysis

niobium, cavity, SRF, factory

1328

T. Schultheiss, J. Rathke
AES, Medford, NY, USA
V. Ravindranath, J. Rose, S.K. Sharma
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by BNL under contract #147322
Over a dozen CESR-B Type SRF cryomodules have been implemented in advanced accelerators around the world. The cryomodule incorporates a niobium cavity operating in liquid helium at approximately 1.2 bar and at 4.5 K, and therefore, is subjected to a differential pressure of 1.2 bar to the beam vacuum. Over the past few decades niobium RRR values have increased, as manufacturing processes have improved, resulting in higher purity niobium and improved thermal properties. Along with these increases may come a decrease of yield strength, therefore, prior designs such as CESR-B, must be evaluated at the newer strength levels when using the newer high purity niobium. In addition to this the DOE directive 10CFR851 requires all DOE laboratories to provide a level of safety equivalent to that of the ASME Boiler and Pressure Vessel codes. The goal of this work was to analyze the CESR-B Type cavity and compare the results to ASME pressure vessel criteria and where necessary modify the design to meet the code criteria.

TUP272

Analysis and Comparison to Test of AlMg3 Seals Near a SRF Cavity

cavity, niobium, SRF, linac

1331

T. Schultheiss, C.M. Astefanous, M.D. Cole, D. Holmes, J. Rathke
AES, Medford, NY, USA
I. Ben-Zvi, D. Kayran, G.T. McIntyre, B. Sheehy, R. Than
BNL, Upton, Long Island, New York, USA
A. Burrill
JLAB, Newport News, Virginia, USA

The Energy Recovery Linac (ERL) presently under construction at Brookhaven National Laboratory is being developed as research and development towards eRHIC, an Electron-Heavy Ion Collider. The experimental 5-cell 703.75 MHz (ECX) cavity was recently evaluated at continuous field levels greater than 10 MV/m. These tests indicated stored energy limits of the cavity on the order of 75 joules. During design of the cavity the cold flange on one side was moved closer to the cavity to allow the cavity to fit into the available chemical processing chamber at Jefferson Laboratory. RF and thermal analysis of the AlMg3 seal region of the closer side indicate this to be the prime candidate limiting the fields. This work presents the analysis results and compares these results to test data.

WEOBS5

Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)

cavity, feedback, emittance, impedance

1427

R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents
ANL, Argonne, USA
J.M. Byrd, L.R. Doolittle, G. Huang
LBNL, Berkeley, California, USA
G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang
JLAB, Newport News, Virginia, USA

Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future.
*A. Zholents et al., NIM A 425, 385 (1999).

Slides WEOBS5 [1.730 MB]

WEOCS6

The Injector Cryomodule for e-Linac at TRIUMF

linac, ISAC, TRIUMF, cavity

1469

R.E. Laxdal, C.D. Beard, S.R. Koscielniak, A. Koveshnikov, A.K. Mitra, T.C. Ries, I. Sekachev, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M. Mondal, V. Naik
DAE/VECC, Calcutta, India

The e-Linac project at TRIUMF, now funded, is specified to accelerate 10mA of electrons to 50MeV using 1.3GHz multi-cell superconducting cavities. The linac consists of three cryomodules; an injector cryomodule with one cavity and two accelerating modules with two cavities each. The injector module is being designed and constructed in collaboration with VECC in Kolkata. The design utilizes a unique box cryomodule with a top-loading cold mass. A 4K phase separator, 2K-4K heat exchanger and Joule-Thompson valve are installed within each module to produce 2K liquid. The design and status of the development will be presented.

Slides WEOCS6 [13.002 MB]

WEOCS7

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source

cavity, HOM, coupling, alignment

1472

H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington
JLAB, Newport News, Virginia, USA
R. Nassiri, G.J. Waldschmidt, G. Wu
ANL, Argonne, USA

Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.

Slides WEOCS7 [7.008 MB]

WEP174

Simulations and Calculations of Cavity-to-cavity Coupling for Elliptical SCRF Cavities in ESS

cavity, coupling, simulation, linac

1813

R. Ainsworth, S. Molloy
Royal Holloway, University of London, Surrey, United Kingdom

The proton linac of the European Spallation Source (ESS) will rely on two families of superconducting cavities for the medium and high beta regions. Presented here are simulations of various cavity designs for different betas. The simulations are performed using the ACE3P codes developed at SLAC National Accelerator Laboratory, and the simulated eigenmode and R/Q spectrum will be shown for each design. Dangerous modes are identified. Of particular importance is the investigations of multiple cavity (cryomodule) configurations. From this, the simulated cavity-to-cavity coupling within a cryomodule is extracted. A theoretical model of this coupling based on the calculated cutoff frequencies, decay lengths, and resonance conditions, has also been developed, and a comparison made with the results of the simulation.

WEP226

Commissioning Results of the ReA RFQ at MSU*

rfq, ion, emittance, acceleration

1912

D. Leitner, C. Benatti, S.W. Krause, D. Morris, S. Nash, J. Ottarson, G. Perdikakis, M. Portillo, R. Rencsok, T. Ropponen, L. Tobos, N.R. Usher, D. Wang
NSCL, East Lansing, Michigan, USA
J. Haeuser
Kress GmbH, Biebergemuend, Germany
O.K. Kester
GSI, Darmstadt, Germany
F. Marti, E. Tanke, X. Wu, Q. Zhao
FRIB, East Lansing, Michigan, USA
A. Schempp, J.S. Schmidt, H. Zimmermann
IAP, Frankfurt am Main, Germany

Funding: Project funded by Michigan State University
The Facility for Rare Isotope Beams (FRIB) is currently in the preliminary design phase at Michigan State University (MSU). FRIB consists of a driver LINAC for the acceleration of heavy ion beams, followed by a fragmentation target station and a ReAccelerator facility (ReA3). ReA3 comprises gas stopper systems, an Electron Beam Ion Trap (EBIT) charge state booster, a room temperature radio frequency quadrupole (RFQ), a LINAC using superconducting quarter wave resonators and an achromatic beam transport and distribution line to the new experimental area. Beams from ReA3 will range from 3 MeV/u for heavy ions to about 6 MeV/u for light ions. The ReA3 RFQ, which is of the 4 rod type, is designed to accelerate ions with an Q/A of 0.2 to 0.5 from 12 keV/u to 600 keV/u. The RFQ operates at a frequency of 80.5 MHz and power levels up to 120 kW at 10% duty factor. In this paper we will report on commissioning results from the ReA3 RFQ using a H²⁺ and He⁺ beam from an auxiliary ion source.

THOCN5

ATLAS Upgrade

cavity, rfq, ion, linac

2110

P.N. Ostroumov, A. Barcikowski, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.W.T. MacDonald, B. Mustapha, R.C. Pardo, S.I. Sharamentov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
ATLAS (Argonne Tandem Linac Accelerator System) upgrade requires several substantial developments in accelerator technologies, such as CW heavy ion RFQ and high-performance cryomodule with low-beta cavities. The upgrade project is well advanced. The physics and engineering design of the RFQ are complete and fabrication of OFE copper parts is in progress. The 3.9-meter length RFQ is composed from 5 strongly coupled segments. High-temperature furnace brazing of the segments is planned for the summer of 2011. The RFQ design includes several innovative features such as trapezoidal vane tip modulation, compact output radial matcher to form an axially symmetric beam. The upgrade project also includes development and construction of a cryomodule containing seven 72.75 MHz SC quarter wave cavities designed for the geometrical β= 0.077 and four SC solenoids. The cavity is designed to obtain an accelerating voltage higher than 2.5 MV. The prototype cavity together with high-power capacitive coupler and piezoelectric tuner has been developed, fabricated and is being tested. This paper reports innovative design features of both RFQ and SRF linac and current status of the project.

Slides THOCN5 [3.070 MB]

THOCS3

R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source

plasma, cavity, SRF, ion

2124

S.-H. Kim, M.T. Crofford
ORNL, Oak Ridge, Tennessee, USA
M. Doleans
NSCL, East Lansing, Michigan, USA
J.D. Mammosser
JLAB, Newport News, Virginia, USA
J. Saunders
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 SNS SCL is reliably operating at 0.93 GeV output energy with an energy reserve of 10MeV with high availability. Most of the cavities exhibit field emission, which directly or indirectly (through heating of end groups) limits the gradients achievable in the high beta cavities in normal operation with the beam. One of the field emission sources would be surface contaminations during surface processing for which mild surface cleaning, if any, will help in reducing field emission. An R&D effort is in progress to develop in-situ surface processing for the cryomodules in the tunnel without disassembly. As the first attempt, in-situ plasma processing has been applied to the CM12 in the SNS SRF facility after the repair work with a promising result. This paper will report the R&D status of plasma processing in the SNS.

Slides THOCS3 [3.294 MB]

THOCS4

RF Power Upgrade for CEBAF at Jefferson Laboratory

klystron, solenoid, controls, cavity

2127

A.J. Kimber, R.M. Nelson
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed.

Slides THOCS4 [3.364 MB]

THOCS6

Progress in Cavity and Cryomodule Design for the Project X Linac

cavity, linac, solenoid, lattice

2133

M.S. Champion, S. Barbanotti, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, J.S. Kerby, S. Nagaitsev, T.H. Nicol, T.J. Peterson, L. Ristori, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

The continuous wave 3 GeV Project X Linac requires the development of two families of cavities and cryomodules at 325 and 650 MHz. The baseline design calls for three types of superconducting single-spoke resonators at 325 MHz having betas of 0.11, 0.22, and 0.42 and two types of superconducting five-cell elliptical cavities having betas of 0.61 and 0.9. These cavities shall accelerate a 1 mA H⁻ beam initially and must support eventual operation at 4 mA. The electromagnetic and mechanical designs of the cavities are in progress and acquisition of prototypes is planned. The heat load to the cryogenic system is up to 25 W per cavity in the 650 MHz section, thus segmentation of the cryogenic system is a major issue in the cryomodule design. Designs for the two families of cryomodules are underway.

Slides THOCS6 [2.241 MB]

THP077

SC Quadrupole for Cryomodule for ERL/ILC

quadrupole, dipole, focusing, linac

2276

A.A. Mikhailichenko
CLASSE, Ithaca, New York, USA

Funding: NSF
We are considering the SC quadrupole where the field formed not only by the current distributions, but with the poles also. This delivers a good quality field in all aperture allowing compact and inexpensive design. This type of quadrupole designed for Cornell ERL could be recommended for ILC also.

THP212

Superconducting Cavity Design for Short-Pulse X-Rays at the Advanced Photon Source

cavity, damping, HOM, coupling

2516

G.J. Waldschmidt, B. Brajuskovic, R. Nassiri
ANL, Argonne, USA
G. Cheng, J. Henry, J.D. Mammosser, R.A. Rimmer, H. Wang
JLAB, Newport News, Virginia, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Superconducting cavities have been analyzed for the short-pulse x-ray (SPX) project at the Advanced Photon Source (APS). Due to the strong damping requirements in the APS storage ring, single-cell superconducting cavities have been designed. The geometry has been optimized for lower-order and higher-order mode damping, reduced peak surface magnetic fields, and compact size. The integration of the cavity assembly, with dampers and waveguide input coupler, into a cryomodule will be discussed.

FROAN1

The European Spallation Source

linac, target, neutron, proton

2549

S. Peggs, H. Danared, M. Eshraqi, H. Hahn, A. Jansson, M. Lindroos, A. Ponton, K. Rathsman, G. Trahern
ESS, Lund, Sweden
S. Bousson
IPN, Orsay, France
R. Calaga
BNL, Upton, Long Island, New York, USA
G. Devanz, R.D. Duperrier
CEA/DSM/IRFU, France
J. Eguia
Fundación TEKNIKER, Eibar (Gipuzkoa), Spain
S. Gammino
INFN/LNS, Catania, Italy
S.P. Møller
ISA, Aarhus, Denmark
C. Oyon
SPRI, Bilbao, Spain
R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
T. Satogata
JLAB, Newport News, Virginia, USA

The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

Slides FROAN1 [1.650 MB]

FROBN2

Technical Challenges in Design and Construction of FRIB

linac, ion, target, acceleration

2561

R.C. York, G. Machicoane
NSCL, East Lansing, Michigan, USA
S. Assadi, G. Bollen, T . Glasmacher, W. Hartung, M.J. Johnson, F. Marti, E. Pozdeyev, M.J. Syphers, E. Tanke, J. Wei, X. Wu, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: Work supported by DOE CA DE-SC0000661 and Michigan State University.
The Facility for Rare Isotope Beams (FRIB) will be a world-leading, DOE national users facility for the study of nuclear structure, reactions and astrophysics on the campus of Michigan State University. A superconducting, heavy-ion, driver linac will be used to provide stable beams of >200 MeV/u at beam powers up to 400 kW (~650 electrical micro-amps for uranium) that will be used to produce rare isotopes by in flight fragment separation. The selected rare isotopes will be used at velocity (~0.5 c), stopped, or reaccelerated. FRIB is a challenging technical project. An overview of the project, project challenges, and mitigating strategies will be presented.

Slides FROBN2 [14.690 MB]

FROBS1

World-wide Experience with SRF Facilities

SRF, survey, vacuum, cavity

2575

A. Hutton, A. Carpenter
JLAB, Newport News, Virginia, USA

The speaker will review and analyze the performance of existing SRF facilities in the world, addressing issues of usage and availability for different customers (HEP research, material sciences, ADS). Lessons learned should be summarized for proposed future facilities (ILC, ProjectX, Muon Collider).

Slides FROBS1 [5.473 MB]

FROBS3

Progress on Superconducting RF for the Cornell Energy-Recovery-Linac

cavity, HOM, SRF, linac

2580

M. Liepe, G.H. Hoffstaetter, S. Posen, J. Sears, V.D. Shemelin, M. Tigner, N.R.A. Valles, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell University is developing the superconducting RF technology required for the construction of a 5 GeV, 100 mA light source driven by an energy-recovery linac. Currently, a 100 mA injector cryomodule is under extensive testing and prototypes of the components of the SRF main linac cryomodule are under development, fabrication and testing. In this paper we give an overview of these recent activities at Cornell.

Slides FROBS3 [10.577 MB]

FROBS5

1.3 GHz Superconducting RF Cavity Program at Fermilab

cavity, SRF, vacuum, diagnostics

2586

C.M. Ginsburg, T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, L.D. Cooley, C.A. Cooper, M.H. Foley, M. Ge, C.J. Grimm, E.R. Harms, A. Hocker, R.D. Kephart, T.N. Khabiboulline, J.R. Leibfritz, A. Lunin, J.P. Ozelis, Y.M. Pischalnikov, A.M. Rowe, W. Schappert, D.A. Sergatskov, A.I. Sukhanov, G. Wu
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC under contract DE-AC02-07CH11359 with the U.S. Department of Energy.
At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules, for Project X, an International Linear Collider, or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

Slides FROBS5 [3.749 MB]