LINAC2012 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
SUPB009	Linear Accelerator based on Parallel Coupled Accelerating Structure	cavity, electron, focusing, klystron	19
	A.E. Levichev, A.M. Barnyakov, V.M. Pavlov BINP SB RAS, Novosibirsk, Russia Y.D. Chernousov ICKC, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

SUPB015	Production and Quality Control of the First Modules of the IFMIF-EVEDA RFQ	cavity, survey, coupling, rfq	38
	F. Scantamburlo, R. Dima, A. Pepato INFN- Sez. di Padova, Padova, Italy C. Roncolato INFN/LNL, Legnaro (PD), Italy
	The IFMIF-EVEDA RFQ, designed to accelerate a 125 mA D⁺ beam from the initial energy of 0.1 MeV to the final energy of 5 MeV at the frequency of 175 MHz, consists of 18 mechanical modules whose length is approximately 54 cm each. The production of the modules has started and, in particular, the modules 16, 17, 15 and 11, plus the prototype modules 1 and 2 have undergone all the production steps, including precision milling and brazing. In this article, the progress of the production, and the quality control during the phases of the production of the modules will be described.

SUPB020	Structural Analysis of the New-Shaped QWR for HIAF in IMP	cavity, simulation, superconducting-cavity, SRF	53
	C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China M.H. Xu IHEP, Beijing, People's Republic of China
	Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085，with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.

SUPB022	First Measurements on the 325 MHz Superconducting CH Cavity	cavity, simulation, linac, coupling	56
	M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany M. Pekeler RI Research Instruments GmbH, Bergisch Gladbach, Germany
	Funding: Work supported by HIM, GSI, BMBF Contr. No. 06FY161I At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.

SUPB027	Mechanical Study of the First Superconducting Half-wave Resonator for Injector II of CADS Project	cavity, simulation, HOM, cryomodule	71
	S. He, Y. He, S.C. Huang, F.F. Wang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	Funding: This work is Supported by the National Natural Science Foundation of China (Grant Agreement 91026001) Within the framework of the China Accelerator-Driven Sub-critical Systems (CADS) project, Institute of Modern Physics (IMP) Chinese Academic of Sciences has proposed a 162.5 MHz Half-Wave Resonator (HWR) Superconducting cavity for low energy section (β=0.09) of high power proton linear accelerators as a new injector II for CIADS. For the geometrical design of superconducting cavities structure mechanical simulations are essential to predict mechanical eigenmodes and the deformation of the cavity walls due to bath pressure effects and the cavity cool-down. Additionally, the tuning analysis has been investigated to control the frequency against microphonics and Lorentz force detuning. Therefore, several RF, static structure, thermal and modal analysis with a three-dimensional Finite-Element Method (FEM) code Traditional ANSYS have been performed.

SUPB029	Impact of Trapped Flux and Systematic Flux Expulsion in Superconducting Niobium	niobium, cavity, SRF, superconductivity	77
	J.M. Vogt, J. Knobloch, O. Kugeler HZB, Berlin, Germany
	The intrinsic quality factor Q₀ of superconducting cavities is known to depend on various factors like niobium material properties, treatment history and magnetic shielding. We already reported an additional impact of temperature gradients during the cool-down on the obtained Q₀. We believe cooling conditions can influence the level of flux trapping and hence the residual resistance. For further studies we have constructed a test stand using niobium rods to study flux trapping. Here we can precisely control the temperature and approach T_c in the superconducting state. Although the sample remains in the superconducting state a change in the amount of trapped flux is visible. The procedure can be applied repeatedly resulting in a significantly lowered level of trapped flux in the sample. Applying a similar procedure to a superconducting cavity could allow for reduction of the magnetic contribution to the surface resistance and result in a significant improvement of Q₀.

SUPB037	The Development of Timing Control System for RFQ	rfq, EPICS, proton, background	89
	J.N. Bai, S. Xiao, T.G. Xu, L. Zeng IHEP, Beijing, People's Republic of China
	A Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.

MO3A04	Accelerator/Decelerator of Slow Neutrons	neutron, focusing, simulation, dipole	133
	M. Kitaguchi Kyoto University, Research Reactor Institute, Osaka, Japan Y. Arimoto, H.M. Shimizu KEK, Ibaraki, Japan P.W. Geltenbort ILL, Grenoble, France S. Imajo Kyoto University, Kyoto, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan Y. Seki RIKEN Nishina Center, Wako, Japan T. Yoshioka Kyushu University, Fukuoka, Japan
	Funding: Supported by the Quantum Beam Fundamentals Development Program MEXT, a Grant-in-Aid for Creative Scientific Research of MEXT Program No.19GS0210 and No.23244047, Yamada Science Foundation, and KEK. An accelerator/decelerator for slow neutron beams has been demonstrated. The energy of a neutron can be increased or decreased by flipping the neutron spin (directly coupled to magnetic dipole moment) in magnetic field. This device is a combination of a gradient magnetic field and an RF magnetic field. Because the RF frequency for the spin flip is a function of the external magnetic field, only neutrons that are located in a specific magnetic field level will be spin-flipped at a given RF frequency. By changing the RF frequency, the energy change can be selected in the gradient magnetic field. The maximum field of the gradient magnet is 1 T, which corresponds to the energy change of 120 neV. The magnetic field linearly decreases to 0.2T within 25 cm. By putting this device on a beamline from a pulsed neutron source, neutron rebuncher is realized. The dense slow neutrons are important to suppress the systematic errors for the measurement of neutron electric dipole moment (nEDM). The combination of spallation neutron source and this neutron rebuncher is suitable to the measurement of nEDM. A review of current status of our plan for nEDM experiment at J-PARC will be also presented.
	Slides MO3A04 [3.750 MB]

MOPLB09	Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector	klystron, coupling, electron, FEL	162
	R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro INFN/LNF, Frascati (Roma), Italy A. Mostacci, L. Palumbo URLS, Rome, Italy
	The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.
	Slides MOPLB09 [1.061 MB]

MOPB003	Recent Improvements to the Control of the CTF3 High-Current Drive Beam	lattice, linac, dipole, optics	180
	B. Constance, R. Corsini, D. Gamba, P.K. Skowroński CERN, Geneva, Switzerland
	In order to demonstrate the feasibility of the CLIC multi-TeV linear collider option, the drive beam complex at the CLIC Test Facility (CTF3) at CERN is providing high-current electron pulses for a number of related experiments. By means of a system of electron pulse compression and bunch frequency multiplication, a fully loaded, 120 MeV linac is used to generate 140 ns electron pulses of around 30 Amperes. Subsequent deceleration of this high-current drive beam demonstrates principles behind the CLIC acceleration scheme, and produces 12 GHz RF power for experimental purposes. As the facility has progressed toward routine operation, a number of studies aimed at improving the drive beam performance have been carried out. Additional feedbacks, automated steering programs, and improved control of optics and dispersion have contributed to a more stable, reproducible drive beam with consequent benefits for the experiments.

MOPB012	First RF Measurement Results for the European XFEL SC Cavity Production	cavity, HOM, factory, higher-order-mode	195
	A.A. Sulimov, P.B. Borowiec, V. Gubarev, J. Iversen, D. Kostin, G. Kreps, K. Krzysik, A. Matheisen, W.-D. Möller, D. Reschke, W. Singer DESY, Hamburg, Germany
	The first reference cavities (RCV) for the European XFEL Project are being tested within the collaboration of Research Instruments (RI), E. ZANON, IFJ-PAN and DESY: - production and warm RF measurements of cavities and their components at RI and ZANON; - surface preparation at DESY; - cold RF tests at DESY by IFJ-PAN. Purpose of the RCV is to establish a stable cavity fabrication and qualification of the surface preparation infrastructure at industry. All necessary RF measurements were done, starting with mechanical fabrication in 2011, till the tuning and cold cavity RF tests in 2012. We present the first results of RF measurements within RCV production for the European XFEL.
	Poster MOPB012 [1.843 MB]

MOPB017	Integration of the European XFEL Accelerating Modules	cavity, linac, vacuum, HOM	207
	E. Vogel, S. Barbanotti, J. Branlard, H. Brueck, S. Choroba, L. Hagge, K. Jensch, V.V. Katalev, D. Kostin, D. Käfer, L. Lilje, A. Matheisen, W.-D. Möller, D. Nölle, B. Petersen, J. Prenting, D. Reschke, H. Schlarb, M. Schmökel, J.K. Sekutowicz, W. Singer, H. Weise DESY, Hamburg, Germany J. Świerbleski, P.B. Borowiec IFJ-PAN, Kraków, Poland S. Berry, O. Napoly, B. Visentin CEA/DSM/IRFU, France A. Bosotti, P. Michelato INFN/LASA, Segrate (MI), Italy W. Kaabi LAL, Orsay, France C. Madec CEA/IRFU, Gif-sur-Yvette, France E.P. Plawski NCBJ, Świerk/Otwock, Poland F. Toral CIEMAT, Madrid, Spain
	The production of the 103 superconducting accelerating modules for the European XFEL is an international effort. Institutes and companies from seven different countries (China, France, Germany, Italy, Poland, Russia and Spain), organized in 12 different work packages contribute with parts, capacity for work and facilities to the production of the modules. Currently the series production of the individual parts started or is approaching. Personnel are trained for the assembly and testing of parts and as well for the complete modules. Here we present an overview and the status of all these activities.

MOPB020	LLRF System Improvement for HLS Linac Upgrade	linac, LLRF, feedback, low-level-rf	213
	G. Huang, D. Jia, K. Jin, H. Lin, Weishi, Zhou. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China Y. Liu USTC, Hefei, Anhui, People's Republic of China
	Funding: supported by NSFC-CAS Joint Fund, contract no. 11079034 The linac beam energy will be upgraded from 200 MeV to 800 MeV, in order to realize the full-energy injection of storage ring at Hefei Light Source. This paper introduces the improvement of linac LLRF system, which is composed of phase reference and driver signal transmission and distribution, auto-phasing system, phase reversal device for SLED. the LLRF prototype has been constructed, and the test results is described in the paper.

MOPB031	Vibration Response Testing of the CEBAF 12 GeV Upgrade Cryomodules	cryomodule, cavity, damping, beam-loading	240
	G.K. Davis, J. Matalevich, T. Powers, M. Wiseman JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 The CEBAF 12 GeV upgrade project includes 80 new 7-cell cavities assembled into 10 cryomodules. These cryomodules were tested during production to characterize their microphonic response in situ. For several early cryomodules, detailed (vibration) modal studies of the cryomodule string were performed during the assembly process to identify the structural contributors to the measured cryomodule microphonic response. Structural modifications were then modeled, implemented, and verified by subsequent modal testing and in-situ microphonic response testing. Interim and final results from this multi-stage process will be reviewed.

MOPB032	Stabilization of the Beam Intensity in the Linac at the CTF3 CLIC Test Facility	linac, gun, feedback, electron	243
	A. Dubrovskiy JINR, Dubna, Moscow Region, Russia B.N. Bathe, S. Srivastava BARC, Mumbai, India F. Tecker CERN, Geneva, Switzerland
	A new electron beam stabilization system has been introduced in CTF3 in order to open new possibilities for CLIC beam studies in ultra-stable conditions and to provide a sustainable tool to keep the beam intensity and energy at its reference values for long term operations. The stabilization system is based on a pulse-to-pulse feedback control of the electron gun to compensate intensity deviations measured at the end of the injector and at the beginning of the linac. Thereby it introduces negligible beam distortions at the end of the linac and it significantly reduces energy deviations. A self-calibration mechanism has been developed to automatically configure the feedback controller for the optimum performance. The residual intensity jitter of 0.045% of the stabilized beam was measured whereas the CLIC requirement is 0.075%.

MOPB048	Linear Accelerator Based on Parallel Coupled Accelerating Structure	cavity, electron, focusing, klystron	282
	A.E. Levichev, A.M. Barnyakov, V.M. Pavlov BINP SB RAS, Novosibirsk, Russia Y.D. Chernousov ICKC, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

MOPB054	Test Results of Tesla-style Cryomodules at Fermilab	cryomodule, cavity, SRF, LLRF	297
	E.R. Harms, K. Carlson, B. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, Jr, A. Hocker, M.J. Kucera, J.R. Leibfritz, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, P. Varghese Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Commissioning and operation of the first Tesla-style Cryomodule (CM-1) at Fermilab was concluded in recent months. It has now been replaced by a second Tesla Type III+ module, RFCA002. It is the first 8-cavity ILC style cryomodule to be built at Fermilab and also the first accelerating cryomodule of the Advanced Superconducting Test Accelerator (ASTA). We report on the operating results of both of these cryomodules.

MOPB057	Mechanical Study of the First Superconducting Half-wave Resonator for Injector II of CADS Project	cavity, simulation, HOM, cryomodule	306
	S. He, Y. He, S.C. Huang, F.F. Wang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	Funding: This work is Supported by the National Natural Science Foundation of China (Grant Agreement 91026001) Within the framework of the China Accelerator-Driven Sub-critical Systems (CADS) project, Institute of Modern Physics (IMP) Chinese Academic of Sciences has proposed a 162.5 MHz Half-Wave Resonator (HWR) Superconducting cavity for low energy section (β=0.09) of high power proton linear accelerators as a new injector II for CIADS. For the geometrical design of superconducting cavities structure mechanical simulations are essential to predict mechanical eigenmodes and the deformation of the cavity walls due to bath pressure effects and the cavity cool-down. Additionally, the tuning analysis has been investigated to control the frequency against microphonics and Lorentz force detuning. Therefore, several RF, static structure, thermal and modal analysis with a three-dimensional Finite-Element Method (FEM) code Traditional ANSYS have been performed.

MOPB062	A New Internal Optical Profilometry System for Characterization of RF Cavity Surfaces – CYCLOPS	cavity, ion, feedback, acceleration	318
	C.E. Reece, A.D. Palczewski, H. Tian JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Jefferson Lab has received and commissioned a new interferometric optical profilometer specifically designed to provide internal surface mapping of elliptical rf cavities. The CavitY CaLibrated Optical Profilometry System – CYCLOPS – provides better than 2 micron lateral resolution and 0.1 micron surface height resolution of programmatically selected locations on the interior surface of multi-cell cavities. The system is being used to provide detailed characterization of surface topographic evolution as a function of applied surface treatments and to investigate particular localized defects. We also intend to use the system for 3D mapping of actual interior rf surface geometry for feedback to structure design model and fabrication tooling. First uses will be illustrated. CYCLOPS was developed and fabricated by MicroDynamics Inc., Woodstock, GA, USA.

MOPB065	Impact of Trapped Magnetic Flux and Systematic Flux Expulsion in Superconducting Niobium	niobium, cavity, SRF, superconductivity	327
	J.M. Vogt, J. Knobloch, O. Kugeler HZB, Berlin, Germany
	The intrinsic quality factor Q₀ of superconducting cavities is known to depend on various factors like niobium material properties, treatment history and magnetic shielding. We already reported an additional impact of temperature gradients during the cool-down on the obtained Q₀. We believe cooling conditions can influence the level of flux trapping and hence the residual resistance. For further studies we have constructed a test stand using niobium rods to study flux trapping. Here we can precisely control the temperature and approach T_c in the superconducting state. Although the sample remains in the superconducting state a change in the amount of trapped flux is visible. The procedure can be applied repeatedly resulting in a significantly lowered level of trapped flux in the sample. Applying a similar procedure to a superconducting cavity could allow for reduction of the magnetic contribution to the surface resistance and result in a significant improvement of Q₀.

MOPB070	Quality Control of Cleanroom Processing Procedures of SRF Cavities for Mass Production	cavity, SRF, acceleration, diagnostics	339
	R. Oweiss, K. Elliott, A. Facco, M. Hodek, I.M. Malloch, J. Popielarski, L. Popielarski, K. Saito 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. Quality control is a key factor in the success of SRF cavity mass production. This paper summarizes ongoing research at the Facility for Rare Isotope Beams FRIB to validate the quality assurance of SRF cavities meanwhile optimizing processing procedures for mass production. Experiments are conducted to correlate surface cleanliness for niobium surfaces with high pressure rinse time using β=0.085 quarter-wave resonators (QWR) cavities. Diagnostic devices; liquid particle counter, surface particle detector and TOC analyzer are used to monitor key parameters for quality control. Rinse water samples are collected during high pressure rinsing to measure liquid particle counts. The SLS 1200 Sampler is used to detect the presence of liquid particles of 0.2 microns and up to 1 micron to set standards for acceptable cleaning thresholds and optimize high pressure rinse time. The QIII+ surface particle detector is used to scan high electric field region for the β=0.085 QWR to ensure high pressure rinsing efficiency. The β=0.085 QWR RF testing data are analyzed and results are presented to demonstrate the correlation between attained acceleration gradients and surface cleanliness.

MOPB071	Process Developments for Superconducting RF Low Beta Resonators for the ReA3 LINAC and Facility for Rare Isotope Beams	cavity, vacuum, SRF, linac	342
	L. Popielarski, C. Compton, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, I.M. Malloch, R. Oweiss, J.P. Ozelis, J. Popielarski, K. Saito FRIB, East Lansing, 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 Facility for Rare Isotope Beams (FRIB) will utilize over 330 superconducting radio frequency (SRF) low beta cavities for its heavy ion driver linac. The SRF department will process and test all cavities prior to string assembly in the cleanroom. The baseline cavity surface and bulk niobium processing procedures have been established. The methods are being optimized for production process rate benchmarking. Additional processes are being developed to increase flexibility and reduce technical risks. This paper will describe procedure developments and experimental results. Topics include high temperature heat treatment for hydrogen degassing, selective chemical etching for cavity frequency tuning, low-temperature bake out and process quality control.

MOPB077	Lorentz Force Detuning Compensation Studies for Long Pulses in ILC type SRF Cavities	cavity, cryomodule, linac, SRF	354
	N. Solyak, G.I. Cancelo, B. Chase, D.J. Crawford, D.R. Edstrom, Jr, E.R. Harms, Y.M. Pischalnikov, W. Schappert Fermilab, Batavia, USA
	Project-X 3-8 GeV pulsed linac is based on ILC type 1.3 GHz elliptical cavities. The cavity will operate at 25 MV/m accelerating gradient, but in contrast with XFEL and ILC projects the required loaded Q is much higher (Q=10⁷) and RF pulse is much longer (~8ms). For these parameters Lorence force detuning (LFD) and microphonics should be controlled at the level <30 Hz. A new algorithm of LFD compensation, developed at Fermilab for ILC cavities was applied for Lorentz force compensation studies for 8ms pulses. In these studies two cavities inside TESLA-type cryomodule at Fermilab NML facility have been powered by one klystron. Studies done for different cavity gradients and different values of loaded Q demonstrated that required compensation are achievable. Detuning measurements and compensation results are presented.

MOPB080	Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector	klystron, coupling, electron, FEL	360
	R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro INFN/LNF, Frascati (Roma), Italy A. Mostacci, L. Palumbo URLS, Rome, Italy
	The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

TUPLB02	Deflecting Structures with Minimized Level of Aberrations	emittance, diagnostics, RF-structure, electromagnetic-fields	445
	V.V. Paramonov RAS/INR, Moscow, Russia
	Funding: in part RBFR N 12-02-00654a Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented.
	Slides TUPLB02 [0.727 MB]

TUPB002	Deflecting Structures with Minimized Level of Aberrations	emittance, diagnostics, RF-structure, electromagnetic-fields	476
	V.V. Paramonov RAS/INR, Moscow, Russia
	Funding: in part RBFR N 12-02-00654a Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented.

TUPB006	Stability Performance of the Injector for SACLA/XFEL at SPring-8	laser, undulator, cavity, FEL	486
	T. Asaka, T. Hasegawa, T. Inagaki, H. Maesaka, T. Ohshima, Y. Otake, S. Takahashi, K. Togawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	To realize the SACLA, it is necessary to obtain stabilities of 10^-4 and 50 fs in the amplitude and time of an acceleration voltage, respectively. The achievement of the rf stabilities were almost satisfactory for the target values. Consequently, the 7 GeV beam energy stability was 0.02% (std.) or less. However, there was XFEL power variation caused by a variation of a beam position in a 40 MeV injector section. A periodically changed beam position of 40 μm (std.) was found out at a cycle of 2 s by Fourier transform method using BPM data. The temperatures of all the injector rf cavities are controlled within 28±0.04˚C by a controller using the cooling water. The AC power supplies of the controller to heat the cooling water are operated at 0.5 Hz by pulse width modulation control with alternatively turning on or off. The strong correlation between laser intensity variation and the modulation frequency of the AC power supplies was found out. We are planning to improve the cavity temperature variation in the order of less than 0.01˚C with DC power supplies to establish continuously regulated the cavity temperature. This plan will reduce the XFEL power variation.

TUPB009	C-Band Accelerating Structure Development and Tests for the SwissFEL	impedance, klystron, FEL, linac	492
	R. Zennaro, J. Alex, H. Blumer, M. Bopp, A. Citterio, T. Kleeb, L. Paly, J.-Y. Raguin PSI, Villigen, Switzerland
	SwissFEL requires a 5.8 GeV beam provided by a C-band linac consisting of 104 two-meter accelerating structures. Each structure is of the constant gradient type and is composed of 113 cups. The cup shape is double-rounded to increase the quality factor. No tuning feature is implemented. For this reason ultra-precise turning is exploited. A strong R&D program has been launched on structure fabrication, which will be followed by a future technology transfer to a commercial company. The program includes the production and test of short structures that can be brazed in the existing PSI vacuum oven and will be completed with the production of the full two-meter prototype once the new full scale brazing oven, presently under construction, is operational. The status of the R&D program, including the production and power test results of the first two test structures, is reported here.

TUPB029	Beam Intensity and Energy Control for the SPIRAL2 Facility	pick-up, linac, ion, rfq	537
	C. Jamet, T.A. André, C. Doutresssoulles, B. Ducoudret, W. Le Coz, G. Ledu, S.L. Leloir, S. Loret GANIL, Caen, France
	The first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, consists of an ion source, a deuteron and a proton source, a RFQ and a superconducting linear accelerator delivering high intensity, up to 5mA and 40 MeV for the deuteron beams. Diagnostic developments have been done to control the intensity and the beam energy by non-interceptive methods at the linac exit. The beam current is measured by using couples of ACCT-DCCT installed along the lines and the beam energy by using a time of flight device. This paper gives explanations about the technical solutions, the results and resolutions for measuring and controlling the beam.

TUPB031	Beam Envelope Analysis and Simulation	linac, ion, simulation, emittance	543
	V.S. Dyubkov, A.S. Plastun MEPhI, Moscow, Russia
	Forming the charge particle beams with small cross-sections and low energies is an actual problem for a linac design. That beams are used actively for isotope therapy, ion implantation, etc. Beam emittance is its quality factor, and it should be matched with a facility channel acceptance. The method for beam dynamics analysis at linac is developed in terms of non-coherent particle oscillation study. Nonlinear beam dynamics is investigated by using this method. It is shown that this technique allows one to realize effective beam emittance control. Analytical results obtained are verified by means of numerical simulation.

TUPB033	Piezoelectric Actuator Based Phase Locking System for IUAC Linac	linac, resonance, heavy-ion, high-voltage	549
	B.K. Sahu, R. Ahuja, G.K. Chowdhury, R.N. Dutt, S. Ghosh, D. Kanjilal, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, A. Pandey, P. Patra, A. Rai, A. Roy, S.K. Suman IUAC, New Delhi, India
	The linac of IUAC consists of three main accelerating modules with each one housing eight superconducting quarter wave resonators. Currently, the phase locking of the resonator is performed by a combination of fast I-Q based electronic tuner and helium gas flow based mechanical tuner. Microphonics measurement on the resonators found the presence of lower frequency vibrations along with main mechanical mode (~60 Hz) of the resonators. Although main mechanical mode of the resonator is damped by using SS balls, the presence of lower frequency vibrations demand more RF power from the amplifier, as the existing mechanical tuner works in time scale of seconds. A combination of piezoelectric actuator based fast tuner along with stepper motor based coarse tuner operating in the time scale of milliseconds is being developed. This scheme is implemented on a few resonators in last linac cryostat. Initial results show that this mechanism can arrest all low frequency vibrations thereby reducing a substantial load from the electronic tuner and improve the dynamics of the phase locking scheme. The implementation scheme along with test results will be presented in detail.

TUPB044	Cryogenic System for the ADS Injector II in IMP, CAS	cryogenics, cryomodule, solenoid, rfq	576
	X.H. Guo, Y.N. Han, T. Jin, X.F. Niu, H.L. Su, J.H. Zhang IMP, Lanzhou, People's Republic of China L.Q. Liu, N. Peng, L.-Y. Xiong TIPC, BeiJing, People's Republic of China
	Funding: Work supported by Accelerator Driven Sub-critical (ADS) program of CAS, China In order to meet the requirements of ADS Injector II project which is now being designed and built in IMP, CAS, a liquid helium cryogenic system with 4.5K & 850W cooling power is being built. This paper presents the primary design and the status of this cryogenic system with different operation models according to the need of superconducting tests. guoxh@impcas.ac.cn

TUPB057	Structural Analysis of the New-Shaped QWR for HIAF in IMP	cavity, simulation, superconducting-cavity, SRF	606
	C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and \beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085，with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.

TUPB061	ADRC Control for Beam Loading and Microphonics	cavity, beam-loading, LLRF, simulation	615
	Z. Zheng, Z. Liu, J. Wei, Y. Zhang, S. Zhao FRIB, East Lansing, Michigan, USA Z. Zheng TUB, Beijing, People's Republic of China
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Superconducting RF (SRF) cavities are subject to many disturbances such as beam loading and microphonics. Although we implemented Proportional Integral (PI) control and Active Disturbance Rejection Control (ADRC) in the Low Level RF (LLRF) system at FRIB to stabilize the RF field, the control loop gains are inadequate in the presence of beam loading and microphonics. An improved scheme is proposed and simulated with much higher gains are achieved. The feasibility to include piezo tuner in ADRC and PI circuit is also presented in this paper.

TUPB062	Longitudinal Dynamic Analysis for the Project X 3-8 GeV Pulsed Linac	cavity, linac, cryomodule, injection	618
	G.I. Cancelo, B. Chase, Y.I. Eidelman, S. Nagaitsev, N. Solyak Fermilab, Batavia, USA
	The Pulsed Linac is a will require over 200 9-cell, 1300 MHz cavities packed in 26 ILC type cryomodules to accelerate 1 mA average beam current from 3GeV to 8 GeV. The architecture of the RF must optimize RF power, beam emittance, and energy gain amid a large number of requirement and constraints. The pulse length is a critical issue. Ideally, a 26 ms pulse would allow direct injection into the Fermilab’s Main Injector, bypassing the need of the Fermilab’s Recicler. High loaded quality factors (QL) are also desirable to minimize RF power. These requirements demand an accurate control of the cavity resonant frequency disturbed by Lorentz Force Detuning and microphonics. Also the LLRF control system must regulate the RF amplitude and phase within tight bounds amid a long list of dynamic disturbances. The present work describes the simulation efforts and measurements at Fermilab facilities.

TUPB071	First Measurements on the 325 MHz Superconducting CH Cavity	cavity, simulation, linac, coupling	636
	M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany M. Pekeler RI Research Instruments GmbH, Bergisch Gladbach, Germany
	Funding: Work supported by GSI, BMBF Contr. No. 06FY7102, 06FY9089I At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.

TUPB092	High Power Amplifier Systems for SARAF Phase II	rf-amplifier, insertion, status, cavity	675
	B. Kaizer, I. Fishman, I.G. Gertz Soreq NRC, Yavne, Israel
	Soreq NRC initiated the establishment of SARAF - Soreq Applied Research Accelerator Facility. SARAF is based on a continuous wave (CW), proton/deuteron RF superconducting linear accelerator with variable energy (5–40 MeV) and current (0.04-5 mA). RF power to each cavity is driven by a High Power Solid State Amplifiers. The paper outlines the design concept of the 10 and 15 kW at 176 MHz power amplifiers that were designed, built, and 10 kW successfully tested. 15 kW is now under construction. The amplifiers are combined from basic 5.5 kW compact 19" 7U water cooled drawer.

TUPB107	Amplitude and Phase Control of the Accelerating Field in the ESS Spoke Cavity	cavity, feedback, beam-loading, simulation	708
	V.A. Goryashko, R.J.M.Y. Ruber, R.A. Yogi, V.G. Ziemann Uppsala University, Uppsala, Sweden
	We report about numerical simulations of the accelerating field dynamics in the ESS spoke cavity in the presence of the beam loading and Lorentz detuning. A slow feedforward is used to cure the Lorentz detuning whereas a fast feedback through a signal oscillator and cavity pre-detuning technique are applied to eliminate the beam loading effect. An analysis performed with a Simulink model shows that a combination of feedforward, feedback and cavity pre-detuning result in a substantially shorter stabilization time of the field voltage and phase on a required level as compared to a control method using only the feedforward and feedback. The latter allows one to obtain smaller magnitude but longer duration of deviations of the instantaneous voltage and phase from the required nominal values. As a result, a series of cavities only with feedforward and feedback needs an extra control technique to mitigate a cumulative systematic error rising in each cavity. In addition, a technique of adiabatic turning off of the RF power in order to prevent a high reflected power in the case of a sudden beam loss is studied.

TUPB108	Uppsala High Power Test Stand for ESS Spoke Cavities	rf-amplifier, linac, power-supply, cryomodule	711
	R.A. Yogi, T.J.C. Ekelöf, V.A. Goryashko, L. Hermansson, M. Noor, R. Santiago Kern, V.G. Ziemann Uppsala University, Uppsala, Sweden D.S. Dancila, A. Rydberg Uppsala University, Department of Engineering Sciences, Uppsala, Sweden K.J. Gajewski, T. Lofnes, R. Wedberg TSL, Uppsala, Sweden R.J.M.Y. Ruber CERN, Geneva, Switzerland
	The European Spallation Source (ESS) is one of the world’s most powerful neutron source. The ESS linac will accelerate 50 mA of protons to 2.5 GeV in 2.86 ms long pulses at a repetition rate of 14 Hz. It produces a beam with 5 MW average power and 125 MW peak power. ESS Spoke Linac consists of 28 superconducting spoke cavities, which will be developed by IPN Orsay, France. These Spoke Cavities will be tested at low power at IPN Orsay and high power testing will be performed at a test stand which will be set up at Uppsala University. The test stand consists of tetrode based RF amplifier chain at 352 MHz, 350 kW power and related RF distribution. Outputs of two tetrodes shall be combined with the hybrid coupler to produce 350 kW power. Preamplifier for a tetrode shall be solid state amplifier. As the spoke cavities are superconducting, the test stand also includes horizontal cryostat, Helium liquefier, test bunker etc. The paper describes features of the test stand in details.

TH1A01	Results Achieved by the S1-Global Collaboration for ILC	cavity, cryomodule, feedback, LLRF	748
	H. Hayano, M. Akemoto, S. Fukuda, K. Hara, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya KEK, Ibaraki, Japan C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith Fermilab, Batavia, USA A. Bosotti, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	The S1-Global collaboration (scope and plans presented at Linac10) ended successfully in 2011. In the S1-Global experiment several variants of ILC components (e.g. cavities, tuners, modules, couplers) proposed by all SCRF collaborators worldwide have been extensively tested and their performances compared, in order to build consensus for the technical choices towards the ILC TDR and to develop further the concept of plug-compatible components for ILC. The experiment has been carried at KEK with contribution of hardware and manpower from all collaborators.
	Slides TH1A01 [6.656 MB]

THPLB02	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, klystron, rfq, LLRF	810
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.
	Slides THPLB02 [1.610 MB]

THPLB08	High-Power RF Conditioning of the TRASCO RFQ	rfq, cavity, vacuum, pick-up	828
	E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri INFN/LNL, Legnaro (PD), Italy M. Desmons CEA/DSM/IRFU, France
	The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.
	Slides THPLB08 [1.384 MB]

THPLB09	Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay	cryomodule, cavity, vacuum, synchrotron	831
	C. Madec CEA, Gif-sur-Yvette, France S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin CEA/DSM/IRFU, France A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé CEA/IRFU, Gif-sur-Yvette, France
	As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m² clean room complex with 120 m² under ISO4, 1325 m² of assembly platforms and 400 m² of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.

THPB015	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, klystron, rfq, LLRF	879
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB040	High-Power RF Conditioning of the TRASCO RFQ	rfq, cavity, vacuum, pick-up	945
	E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri INFN/LNL, Legnaro (PD), Italy M. Desmons CEA/DSM/IRFU, France
	The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.

THPB042	Production and Quality Control of the First Modules of the IFMIF-EVEDA RFQ	cavity, survey, coupling, rfq	948
	F. Scantamburlo, R. Dima, A. Pepato INFN- Sez. di Padova, Padova, Italy C. Roncolato INFN/LNL, Legnaro (PD), Italy
	The IFMIF/EVEDA RFQ, designed to accelerate a 125mA D⁺ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz, consists of 18 modules with length of ~550 mm each. The production of the modules has been started and 2 prototype modules plus module 16 have undergone all the production steps, including precision milling and brazing. The progress of the construction and especially the fine tuning of the design and engineering phase are reported.

THPB044	Plans for an Integrated Front-End Test Stand at the Spallation Neutron Source	rfq, klystron, ion, ion-source	954
	M.S. Champion, A.V. Aleksandrov, M.T. Crofford, D. Heidenreich, Y.W. Kang, J. Moss, R.T. Roseberry, J.P. Schubert ORNL, Oak Ridge, Tennessee, USA
	Funding: Work performed at Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. A spare Radio-Frequency Quadrupole (RFQ) is presently being fabricated by industry with delivery to Oak Ridge National Laboratory planned in late 2012. The establishment of a test stand at the Spallation Neutron Source site is underway so that complete acceptance testing can be performed during the winter of 2012-2013. This activity is the first step in the establishment of an integrated front-end test stand that will include an ion source, low-energy beam transport (LEBT), RFQ, medium-energy beam transport, diagnostics, and a beam dump. The test stand will be capable of delivering an H⁻ ion beam of up to 50 mA with a pulse length of 1 ms and a repetition rate of 60 Hz or a proton beam of up to 50 mA, 100 μs, 1 Hz. The test stand will enable the following activities: complete ion source characterization; development of a magnetic LEBT chopper; development of a two-source layout; development of beam diagnostics; and study of beam dynamics of high intensity beam.

THPB073	Initial RF Tests of the Diamond S-Band Photocathode Gun	gun, cathode, cavity, coupling	1002
	C. Christou, S.A. Pande Diamond, Oxfordshire, United Kingdom
	An S-band photocathode electron gun designed to operate at repetition rates up to 1 kHz CW has been designed at Diamond and manufactured at FMB. The first test results of this gun are presented. Low-power RF measurements have been carried out to verify the RF design of the gun, and high-power conditioning and RF test has begun. Initial high power tests have been carried out at 5 Hz repetition rate using the S-band RF plant normally used to power the Diamond linac: the benefits and limitations of this approach are considered, together with plans for further testing. J. H. Han et al, NIM A 647(2011) 17-24

THPB081	The Development of Timing Control System for RFQ	rfq, EPICS, proton, background	1014
	J.N. Bai, S. Xiao, T.G. Xu, L. Zeng IHEP, Beijing, People's Republic of China
	Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.

THPB083	Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay	cryomodule, cavity, vacuum, synchrotron	1017
	C. Madec CEA, Gif-sur-Yvette, France S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin CEA/DSM/IRFU, France A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé CEA/IRFU, Gif-sur-Yvette, France
	As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m² clean room complex with 120 m² under ISO4, 1325 m² of assembly platforms and 400 m² of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.
	Slides THPB083 [1.868 MB]

THPB084	A Low-Level RF Control System for a Quarter-Wave Resonator	LLRF, cavity, resonance, ion	1020
	J.-W. Kim, D.G. Kim IBS, Daejeon, Republic of Korea C.K. Hwang KAERI, Daejon, Republic of Korea
	A low-level rf control system was designed and built for an rf deflector, which is a quarter wave resonator and was designed to deflect a secondary electron beam to measure the bunch length of an ion beam. The deflector has a resonance frequency at near 88 MHz, and its required phase stability is approximately ±1° and amplitude stability less than ±1%. The control system consists of analog input and output components, and a digital system based on an FPGA for signal processing. It is a cost effective system, while meeting the stability requirements. Some basic properties of the control system were measured. Then the capability of the rf control has been tested using a mechanical vibrator made of a dielectric rod attached to an audio speaker system, which can induce regulated perturbation in the electric fields of the resonator. The control system is flexible such that its parameters can be easily configured to compensate for disturbance induced in the resonator.

THPB085	LLRF Automation for the 9mA ILC Tests at FLASH	cavity, feedback, cryomodule, beam-loading	1023
	J. Branlard, V. Ayvazyan, O. Hensler, H. Schlarb, Ch. Schmidt, N.J. Walker, M. Walla DESY, Hamburg, Germany G.I. Cancelo, B. Chase Fermilab, Batavia, USA J. Carwardine ANL, Argonne, USA W. Cichalewski, W. Jałmużna TUL-DMCS, Łódź, Poland S. Michizono KEK, Ibaraki, Japan
	Since 2009 and under the scope of the International Linear Collider (ILC) R&D, a series of studies takes place twice a year at the Free electron Laser accelerator in Hamburg, (FLASH) DESY, in order to investigate technical challenges related to the high-gradient, high-beam-current design of the ILC. Such issues as operating cavities near their quench limit with high beam loading or in klystron saturation regime are investigated, always pushing the limits of FLASH nominal operational conditions. To support these studies, a series of automation algorithms have been developed and implemented at DESY. These include automatic detection of cavity quenches, automatic adjustment of the superconducting cavity quality factor, and automatic compensation of detuning due to Lorentz forces. This paper explains the functionality of these automation tools, details about their implementation, and shows the experience acquired during the last 9mA ILC test which took place at DESY in February 2012. The benefit of these algorithms and the R&D results these automation tools have permitted will be clearly explained.

THPB086	Precision Regulation of RF Fields with MIMO Controllers and Cavity-based Notch Filters	cavity, LLRF, resonance, feedback	1026
	Ch. Schmidt, J. Branlard, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany W. Jałmużna TUL-DMCS, Łódź, Poland
	The European XFEL requires a high precision control of the electron beam, generating a specific pulsed laser light demanded by user experiments. The low level radio frequency (LLRF) control system is certainly one of the key players for the regulation of accelerating RF fields. A uTCA standard LLRF system was developed and is currently under test at DESY. Its first experimental results showed the system performance capabilities. Investigation of regulation limiting factors evidenced the need for control over fundamental cavity modes, which is done using complex controller structures and filter techniques. The improvement in measurement accuracy and detection bandwidth increased the regulation performance and contributed to integration of further control subsystems.

THPB091	Machine Protection Issues and Solutions for Linear Accelerator Complexes	beam-losses, instrumentation, radiation, linac	1032
	M. Jonker, H. Schmickler, R. Schmidt, D. Schulte CERN, Geneva, Switzerland M.C. Ross SLAC, Menlo Park, California, USA
	The workshop “Machine Protection focusing on Linear Accelerator Complexes” was held from 6-8 June 2012 at Cern. This workshop brought together experts working on machine protection systems for accelerator facilities with high brilliance or large stored beam energies, with the main focus on linear accelerators and their injectors. An overview of the machine protection systems for several accelerators was given. Beam loss mechanisms and their detection were discussed. Mitigation of failures and protection systems were presented. This paper summarises the workshop and reviews the current state of the art in machine protection systems.

Paper

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Other Keywords

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SUPB009

Linear Accelerator based on Parallel Coupled Accelerating Structure

cavity, electron, focusing, klystron

19

A.E. Levichev, A.M. Barnyakov, V.M. Pavlov
BINP SB RAS, Novosibirsk, Russia
Y.D. Chernousov
ICKC, Novosibirsk, Russia
V. Ivannikov, I.V. Shebolaev
ICKC SB RAS, Novosibirsk, Russia

Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

SUPB015

Production and Quality Control of the First Modules of the IFMIF-EVEDA RFQ

cavity, survey, coupling, rfq

38

F. Scantamburlo, R. Dima, A. Pepato
INFN- Sez. di Padova, Padova, Italy
C. Roncolato
INFN/LNL, Legnaro (PD), Italy

The IFMIF-EVEDA RFQ, designed to accelerate a 125 mA D⁺ beam from the initial energy of 0.1 MeV to the final energy of 5 MeV at the frequency of 175 MHz, consists of 18 mechanical modules whose length is approximately 54 cm each. The production of the modules has started and, in particular, the modules 16, 17, 15 and 11, plus the prototype modules 1 and 2 have undergone all the production steps, including precision milling and brazing. In this article, the progress of the production, and the quality control during the phases of the production of the modules will be described.

SUPB020

Structural Analysis of the New-Shaped QWR for HIAF in IMP

cavity, simulation, superconducting-cavity, SRF

53

C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China
M.H. Xu
IHEP, Beijing, People's Republic of China

Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085，with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.

SUPB022

First Measurements on the 325 MHz Superconducting CH Cavity

cavity, simulation, linac, coupling

56

M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany
M. Pekeler
RI Research Instruments GmbH, Bergisch Gladbach, Germany

Funding: Work supported by HIM, GSI, BMBF Contr. No. 06FY161I
At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.

SUPB027

Mechanical Study of the First Superconducting Half-wave Resonator for Injector II of CADS Project

cavity, simulation, HOM, cryomodule

71

S. He, Y. He, S.C. Huang, F.F. Wang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: This work is Supported by the National Natural Science Foundation of China (Grant Agreement 91026001)
Within the framework of the China Accelerator-Driven Sub-critical Systems (CADS) project, Institute of Modern Physics (IMP) Chinese Academic of Sciences has proposed a 162.5 MHz Half-Wave Resonator (HWR) Superconducting cavity for low energy section (β=0.09) of high power proton linear accelerators as a new injector II for CIADS. For the geometrical design of superconducting cavities structure mechanical simulations are essential to predict mechanical eigenmodes and the deformation of the cavity walls due to bath pressure effects and the cavity cool-down. Additionally, the tuning analysis has been investigated to control the frequency against microphonics and Lorentz force detuning. Therefore, several RF, static structure, thermal and modal analysis with a three-dimensional Finite-Element Method (FEM) code Traditional ANSYS have been performed.

SUPB029

Impact of Trapped Flux and Systematic Flux Expulsion in Superconducting Niobium

niobium, cavity, SRF, superconductivity

77

J.M. Vogt, J. Knobloch, O. Kugeler
HZB, Berlin, Germany

The intrinsic quality factor Q₀ of superconducting cavities is known to depend on various factors like niobium material properties, treatment history and magnetic shielding. We already reported an additional impact of temperature gradients during the cool-down on the obtained Q₀. We believe cooling conditions can influence the level of flux trapping and hence the residual resistance. For further studies we have constructed a test stand using niobium rods to study flux trapping. Here we can precisely control the temperature and approach T_c in the superconducting state. Although the sample remains in the superconducting state a change in the amount of trapped flux is visible. The procedure can be applied repeatedly resulting in a significantly lowered level of trapped flux in the sample. Applying a similar procedure to a superconducting cavity could allow for reduction of the magnetic contribution to the surface resistance and result in a significant improvement of Q₀.

SUPB037

The Development of Timing Control System for RFQ

rfq, EPICS, proton, background

89

J.N. Bai, S. Xiao, T.G. Xu, L. Zeng
IHEP, Beijing, People's Republic of China

A Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.

MO3A04

Accelerator/Decelerator of Slow Neutrons

neutron, focusing, simulation, dipole

133

M. Kitaguchi
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Arimoto, H.M. Shimizu
KEK, Ibaraki, Japan
P.W. Geltenbort
ILL, Grenoble, France
S. Imajo
Kyoto University, Kyoto, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
Y. Seki
RIKEN Nishina Center, Wako, Japan
T. Yoshioka
Kyushu University, Fukuoka, Japan

Funding: Supported by the Quantum Beam Fundamentals Development Program MEXT, a Grant-in-Aid for Creative Scientific Research of MEXT Program No.19GS0210 and No.23244047, Yamada Science Foundation, and KEK.
An accelerator/decelerator for slow neutron beams has been demonstrated. The energy of a neutron can be increased or decreased by flipping the neutron spin (directly coupled to magnetic dipole moment) in magnetic field. This device is a combination of a gradient magnetic field and an RF magnetic field. Because the RF frequency for the spin flip is a function of the external magnetic field, only neutrons that are located in a specific magnetic field level will be spin-flipped at a given RF frequency. By changing the RF frequency, the energy change can be selected in the gradient magnetic field. The maximum field of the gradient magnet is 1 T, which corresponds to the energy change of 120 neV. The magnetic field linearly decreases to 0.2T within 25 cm. By putting this device on a beamline from a pulsed neutron source, neutron rebuncher is realized. The dense slow neutrons are important to suppress the systematic errors for the measurement of neutron electric dipole moment (nEDM). The combination of spallation neutron source and this neutron rebuncher is suitable to the measurement of nEDM. A review of current status of our plan for nEDM experiment at J-PARC will be also presented.

Slides MO3A04 [3.750 MB]

MOPLB09

Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector

klystron, coupling, electron, FEL

162

R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro
INFN/LNF, Frascati (Roma), Italy
A. Mostacci, L. Palumbo
URLS, Rome, Italy

The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

Slides MOPLB09 [1.061 MB]

MOPB003

Recent Improvements to the Control of the CTF3 High-Current Drive Beam

lattice, linac, dipole, optics

180

B. Constance, R. Corsini, D. Gamba, P.K. Skowroński
CERN, Geneva, Switzerland

In order to demonstrate the feasibility of the CLIC multi-TeV linear collider option, the drive beam complex at the CLIC Test Facility (CTF3) at CERN is providing high-current electron pulses for a number of related experiments. By means of a system of electron pulse compression and bunch frequency multiplication, a fully loaded, 120 MeV linac is used to generate 140 ns electron pulses of around 30 Amperes. Subsequent deceleration of this high-current drive beam demonstrates principles behind the CLIC acceleration scheme, and produces 12 GHz RF power for experimental purposes. As the facility has progressed toward routine operation, a number of studies aimed at improving the drive beam performance have been carried out. Additional feedbacks, automated steering programs, and improved control of optics and dispersion have contributed to a more stable, reproducible drive beam with consequent benefits for the experiments.

MOPB012

First RF Measurement Results for the European XFEL SC Cavity Production

cavity, HOM, factory, higher-order-mode

195

A.A. Sulimov, P.B. Borowiec, V. Gubarev, J. Iversen, D. Kostin, G. Kreps, K. Krzysik, A. Matheisen, W.-D. Möller, D. Reschke, W. Singer
DESY, Hamburg, Germany

The first reference cavities (RCV) for the European XFEL Project are being tested within the collaboration of Research Instruments (RI), E. ZANON, IFJ-PAN and DESY: - production and warm RF measurements of cavities and their components at RI and ZANON; - surface preparation at DESY; - cold RF tests at DESY by IFJ-PAN. Purpose of the RCV is to establish a stable cavity fabrication and qualification of the surface preparation infrastructure at industry. All necessary RF measurements were done, starting with mechanical fabrication in 2011, till the tuning and cold cavity RF tests in 2012. We present the first results of RF measurements within RCV production for the European XFEL.

Poster MOPB012 [1.843 MB]

MOPB017

Integration of the European XFEL Accelerating Modules

cavity, linac, vacuum, HOM

207

E. Vogel, S. Barbanotti, J. Branlard, H. Brueck, S. Choroba, L. Hagge, K. Jensch, V.V. Katalev, D. Kostin, D. Käfer, L. Lilje, A. Matheisen, W.-D. Möller, D. Nölle, B. Petersen, J. Prenting, D. Reschke, H. Schlarb, M. Schmökel, J.K. Sekutowicz, W. Singer, H. Weise
DESY, Hamburg, Germany
J. Świerbleski, P.B. Borowiec
IFJ-PAN, Kraków, Poland
S. Berry, O. Napoly, B. Visentin
CEA/DSM/IRFU, France
A. Bosotti, P. Michelato
INFN/LASA, Segrate (MI), Italy
W. Kaabi
LAL, Orsay, France
C. Madec
CEA/IRFU, Gif-sur-Yvette, France
E.P. Plawski
NCBJ, Świerk/Otwock, Poland
F. Toral
CIEMAT, Madrid, Spain

The production of the 103 superconducting accelerating modules for the European XFEL is an international effort. Institutes and companies from seven different countries (China, France, Germany, Italy, Poland, Russia and Spain), organized in 12 different work packages contribute with parts, capacity for work and facilities to the production of the modules. Currently the series production of the individual parts started or is approaching. Personnel are trained for the assembly and testing of parts and as well for the complete modules. Here we present an overview and the status of all these activities.

MOPB020

LLRF System Improvement for HLS Linac Upgrade

linac, LLRF, feedback, low-level-rf

213

G. Huang, D. Jia, K. Jin, H. Lin, Weishi, Zhou. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China
Y. Liu
USTC, Hefei, Anhui, People's Republic of China

Funding: supported by NSFC-CAS Joint Fund, contract no. 11079034
The linac beam energy will be upgraded from 200 MeV to 800 MeV, in order to realize the full-energy injection of storage ring at Hefei Light Source. This paper introduces the improvement of linac LLRF system, which is composed of phase reference and driver signal transmission and distribution, auto-phasing system, phase reversal device for SLED. the LLRF prototype has been constructed, and the test results is described in the paper.

MOPB031

Vibration Response Testing of the CEBAF 12 GeV Upgrade Cryomodules

cryomodule, cavity, damping, beam-loading

240

G.K. Davis, J. Matalevich, T. Powers, M. Wiseman
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
The CEBAF 12 GeV upgrade project includes 80 new 7-cell cavities assembled into 10 cryomodules. These cryomodules were tested during production to characterize their microphonic response in situ. For several early cryomodules, detailed (vibration) modal studies of the cryomodule string were performed during the assembly process to identify the structural contributors to the measured cryomodule microphonic response. Structural modifications were then modeled, implemented, and verified by subsequent modal testing and in-situ microphonic response testing. Interim and final results from this multi-stage process will be reviewed.

MOPB032

Stabilization of the Beam Intensity in the Linac at the CTF3 CLIC Test Facility

linac, gun, feedback, electron

243

A. Dubrovskiy
JINR, Dubna, Moscow Region, Russia
B.N. Bathe, S. Srivastava
BARC, Mumbai, India
F. Tecker
CERN, Geneva, Switzerland

A new electron beam stabilization system has been introduced in CTF3 in order to open new possibilities for CLIC beam studies in ultra-stable conditions and to provide a sustainable tool to keep the beam intensity and energy at its reference values for long term operations. The stabilization system is based on a pulse-to-pulse feedback control of the electron gun to compensate intensity deviations measured at the end of the injector and at the beginning of the linac. Thereby it introduces negligible beam distortions at the end of the linac and it significantly reduces energy deviations. A self-calibration mechanism has been developed to automatically configure the feedback controller for the optimum performance. The residual intensity jitter of 0.045% of the stabilized beam was measured whereas the CLIC requirement is 0.075%.

MOPB048

Linear Accelerator Based on Parallel Coupled Accelerating Structure

cavity, electron, focusing, klystron

282

A.E. Levichev, A.M. Barnyakov, V.M. Pavlov
BINP SB RAS, Novosibirsk, Russia
Y.D. Chernousov
ICKC, Novosibirsk, Russia
V. Ivannikov, I.V. Shebolaev
ICKC SB RAS, Novosibirsk, Russia

Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

MOPB054

Test Results of Tesla-style Cryomodules at Fermilab

cryomodule, cavity, SRF, LLRF

297

E.R. Harms, K. Carlson, B. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, Jr, A. Hocker, M.J. Kucera, J.R. Leibfritz, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, P. Varghese
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Commissioning and operation of the first Tesla-style Cryomodule (CM-1) at Fermilab was concluded in recent months. It has now been replaced by a second Tesla Type III+ module, RFCA002. It is the first 8-cavity ILC style cryomodule to be built at Fermilab and also the first accelerating cryomodule of the Advanced Superconducting Test Accelerator (ASTA). We report on the operating results of both of these cryomodules.

MOPB057

Mechanical Study of the First Superconducting Half-wave Resonator for Injector II of CADS Project

cavity, simulation, HOM, cryomodule

306

S. He, Y. He, S.C. Huang, F.F. Wang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: This work is Supported by the National Natural Science Foundation of China (Grant Agreement 91026001)
Within the framework of the China Accelerator-Driven Sub-critical Systems (CADS) project, Institute of Modern Physics (IMP) Chinese Academic of Sciences has proposed a 162.5 MHz Half-Wave Resonator (HWR) Superconducting cavity for low energy section (β=0.09) of high power proton linear accelerators as a new injector II for CIADS. For the geometrical design of superconducting cavities structure mechanical simulations are essential to predict mechanical eigenmodes and the deformation of the cavity walls due to bath pressure effects and the cavity cool-down. Additionally, the tuning analysis has been investigated to control the frequency against microphonics and Lorentz force detuning. Therefore, several RF, static structure, thermal and modal analysis with a three-dimensional Finite-Element Method (FEM) code Traditional ANSYS have been performed.

MOPB062

A New Internal Optical Profilometry System for Characterization of RF Cavity Surfaces – CYCLOPS

cavity, ion, feedback, acceleration

318

C.E. Reece, A.D. Palczewski, H. Tian
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Jefferson Lab has received and commissioned a new interferometric optical profilometer specifically designed to provide internal surface mapping of elliptical rf cavities. The CavitY CaLibrated Optical Profilometry System – CYCLOPS – provides better than 2 micron lateral resolution and 0.1 micron surface height resolution of programmatically selected locations on the interior surface of multi-cell cavities. The system is being used to provide detailed characterization of surface topographic evolution as a function of applied surface treatments and to investigate particular localized defects. We also intend to use the system for 3D mapping of actual interior rf surface geometry for feedback to structure design model and fabrication tooling. First uses will be illustrated. CYCLOPS was developed and fabricated by MicroDynamics Inc., Woodstock, GA, USA.

MOPB065

Impact of Trapped Magnetic Flux and Systematic Flux Expulsion in Superconducting Niobium

niobium, cavity, SRF, superconductivity

327

J.M. Vogt, J. Knobloch, O. Kugeler
HZB, Berlin, Germany

The intrinsic quality factor Q₀ of superconducting cavities is known to depend on various factors like niobium material properties, treatment history and magnetic shielding. We already reported an additional impact of temperature gradients during the cool-down on the obtained Q₀. We believe cooling conditions can influence the level of flux trapping and hence the residual resistance. For further studies we have constructed a test stand using niobium rods to study flux trapping. Here we can precisely control the temperature and approach T_c in the superconducting state. Although the sample remains in the superconducting state a change in the amount of trapped flux is visible. The procedure can be applied repeatedly resulting in a significantly lowered level of trapped flux in the sample. Applying a similar procedure to a superconducting cavity could allow for reduction of the magnetic contribution to the surface resistance and result in a significant improvement of Q₀.

MOPB070

Quality Control of Cleanroom Processing Procedures of SRF Cavities for Mass Production

cavity, SRF, acceleration, diagnostics

339

R. Oweiss, K. Elliott, A. Facco, M. Hodek, I.M. Malloch, J. Popielarski, L. Popielarski, K. Saito
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.
Quality control is a key factor in the success of SRF cavity mass production. This paper summarizes ongoing research at the Facility for Rare Isotope Beams FRIB to validate the quality assurance of SRF cavities meanwhile optimizing processing procedures for mass production. Experiments are conducted to correlate surface cleanliness for niobium surfaces with high pressure rinse time using β=0.085 quarter-wave resonators (QWR) cavities. Diagnostic devices; liquid particle counter, surface particle detector and TOC analyzer are used to monitor key parameters for quality control. Rinse water samples are collected during high pressure rinsing to measure liquid particle counts. The SLS 1200 Sampler is used to detect the presence of liquid particles of 0.2 microns and up to 1 micron to set standards for acceptable cleaning thresholds and optimize high pressure rinse time. The QIII+ surface particle detector is used to scan high electric field region for the β=0.085 QWR to ensure high pressure rinsing efficiency. The β=0.085 QWR RF testing data are analyzed and results are presented to demonstrate the correlation between attained acceleration gradients and surface cleanliness.

MOPB071

Process Developments for Superconducting RF Low Beta Resonators for the ReA3 LINAC and Facility for Rare Isotope Beams

cavity, vacuum, SRF, linac

342

L. Popielarski, C. Compton, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, I.M. Malloch, R. Oweiss, J.P. Ozelis, J. Popielarski, K. Saito
FRIB, East Lansing, 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 Facility for Rare Isotope Beams (FRIB) will utilize over 330 superconducting radio frequency (SRF) low beta cavities for its heavy ion driver linac. The SRF department will process and test all cavities prior to string assembly in the cleanroom. The baseline cavity surface and bulk niobium processing procedures have been established. The methods are being optimized for production process rate benchmarking. Additional processes are being developed to increase flexibility and reduce technical risks. This paper will describe procedure developments and experimental results. Topics include high temperature heat treatment for hydrogen degassing, selective chemical etching for cavity frequency tuning, low-temperature bake out and process quality control.

MOPB077

Lorentz Force Detuning Compensation Studies for Long Pulses in ILC type SRF Cavities

cavity, cryomodule, linac, SRF

354

N. Solyak, G.I. Cancelo, B. Chase, D.J. Crawford, D.R. Edstrom, Jr, E.R. Harms, Y.M. Pischalnikov, W. Schappert
Fermilab, Batavia, USA

Project-X 3-8 GeV pulsed linac is based on ILC type 1.3 GHz elliptical cavities. The cavity will operate at 25 MV/m accelerating gradient, but in contrast with XFEL and ILC projects the required loaded Q is much higher (Q=10⁷) and RF pulse is much longer (~8ms). For these parameters Lorence force detuning (LFD) and microphonics should be controlled at the level <30 Hz. A new algorithm of LFD compensation, developed at Fermilab for ILC cavities was applied for Lorentz force compensation studies for 8ms pulses. In these studies two cavities inside TESLA-type cryomodule at Fermilab NML facility have been powered by one klystron. Studies done for different cavity gradients and different values of loaded Q demonstrated that required compensation are achievable. Detuning measurements and compensation results are presented.

MOPB080

Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector

klystron, coupling, electron, FEL

360

R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro
INFN/LNF, Frascati (Roma), Italy
A. Mostacci, L. Palumbo
URLS, Rome, Italy

The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

TUPLB02

Deflecting Structures with Minimized Level of Aberrations

emittance, diagnostics, RF-structure, electromagnetic-fields

445

V.V. Paramonov
RAS/INR, Moscow, Russia

Funding: in part RBFR N 12-02-00654a
Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented.

Slides TUPLB02 [0.727 MB]

TUPB002

Deflecting Structures with Minimized Level of Aberrations

emittance, diagnostics, RF-structure, electromagnetic-fields

476

V.V. Paramonov
RAS/INR, Moscow, Russia

Funding: in part RBFR N 12-02-00654a
Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented.

TUPB006

Stability Performance of the Injector for SACLA/XFEL at SPring-8

laser, undulator, cavity, FEL

486

T. Asaka, T. Hasegawa, T. Inagaki, H. Maesaka, T. Ohshima, Y. Otake, S. Takahashi, K. Togawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

To realize the SACLA, it is necessary to obtain stabilities of 10^-4 and 50 fs in the amplitude and time of an acceleration voltage, respectively. The achievement of the rf stabilities were almost satisfactory for the target values. Consequently, the 7 GeV beam energy stability was 0.02% (std.) or less. However, there was XFEL power variation caused by a variation of a beam position in a 40 MeV injector section. A periodically changed beam position of 40 μm (std.) was found out at a cycle of 2 s by Fourier transform method using BPM data. The temperatures of all the injector rf cavities are controlled within 28±0.04˚C by a controller using the cooling water. The AC power supplies of the controller to heat the cooling water are operated at 0.5 Hz by pulse width modulation control with alternatively turning on or off. The strong correlation between laser intensity variation and the modulation frequency of the AC power supplies was found out. We are planning to improve the cavity temperature variation in the order of less than 0.01˚C with DC power supplies to establish continuously regulated the cavity temperature. This plan will reduce the XFEL power variation.

TUPB009

C-Band Accelerating Structure Development and Tests for the SwissFEL

impedance, klystron, FEL, linac

492

R. Zennaro, J. Alex, H. Blumer, M. Bopp, A. Citterio, T. Kleeb, L. Paly, J.-Y. Raguin
PSI, Villigen, Switzerland

SwissFEL requires a 5.8 GeV beam provided by a C-band linac consisting of 104 two-meter accelerating structures. Each structure is of the constant gradient type and is composed of 113 cups. The cup shape is double-rounded to increase the quality factor. No tuning feature is implemented. For this reason ultra-precise turning is exploited. A strong R&D program has been launched on structure fabrication, which will be followed by a future technology transfer to a commercial company. The program includes the production and test of short structures that can be brazed in the existing PSI vacuum oven and will be completed with the production of the full two-meter prototype once the new full scale brazing oven, presently under construction, is operational. The status of the R&D program, including the production and power test results of the first two test structures, is reported here.

TUPB029

Beam Intensity and Energy Control for the SPIRAL2 Facility

pick-up, linac, ion, rfq

537

C. Jamet, T.A. André, C. Doutresssoulles, B. Ducoudret, W. Le Coz, G. Ledu, S.L. Leloir, S. Loret
GANIL, Caen, France

The first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, consists of an ion source, a deuteron and a proton source, a RFQ and a superconducting linear accelerator delivering high intensity, up to 5mA and 40 MeV for the deuteron beams. Diagnostic developments have been done to control the intensity and the beam energy by non-interceptive methods at the linac exit. The beam current is measured by using couples of ACCT-DCCT installed along the lines and the beam energy by using a time of flight device. This paper gives explanations about the technical solutions, the results and resolutions for measuring and controlling the beam.

TUPB031

Beam Envelope Analysis and Simulation

linac, ion, simulation, emittance

543

V.S. Dyubkov, A.S. Plastun
MEPhI, Moscow, Russia

Forming the charge particle beams with small cross-sections and low energies is an actual problem for a linac design. That beams are used actively for isotope therapy, ion implantation, etc. Beam emittance is its quality factor, and it should be matched with a facility channel acceptance. The method for beam dynamics analysis at linac is developed in terms of non-coherent particle oscillation study. Nonlinear beam dynamics is investigated by using this method. It is shown that this technique allows one to realize effective beam emittance control. Analytical results obtained are verified by means of numerical simulation.

TUPB033

Piezoelectric Actuator Based Phase Locking System for IUAC Linac

linac, resonance, heavy-ion, high-voltage

549

B.K. Sahu, R. Ahuja, G.K. Chowdhury, R.N. Dutt, S. Ghosh, D. Kanjilal, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, A. Pandey, P. Patra, A. Rai, A. Roy, S.K. Suman
IUAC, New Delhi, India

The linac of IUAC consists of three main accelerating modules with each one housing eight superconducting quarter wave resonators. Currently, the phase locking of the resonator is performed by a combination of fast I-Q based electronic tuner and helium gas flow based mechanical tuner. Microphonics measurement on the resonators found the presence of lower frequency vibrations along with main mechanical mode (~60 Hz) of the resonators. Although main mechanical mode of the resonator is damped by using SS balls, the presence of lower frequency vibrations demand more RF power from the amplifier, as the existing mechanical tuner works in time scale of seconds. A combination of piezoelectric actuator based fast tuner along with stepper motor based coarse tuner operating in the time scale of milliseconds is being developed. This scheme is implemented on a few resonators in last linac cryostat. Initial results show that this mechanism can arrest all low frequency vibrations thereby reducing a substantial load from the electronic tuner and improve the dynamics of the phase locking scheme. The implementation scheme along with test results will be presented in detail.

TUPB044

Cryogenic System for the ADS Injector II in IMP, CAS

cryogenics, cryomodule, solenoid, rfq

576

X.H. Guo, Y.N. Han, T. Jin, X.F. Niu, H.L. Su, J.H. Zhang
IMP, Lanzhou, People's Republic of China
L.Q. Liu, N. Peng, L.-Y. Xiong
TIPC, BeiJing, People's Republic of China

Funding: Work supported by Accelerator Driven Sub-critical (ADS) program of CAS, China
In order to meet the requirements of ADS Injector II project which is now being designed and built in IMP, CAS, a liquid helium cryogenic system with 4.5K & 850W cooling power is being built. This paper presents the primary design and the status of this cryogenic system with different operation models according to the need of superconducting tests.
guoxh@impcas.ac.cn

TUPB057

Structural Analysis of the New-Shaped QWR for HIAF in IMP

cavity, simulation, superconducting-cavity, SRF

606

C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and \beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085，with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.

TUPB061

ADRC Control for Beam Loading and Microphonics

cavity, beam-loading, LLRF, simulation

615

Z. Zheng, Z. Liu, J. Wei, Y. Zhang, S. Zhao
FRIB, East Lansing, Michigan, USA
Z. Zheng
TUB, Beijing, People's Republic of China

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Superconducting RF (SRF) cavities are subject to many disturbances such as beam loading and microphonics. Although we implemented Proportional Integral (PI) control and Active Disturbance Rejection Control (ADRC) in the Low Level RF (LLRF) system at FRIB to stabilize the RF field, the control loop gains are inadequate in the presence of beam loading and microphonics. An improved scheme is proposed and simulated with much higher gains are achieved. The feasibility to include piezo tuner in ADRC and PI circuit is also presented in this paper.

TUPB062

Longitudinal Dynamic Analysis for the Project X 3-8 GeV Pulsed Linac

cavity, linac, cryomodule, injection

618

G.I. Cancelo, B. Chase, Y.I. Eidelman, S. Nagaitsev, N. Solyak
Fermilab, Batavia, USA

The Pulsed Linac is a will require over 200 9-cell, 1300 MHz cavities packed in 26 ILC type cryomodules to accelerate 1 mA average beam current from 3GeV to 8 GeV. The architecture of the RF must optimize RF power, beam emittance, and energy gain amid a large number of requirement and constraints. The pulse length is a critical issue. Ideally, a 26 ms pulse would allow direct injection into the Fermilab’s Main Injector, bypassing the need of the Fermilab’s Recicler. High loaded quality factors (QL) are also desirable to minimize RF power. These requirements demand an accurate control of the cavity resonant frequency disturbed by Lorentz Force Detuning and microphonics. Also the LLRF control system must regulate the RF amplitude and phase within tight bounds amid a long list of dynamic disturbances. The present work describes the simulation efforts and measurements at Fermilab facilities.

TUPB071

First Measurements on the 325 MHz Superconducting CH Cavity

cavity, simulation, linac, coupling

636

M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany
M. Pekeler
RI Research Instruments GmbH, Bergisch Gladbach, Germany

Funding: Work supported by GSI, BMBF Contr. No. 06FY7102, 06FY9089I
At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.

TUPB092

High Power Amplifier Systems for SARAF Phase II

rf-amplifier, insertion, status, cavity

675

B. Kaizer, I. Fishman, I.G. Gertz
Soreq NRC, Yavne, Israel

Soreq NRC initiated the establishment of SARAF - Soreq Applied Research Accelerator Facility. SARAF is based on a continuous wave (CW), proton/deuteron RF superconducting linear accelerator with variable energy (5–40 MeV) and current (0.04-5 mA). RF power to each cavity is driven by a High Power Solid State Amplifiers. The paper outlines the design concept of the 10 and 15 kW at 176 MHz power amplifiers that were designed, built, and 10 kW successfully tested. 15 kW is now under construction. The amplifiers are combined from basic 5.5 kW compact 19" 7U water cooled drawer.

TUPB107

Amplitude and Phase Control of the Accelerating Field in the ESS Spoke Cavity

cavity, feedback, beam-loading, simulation

708

V.A. Goryashko, R.J.M.Y. Ruber, R.A. Yogi, V.G. Ziemann
Uppsala University, Uppsala, Sweden

We report about numerical simulations of the accelerating field dynamics in the ESS spoke cavity in the presence of the beam loading and Lorentz detuning. A slow feedforward is used to cure the Lorentz detuning whereas a fast feedback through a signal oscillator and cavity pre-detuning technique are applied to eliminate the beam loading effect. An analysis performed with a Simulink model shows that a combination of feedforward, feedback and cavity pre-detuning result in a substantially shorter stabilization time of the field voltage and phase on a required level as compared to a control method using only the feedforward and feedback. The latter allows one to obtain smaller magnitude but longer duration of deviations of the instantaneous voltage and phase from the required nominal values. As a result, a series of cavities only with feedforward and feedback needs an extra control technique to mitigate a cumulative systematic error rising in each cavity. In addition, a technique of adiabatic turning off of the RF power in order to prevent a high reflected power in the case of a sudden beam loss is studied.

TUPB108

Uppsala High Power Test Stand for ESS Spoke Cavities

rf-amplifier, linac, power-supply, cryomodule

711

R.A. Yogi, T.J.C. Ekelöf, V.A. Goryashko, L. Hermansson, M. Noor, R. Santiago Kern, V.G. Ziemann
Uppsala University, Uppsala, Sweden
D.S. Dancila, A. Rydberg
Uppsala University, Department of Engineering Sciences, Uppsala, Sweden
K.J. Gajewski, T. Lofnes, R. Wedberg
TSL, Uppsala, Sweden
R.J.M.Y. Ruber
CERN, Geneva, Switzerland

The European Spallation Source (ESS) is one of the world’s most powerful neutron source. The ESS linac will accelerate 50 mA of protons to 2.5 GeV in 2.86 ms long pulses at a repetition rate of 14 Hz. It produces a beam with 5 MW average power and 125 MW peak power. ESS Spoke Linac consists of 28 superconducting spoke cavities, which will be developed by IPN Orsay, France. These Spoke Cavities will be tested at low power at IPN Orsay and high power testing will be performed at a test stand which will be set up at Uppsala University. The test stand consists of tetrode based RF amplifier chain at 352 MHz, 350 kW power and related RF distribution. Outputs of two tetrodes shall be combined with the hybrid coupler to produce 350 kW power. Preamplifier for a tetrode shall be solid state amplifier. As the spoke cavities are superconducting, the test stand also includes horizontal cryostat, Helium liquefier, test bunker etc. The paper describes features of the test stand in details.

TH1A01

Results Achieved by the S1-Global Collaboration for ILC

cavity, cryomodule, feedback, LLRF

748

H. Hayano, M. Akemoto, S. Fukuda, K. Hara, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya
KEK, Ibaraki, Japan
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith
Fermilab, Batavia, USA
A. Bosotti, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

The S1-Global collaboration (scope and plans presented at Linac10) ended successfully in 2011. In the S1-Global experiment several variants of ILC components (e.g. cavities, tuners, modules, couplers) proposed by all SCRF collaborators worldwide have been extensively tested and their performances compared, in order to build consensus for the technical choices towards the ILC TDR and to develop further the concept of plug-compatible components for ILC. The experiment has been carried at KEK with contribution of hardware and manpower from all collaborators.

Slides TH1A01 [6.656 MB]

THPLB02

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, klystron, rfq, LLRF

810

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

Slides THPLB02 [1.610 MB]

THPLB08

High-Power RF Conditioning of the TRASCO RFQ

rfq, cavity, vacuum, pick-up

828

E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri
INFN/LNL, Legnaro (PD), Italy
M. Desmons
CEA/DSM/IRFU, France

The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.

Slides THPLB08 [1.384 MB]

THPLB09

Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay

cryomodule, cavity, vacuum, synchrotron

831

C. Madec
CEA, Gif-sur-Yvette, France
S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin
CEA/DSM/IRFU, France
A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé
CEA/IRFU, Gif-sur-Yvette, France

As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m² clean room complex with 120 m² under ISO4, 1325 m² of assembly platforms and 400 m² of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.

THPB015

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, klystron, rfq, LLRF

879

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB040

High-Power RF Conditioning of the TRASCO RFQ

rfq, cavity, vacuum, pick-up

945

E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri
INFN/LNL, Legnaro (PD), Italy
M. Desmons
CEA/DSM/IRFU, France

The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.

THPB042

Production and Quality Control of the First Modules of the IFMIF-EVEDA RFQ

cavity, survey, coupling, rfq

948

F. Scantamburlo, R. Dima, A. Pepato
INFN- Sez. di Padova, Padova, Italy
C. Roncolato
INFN/LNL, Legnaro (PD), Italy

The IFMIF/EVEDA RFQ, designed to accelerate a 125mA D⁺ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz, consists of 18 modules with length of ~550 mm each. The production of the modules has been started and 2 prototype modules plus module 16 have undergone all the production steps, including precision milling and brazing. The progress of the construction and especially the fine tuning of the design and engineering phase are reported.

THPB044

Plans for an Integrated Front-End Test Stand at the Spallation Neutron Source

rfq, klystron, ion, ion-source

954

M.S. Champion, A.V. Aleksandrov, M.T. Crofford, D. Heidenreich, Y.W. Kang, J. Moss, R.T. Roseberry, J.P. Schubert
ORNL, Oak Ridge, Tennessee, USA

Funding: Work performed at Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
A spare Radio-Frequency Quadrupole (RFQ) is presently being fabricated by industry with delivery to Oak Ridge National Laboratory planned in late 2012. The establishment of a test stand at the Spallation Neutron Source site is underway so that complete acceptance testing can be performed during the winter of 2012-2013. This activity is the first step in the establishment of an integrated front-end test stand that will include an ion source, low-energy beam transport (LEBT), RFQ, medium-energy beam transport, diagnostics, and a beam dump. The test stand will be capable of delivering an H⁻ ion beam of up to 50 mA with a pulse length of 1 ms and a repetition rate of 60 Hz or a proton beam of up to 50 mA, 100 μs, 1 Hz. The test stand will enable the following activities: complete ion source characterization; development of a magnetic LEBT chopper; development of a two-source layout; development of beam diagnostics; and study of beam dynamics of high intensity beam.

THPB073

Initial RF Tests of the Diamond S-Band Photocathode Gun

gun, cathode, cavity, coupling

1002

C. Christou, S.A. Pande
Diamond, Oxfordshire, United Kingdom

An S-band photocathode electron gun designed to operate at repetition rates up to 1 kHz CW has been designed at Diamond and manufactured at FMB*. The first test results of this gun are presented. Low-power RF measurements have been carried out to verify the RF design of the gun, and high-power conditioning and RF test has begun. Initial high power tests have been carried out at 5 Hz repetition rate using the S-band RF plant normally used to power the Diamond linac: the benefits and limitations of this approach are considered, together with plans for further testing.
* J. H. Han et al, NIM A 647(2011) 17-24

THPB081

The Development of Timing Control System for RFQ

rfq, EPICS, proton, background

1014

J.N. Bai, S. Xiao, T.G. Xu, L. Zeng
IHEP, Beijing, People's Republic of China

Timing control system based on VME configuration is developed to meet the need of 3.5 MeV RFQ. An EPICS driver is provided to control its work. The timing control system satisfies request after examination. In the future, it will be used in the machine running. This paper introduces the Timing control hardware, VME interface, EPICS driver for Timing control system and MEDM operator interface.

THPB083

Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay

cryomodule, cavity, vacuum, synchrotron

1017

C. Madec
CEA, Gif-sur-Yvette, France
S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin
CEA/DSM/IRFU, France
A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé
CEA/IRFU, Gif-sur-Yvette, France

As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m² clean room complex with 120 m² under ISO4, 1325 m² of assembly platforms and 400 m² of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.

Slides THPB083 [1.868 MB]

THPB084

A Low-Level RF Control System for a Quarter-Wave Resonator

LLRF, cavity, resonance, ion

1020

J.-W. Kim, D.G. Kim
IBS, Daejeon, Republic of Korea
C.K. Hwang
KAERI, Daejon, Republic of Korea

A low-level rf control system was designed and built for an rf deflector, which is a quarter wave resonator and was designed to deflect a secondary electron beam to measure the bunch length of an ion beam. The deflector has a resonance frequency at near 88 MHz, and its required phase stability is approximately ±1° and amplitude stability less than ±1%. The control system consists of analog input and output components, and a digital system based on an FPGA for signal processing. It is a cost effective system, while meeting the stability requirements. Some basic properties of the control system were measured. Then the capability of the rf control has been tested using a mechanical vibrator made of a dielectric rod attached to an audio speaker system, which can induce regulated perturbation in the electric fields of the resonator. The control system is flexible such that its parameters can be easily configured to compensate for disturbance induced in the resonator.

THPB085

LLRF Automation for the 9mA ILC Tests at FLASH

cavity, feedback, cryomodule, beam-loading

1023

J. Branlard, V. Ayvazyan, O. Hensler, H. Schlarb, Ch. Schmidt, N.J. Walker, M. Walla
DESY, Hamburg, Germany
G.I. Cancelo, B. Chase
Fermilab, Batavia, USA
J. Carwardine
ANL, Argonne, USA
W. Cichalewski, W. Jałmużna
TUL-DMCS, Łódź, Poland
S. Michizono
KEK, Ibaraki, Japan

Since 2009 and under the scope of the International Linear Collider (ILC) R&D, a series of studies takes place twice a year at the Free electron Laser accelerator in Hamburg, (FLASH) DESY, in order to investigate technical challenges related to the high-gradient, high-beam-current design of the ILC. Such issues as operating cavities near their quench limit with high beam loading or in klystron saturation regime are investigated, always pushing the limits of FLASH nominal operational conditions. To support these studies, a series of automation algorithms have been developed and implemented at DESY. These include automatic detection of cavity quenches, automatic adjustment of the superconducting cavity quality factor, and automatic compensation of detuning due to Lorentz forces. This paper explains the functionality of these automation tools, details about their implementation, and shows the experience acquired during the last 9mA ILC test which took place at DESY in February 2012. The benefit of these algorithms and the R&D results these automation tools have permitted will be clearly explained.

THPB086

Precision Regulation of RF Fields with MIMO Controllers and Cavity-based Notch Filters

cavity, LLRF, resonance, feedback

1026

Ch. Schmidt, J. Branlard, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
W. Jałmużna
TUL-DMCS, Łódź, Poland

The European XFEL requires a high precision control of the electron beam, generating a specific pulsed laser light demanded by user experiments. The low level radio frequency (LLRF) control system is certainly one of the key players for the regulation of accelerating RF fields. A uTCA standard LLRF system was developed and is currently under test at DESY. Its first experimental results showed the system performance capabilities. Investigation of regulation limiting factors evidenced the need for control over fundamental cavity modes, which is done using complex controller structures and filter techniques. The improvement in measurement accuracy and detection bandwidth increased the regulation performance and contributed to integration of further control subsystems.

THPB091

Machine Protection Issues and Solutions for Linear Accelerator Complexes

beam-losses, instrumentation, radiation, linac

1032

M. Jonker, H. Schmickler, R. Schmidt, D. Schulte
CERN, Geneva, Switzerland
M.C. Ross
SLAC, Menlo Park, California, USA

The workshop “Machine Protection focusing on Linear Accelerator Complexes” was held from 6-8 June 2012 at Cern. This workshop brought together experts working on machine protection systems for accelerator facilities with high brilliance or large stored beam energies, with the main focus on linear accelerators and their injectors. An overview of the machine protection systems for several accelerators was given. Beam loss mechanisms and their detection were discussed. Mitigation of failures and protection systems were presented. This paper summarises the workshop and reviews the current state of the art in machine protection systems.