Keyword: linac
Paper Title Other Keywords Page
SUPB003 Feasibility Study of Short Pulse Mode Operation for Multi-turn ERL Light Source emittance, simulation, undulator, acceleration 4
 
  • T. Atkinson, A.V. Bondarenko, A.N. Matveenko, Y. Petenev
    HZB, Berlin, Germany
 
  The optics and simulation group at HZB are designing Germany’s future light source. Based on the emerging Energy Recovery Linac super conducting technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photons of Angstrom wavelength at 6 GeV. The FSF is intended to be a multi-user facility and offer a wide variety of operation modes. A low emittance ~0.1 μm rad mode will operate in conjunction with a short-pulse ~10 fs mode. This paper highlights the physical limitations when trying to offer interchangeable modes and preserve beam high quality.  
 
SUPB004 Linac Optics Design for Multi-turn ERL Light Source cavity, optics, acceleration, cryomodule 7
 
  • Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
    HZB, Berlin, Germany
 
  The optics simulation group at HZB is designing a multi-turn energy recovery linac-based light source. Using the superconducting Linac technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photon beams of angstrom wavelength at 6 GeV. The FSF is intended to be a multi-user facility and offer a variety of operation modes. In this paper a design of transverse optic of the beam motion in the Linacs is presented. An important point in the optics design was minimization of the beta-functions in the linac at all beam passes to suppress beam break-up (BBU) instability.  
 
SUPB006 Study of Beam-Based Alignment for Shanghai Soft X-Ray FEL Facility simulation, emittance, alignment, FEL 10
 
  • D. Gu, Q. Gu, D. Huang, M. Zhang, M.H. Zhao
    SINAP, Shanghai, People's Republic of China
 
  In linear accelerators, dispersion caused by quadrupole misalignment and transverse wake-field effect caused by alignment errors of accelerate structures will lead to a significant emittance growth. There are more stringent restrictions on SXFEL, the traditional optical alignment can no longer meet its requirements, but the Beam-Based Alignment(BBA) method allows more precise alignment, further reduce the Linac errors to meet SXFEL requirements .In undulator sections, orbit changes are not only caused by misalignments of quadrupole magnet position ,but also the errors of undulator magnetic. In order to achieve alignment accuracy over longer distance, we measuring BPM data under different conditions and using SVD algorithm for calculation and analysis, we can get the quadrupole magnet errors and BPM offset. With the method above, software based on MATLAB has been designed and compared the results with other software.  
 
SUPB007 On-Line Dispersion Free Steering for the Main Linac of CLIC emittance, ground-motion, feedback, simulation 13
 
  • J. Pfingstner, D. Schulte
    CERN, Geneva, Switzerland
 
  For future linear colliders as well as for light sources, ground motion effects are a severe problem for the accelerator performance. After a few minutes, orbit feedback systems are not sufficient to mitigate all ground motion effects and additional long term methods will have to be deployed. In this paper, the long term ground motion effects in the main linac of the Compact Linear Collider (CLIC) are analysed via simulation studies. The primary growth of the projected emittance is identified to originate from chromatic dilutions due to dispersive beam orbits. To counter this effect, an on-line identification algorithm is applied to measure the dispersion parasitically. This dispersion estimate is used to correct the beam orbit with an iterative dispersion free steering algorithm. The presented results are not only of interest for the CLIC project, but for all linacs in which the dispersive orbit has to be corrected over time.  
 
SUPB008 Specifications of the Distributed Timing System for the CLIC Main Linac luminosity, monitoring, collider, acceleration 16
 
  • A. Gerbershagen, A. Andersson, D. Schulte
    CERN, Geneva, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • F.Ö. Ilday
    Bilkent University, Bilkent, Ankara, Turkey
 
  The longitudinal phase stability of CLIC main and drive beams is a crucial element of CLIC design. In order to measure and to control the phase, a distributed phase monitoring system has been proposed. The system measures the beam phase every 900 m. The relative phase between the measurement points is synchronized with an external reference system via a chain of reference lines. This paper presents the simulations of error propagation in the proposed distributed monitoring system and the impact on the drive and main beam phase errors and the luminosity. Based on the results the error tolerances for the proposed system are detailed.  
 
SUPB010 Measurements of a Reduced Energy Spread of a Recirculating Linac by Non-Isochronous Beam Dynamics recirculation, electron, synchrotron, acceleration 22
 
  • F. Hug, C. Burandt, M. Konrad, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • R. Eichhorn
    Cornell University, Ithaca, New York, USA
 
  Funding: supported by DFG through SFB 634
The Superconducting Linear Accelerator S-DALINAC at the University of Darmstadt (Germany) is a recirculating linac with two recirculations providing beams for measurements in nuclear physics at small momentum transfers. For these experiments an energy spread of better than 10-4 (rms) is needed. Currently acceleration in the linac section is done on crest of the accelerating field. The recirculation path is operated achromatic and isochronous. In this recirculation scheme the energy spread of the resulting beam in the ideal case is determined by the electron bunch length. Taking into account the stability of the RF system the energy spread increases drastically to more than 10-3 (rms). We will present a new non-isochronous recirculation scheme which helps cancelling out these errors from the rf-control. This scheme uses longitudinal dispersion in the recirculation paths and an acceleration off-crest with a certain phase with respect to the maximum. We will present results of the commissioning of the new system including measurements of the longitudinal dispersion in the recirculation arcs as well as measurements of the resulting energy spread using an electron spectrometer.
 
 
SUPB011 Computational Model Analysis for Experimental Observation of Optical Current Noise Suppression Below the Shot-noise Limit plasma, electron, simulation, beam-transport 25
 
  • A. Nause, A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
 
  Funding: We acknowledge support of the Israel Science Foundation grant
We report first demonstration of optical frequency current shot-noise suppression in a relativistic e-beam. This process is made possible by collective Coulomb interaction between the electrons of a cold intense beam during beam drift, and is essentially a process of longitudinal beam-plasma oscillation [1]. Suppression of beam current noise below the classical “shot-noise” level has been known in the microwave tubes art [2]. This is the first time that it is demonstrated in the optical regime. We predict that the scheme can be extended to the XUV and possibly to shorter wavelengths with further development of technology. The fundamental current shot-noise determines the level of incoherent spontaneous radiation emission from electron-beam optical radiation sources and SASE-FELs [3]. Suppressing shot-noise would make it possible to attain spontaneous emission sub-radiance [4] and surpass the classical coherence limits of seed-injected FELs. The effect was demonstrated by measuring sub-linear growth as a function of current of the OTR Radiation. This finding indicates that the beam charge homogenizes due to the collective interaction, and its distribution becomes sub-Poissonian.
[1] A. Gover, E. Dyunin, PRL, 102, 154801, 2009
[2] H. Haus, N. Robinson, Proc. IRE, 43, 981 (1955)
[3] P. Emma, et al , Nature Photonics 4, 641 (2010)
[4] A. Dicke, Phys. Rev. 93, 99 (1954)
 
 
SUPB017 Tuning Studies on 4-rod-RFQs rfq, simulation, resonance, coupling 44
 
  • J.S. Schmidt, B. Klump, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  A NI LabVIEW based Tuning Software has been devel- oped to structure the tuning process of 4-rod Radio Fre- quency Quadrupole s (RFQs). Its results are compared to measurement data of 4-rod RFQs in different frequency ranges. For the optimization of RFQ design parameters, a certain voltage distribution along the electrodes of an RFQ is assumed. Therefore an accurate tuning of the voltage distribution is very important for the beam dynamic prop- erties of an RFQ. A variation can lead to particle losses and reduced beam quality especially at higher frequencies. Our electrode design usually implies a constant longitudi- nal voltage distribution. For its adjustment tuning plates are used between the stems of the 4-rod-RFQ. These pre- dictions are based, in contrast to other simulations, on mea- surements to define the characteristics of the RFQ as it was build - not depending on assumptions of the design. This will lead to a totally new structured process of tuning 4- rod-RFQs in a broad range of frequencies by using the pre- dictions of a software. The results of these studies are pre- sented in this paper.  
 
SUPB018 Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices cavity, simulation, proton, lattice 47
 
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
  • S. Molloy
    ESS, Lund, Sweden
 
  The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.  
 
SUPB022 First Measurements on the 325 MHz Superconducting CH Cavity cavity, simulation, controls, 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.
 
 
SUPB023 Status of the Superconducting CW Demonstrator for GSI cavity, simulation, solenoid, cryogenics 59
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
 
  Funding: Helmholtz Institut Mainz (HIM), GSI, BMBF Contr. No. 06FY7102
Since the existing UNILAC at GSI will be used as an injector for the FAIR facility a new superconducting (sc) continous wave (cw) LINAC is highly requested by a broad community of future users to fulfil the requirements of nuclear chemistry, especially in the research field of Super Heavy Elements (SHE). This LINAC is under design in collaboration with the Institute for Applied Physics (IAP) of Frankfurt University, GSI and the Helmholtz Institut Mainz (HIM). It will consist of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz which provide an energy up to 7.3 AMeV. Currently, a prototype of the cw LINAC is under development. This demonstrator comprises the first sc CH cavity of the LINAC embedded between two sc solenoids mounted in a horizontal cryomodule. One important milestone of the project will be a full performance test of the demonstrator by injecting and accelerating a beam from the GSI High Charge State Injector (HLI) in 2014. The status of the demonstrator is presented.
 
 
SUPB028 The Superconducting CH Cavity Development in IMP* cavity, simulation, niobium, resonance 74
 
  • M.X. Xu, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Z.J. Wang, J.W. Xia, 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: Work supported by 91026001 Nature Science Foundation of China
The Cross-Bar H-type (CH) cavity is a multi-gap drift tube structure operated in the H21 mode [1]. The Institute of Modern Physics (IMP) has been doing research and development on this type of superconducting CH cavity which can work at the C-ADS (accelerator driver sub-critical system of China). A new geometry CH cavity has been proposed which have smaller radius. It’s suitable in fabrication, and it’s can reduce cost too .Detailed numerical simulations with CST MicroWave Studio have been performed. An overall surface reduction of 30% against the old structure seems feasible. A copper model CH cavity is being fabrication for validating the simulations and the procedure of fabricating niobium cavity.
 
 
SUPB031 The Nonresonant Perturbation Theory Based Field Measurement and Tuning of a Linac Accelerating Structure RF-structure, electromagnetic-fields, pick-up, feedback 80
 
  • W. Fang, Q. Gu, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  • D.C. Tong
    TUB, Beijing, People's Republic of China
 
  Assisted by the bead pull technique, the nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure. The method is capable of making non-touch measurement, amplitude and phase diagnostics, real time mismatch feedback and field tuning. Main considerations on measurement system and of C-band traveling-wave structure are described, the bead pull measurement and the tuning of the C-band traveling-wave linac accelerating structure are presented.  
 
MO1A01 Operational Experience and Future Goals of the SARAF Linac at SOREQ proton, target, neutron, cavity 100
 
  • D. Berkovits, A. Arenshtam, Y. Ben Aliz, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I. Gavish, I.G. Gertz, A. Grin, S. Halfon, D. Har-Even, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, A. Kreisel, G. Lempert, J. Luner, I. Mardor, A. Perry, E. Reinfeld, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, L. Weissman, E. Zemach
    Soreq NRC, Yavne, Israel
 
  SARAF-phase 1 at SOREQ, with its single 6 half-wave resonators cryomodule, is the first high current, superconducting low-beta linac in operation and it is presently delivering cw proton beams in the mA range. A phase 2 is foreseen for this linac which will allow acceleration up to 40 MeV of 2 mA cw proton and deuteron beams. The project status, the operational experience and the future goals of SARAF should be described.  
slides icon Slides MO1A01 [3.276 MB]  
 
MO1A03 SRF Linac Technology Development at Fermilab cavity, SRF, cryogenics, status 110
 
  • V.P. Yakovlev, C.M. Ginsburg
    Fermilab, Batavia, USA
 
  Superconducting linear accelerators are developing for different applications – for fundamental researches in High-Energy and High – Intensity Frontiers, nuclear physics, energetics, neutron spallation sources, synchrotron radiation sources, etc. The linac applications dictate the requirements for superconducting acceleration system, and, thus, for SRF technology. Fermilab is currently involved in two projects: ILC and Project X, both are based on SRF technology. For High-Intensity Frontier investigations, the Project X – a multi-experiment facility is developing based on 3 GeV, CW H linac in the frame of a wide collaboration of US National Laboratories. In a CW H linac several families of SC cavities are used: half-wave resonators (162.5 MHz); single-spoke cavities, SSR1 and SSR2 (325 MHz); elliptical 5-cell β=0.6 and β=0.9 cavities (650 MHz). Pulsed 3-8 GeV linac and ILC linac are based on 9-cell 1.3 GHz cavities. In the paper the basic requirements and the status of development of SC accelerating cavities, auxiliaries (couplers, tuners, etc.) and cryomodules are presented as well as technology challenges caused by their specifics.  
slides icon Slides MO1A03 [3.551 MB]  
 
MO2A02 Increased Understanding of Beam Losses from the SNS Linac Proton Experiment proton, focusing, optics, quadrupole 115
 
  • J. Galambos, A.V. Aleksandrov, M.A. Plum, A.P. Shishlo
    ORNL, Oak Ridge, Tennessee, USA
  • E. Laface
    ESS, Lund, Sweden
  • V.A. Lebedev
    Fermilab, Batavia, USA
 
  The SNS Linac has been in operation for 6 years, with its power being gradually increased. A major operation goal is the decrease of beam loss. It has been recently suggested that intra- H–beam stripping contributes significantly to beam losses in an H linac. This was tested experimentally at SNS by accelerating a proton beam. Experimental analysis results are in good agreement with the theoretical estimates. In this paper we present the operational status and experience at the SNS linac, with emphasis on understanding beam loss in terms of intra-H–beam stripping.  
slides icon Slides MO2A02 [12.869 MB]  
 
MO3A01 Development of H-mode Linacs for the FAIR Project DTL, proton, ion, cavity 120
 
  • G. Clemente, W.A. Barth, L. Groening, S. Mickat, B. Schlitt, W. Vinzenz
    GSI, Darmstadt, Germany
  • R. M. Brodhage, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  H-mode cavities offer outstanding shunt impedances at low beam energies and enable the acceleration of intense ion beams. Crossed-bar H-cavities extend these properties to energies even beyond 100 MeV. Thus, the designs of the new injector linacs for FAIR, i.e. a 70 MeV, 70 mA proton driver for pbar-production and a cw intermediate mass, superconducting ion linac are based on these novel cavities. Several prototypes (normal & super-conducting) have been built and successfully tested. Moreover, designs for a replacement of the 80 MV Alvarez section of the GSI - Unilac will be discussed to improve the capabilities as the future FAIR heavy ion injector.  
slides icon Slides MO3A01 [2.741 MB]  
 
MOPLB01 Emittance Control for Different FACET Beam Setups in the SLAC Linac quadrupole, emittance, klystron, wakefield 138
 
  • F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.
 
slides icon Slides MOPLB01 [0.826 MB]  
 
MOPLB02 Positron Injector Linac Upgrade for SuperKEKB positron, electron, quadrupole, target 141
 
  • T. Kamitani, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, T. Higo, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
    KEK, Ibaraki, Japan
  • D. Satoh
    TIT, Tokyo, Japan
 
  The KEKB B-factory is under an upgrade construction for the SuperKEKB. To achieve 40 times higher luminosity, the linac is required to inject electrons and positrons with higher intensities (e-: 1 nC → 5 nC, e+: 1 nC → 4 nC) and lower emittances (e-: 300 → 20 μm, e+: 2100 → 10 μm). This paper describes the upgrade scheme of the positron source. A new positron capture section will have larger transverse and energy acceptances by introducing a flux concentrator and large aperture L-band and S-band accelerating structures. Beam line layout and quadrupole focusing system will be rearranged for the enlarged beam acceptance. Beam optics is designed to be compatible for positron and electron beams with different energies and emittances. Pulsed quadrupoles and steering magnets are added for better flexibility in optics and orbit tuning. Parameter optimization of the positron source by optics calculation and particle tracking simulation is described.  
slides icon Slides MOPLB02 [0.575 MB]  
 
MOPLB03 Advances in Beam Tests of Dielectric Based Accelerating Structures wakefield, acceleration, electron, laser 144
 
  • A. Kanareykin, S.P. Antipov, J.E. Butler, C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • W. Gai
    ANL, Argonne, USA
  • V. Yakimenko
    BNL, Upton, Long Island, New York, USA
 
  Funding: US Department of Energy
Diamond is being evaluated as a dielectric material for dielectric loaded accelerating structures. It has a very low microwave loss tangent, high thermal conductivity, and supports high RF breakdown fields. We report on progress in our recent beam tests of the diamond based accelerating structures of the Ka-band and THz frequency ranges. Wakefield breakdown test of a diamond-loaded accelerating structure has been carried out at the ANL/AWA accelerator. The high charge beam from the AWA linac (~70 nC, σz = 2.5 mm) was passed through a rectangular diamond loaded resonator and induce an intense wakefield. A groove is cut on the diamond to enhance the field. Electric fields up to 0.3 GV/m has been detected on the diamond surface to attempt to initiate breakdown. A surface analysis of the diamond has been performed before and after the beam test. Wakefield effects in a 250 GHz planar diamond accelerating structure has been observed at BNL/ATF accelerator as well. We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism.
 
slides icon Slides MOPLB03 [1.986 MB]  
 
MOPLB04 A 10 MeV L-band Linac for Irradiation Applications in China electron, gun, klystron, simulation 147
 
  • G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  • Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu
    Institute of High Energy Physics (IHEP), People's Republic of China
  • Z. Li, X. Zhang
    Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China
 
  The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.  
slides icon Slides MOPLB04 [1.800 MB]  
 
MOPLB06 Fermilab 1.3 GHz Superconducting RF Cavity and Cryomodule Program for Future Linacs cavity, cryomodule, status, linear-collider 153
 
  • C.M. Ginsburg
    Fermilab, Batavia, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The proposed Project X accelerator and the International Linear Collider are based on superconducting RF technology. As a critical part of this effort, Fermilab has developed an extensive program in 1.3 GHz SRF cavity and cryomodule development. This program includes cavity inspection, surface processing, clean assembly, low-power bare cavity tests and pulsed high-power dressed cavity tests. Well performing cavities have been assembled into cryomodules for pulsed high-power tests and will be tested with beam. In addition, peripheral hardware such as tuners and couplers are under development. The current status and accomplishments of the Fermilab 1.3 GHz activity will be described, as well as the R&D program to extend the existing SRF pulsed operational experience into the CW regime.
 
slides icon Slides MOPLB06 [1.508 MB]  
 
MOPLB11 The Upgraded Argonne Wakefield Accelerator Facility (AWA): a Test-Bed for the Development of High Gradient Accelerating Structures and Wakefield Measurements wakefield, electron, gun, acceleration 168
 
  • M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof
    ANL, Argonne, USA
  • S.P. Antipov, C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • E.E. Wisniewski
    Illinois Institute of Technology, Chicago, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
Electron beam driven wakefield acceleration is a bona fide path to reach high gradient acceleration of electrons and positrons. With the goal of demonstrating the feasibility of this concept with realistic parameters, well beyond a proof-of-principle scenario, the AWA Facility is currently undergoing a major upgrade that will enable it to achieve accelerating gradients of hundreds of MV/m and energy gains on the order of 100 MeV per structure. A key aspect of the studies and experiments carried out at the AWA facility is the use of relatively short RF pulses (15 – 25 ns), which is believed to mitigate the risk of breakdown and structure damage. The upgraded facility will utilize long trains of high charge electron bunches to drive wakefields in the microwave range of frequencies (8 to 26 GHz), generating RF pulses with GW power levels.
 
slides icon Slides MOPLB11 [0.900 MB]  
 
MOPB001 Emittance Control for Different FACET Beam Setups in the SLAC Linac quadrupole, emittance, klystron, wakefield 174
 
  • F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.
 
 
MOPB002 Positron Injector Linac Upgrade for SuperKEKB positron, electron, quadrupole, target 177
 
  • T. Kamitani, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, T. Higo, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
    KEK, Ibaraki, Japan
  • D. Satoh
    TIT, Tokyo, Japan
 
  The KEKB B-factory is under an upgrade construction for the SuperKEKB. To achieve 40 times higher luminosity, the linac is required to inject electrons and positrons with higher intensities (e-: 1 nC → 5 nC, e+: 1 nC → 4 nC) and lower emittances (e-: 300 → 20 μm, e+: 2100 → 10 μm). This paper describes the upgrade scheme of the positron source. A new positron capture section will have larger transverse and energy acceptances by introducing a flux concentrator and large aperture L-band and S-band accelerating structures. Beam line layout and quadrupole focusing system will be rearranged for the enlarged beam acceptance. Beam optics is designed to be compatible for positron and electron beams with different energies and emittances. Pulsed quadrupoles and steering magnets are added for better flexibility in optics and orbit tuning. Parameter optimization of the positron source by optics calculation and particle tracking simulation is described.  
 
MOPB003 Recent Improvements to the Control of the CTF3 High-Current Drive Beam lattice, controls, 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.  
 
MOPB004 Design and Operation of a Compact 1 MeV X-band Linac cavity, electron, gun, target 183
 
  • G. Burt, T.N. Abram, P.K. Ambattu, C. Lingwood
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • I. Burrows, T. Hartnett, J.P. Hindley, C.J. White
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • P.A. Corlett, A.R. Goulden, P.A. McIntosh, K.J. Middleman, Y.M. Saveliev, R.J. Smith
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  A compact 1 MeV linac has been produced at the Cockcroft Institute using X-band RF technology. The linac is powered by a high power X-band magnetron and has a 17 keV 200 mA thermionic gun with a focus electrode for pulsing. A bi-periodic structure with on-axis coupling is used to minimise the radial size of the linac and to reduce the surface electric fields.  
 
MOPB007 Study of Microbunching Instabilitity in the Linac of the Shanghai Soft X-Ray Free Electron Laser Facility impedance, FEL, simulation, electron 189
 
  • D. Huang, Q. Gu, M. Zhang
    SINAP, Shanghai, People's Republic of China
 
  The microbunching instability in the LINAC of a FEL facility has always been an issue which may degrade the quality of the electron beam. As the result, the whole facility may not be working properly. Shanghai soft X-ray FEL project (SXFEL), which is planned to start construction by the end of 2012, will be the first X-ray FEL facility in China. In this article, detailed study will be given based on the physical design of the facility to gain better understanding and control over the possible microbunching instability in SXFEL, which is critical to the success of the project. Moreover, the contribution of the possible plasma effects to the instability will also be studied by modifying the physical model of the longitudinal space charge (LSC) impedance.  
 
MOPB014 Electron Model of a Dogbone RLA with Multi-Pass Arcs electron, quadrupole, dipole, optics 201
 
  • S.A. Bogacz, G.A. Krafft, V.S. Morozov, Y. Roblin
    JLAB, Newport News, Virginia, USA
  • K.B. Beard
    Muons. Inc., USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351
The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in a 25x7 m area. The scheme utilizes only fixed field magnets for both injection and extraction. The hardware requirements are not very demanding making it straightforward to implement the scaled design using available equipment.
 
 
MOPB016 In-situ Measurement of Beam-induced Fields in the S-band Accelerating Structures of the Diamond Light Source linac multipole, higher-order-mode, dipole, wakefield 204
 
  • C. Christou
    Diamond, Oxfordshire, United Kingdom
 
  The Diamond pre-injector linac uses two 5.2 m DESY linac II-type accelerating structures to generate a 100 MeV electron beam suitable for injection into the booster synchrotron. The structures are powered independently by two high-power S-band klystrons and are designed to operate at 3 GHz. Higher order modes up to 14 GHz induced by beam in unpowered accelerating and bunching structures have been directly measured using directional couplers in the high-power waveguide network. These modes are compared with an electromagnetic simulation of the structures. The negative impact of higher-order wakes on the bunch trains used at Diamond is considered, and the use of the multipole field measurement for alignment of the beam to the structure is investigated.  
 
MOPB017 Integration of the European XFEL Accelerating Modules cavity, controls, 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 controls, 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.
 
 
MOPB021 Bunch-by-bunch Phase Modulation for Linac Beam-loading Compensation beam-loading, impedance, injection, bunching 216
 
  • 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
If the linac is loaded by a high current, long pulse multi-bunch beam, the energy of the beam drops with time during the pulse. The bunch phase modulation method is introduced to compensate the beam loading. In this method the beam phase in the RF accelerating filed is changed bunch-by-bunch, the beam energy gain in the RF filed gradually grows up, which cancels the drop due to beam loading. The relationship between the beam phase distribution and the linac parameters is calculated in this paper.
 
 
MOPB022 RF Characteristic Studies on the Whole Accelerating Structure for the BEPCII Linear Accelerator simulation, vacuum, impedance, electromagnetic-fields 219
 
  • S. Pei, M. Hou, X. Li, J.R. Zhang
    IHEP, Beijing, People's Republic of China
  • B.L. Wang
    SINAP, Shanghai, People's Republic of China
 
  An accelerating structure is one device to boost the particle energy. 2856 MHz 3 m long travelling wave disk-loaded accelerating structure is applied in BEPCII linac, its RF characteristics are mainly determined by the 84 regular cells located between the input and output couplers. Input and output couplers need to be included when the whole structure RF characteristics are simulated before fabrication; otherwise it would be difficult to obtain the travelling wave fields excited in the whole structure. If the real 3D couplers are modelled during the design process, a large amount of computer resources and time need to be used. However, if the redesigned azimuth symmetric coupler is used to replace the real 3D one during the simulation process, much less computer resources and time are required. With this method proposed here, the simulation results agree well with the theoretically calculated and experimentally measured ones.
*peisl@ihep.ac.cn
 
 
MOPB023 Progress on the Design and Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source klystron, electron, gun, neutron 222
 
  • S. Pei, J. Cao, Y.L. Chi, B. Deng, C.D. Deng, H.S. Guo, D.Y. He, X. He, M. Hou, X.C. Kong, Q. Le, X. Li, J. Liu, R.L. Liu, W.B. Liu, K. Lv, C. Ma, H.Z. Ma, G. Pei, H. Song, L. Wang, S.H. Wang, X. Wang, Q. Yang, J. Yue, J.R. Zhang, F. Zhao, J.B. Zhao, J.X. Zhao, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  • M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
  • Y. Gohar
    ANL, Argonne, USA
 
  IHEP in China is designing and constructing a 100 MeV / 100 kW electron linac for NSC KIPT, which will be used as the driver of a neutron source based on a subcritical assembly. Recently, the physical design has been finalized. The chicane scheme instead of the RF chopper one has been selected. The mechanical design is on-going and will be finished in the very near future. The injector part of the machine has been installed in the experimental hall #2 of IHEP and is being commissioned and tested. The progress on the machine design and construction are reported, initial testing and commissioning results of the injector are also presented.
*peisl@ihep.ac.cn
 
 
MOPB024 Beam Dynamics Simulation and Optimization for 10 MeV Superconducting e-Linac Injector for VECC-RIB Facility electron, TRIUMF, gun, emittance 225
 
  • A. Chakrabarti, S. Dechoudhury, V. Naik
    VECC, Kolkata, India
  • F. Ames, R.A. Baartman, Y.-C. Chao, R.E. Laxdal, M. Marchetto, L. Merminga, F. Yan
    TRIUMF, Vancouver, Canada
  • G. Goh
    SFU, Burnaby, BC, Canada
 
  Funding: This project is funded by Department of Atomic Energy, India
In the first phase of ongoing collaboration between VECC (India) and TRIUMF (Canada) a 10 MeV superconducting electron linac injector will be installed at VECC. This will constitute a 100 keV DC thermionic gun with grid delivering pulsed electron beam at 650 MHz. Owing to low energy from the gun, a capture cryo-module (CCM) consisting of two β = 1 single cell elliptical cavities (frequency = 1.3 GHz) will be inserted before a 9-cell β = 1 elliptical cavity that will provide acceleration to 10 MeV. The present paper depicts the beam dynamics simulation and optimization of different parameters for the injector with a realistic simulated beam emittance from the electron gun.
 
 
MOPB026 TRIUMF/VECC e-Linac Injector Beam Test diagnostics, gun, cryomodule, cavity 231
 
  • R.E. Laxdal, F. Ames, Y.-C. Chao, K. Fong, C. Gong, A. Laxdal, M. Marchetto, W.R. Rawnsley, S. Saminathan, V.A. Verzilov, Q. Zheng, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
  • J.M. Abernathy, D. Karlen, D.W. Storey
    Victoria University, Victoria, B.C., Canada
  • A. Chakrabarti, V. Naik
    VECC, Kolkata, India
 
  TRIUMF is collaborating with VECC on the design of a 10 MeV injector cryomodule to be used as a front end for a high intensity electron linac. A electron gun and low energy beam transport (LEBT) have been installed in a test area to act as the injector for the cryomodule test. The LEBT includes a wide variety of diagnostics to fully characterize the beam from the gun. A series of beam tests are being conducted during the stage installation. The test configuration details and results of beam tests will be presented.  
 
MOPB030 Performance of First C100 Cryomodules for the CEBAF 12 GeV Upgrade Project cryomodule, cavity, vacuum, instrumentation 237
 
  • M.A. Drury, A. Burrill, G.K. Davis, J. Hogan, L.K. King, F. Marhauser, H. Park, J.P. Preble, C.E. Reece, A.V. Reilly, R.A. Rimmer, H. Wang, M. Wiseman
    JLAB, Newport News, Virginia, USA
 
  Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the project is a doubling of the available beam energy of CEBAF from 6 GeV to 12 GeV. This increase in beam energy will be due primarily to the construction and installation of ten “C100” cryomodules in the CEBAF linacs. The C100 cryomodules are designed to deliver an average 108 MV each from a string of eight seven-cell, electropolished superconducting RF cavities operating at an average accelerating gradient of 19.2 MV/m. The new cryomodules fit in the same available linac space as the original CEBAF 20 MV cryomodules. Cryomodule production started in September 2010. Initial acceptance testing started in June 2011. The first two C100 cryomodules were installed and tested from August 2011 through October 2011, and successfully operated during the last period of the CEBAF 6 GeV era, which ended in May 2012. This paper will present the results of acceptance testing and commissioning of the C100 style cryomodules to date.
 
 
MOPB032 Stabilization of the Beam Intensity in the Linac at the CTF3 CLIC Test Facility gun, controls, 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%.  
 
MOPB033 High Power Coupler Test for TRIUMF E-linac SC Cavities vacuum, TRIUMF, electron, monitoring 246
 
  • A.K. Mitra, Z.T. Ang, S. Calic, P.R. Harmer, S.R. Koscielniak, R.E. Laxdal, W.R. Rawnsley, R.W. Shanks
    TRIUMF, Vancouver, Canada
 
  TRIUMF has been funded to build an electron linac with a final energy of 50 MeV and 500 kW beam power using TESLA type 9 cell superconducting cavities operating at 1.3 GHz at 2 Kelvin. The e-linac consists of an electron gun, buncher cavity, injector cryomodule, and two main-linac cryomodules. The injector module has one 9-cell cavity whereas each of the accelerating main-linac cryomodules contains two 9-cell cavities. It is scheduled to install the injector and one main accelerating cryomodule by 2014. Six power couplers, each rated for 60 kW cw, have been procured for three cavities. The injector cryomodule will be fed by a 30 kW cw inductive Output Tube (IOT) and the accelerating cryomodule will be powered by a 290 kW cw klystron. In order to install the power couplers in the cavities, they are to be assembled and conditioned with high power rf source. A power coupler test station has been built and tests of two power couplers have began. A 30 kW IOT has been commissioned to full output power and it will be used for the power coupler test. In this paper, test results of the rf conditioning of the power couplers under pulse and cw mode will be described.  
 
MOPB034 Novel Technique of Suppressing TBBU in High-energy ERLs HOM, SRF, electron, lattice 249
 
  • V. Litvinenko
    BNL, Upton, Long Island, New York, USA
 
  Energy recovery linacs (ERLs) is emerging generation of accelerators promising revolutionize the fields of high-energy physics and photon sciences. One potential weakness of these devices is transverse beam-breakup instability, which may severely limit available beam current. In this paper I am presenting new idea [1] developed for high-energy ERL which could be used for eRHIC, LHeC and, potentially, ILC: a concept of using main ERL linacs and natural chromaticity to suppressing TBBU instabilities by simplifying an ERL lattice. As demonstration of this method, I present tow specific example of eRHIC and LHeC ERLs.
[1] V.N. Litvinenko, Chromaticity of the lattice and beam stability in energy recovery linacs, submitted to PR ST-AB
 
 
MOPB035 The Linear Accelerating Structure Development for HLS Upgrade cavity, electron, injection, bunching 252
 
  • K. Jin, Y. Hong, G. Huang, D. Jia, S.C. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Hefei Light Source (HLS) is mainly composed of an 800 MeV electron storage ring and a 200 MeV constant-impedance Linac functioning as its injector. A new Linac is developed in view of the Full Energy Injection and the Top-up Injection scheme will be adopted in the HLS upgrade. In this paper, an 800 MeV linear accelerating system construction, the constant-gradient structure design and the symmetry couplers consideration will be described in detail. The manufacture technology, the RF measurement, the high power test results and the accelerating system operation are presented.  
 
MOPB036 Feasibility Study of Short Pulse Mode Operation for Multi-turn ERL Light Source emittance, simulation, undulator, acceleration 255
 
  • T. Atkinson, A.V. Bondarenko, A.N. Matveenko, Y. Petenev
    HZB, Berlin, Germany
 
  The optics and simulation group at HZB are designing Germany’s future light source. Based on the emerging Energy Recovery Linac super conducting technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photons of Angstrom wavelength at 6 GeV. The FSF is intended to be a multi-user facility and offer a wide variety of operation modes. A low emittance ~0.1 μm rad mode will operate in conjunction with a short-pulse ~10 fs mode. This paper highlights the physical limitations when trying to offer interchangeable modes and preserve beam high quality.  
 
MOPB037 Linac Optics Design for Multi-turn ERL Light Source cavity, optics, acceleration, cryomodule 258
 
  • Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
    HZB, Berlin, Germany
 
  The optics simulation group at HZB is designing a multi-turn energy recovery linac-based light source. Using the superconducting Linac technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photon beams of angstrom wavelength at 6 GeV. The FSF is intended to be a multi-user facility and offer a variety of operation modes. In this paper a design of transverse optic of the beam motion in the Linacs is presented. An important point in the optics design was minimization of the beta-functions in the linac at all beam passes to suppress beam break-up (BBU) instability.  
 
MOPB038 Single Shot Bunch-by-Bunch Beam Emittance Measurement of the SPring-8 Linac injection, emittance, electron, dipole 261
 
  • Y. Shoji, K. Takeda
    LASTI, Hyogo, Japan
 
  Bunch by bunch emittance of a single shot beam from the SPring-8 electron linac was measured. The linac is operated as an injector to the electron storage ring, NewSUBARU. A high beam stability is required for the stable top-up injection into the ring with a small acceptance. We used the electron ring as a part of the measurement system. The electron beam from the linac was injected into the ring and circulated for many turns. The beam profiles were recorded by a dual-sweep streak camera using the visible light in the ring. The fast sweep separated the bunches in 1 ns macro pulse and the slow sweep separated the profiles at different revolutions. It enabled a multi-record of beam profiles in one camera frame. Betatron oscillation in the ring produced the phase space rotation for the reconstruction of the beam emittance. The ring parameters were optimized for the measurement because the beam storage was not necessary. A stability of the linac beam was evaluated from the shot by shot fluctuation of the emittance and the bunch structure. We also compared the emittances of a front bunch and a rear bunch in the same pulse.  
 
MOPB041 Advances in Beam Tests of Dielectric Based Accelerating Structures wakefield, acceleration, electron, laser 264
 
  • A. Kanareykin, S.P. Antipov, J.E. Butler, C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • W. Gai
    ANL, Argonne, USA
  • V. Yakimenko
    BNL, Upton, Long Island, New York, USA
 
  Funding: US Department of Energy
Diamond is being evaluated as a dielectric material for dielectric loaded accelerating structures. It has a very low microwave loss tangent, high thermal conductivity, and supports high RF breakdown fields. We report on progress in our recent beam tests of the diamond based accelerating structures of the Ka-band and THz frequency ranges. Wakefield breakdown test of a diamond-loaded accelerating structure has been carried out at the ANL/AWA accelerator. The high charge beam from the AWA linac (~70 nC, σz = 2.5 mm) was passed through a rectangular diamond loaded resonator and induce an intense wakefield. A groove is cut on the diamond to enhance the field. Electric fields up to 0.3 GV/m has been detected on the diamond surface to attempt to initiate breakdown. A surface analysis of the diamond has been performed before and after the beam test. Wakefield effects in a 250 GHz planar diamond accelerating structure has been observed at BNL/ATF accelerator as well. We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism.
 
 
MOPB042 On-line Dispersion Free Steering for the Main Linac of CLIC emittance, ground-motion, feedback, simulation 267
 
  • J. Pfingstner, D. Schulte
    CERN, Geneva, Switzerland
 
  For future linear colliders as well as for light sources, ground motion effects are a severe problem for the accelerator performance. After a few minutes, orbit feedback systems are not sufficient to mitigate all ground motion effects and additional long term methods will have to be deployed. In this paper, the long term ground motion effects in the main linac of the Compact Linear Collider (CLIC) are analysed via simulation studies. The primary growth of the projected emittance is identified to originate from chromatic dilutions due to dispersive beam orbits. To counter this effect, an on-line identification algorithm is applied to measure the dispersion parasitically. This dispersion estimate is used to correct the beam orbit with an iterative dispersion free steering algorithm. The presented results are not only of interest for the CLIC project, but for all linacs in which the dispersive orbit has to be corrected over time.  
 
MOPB045 Specifications of the Distributed Timing System for the CLIC Main Linac luminosity, monitoring, collider, acceleration 273
 
  • A. Gerbershagen, A. Andersson, D. Schulte
    CERN, Geneva, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • F.Ö. Ilday
    Bilkent University, Bilkent, Ankara, Turkey
 
  The longitudinal phase stability of CLIC main and drive beams is a crucial element of CLIC design. In order to measure and to control the phase, a distributed phase monitoring system has been proposed. The system measures the beam phase every 900 m. The relative phase between the measurement points is synchronized with an external reference system via a chain of reference lines. This paper presents the simulations of error propagation in the proposed distributed monitoring system and the impact on the drive and main beam phase errors and the luminosity. Based on the results the error tolerances for the proposed system are detailed.  
 
MOPB046 A 10 MeV L-band Linac for Irradiation Applications in China electron, gun, klystron, simulation 276
 
  • G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, X.W. Yang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  • Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu
    Institute of High Energy Physics (IHEP), People's Republic of China
  • Z. Li, X. Zhang
    Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China
 
  The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.  
 
MOPB051 Changing Attitude to Radiation Hazards and Consequent Opportunities for LINAC Applications radiation, electron, background, status 288
 
  • Y. Socol
    Falcon Analytics, Netanya, Israel
 
  High-energy LINACs unavoidably yield ionizing radiation. This fact makes them subject to strict regulations and considerably limits applications. During the last two decades the attitude to ionizing radiation hazards seems to become more balanced, as opposed to "radiophobia" of the Cold-War era. Scientifically, the linear no-threshold (LNT) model of radiation damage is more and more questioned. Moreover, the hypotheses of radiation hormesis - beneficial effect of low-dose radiation - is studied. While this scientific debate has not yet given fruit regarding radiation regulation and policy, we may expect this in near to middle term. Namely, the ALARA (as low as reasonably achievable) demand is anticipated to be substituted by some tolerance level, which in turn is anticipated to be very high according to the present standards. The presentation will review the present status of the radiation-hazard debate, and outline anticipated opportunities for LINAC applications, like compact designs and wider industrial outreach.  
 
MOPB052 Fermilab 1.3 GHz Superconducting RF Cavity and Cryomodule Program for Future Linacs cavity, cryomodule, status, linear-collider 291
 
  • C.M. Ginsburg
    Fermilab, Batavia, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The proposed Project X accelerator and the International Linear Collider are based on superconducting RF technology. As a critical part of this effort, Fermilab has developed an extensive program in 1.3 GHz SRF cavity and cryomodule development. This program includes cavity inspection, surface processing, clean assembly, low-power bare cavity tests and pulsed high-power dressed cavity tests. Well performing cavities have been assembled into cryomodules for pulsed high-power tests and will be tested with beam. In addition, peripheral hardware such as tuners and couplers are under development. The current status and accomplishments of the Fermilab 1.3 GHz activity will be described, as well as the R&D program to extend the existing SRF pulsed operational experience into the CW regime.
 
 
MOPB059 The Superconducting CH Cavity Development in IMP* cavity, simulation, niobium, resonance 309
 
  • M.X. Xu, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Z.J. Wang, J.W. Xia, 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: Work supported by 91026001 Nature Science Foundation of China
The Cross-Bar H-type (CH) cavity is a multi-gap drift tube structure operated in the H21 mode [1]. The Institute of Modern Physics (IMP) has been doing research and development on this type of superconducting CH cavity which can work at the C-ADS (accelerator driver sub-critical system of China). A new geometry CH cavity has been proposed which have smaller radius. It’s suitable in fabrication, and it’s can reduce cost too .Detailed numerical simulations with CST MicroWave Studio have been performed. An overall surface reduction of 30% against the old structure seems feasible. A copper model CH cavity is being fabrication for validating the simulations and the procedure of fabricating niobium cavity.
 
 
MOPB063 Superconducting RF Linac for eRHIC cavity, SRF, HOM, electron 321
 
  • S.A. Belomestnykh, I. Ben-Zvi, J.C. Brutus, H. Hahn, D. Kayran, V. Litvinenko, G.J. Mahler, G.T. McIntyre, V. Ptitsyn, R. Than, J.E. Tuozzolo, W. Xu, A. Zaltsman
    BNL, Upton, Long Island, New York, USA
  • S.A. Belomestnykh
    Stony Brook University, Stony Brook, USA
 
  Funding: Work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
eRHIC will collide high-intensity hadron beams from RHIC with 50-mA electron beam from a six-pass 30-GeV Energy Recovery Linac (ERL), which will utilize 704 MHz superconducting RF accelerating structures. This presentation describes the eRHIC SRF linac requirements, layout and parameters, 5-cell SRF cavity with a new HOM damping scheme, project status and plans.
 
 
MOPB066 Alternative Approaches for HOM-Damped Cavities multipole, cavity, acceleration, HOM 330
 
  • B. Riemann, T. Weis
    DELTA, Dortmund, Germany
  • A. Neumann
    HZB, Berlin, Germany
 
  Funding: this work is partly funded by BMBF contract no. 05K10PEA
Elliptical cavities have been a standard in SRF linac technology for 30 years. We present another approach to base cell geometry based on Bezier splines, that leads to equal performance levels and is much more flexible in terms of optimization. Using the BERLinPro main linac as an example, a spline multicell cavity is designed with equal performance goals. For the damping of higher order modes (HOMs), the installation of waveguides at the ends of a multicell cavity is a common approach.
 
 
MOPB067 Results and Performance Simulations of the Main Linac Design for BERLinPro cavity, HOM, quadrupole, dipole 333
 
  • A. Neumann, W. Anders, J. Knobloch
    HZB, Berlin, Germany
  • K. Brackebusch, T. Flisgen, T. Galek, K. Papke, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  • B. Riemann, T. Weis
    DELTA, Dortmund, Germany
 
  Funding: this work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC
The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities damped by on the whole five waveguides at both ends. Eigenmode computations for geometrical figures of merit show that the present design should allow successful CW linac operation at the maximum beam current of 100 mA/77 pC bunch charge. To verify the results, the external Q factors are compared to the results of S-Parameter simulations that are postprocessed by a pole-fitting technique. First results of scattering parameter measurement on a room-temperature aluminium model are discussed. An outlook presenting the possibilities of combined multi-cavity simulations is included.
 
 
MOPB071 Process Developments for Superconducting RF Low Beta Resonators for the ReA3 LINAC and Facility for Rare Isotope Beams cavity, vacuum, controls, SRF 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.
 
 
MOPB072 Multipole Expansion of the Fields in Superconducting High-Velocity Spoke Cavities cavity, multipole, quadrupole, simulation 345
 
  • R.G. Olave, J.R. Delayen, C.S. Hopper
    ODU, Norfolk, Virginia, USA
 
  Multi-spokes superconducting cavities in the high-beta regime are being considered for a number of applications. In order to accurately model the dynamics of the particles in such cavities, knowledge of the fields off-axis are needed. We present a study of the multipoles expansion of the fields from an EM simulation field data for a two-spoke cavity operating at 325 MHz, β = 0.82 and 500 MHz, β = 1.  
 
MOPB073 Cold Testing of Superconducting 72 MHz Quarter-wave Cavities for ATLAS cavity, cryomodule, niobium, accelerating-gradient 348
 
  • M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Kedzie, R.C. Murphy, P.N. Ostroumov, T. Reid
    ANL, Argonne, USA
 
  A set of seven 72 MHz β=0.077 superconducting quarter-wave cavities for a beam intensity upgrade of the ATLAS heavy-ion accelerator has been completed. Cavities have been fabricated using the lessons learned from the worldwide effort to extend the performance of niobium cavities close to the limits of the material. Key developments include the use of electropolishing on the completed cavity and with a temperature control system substantially upgraded from that for elliptical-cell EP systems. Wire EDM, used instead of traditional niobium machining, appears to be effective in eliminating performance limiting defects near the weld seams. Hydrogen degassing at 600C after electropolishing permits practical acceleration at 2 Kelvin with Bpeak>120 mT and cavity voltages>5 MV/cavity.  
 
MOPB077 Lorentz Force Detuning Compensation Studies for Long Pulses in ILC type SRF Cavities cavity, cryomodule, controls, 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.  
 
MOPB081 Travelling Wave Accelerating Structures with a Large Phase Advance acceleration, electron, impedance, proton 363
 
  • V.V. Paramonov
    RAS/INR, Moscow, Russia
 
  The electrons acceleration is considered in higher pass bands of TM01 wave for disk loaded waveguide, resulting in the possibility of traveling wave accelerating structures with an operating field phase advance between 180 – 1260 degrees per cell. With an appropriate shape optimization and some additional elements in cells proposed traveling wave structures have small transverse dimensions and high RF efficiency of standing wave operation. Examples of proposed structures together with RF and dispersion properties are presented.  
 
MOPB082 RF Parameters of the TE - Type Deflecting Structure for S-Band Frequency Range impedance, ion, multipole, heavy-ion 366
 
  • V.V. Paramonov, L.V. Kravchuk
    RAS/INR, Moscow, Russia
  • K. Flöttmann
    DESY, Hamburg, Germany
 
  Funding: in part RBFR N 12-02-0654-a
Effective compact deflecting structure* has been proposed for L-band frequency range preferably. RF parameters of this structure considered for S-band frequency range both for traveling and standing wave operation.
* -V. Paramonov, L. Kravchuk, INR, S. Korepanov. Effective Standing Wave RF Structure for Particle Beam Deflector. Proc. 2006 Linac Conference, p. 649
 
 
MOPB083 Operational experience with the FERMI@Elettra S-band RF System FEL, klystron, gun, LLRF 369
 
  • A. Fabris, P. Delgiusto, F. Gelmetti, M.M. Milloch, A. Milocco, F. Pribaz, C. Serpico, N. Sodomaco, R. Umer, L. Veljak
    ELETTRA, Basovizza, Italy
 
  FERMI@Elettra is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The machine is presently under commissioning and the first FEL line (FEL-1) will be opened to the users by the end of 2012. The 1.5 GeV linac is based on S-band technology. The S-band system is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, eighteen accelerating structures and the RF deflectors. The S-band system has been set into operation in different phases starting from the second half of 2009. This paper provides an overview of the performance of the system, discussing the achieved results, the strategies adopted to assure them and possible upgrade paths to increase the operability and safety margins of the system.  
 
MOPB086 The Nonresonant Perturbation Theory Based Field Measurement and Tuning of a Linac Accelerating Structure RF-structure, electromagnetic-fields, pick-up, feedback 375
 
  • W. Fang, Q. Gu, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  • D.C. Tong
    TUB, Beijing, People's Republic of China
 
  Assisted by the bead pull technique, the nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure. The method is capable of making non-touch measurement, amplitude and phase diagnostics, real time mismatch feedback and field tuning. Main considerations on measurement system and of C-band traveling-wave structure are described, the bead pull measurement and the tuning of the C-band traveling-wave linac accelerating structure are presented.  
 
MOPB087 S-Band Loads for SLAC Linac klystron, vacuum, plasma, insertion 378
 
  • A. Krasnykh, F.-J. Decker
    SLAC, Menlo Park, California, USA
  • R.W. LeClair
    INTA, Santa Clara, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515 and SBIR grant number DE-SC0007661
The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.
[1] “The Stanford Two-Mile Accelerator”, p. 376-381, R. B. Neal, General Editor, 1968, W. A. Benjamin, Inc., NY Amsterdam
 
 
MOPB088 Fabrication Tests for IMP 162.5 MHz RFQ rfq, vacuum, cavity, gun 381
 
  • B. Zhang
    IMP, Lanzhou, People's Republic of China
 
  The RFQ for one of front ends of C-ADS is designed. The frequency of the RFQ is 162.5 MHz and the energy is 2.1 MeV. The beam intensity is 15 mA and it works at CW mode. Because of low frequency, the four-wing structure is big size. It makes fabrication will take more risks. Therefore, four fabrication testing were planned and done to minimize the technic risks. The description about fabrication and testing results are presented in the paper.  
 
MOPB091 The Injector Cryomodule for the ARIEL e-Linac at TRIUMF cryomodule, cavity, TRIUMF, cryogenics 389
 
  • R.E. Laxdal, A. Koveshnikov, N. Muller, W.R. Rawnsley, G. Stanford, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
  • M. Ahammed, M. Mondrel
    VECC, Kolkata, India
 
  The ARIEL project at TRIUMF includes a 50 MeV-10 mA electron linear accelerator (e-Linac) using 1.3 GHz superconducting technology. The accelerator is divided into three cryomodules including a single cavity injector cryomodule (ICM) and two accelerating cryomodules with two cavities each. The ICM is being built first. The ICM utilizes a unique top-loading box vacuum vessel. The shape allows the addition of a 4 K/2 K cryogenic unit that accepts near atmospheric LHe and converts to 2 K liquid inside the cryomodule. The cryomodule design is complete and in fabrication. The 4 K/2 K cryogenic unit has been assembled and tested in a test cryostat. The paper will describe the design of the cryomodule and the results of the cryogenic tests.  
 
MOPB093 The Upgraded Argonne Wakefield Accelerator Facility (AWA): a Test-Bed for the Development of High Gradient Accelerating Structures and Wakefield Measurements wakefield, electron, gun, acceleration 392
 
  • M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof
    ANL, Argonne, USA
  • S.P. Antipov, C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • E.E. Wisniewski
    Illinois Institute of Technology, Chicago, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
Electron beam driven wakefield acceleration is a bona fide path to reach high gradient acceleration of electrons and positrons. With the goal of demonstrating the feasibility of this concept with realistic parameters, well beyond a proof-of-principle scenario, the AWA Facility is currently undergoing a major upgrade that will enable it to achieve accelerating gradients of hundreds of MV/m and energy gains on the order of 100 MeV per structure. A key aspect of the studies and experiments carried out at the AWA facility is the use of relatively short RF pulses (15 – 25 ns), which is believed to mitigate the risk of breakdown and structure damage. The upgraded facility will utilize long trains of high charge electron bunches to drive wakefields in the microwave range of frequencies (8 to 26 GHz), generating RF pulses with GW power levels.
 
 
MOPB094 Simulation Study on the Longitudinal Bunch Shape Measurement by RF Chopper at J-PARC Linac cavity, emittance, simulation, DTL 395
 
  • T. Maruta
    JAEA/J-PARC, Tokai-mura, Japan
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  A RF chopper is placed in the medium energy transport section (MEBT1) at J-PARC linac. The chopper is normally driven at synchronous phase of 0 degree to give a maximum deflection. The chopper has two RF gaps and both of them deflect a beam bunch horizontally while RF is on. In the MEBT1 section, while we have a transverse emittance monitor, there is no longitudinal monitor. It is hard to newly place a longitudinal beam monitor there due to space limitation. We conduct a simulation which studies on the usability of the chopper to a longitudinal beam monitor. When the synchronous phase of the chopper is ± 90 degree, the longitudinal beam profile is projected to horizontal beam distribution. In this presentation, we introduce simulation results.  
 
MOPB096 Beam Loss Mitigation in J-PARC Linac after the Tohoku Earthquake multipactoring, beam-losses, radiation, beam-transport 401
 
  • M. Ikegami, Z. Fang, K. Futatsukawa, T. Miyao
    KEK, Ibaraki, Japan
  • Y. Liu
    KEK/JAEA, Ibaraki-Ken, Japan
  • T. Maruta, A. Miura, J. Tamura, G.H. Wei
    JAEA/J-PARC, Tokai-mura, Japan
  • H. Sako
    JAEA, Ibaraki-ken, Japan
 
  The beam operation of J-PARC linac was interrupted by the Tohoku earthquake in March 2011. After significant effort for its restoration, we have resumed the beam operation of J-PARC linac in December 2011. After resumption of beam operation, we have been suffering from beam losses which were not observed before the earthquake. Tackling with the beam loss issues, we have been reached the comparable beam power for user operation to the one before the earthquake. In this paper, we present the experience in the beam start-up tuning after the earthquake with emphasis on the beam loss mitigation efforts.  
 
TU1A01 Status of the IFMIF-EVEDA 9 MeV 125 mA Deuteron Linac rfq, cavity, solenoid, SRF 407
 
  • A. Mosnier
    Fusion for Energy, Garching, Germany
 
  The scope of IFMIF/EVEDA has been recently revised to set priority on the validation activities, especially on the Accelerator Prototype (LIPAc) with extending the duration up to mid 2017 in order to better fit the development of the challenging components and the commissioning of the whole accelerator. The present status of LIPAc, currently under construction at Rokkasho in Japan, outlines of the engineering design and of the developments of the major components will be reported. In conclusion, the expected outcomes of the engineering work, associated with the experimental program will be presented.  
slides icon Slides TU1A01 [7.602 MB]  
 
TU1A03 Chinese ADS Project and Proton Accelerator Development proton, rfq, target, neutron 412
 
  • Y.L. Chi, S. Fu, W.M. Pan, P. Sha
    IHEP, Beijing, People's Republic of China
  • Q.Z. Xing
    TUB, Beijing, People's Republic of China
 
  Interest in the feasibility of ADS has increased dramatically in the last decade. This talk will briefly introduce the technologies presently available for ADS applications and provide a review of the ongoing R&D and construction activities in China, with particular emphasis on the challenges presented by the development of a high intensity, SRF CW proton Linac.  
slides icon Slides TU1A03 [3.803 MB]  
 
TU1A04 FRIB Accelerator Status and Challenges ion, cavity, cryomodule, target 417
 
  • J. Wei, E.C. Bernard, N.K. Bultman, F. Casagrande, S. Chouhan, C. Compton, K.D. Davidson, A. Facco, P.E. Gibson, T . Glasmacher, K. Holland, M.J. Johnson, S. Jones, D. Leitner, M. Leitner, G. Machicoane, F. Marti, D. Morris, J.P. Ozelis, S. Peng, J. Popielarski, L. Popielarski, E. Pozdeyev, T. Russo, K. Saito, R.C. Webber, M. Williams, Y. Yamazaki, A. Zeller, Y. Zhang, Q. Zhao
    FRIB, East Lansing, USA
  • D. Arenius, V. Ganni
    JLAB, Newport News, Virginia, USA
  • J.A. Nolen
    ANL, Argonne, 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) at MSU includes a driver linac that can accelerate all stable isotopes to energies beyond 200 MeV/u at beam powers up to 400 kW. The linac consists of 330 superconducting quarter- and half-wave resonators operating at 2 K temperature. Physical challenges include acceleration of multiple charge states of beams to meet beam-on-target requirements, efficient production and acceleration of intense heavy-ion beams from low to intermediate energies, accommodation of multiple charge stripping scenarios (liquid lithium, helium gas, and carbon foil) and ion species, designs for both baseline in-flight fragmentation and ISOL upgrade options, and design considerations of machine availability, tunability, reliability, maintainability, and upgradability. We report on the FRIB accelerator design and developments with emphasis on technical challenges and progress.
 
slides icon Slides TU1A04 [4.531 MB]  
 
TU1A05 Status and Commissioning Plan of the PEFP 100-MeV Linear Accelerator DTL, proton, klystron, site 422
 
  • H.-J. Kwon, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
    KAERI, Daejon, Republic of Korea
 
  Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government.
One of the goals of the Proton Engineering Frontier Project (PEFP) is to develop a 100 MeV proton linear accelerator, which consists of 50 keV proton injector, 3 MeV radio frequency quadrupole (RFQ), 20 MeV/100 MeV drift tube linac (DTL) and 20 MeV/100 MeV beam lines. The 100 MeV linear accelerator and beam line components have been installed in the tunnel and experimental hall. After the completion of the utility commissioning, the commissioning of the accelerator starts with a goal of the beam delivery to the 100 MeV target room located at the end of the beam line in 2012. In this paper, the status and commissioning plan of the PEFP 100 MeV linear accelerator are presented.
 
slides icon Slides TU1A05 [6.795 MB]  
 
TU2A03 LCLS Operation Experience and LCLS-II Design undulator, electron, photon, FEL 432
 
  • T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
 
  This talk will report the operations experience at LCLS and will describe the LCLS-II, a new X-ray FEL facility that uses the middle 1/3 of the SLAC linac as compared to the LCLS which uses the last 1/3 of the SLAC linac.  
slides icon Slides TU2A03 [4.761 MB]  
 
TU2A04 High Current ERL at BNL electron, gun, SRF, cavity 437
 
  • I. Ben-Zvi
    BNL, Upton, Long Island, New York, USA
 
  The electron hadron collider eRHIC will collide polarized and unpolarized electrons with a current of 50 mA and energy in the range of 5 GeV to 30 GeV with hadron beams, including heavy ions or polarized light ions of the RHIC storage ring. The electron beam will be generated in an energy recovery linac contained inside the RHIC tunnel, comprising six passes through two linac section of about 2.5 GeV each. The electron ERL poses many challenges in term of a high-current high-polarization electron gun, HOM damping in the linac, crab cavities, harmonic cavities and beam stability.  
slides icon Slides TU2A04 [2.227 MB]  
 
TUPLB01 The Swiss FEL RF Gun: RF Design and Thermal Analysis gun, coupling, electron, cathode 442
 
  • J.-Y. Raguin, M. Bopp, A. Citterio, A. Scherer
    PSI, Villigen, Switzerland
 
  We report here on the design of a dual-feed S-band 2.5 cell RF gun, developed in the framework of SwissFEL, capable of operating at 100 Hz repetition rate. As in the LCLS RF gun, z-coupling, to reduce the pulsed surface heating, and a racetrack coupling cell shape, to minimize the quadrupolar component of the fields, have been adopted. The cell lengths and the iris thicknesses are as in the PHIN gun operating at CERN. However the irises aperture has been enlarged to obtain a frequency separation between the operating π mode and the π/2 mode higher than 15 MHz. An amplitude modulation scheme of the RF power, which allows one to obtain a flat plateau of 150 ns for multibunch operation and a reduced average power is presented as well. With an RF pulse duration of 1μs it is shown that operation at 100 MV/m and 100 Hz repetition rate is feasible with very reasonable thermal stresses.  
slides icon Slides TUPLB01 [1.679 MB]  
 
TUPLB05 Computational Model Analysis for Experimental Observation of Optical Current Noise Suppression below the Shot-Noise Limit plasma, electron, simulation, beam-transport 451
 
  • A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
  • A. Nause
    University of Tel Aviv, Tel Aviv, Israel
 
  Funding: We acknowledge support of the Israel Science Foundation grant
We report first demonstration of optical frequency current shot-noise suppression in a relativistic e-beam. This process is made possible by collective Coulomb interaction between the electrons of a cold intense beam during beam drift, and is essentially a process of longitudinal beam-plasma oscillation [1]. Suppression of beam current noise below the classical “shot-noise” level has been known in the microwave tubes art [2]. This is the first time that it is demonstrated in the optical regime. We predict that the scheme can be extended to the XUV and possibly to shorter wavelengths with further development of technology. The fundamental current shot-noise determines the level of incoherent spontaneous radiation emission from electron-beam optical radiation sources and SASE-FELs [3]. Suppressing shot-noise would make it possible to attain spontaneous emission sub-radiance [4] and surpass the classical coherence limits of seed-injected FELs. The effect was demonstrated by measuring sub-linear growth as a function of current of the OTR Radiation. This finding indicates that the beam charge homogenizes due to the collective interaction, and its distribution becomes sub-Poissonian.
[1] A. Gover, E. Dyunin, PRL, 102, 154801, 2009
[2] H. Haus, N. Robinson, Proc. IRE, 43, 981 (1955)
[3] P. Emma, et al , Nature Photonics 4, 641 (2010)
[4] A. Dicke, Phys. Rev. 93, 99 (1954)
 
 
TUPLB06 Status of the Rare Isotope Science Project in Korea ISOL, ion, cyclotron, target 455
 
  • J.-W. Kim
    IBS, Daejeon, Republic of Korea
 
  Funding: National Research Foundation of Korea
A heavy-ion accelerator facility is being designed in Korea for the production of rare isotope beams under the name of rare isotope science project (RISP). The project is funded and officially started in Jan. 2012. The accelerator complex is composed of three main accelerators: a superconducting linac to use in-flight fragmentation (IF) method in generating isotope beams, a 70 kW proton cyclotron for the ISOL method, and a superconducting post accelerator for re-acceleration of rare isotope beams to the energy range of 18 MeV/u. The minimum energy of a U beam required for the IF driver is 200 MeV/u at the beam power of 400 kW. The beam current of U ions in high charge states is limited by the performance of existing ECR ion sources. This facility will be unique in the aspect that state-of-art accelerators are facilitated for both the IF and ISOL drivers and combined to produce extreme exotic beams. Also, standalone operation of each accelerator will allow us to accommodate diverse users from beam application fields as well as nuclear physics. The current status of the design efforts will be presented.
 
slides icon Slides TUPLB06 [1.901 MB]  
 
TUPLB09 Design and Beam Test of Six-electrode BPMs for Second-order Moment Measurement factory, electron, multipole, storage-ring 464
 
  • K. Yanagida, H. Hanaki, S. Suzuki
    JASRI/SPring-8, Hyogo-ken, Japan
 
  In the SPring-8 linac, four-electrode beam position monitors (BPMs) have been utilized for the measurement of the transverse first-order moments, which correspond to the centroids of beam charge distributions. We have planed to measure the transverse second-order moments of beams to obtain information of beam optics and its energy deviations during the top-up beam injection without destruction of beams. Therefore, six-electrode BPMs with circular and quasi-ellipse cross-sections have been developed on the basis of a newly introduced theory. A low-noise signal processor for the six-electrode BPM has also been developed to perform fine measurement. We expected the following resolutions determined by the S/N ratio of the circuit; the first order moments (beam positions) > 1 μm, and the second order moments with a size > 110 μm. The first beam test was carried out using the six-electrode BPM with circular cross-section and the old signal processor. The measured sensitivities and resolutions of the second-order moments showed good agreement with the theory.  
slides icon Slides TUPLB09 [8.248 MB]  
 
TUPB005 Computational Model Analysis for Experimental Observation of Optical Current Noise Suppression Below the Shot-noise Limit plasma, electron, simulation, beam-transport 482
 
  • A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
  • A. Nause
    University of Tel Aviv, Tel Aviv, Israel
 
  Funding: We acknowledge support of the Israel Science Foundation grant
We report first demonstration of optical frequency current shot-noise suppression in a relativistic e-beam. This process is made possible by collective Coulomb interaction between the electrons of a cold intense beam during beam drift, and is essentially a process of longitudinal beam-plasma oscillation.[1] Suppression of beam current noise below the classical “shot-noise” level has been known in the microwave tubes art [2]. This is the first time that it is demonstrated in the optical regime. We predict that the scheme can be extended to the XUV and possibly to shorter wavelengths with further development of technology. The fundamental current shot-noise determines the level of incoherent spontaneous radiation emission from electron-beam optical radiation sources and SASE-FELs [3]. Suppressing shot-noise would make it possible to attain spontaneous emission sub-radiance [4] and surpass the classical coherence limits of seed-injected FELs. The effect was demonstrated by measuring sub-linear growth as a function of current of the OTR Radiation. This finding indicates that the beam charge homogenizes due to the collective interaction, and its distribution becomes sub-Poissonian.
[1] A. Gover, E. Dyunin, PRL, 102, 154801, 2009
[2] H. Haus, N. Robinson, Proc. IRE, 43, 981 (1955)
[3] P. Emma, et al , Nature Photonics 4, 641 (2010)
[4] A. Dicke, Phys. Rev. 93, 99 (1954)
 
 
TUPB008 Major Trends in Linac Design for X-ray FELs electron, FEL, cathode, emittance 489
 
  • A. Zholents
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-06CH11357.
Major trends in the contemporary linac designs for x-ray free-electron lasers (XFELs) are outlined starting with identification of the key performance parameters, continuing with considerations of the design options for the electron gun and linac, and finishing with electron beam manipulation in the phase space.
 
 
TUPB009 C-Band Accelerating Structure Development and Tests for the SwissFEL impedance, controls, klystron, FEL 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.  
 
TUPB010 The Swiss FEL RF Gun: RF Design and Thermal Analysis gun, coupling, electron, cathode 495
 
  • J.-Y. Raguin, M. Bopp, A. Citterio, A. Scherer
    PSI, Villigen, Switzerland
 
  We report here on the design of a dual-feed S-band 2.5 cell RF gun, developed in the framework of SwissFEL, capable of operating at 100 Hz repetition rate. As in the LCLS RF gun, z-coupling, to reduce the pulsed surface heating, and a racetrack coupling cell shape, to minimize the quadrupolar component of the fields, have been adopted. The cell lengths and the iris thicknesses are as in the PHIN gun operating at CERN. However the irises aperture has been enlarged to obtain a frequency separation between the operating π mode and the π/2 mode higher than 15 MHz. An amplitude modulation scheme of the RF power, which allows one to obtain a flat plateau of 150 ns for multibunch operation and a reduced average power is presented as well. With an RF pulse duration of 1μs it is shown that operation at 100 MV/m and 100 Hz repetition rate is feasible with very reasonable thermal stresses.  
 
TUPB011 The Swiss FEL S-Band Accelerating Structure: RF Design accelerating-gradient, gun, FEL, impedance 498
 
  • J.-Y. Raguin
    PSI, Villigen, Switzerland
 
  The Swiss FEL accelerator concept consists of a 450 MeV S-band injector Linac at 2998.8 GHz followed by the main linac at the C-band frequency aiming at a final energy of 5.8 GeV. The injector has six four-meter long S-band accelerating structures that shall operate with gradients up to 20 MV/m and with a 100 Hz repetition rate. Each structure has 122 cells, including the two coupler cells and operates with a 2π/3 phase advance. The design presented is such that the average dissipated RF power is constant over the whole length of the structure. The cells consist of cups and the cell irises have an elliptical profile to minimize the peak surface electric field. The coupler cells are of the double-feed type with a racetrack cross-section to cancel the dipolar components of the fields and to minimize its quadrupolar components.  
 
TUPB012 The Swiss FEL C-Band Accelerating Structure: RF Design and Thermal Analysis accelerating-gradient, klystron, FEL, impedance 501
 
  • J.-Y. Raguin, M. Bopp
    PSI, Villigen, Switzerland
 
  The Swiss FEL accelerator concept consists of a 450 MeV S-band injector linac followed by the main linac in C-band aiming at a final energy of 5.8 GeV. The two-meter long C-band accelerating structures have 113 cells, including the two coupler cells, and operate with a 2π/3 phase advance. The structure is of the constant-gradient type with rounded wall cells and has an average iris radius of 6.44 mm, a radius compatible with the impact of the short-range wakefields on the whole linac beam dynamics. The cell irises have an elliptical profile to minimize the peak surface electric fields and the coupler cells are of the J-type. We report here on the RF design of the structure, as well as on its thermal analysis, to target operational conditions with an accelerating gradient of about 28 MV/m and a repetition rate of 100 Hz.  
 
TUPB014 Comparative Design of Single Pass, Photo-cathode RF-LINAC FEL for the THz Frequency Range: Self Amplification vs. Enhanced Super-radiance FEL, radiation, electron, wiggler 507
 
  • Yu. Lurie, Y. Pinhasi
    Ariel University Center of Samaria, Faculty of Engineering, Ariel, Israel
 
  Self amplified spontaneous emission and enhanced super-radiance are discussed and compared as possible configurations in the construction of a single-pass, photo-cathode RF-LINAC FEL source for THz radiation, being developed in Ariel University Center of Samaria. Numerical simulations carried out using 3D, space-frequency approach demonstrate the charge squared dependence of the radiation power in both cases, the characteristic typical to super-radiant emission. The comparison reveals a high efficiency of an enhanced super-radiance FEL, which however can only be achieved with ultra-short (the radiation wavelength long or shorter) drive electron beam bunches at a proper energy chirping.  
 
TUPB015 Warm Beamlines and Infrastructure in the European XFEL shielding, diagnostics, radiation, klystron 510
 
  • M. Hüning
    DESY, Hamburg, Germany
 
  The European XFEL is driven by a superconducting linear accelerator. In the main accelerator tunnel the accelerator modules will be suspended from the tunnel ceiling. The warm sections like bunch compressors will be installed on girders supported from the floor. The accelerator infrastructure like klystrons and electronic racks will be installed in the accelerator tunnel in close proximity to the electron beamline.  
 
TUPB018 Study of Beam-Based Alignment for Shanghai Soft X-Ray FEL Facility simulation, emittance, alignment, FEL 513
 
  • D. Gu, Q. Gu, D. Huang, M. Zhang, M.H. Zhao
    SINAP, Shanghai, People's Republic of China
 
  In linear accelerators, dispersion caused by quadrupole misalignment and transverse wake-field effect caused by alignment errors of accelerate structures will lead to a significant emittance growth. There are more stringent restrictions on SXFEL, the traditional optical alignment can no longer meet its requirements, but the Beam-Based Alignment(BBA) method allows more precise alignment, further reduce the Linac errors to meet SXFEL requirements .In undulator sections, orbit changes are not only caused by misalignments of quadrupole magnet position ,but also the errors of undulator magnetic. In order to achieve alignment accuracy over longer distance, we measuring BPM data under different conditions and using SVD algorithm for calculation and analysis, we can get the quadrupole magnet errors and BPM offset. With the method above, software based on MATLAB has been designed and compared the results with other software.  
 
TUPB021 Study of Plasma Effect in Longitudinal Space Charge Induced Microbunching Instability plasma, electron, impedance, space-charge 522
 
  • D. Huang, Q. Gu
    SINAP, Shanghai, People's Republic of China
  • K.Y. Ng
    Fermilab, Batavia, USA
 
  The longitudinal space charge (LSC) plays an important role in introducing the microbunching instability in the LINAC of a free electron laser (FEL) facility. The current model of LSC impedance [1] derived from the fundamental electromagnetic theory [2] is widely used to explain the growth of the microbunching instability [3]. However, in the case of highly bright relativistic electron beams, the plasma effect starts to play a role. In this article, the basic model of LSC impedance including the plasma effect is built , and the modifications to the microbunching instability based on the new model are discussed in various conditions.
[1] Marco Venturini, Phys Rev. ST Accel. Beams 11, 034401 (2008)
[2] J. D. Jackson, Classical Electrodynamics (Wiley, 1999)
[3] Z. Huang, et. al., Phys, Rev. ST Accel. Beams 7, 074401 (2004)
 
 
TUPB022 A Passive Linearizer for Bunch Compression FEL, electron, laser, emittance 525
 
  • Q. Gu, M. Zhang, M.H. Zhao
    SINAP, Shanghai, People's Republic of China
 
  In high gain free electron laser (FEL) facility design and operation, a high bunch current is required to get lasing with a reasonable gain length. Because of the current limitation of the electron source due to the space charge effect, a compression system is commonly used to compress the electron beam to the exact current needed. Before the bunch compression, the nonlinear energy spread due to the finite bunch length should be compensated; otherwise the longitudinal profile of bunch will be badly distorted. Usually an X band accelerating structure is used to compensate the nonlinear energy spread while decelerating the beam. For UV FEL facility, the X band system is too expensive comparing to the whole facility. In this paper, we present a corrugated structure as a passive linearizer, and the preliminary study of the beam dynamics is also shown.  
 
TUPB026 Measurements of a Reduced Energy Spread of a Recirculating Linac by Non-isochronous Beam Dynamics recirculation, electron, synchrotron, acceleration 531
 
  • F. Hug, C. Burandt, M. Konrad, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • R. Eichhorn
    Cornell University, Ithaca, New York, USA
 
  Funding: supported by DFG through SFB 634
The Superconducting Linear Accelerator S-DALINAC at the University of Darmstadt (Germany) is a recirculating linac with two recirculations providing beams for measurements in nuclear physics at small momentum transfers. For these experiments an energy spread of better than 10-4 (rms) is needed. Currently acceleration in the linac section is done on crest of the accelerating field. The recirculation path is operated achromatic and isochronous. In this recirculation scheme the energy spread of the resulting beam in the ideal case is determined by the electron bunch length. Taking into account the stability of the RF system the energy spread increases drastically to more than 10-3 (rms). We will present a new non-isochronous recirculation scheme which helps cancelling out these errors from the rf-control. This scheme uses longitudinal dispersion in the recirculation paths and an acceleration off-crest with a certain phase with respect to the maximum. We will present results of the commissioning of the new system including measurements of the longitudinal dispersion in the recirculation arcs as well as measurements of the resulting energy spread using an electron spectrometer.
 
 
TUPB028 Status of the Rare Isotope Science Project in Korea ISOL, ion, cyclotron, target 534
 
  • J.-W. Kim
    IBS, Daejeon, Republic of Korea
 
  Funding: National Research Foundation of Korea
A heavy-ion accelerator facility is being designed in Korea for the production of rare isotope beams under the name of rare isotope science project (RISP). The project is funded and officially started in Jan. 2012. The accelerator complex is composed of three main accelerators: a superconducting linac to use in-flight fragmentation (IF) method in generating isotope beams, a 70 kW proton cyclotron for the ISOL method, and a superconducting post accelerator for re-acceleration of rare isotope beams to the energy range of 18 MeV/u. The minimum energy of a U beam required for the IF driver is 200 MeV/u at the beam power of 400 kW. The beam current of U ions in high charge states is limited by the performance of existing ECR ion sources. This facility will be unique in the aspect that state-of-art accelerators are facilitated for both the IF and ISOL drivers and combined to produce extreme exotic beams. Also, standalone operation of each accelerator will allow us to accommodate diverse users from beam application fields as well as nuclear physics. The current status of the design efforts will be presented.
 
 
TUPB029 Beam Intensity and Energy Control for the SPIRAL2 Facility pick-up, controls, 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.  
 
TUPB030 Overview of the Superconducting Linacs of the Rare Isotope Science Project cryomodule, ion, diagnostics, heavy-ion 540
 
  • D. Jeon, C. Choi, J.D. Joo, H.C. Jung, H.J. Kim, H.J. Kim, S.K. Kim, Y.H. Kim, J.H. Lee, G.-T. Park, J. Song
    IBS, Daejeon, Republic of Korea
  • Y.Y. Lee
    KAERI, Daejon, Republic of Korea
 
  The Rare Isotope Science Project is launched in Korea to build a IF and ISOL facilities. The IF driver superconducting linac is to accelerate ion beams up to 200 MeV/u for U beam and 600 MeV for proton beam. The ISOL post linac is a superconducting linac to accelerate up to 18 MeV/u for U beam. General layout of SC linac is discussed.  
 
TUPB031 Beam Envelope Analysis and Simulation ion, simulation, emittance, controls 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.  
 
TUPB032 Beam Dynamics of the Linac ALPI-PIAVE in View of Possible Upgrades Scenario for the SPES Project. rfq, emittance, ion, injection 546
 
  • M. Comunian, C. Roncolato
    INFN/LNL, Legnaro (PD), Italy
  • B.B. Chalykh
    ITEP, Moscow, Russia
 
  At the Legnaro National Laboratories it is operating a Super Conducting linac for nuclear studies named ALPI. The ALPI linac is injected either by a XTU tandem, up to 14 MV, or by the s-c PIAVE injector, made with 2 SC-RFQ. In this article will be report the beam dynamics simulations for some possible scenario upgrade of the linac operate by a new injector, made with a new RFQ.  
 
TUPB033 Piezoelectric Actuator Based Phase Locking System for IUAC Linac controls, 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.  
 
TUPB035 A New Design of the RFQ Channel for GSI HITRAP Facility rfq, simulation, ion, DTL 555
 
  • S.G. Yaramyshev, W.A. Barth, G. Clemente, L.A. Dahl, V. Gettmann, F. Herfurth, M. Kaiser, M.T. Maier, D. Neidherr, A. Orzhekhovskaya, H. Vormann, G. Vorobjev
    GSI, Darmstadt, Germany
  • R. Repnow
    MPI-K, Heidelberg, Germany
 
  The HITRAP linac at GSI is designed to decelerate ions with mass to charge ratio of A/Z<3 from 4 MeV/u to 6 keV/u for experiments with ion traps. The particles are decelerated to 500 keV/u with an IH-DTL stucture and finally to 6 keV/u with a 4-rod RFQ. During commissioning stage the deceleration to approx. 500 keV/u was successfully demonstrated, while no particles behind the RFQ with an energy of 6 keV/u were observed. Dedicated simulations with DYNAMION code, based on 3D-fotometrie of the fabricated RFQ electrodes were successfully performed comprehending the commissioning results. In a second step the simulations have been experimentally confirmed at a test-stand (MPI, Heidelberg). An input energy, accepted by the RFQ channel is significantly higher than design value. For this reason the longitudinal beam emittance after deceleration with IH structure does not fit to the longitudinal RFQ acceptance. To solve this problem a new design of the RFQ channel with a correct input energy has been started. New RFQ parameters and the results of the beam dynamics simulations are presented in this paper.  
 
TUPB036 Design of Re-Buncher Cavity for Heavy-ion LINAC in IMP cavity, DTL, simulation, impedance 558
 
  • L.P. Sun, X. Du, Y. He, A. Shi, C. Zhang, Z.L. Zhang
    IMP, Lanzhou, People's Republic of China
 
  A re-buncher with spiral arms for a heavy ion linear accelerator named as SSC-LNAC at HIRFL (the heavy ion research facility of Lanzhou) has been constructed. The re-buncher, which is used for beam longitudinal modulation and match between the RFQ and DTL, is designed to be operated in continuous wave (CW) mode at the Medium-Energy Beam-Transport (MEBT) line to maintain the beam intensity and quality. Because of the longitudinal space limitation, the re-buncher has to be very compact and will be built with four gaps. We determined the key parameters of the re-buncher cavity from the simulations using Microwave Studio software, such as the resonant frequency, the quality factor Q and the shunt impedance. The detailed design of a 53.667 MHz spiral cavity and measurement results of its prototype will be presented.  
 
TUPB039 Conceptual Design of Superconducting Heavy Ion Linear Injector for HIAF cryomodule, ion, solenoid, cavity 561
 
  • Z.J. Wang, Y. He, H. Jia, C. Li, S.H. Liu, W. Wu, X.B. Xu, B. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  A heavy ion accelerator facility, High Intensity Heavy Ion Accelerator Facility (HIAF), has been promoted by Institute of Modern Physics (IMP)of Chinese Academy of Sciences (CAS). The injector of the accelerator facility is a superconducting linac. It is a high intensity heavy ion linac and works on pulse mode. The final energy is 150 MeV/u. The accelerated species are from P to Uranium. The linac works with both laser and ECR ion source. The designed current is 20 emA. The general concept of HIAF and the preliminary design of linear injector are presented in the paper.  
 
TUPB040 Status of the Linac SRF Acquisition for FRIB cryomodule, cavity, SRF, status 564
 
  • M. Leitner, E.C. Bernard, J. Binkowski, B. Bird, S. Bricker, S. Chouhan, C. Compton, K. Elliott, B. Enkhbat, A.D. Fox, L.L. Harle, M. Hodek, M.J. Johnson, I.M. Malloch, D. R. Miller, S.J. Miller, T. Nellis, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, K. Saito, M. Shuptar, G.J. Velianoff, J. Wei, M. Williams, K. Witgen, Y. Xu, Y. Yamazaki, Y. Zhang
    FRIB, East Lansing, USA
  • A. Facco
    INFN/LNL, Legnaro (PD), Italy
 
  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 a high-intensity, superconducting heavy-ion driver linac to provide stable ion beams from protons to uranium up to energies of >200 MeV/u and at a beam power of up to 400 kW. The ions are accelerated to about 0.5 MeV/u using a room-temperature 80.5 MHz RFQ and injected into a superconducting cw linac consisting of 330 individual low-beta cavities in 49 cryomodules operating at 2 K. This paper discusses the current status of the linac SRF acquisition strategy as the project phases into construction mode.
 
 
TUPB041 Scattering of  H Stripped Electrons  from SEM Grids and Wire Scanners at the CERN LINAC4 electron, simulation, scattering, polarization 567
 
  • F. Roncarolo, E. Chevallay, M. Duraffourg, G.J. Focker, C. Heßler, U. Raich, VC. Vuitton, F. Zocca
    CERN, Geneva, Switzerland
  • B. Cheymol
    ESS, Lund, Sweden
 
  At the CERN LINAC4, wire grids and scanners will be used to characterize the H beam transverse profile at different stages along the acceleration to 160 MeV. The wire signal will be determined by the balance between secondary emission and number of charges stopped in the wire, which will depend on the wire material and diameter, the possible choice of biasing (DC) the wires and the beam energy. The outermost electrons of H ions impinging on a wire are stripped in the first nanometers of material. A portion of such electrons are scattered away from the wire and can reach the neighboring wires.  In addition, scattered electrons hitting the surrounding beam pipe generate secondary electrons that can also perturb the measurement. Monte Carlo simulations, analytical calculations and a laboratory experiment allowed quantifying the amount of scattering and the scattered particles distributions. The experiment was based on 70 keV electrons, well reproducing the case of 128 MeV H ions. For all the LINAC4 simulated cases the predicted effect on the beam size reconstruction results in a relative error of less than 5%.  
 
TUPB042 Progress on RFQIII Fabrication in J-PARC Linac rfq, vacuum, cavity, alignment 570
 
  • T. Morishita
    JAEA/LINAC, Ibaraki-ken, Japan
  • K. Hasegawa, Y. Kondo
    JAEA, Ibaraki-ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
 
  The J-PARC accelerator comprises an injector linac, a 3 GeV Rapid-Cycling Synchrotron and a 50 GeV Main Ring. The J-PARC linac has been operating for users with the beam energy of 181 MeV. The energy (to 400 MeV) and current (to 50 mA) upgrade of the linac is scheduled for 1MW operation at RCS. For the current upgrade, the fabrication of a new RFQ, which is designed for 50 mA acceleration, has been started. The engineering design and the fabrication technologies were carefully chosen to reduce the discharge risk during the operation. For good vacuum pumping, vanes and ports are brazed for the direct pumping through slits at the tuners. Also, we tried a chemical polishing to improve the smoothness of the vane surface. In this paper, we present the fabrication progress of a new RFQ in J-PARC linac.  
 
TUPB043 One Design of Heavy Ion Linac Injector for CSRm ion, heavy-ion, emittance, acceleration 573
 
  • X.H. Zhang, J.W. Xia, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
 
  The design of heavy ion linac as one new injector of the main Cooling Storage Ring (CSRm) has been discussed. The linac design is based on interdigital H mode drift tube with KONUS (Kombinierte Null Grad Struktur). A high acceleration rate with zero degree synchronous particle phase acceleration reduce the length of IH-KONUS linac and the cost in comparison with conventional linac based on Alvarez structure. To reduce the effect of emittance growth, the RFQ structure is used in front of the IH-KONUS linac. In this linac, the design particle 238U28+ will be accelerated to 7 AMeV, and the transmission of Uranium beam can reach up to 80%. In this report, the initial physics design of the main linac is presented.  
 
TUPB047 Status of the Superconducting RF Activities for the HIE ISOLDE Project cavity, factory, niobium, SRF 582
 
  • W. Venturini Delsolaro, L. Alberty Vieira, S. Calatroni, O. Capatina, A. D'Elia, B. Delaup, M.A. Fraser, N.M. Jecklin, Y. Kadi, P. Maesen, I. Mondino, E. Montesinos, M. Therasse, D. Valuch
    CERN, Geneva, Switzerland
 
  The planned upgrade of the REX ISOLDE facility at CERN will boost the energy of the machine from 3 MeV/u up to 10 MeV/u with beams of mass-to-charge ratio 2.5 < A/q < 4. For this purpose, a new superconducting post accelerator based on independently phased 101.28 MHz Quarter Wave Resonators (QWR) will replace part of the normal conducting Linac. The QWRs make use of the Niobium sputtering on Copper technology which was successfully applied to LEP2, LHC and to the energy upgrade of the ALPI Linac at INFN-LNL. The status of advancement of the project will be detailed, limited to the SRF activities.  
 
TUPB048 Discussion of the Optimisation of a Linac Lattice to Minimise Disruption by a Class of Parasitic Modes cavity, coupling, simulation, lattice 585
 
  • S. Molloy
    ESS, Lund, Sweden
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
 
  It is well known that each resonant mode in the RF spectrum of multi-cell accelerating cavities will split into a passband containing a number of modes, and that the coupling of these modes to the beam is dependent on the velocity of the accelerated particles. If these modes are found to degrade the quality of the beam, it is possible to take various measures to damp them, and thus keep their effect below some critical threshold. In the case of the parasitic modes within the same passband as the fundamental accelerating mode, their frequency is typically too close to that of the fundamental to allow their power to be safely extracted, and so cavity designers must rely on the natural damping of the cavity itself. This note contains a theoretical discussion of the coupling of the beam to these passband modes for a large class of accelerating cavities, and provides a mathematical model for use during the design and optimisation of linacs.  
 
TUPB049 Superconducting Low Beta Niobium Resonator for Heavy Ions niobium, ion, DTL, heavy-ion 588
 
  • P.N. Prakash, K.K. Mistri, A. Roy, J. Sacharias, S.S. Sonti
    IUAC, New Delhi, India
 
  For the high current injector at Inter-University Accelerator Centre, a new superconducting niobium resonator optimized for β = 0.05 operating at 97 MHz, has been designed and fabricated. This resonator has the highest frequency in its class among the superconducting structures designed for such low velocity particles. The resonator has been carefully modeled using Microwave Studio code to minimize the peak magnetic field in order to achieve high accelerating gradients in it. Even though the resonance frequency is high, the physical dimensions of the resonator are large enough to allow processing of its superconducting surface effectively. The mechanical design of the resonator has been modeled using ANSYS multiphysics to increase the frequency of the lowest mechanical eigenmode of the central co-axial line, and also reduce liquid helium induced pressure fluctuations in the resonator. Bead pull measurements have been performed on the niobium resonator and they match with the design values very well. Cold tests at 4.2 K will be performed in the next few weeks. This paper will briefly present the design of the low beta resonator and details of the results from the cold tests.  
 
TUPB052 Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices cavity, simulation, proton, lattice 591
 
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
  • S. Molloy
    ESS, Lund, Sweden
 
  The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.  
 
TUPB053 Main Coupler Design for Project X vacuum, cavity, radiation, cryomodule 594
 
  • S. Kazakov, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, V. Poloubotko, O. Pronitchev, V.P. Yakovlev
    Fermilab, Batavia, USA
  • M.S. Champion
    ORNL, Oak Ridge, Tennessee, USA
 
  A multi-megawatt proton/H source, Project X, is under development at Fermi National Accelerator Laboratory. Main element of it is a 3 GeV superconducting proton linac which includes 5 families of superconducting cavities of three frequencies: 162.5, 325 and 650 MHz. Scope of this paper is the development of power couplers for 325 and 650 MHz at FNAL. Upgraded version of the accelerator will require two types of couplers, which reliably can operate at CW power level ~25 kW at 325 MHz and ~100 kW at 650 MHz respectively. In this paper we are describing the current design of these devices.  
 
TUPB054 Coherent Effects of High Current Beam in Project-X Linac HOM, cavity, emittance, cryogenics 597
 
  • A.I. Sukhanov, I.V. Gonin, T.N. Khabiboulline, A. Lunin, A. Saini, N. Solyak, A. Vostrikov, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Resonance excitation of longitudinal high order modes in superconducting RF structures of Project X CW linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical (ADS) systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of linac, which is more suitable for high current operation.  
 
TUPB055 R&D of IMP Superconducting HWR for China ADS cavity, simulation, niobium, proton 600
 
  • W.M. Yue, X.L. Guo, S. He, Y. He, R.X. Wang, P.R. Xiong, M.X. Xu, B. Zhang, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  The R&D program of IMP superconducting HWR is based on the China ADS, The aim is to build and test a HWR prototype on December 2012. We have designed a 162.5 MHz β=0.09 half-wave resonator (HWR), and a copper HWR has been fabricated in January 2012. The fabrication of a Nb HWR will be completed by September 2012, and the fabrication of a slow tuner and a high power coupler for this HWR will be completed then. In this poster, we present the HWR electromagnetic design, mechanical design, fabrication arts, copper HWR RF test result, the design of the slow tuner and the power coupler.  
 
TUPB062 Longitudinal Dynamic Analysis for the Project X 3-8 GeV Pulsed Linac cavity, controls, 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.  
 
TUPB067 Development of a Superconducting Half-Wave Resonator for PXIE cavity, simulation, cryomodule, niobium 624
 
  • Z.A. Conway, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov, K.W. Shepard
    ANL, Argonne, USA
  • I.V. Gonin, A. Lunin, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under contract DE-AC02-76CH03000 and DE-AC02-06CH11357
An ambitious upgrade to the FNAL accelerator complex is progressing in the Project-X Injector Experiment (PXIE). The PXIE accelerator requires 8 superconducting half-wave resonators optimized for the acceleration of 1 mA β = 0.11 H ion beams. Here we present the status of the half-wave resonator development, focusing particularly on cavity design, with a brief update on prototype fabrication.
 
 
TUPB069 BEAMDULAC-SCL Code for Complex Approach of Beam Dynamic Investigation in SC LINAC ion, simulation, focusing, solenoid 630
 
  • A.V. Samoshin
    MEPhI, Moscow, Russia
 
  Periodic sequences of independently phased accelerating cavities and focusing solenoids are used in MeV and GeV energy range linacs. The beam dynamic investigation is difficult for such superconducting linear accelerator. The matrix calculation was preferably used for primary choused of accelerating structure parameters. This method does not allows properly investigate the longitudinal motion. The smooth approximation can be used to investigate the nonlinear ion beam dynamics in such accelerating structure and to calculate longitudinal and transverse acceptances. The potential function and the equation of motion in the Hamilton form are devised by the smooth approximation. The advantages and disadvantages of each method will describe, the results of investigation will compare. The user friendly software BEAMDULAC-SCL for ion beam dynamic analysis was created. A numerical simulation of beam dynamics in the real field are carried out for the different variants of the accelerator structure based on previously analytically obtained results.  
 
TUPB070 Development of Proton Therapy at the SC Linac with BEAMDULAC-SCL Code focusing, solenoid, proton, acceleration 633
 
  • A.V. Samoshin, S.M. Polozov
    MEPhI, Moscow, Russia
 
  Proton cancer therapy complexes are conventionally developing based on synchrotrons and cyclotrons. High electrical power consumption and especial devices necessary to energy variation (as slow extraction systems and degraders) are the main problems of such complexes. At once SC linacs based on short independently phased quarter and half wave cavities have a serious progress at present. Linear accelerator consumes less power comparably with cyclic and the energy variation can be easily realized by means of RF field amplitude and phase variation in a number of cavities. The accelerator’s modular configuration which is now widely used in FRIBs * or SNSs can be applied for therapy linac also (see for example **). It is possible to choose the SC linac parameters and proton and ion beams stability study with help of the BEAMDULAC-SCL code. This software also allows providing of the structure optimization and the beam dynamics control.
* P.N. Ostroumov and et al., Proc. of PAC2001, p.4080.
** C.Ronsivalle et al. Proc. of IPAC 2011, p. 3580.
 
 
TUPB071 First Measurements on the 325 MHz Superconducting CH Cavity cavity, simulation, controls, 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.
 
 
TUPB072 Status of the Superconducting CW Demonstrator for GSI cavity, simulation, solenoid, cryogenics 639
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
 
  Funding: Helmholtz Institut Mainz (HIM), GSI, BMBF Contr. No. 06FY7102
Since the existing UNILAC at GSI will be used as an injector for the FAIR facility a new superconducting (sc) continous wave (cw) LINAC is highly requested by a broad community of future users to fulfil the requirements of nuclear chemistry, especially in the research field of Super Heavy Elements (SHE). This LINAC is under design in collaboration with the Institute for Applied Physics (IAP) of Frankfurt University, GSI and the Helmholtz Institut Mainz (HIM). It will consist of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz which provide an energy up to 7.3 AMeV. Currently, a prototype of the cw LINAC is under development. This demonstrator comprises the first sc CH cavity of the LINAC embedded between two sc solenoids mounted in a horizontal cryomodule. One important milestone of the project will be a full performance test of the demonstrator by injecting and accelerating a beam from the GSI High Charge State Injector (HLI) in 2014. The status of the demonstrator is presented.
 
 
TUPB074 Superconducting CW Heavy Ion Linac at GSI ion, heavy-ion, cavity, solenoid 645
 
  • W.A. Barth, V. Gettmann, S. Mickat
    GSI, Darmstadt, Germany
  • W.A. Barth, P. Gerhard
    HIM, Mainz, Germany
 
  Funding: Helmholtz Institute Mainz (HIM)
An upgrade program has to be realized in the next years, such that enhanced primary beam intensities at the experiment target are available. For this a new sc 28 GHz full performance ECR ion source is under development. Via a new low energy beam line an already installed new RFQ and an IH-DTL will provide for cw-heavy ion beams with high average beam intensity. It is planned to build a new cw-heavy ion-linac behind this high charge state injector. In preparation an R&D program is still ongoing: The first linac section comprising a sc CH-cavity embedded by two sc solenoids (financed by HIM) as a demonstrator will be tested with beam at the GSI High Charge Injector (HLI).The new linac should feed the GSI flagship experiments SHIP and TASCA, as well as material research, biophysics and plasma physics experiments in the MeV/u-area. The linac will be integrated in the GSI-UNILAC-environment; it is housed by the existing constructions. Different layout scenarios of a multipurpose high intensity heavy ion facility will be presented as well as the schedule for preparation and integration of the new cw-linac.
 
 
TUPB075 Beam Dynamics Design of China ADS Proton Linac cavity, emittance, rfq, proton 648
 
  • Z. Li, P. Cheng, H. Geng, Z. Guo, C. Meng, B. Sun, J.Y. Tang, F. Yan
    IHEP, Beijing, People's Republic of China
 
  Funding: Supported by China ADS Program(XDA03020000), National Natural Science Fundation of China (10875099) and IHEP Special Fundings(Y0515550U1)
It is widely accepted that the Accelerator Driven System (ADS) is one of the most promising technical approach to solve the problem of the nuclear wastes, a potential threaten to the sustainable development of the nuclear fission energy. An ADS study program is approved by Chinese Academy of Sciences at 2011, which aims to design and built an ADS demonstration facility with the capability of more than 1000 MW thermal power within the following 25 years. The 15 MW driver accelerator will be designed and constructed by the Institute of High Energy Physics(IHEP) and Institute of Modern Physics(IMP) of China Academy of Sciences. This linac is characterized by the 1.5 GeV energy, 10mA current and CW operation. It is composed by two parallel 10 MeV injectors and a main linac integrated with fault tolerance design. The superconducting acceleration structures are employed except the RFQ. In this paper the general considerations and the beam dynamics design of the driver accelerator will be presented.
 
 
TUPB077 Thorium Energy neutron, target, proton, cyclotron 651
 
  • S. Peggs
    BNL, Upton, Long Island, New York, USA
  • R. Cywinski, R. Seviour
    University of Huddersfield, Huddersfield, United Kingdom
  • S. Peggs
    ESS, Lund, Sweden
 
  The potential for using thorium as an alternative or supplement for uranium in fission power generation has long been recognised, with growing concerns over nuclear waste, safety and proliferation. Thorium may be used in solid fuel form, or in molten salt systems. In some approaches the fuel can incorporate components from spent nuclear fuel (minor actinides, plutonium) to also serve a transmutation function. We consider the benefits and drawbacks of using an accelerator driven subcritical system, for both solid fuel and molten salt cases, in particular addressing the power and reliability requirements of the accelerator. We outline the research that will be necessary to lead to an informed choice.  
 
TUPB079 Design and Beam Test of Six-Electrode BPMs for Second-Order Moment Measurement factory, electron, multipole, storage-ring 654
 
  • K. Yanagida, H. Hanaki, S. Suzuki
    JASRI/SPring-8, Hyogo-ken, Japan
 
  In the SPring-8 linac, four-electrode beam position monitors (BPMs) have been utilized for the measurement of the transverse first-order moments, which correspond to the centroids of beam charge distributions. We have planed to measure the transverse second-order moments of beams to obtain information of beam optics and its energy deviations during the top-up beam injection without destruction of beams. Therefore, six-electrode BPMs with circular and quasi-ellipse cross-sections have been developed on the basis of a newly introduced theory. A low-noise signal processor for the six-electrode BPM has also been developed to perform fine measurement. We expected the following resolutions determined by the S/N ratio of the circuit; the first order moments (beam positions) >1 μm, and the second order moments with a size >110 μm. The first beam test was carried out using the six-electrode BPM with circular cross-section and the old signal processor. The measured sensitivities and resolutions of the second-order moments showed good agreement with the theory.  
 
TUPB082 Beam Loss Track Measurements by a Fast Trigger Scheme in J-PARC Linac background, proton, simulation, neutron 663
 
  • H. Sako, T. Maruta, A. Miura
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  Funding: Work partially supported by Grant-in-Aid for Challenging Exploratory Research
In J-PARC Linac, highest beam loss has been observed at the ACS (Annular-Coupled Structure linac) section. The primary source of the beam loss is considered to be H0 produced by an interaction of H beams with remnant gas. The H0 hits the beam duct, converted to H+, and escapes from the beam duct. To detect the H+'s and estimate the absolute magnitude of the beam loss, we constructed a detector system, which consists of 6 planes of hodoscopes made of 16 scintillation fibers with 64 x 64 mm2 area. The scintillation light is measured by multi-anode photomultipliers. In the ACS section, two planes to measure horizontal positions are installed, and at about 1 m downstream positions, two planes for horizontal measurements and two for vertical measurements are placed. We will reconstruct charged particles passing through all the 6 planes, and measure the velocity by time-of-flight and energy loss to identify particle species. We present new measurements since the recovery of the J-PARC after the earthquake started in April 2012 by a new fast trigger scheme using dynode signals of photomultipliers in order to improve signal-to-noise ratios.
 
 
TUPB084 High Dynamic-Range High Speed Linac Current Measurements neutron, monitoring, injection, feedback 666
 
  • C. Deibele
    ORNL, Oak Ridge, Tennessee, USA
  • D. Curry, R. Dickson
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure risetimes on the order of 10 nanoseconds.
 
 
TUPB091 176 MHz Solid State Microwave Generator Design impedance, simulation, scattering, resonance 672
 
  • A.Yu. Smirnov, E.V. Ivanov, A.A. Krasnov, K.I. Nikolskiy, N.V. Tikhomirova
    Siemens Research Center, Moscow,, Russia
  • O. Heid, T.J.S. Hughes
    Siemens AG, Erlangen, Germany
 
  This paper concerns the R&D work upon design of a compact RF amplifier to be used for superconducting CW cavities. The machine under development will operate at 176 MHz with output power of 25 kW in continuous wave regime. It consists of 50 push-pull PCB modules (approx. 500W output power each), connected in parallel to several radial filter rings, which both allow class-F operation and combine the power from the modules, delivering it to a single 50 Ω coax cable. The CST simulations ad the design of 324 MHz test prototype are presented.  
 
TUPB093 Compact 4 kW Variable RF Power Coupler for FRIB Quarter-wave Cavities cavity, cryomodule, vacuum, simulation 678
 
  • M.P. Kelly, Z.A. Conway, M. Kedzie, S.V. Kutsaev
    ANL, Argonne, USA
  • J.L. Crisp, L.L. Harle
    FRIB, East Lansing, Michigan, USA
 
  A new compact 4 kW power coupler has been designed and prototyped at Argonne National Laboratory in collaboration with Michigan State University. The coupler is intended for use on the β=0.085 80.5 MHz superconducting quarter-wave cavities for the FRIB driver linac and also for the planned ReA6 quarter-wave cavity cryomodule. The design has a cold RF window and a 3 cm variable bellows section. The 16 cm overall length of the RF window and bellows facilitates a simple and compact installation onto the cavity inside the clean room. A prototype have been cold tested with high power under realistic conditions at Argonne and results are presented.  
 
TUPB095 Design of Coupler for Direct Coupled Amplifier to Drift Tube Linac Cavities of the Injector RILAC2 for RIKEN RI Beam Factory cavity, impedance, DTL, coupling 684
 
  • K. Suda, S. Arai, Y. Chiba, O. Kamigaito, M. Kase, H. Okuno, N. Sakamoto, Y. Watanabe, K. Yamada
    RIKEN Nishina Center, Wako, Japan
 
  A new linac RILAC2 was constructed at RIKEN RI Beam Factory as an injector for very heavy ions such as uranium and xenon of a high mass to charge ratio m/q  ∼  7, but high intensity ions can be extracted from an ion source. Three drift tube linac cavities, operate in continuous wave mode at 36.5 MHz, have been designed and built. In order to reduce an installation area, and to save a construction cost, we adopted a direct coupling method for a power amplifier without using a long transmission line. A complicated design procedure was performed in order to take into account a change of resonant frequency of the cavity caused by a capacitance of a power tube used in the amplifier. A design of the coupler, as well as the cavity was performed using a three-dimensional electromagnetic calculation code, CST Microwave Studio (MWS). The measured input impedance seen from the amplifier (700 – 1100 Ω) was reproduced well by the calculation of MWS. Also, in order to examine MWS, a case of a coupling with 50 Ω were calculated. The coupling conditions obtained by MWS were compared with the measurement and a calculation with a lumped circuit model.  
 
TUPB099 Input Coupler of the J-PARC DTL coupling, DTL, vacuum, cavity 690
 
  • F. Naito, K. Nanmo, H. Tanaka
    KEK, Ibaraki, Japan
  • K. Hirano, T. Ito
    JAEA/J-PARC, Tokai-mura, Japan
 
  Each tank of J-PARC DTL has two input couplers. The coupler has a movable coupling loop with an capacitive element which increase the coupling with the tank. The loop position is the outside of the tank, where is the atmosphere. The tank vacuum is kept by the ceramic window on the wall for the coupler port. The ceramic is made of Aluminum oxide of 99.7 % purity. RF properties and the mechanical structure of the coupler were designed adequately in order to achieve the desired performance. We will report the design of the coupler in detail and the experiences for the practical operation of the DTL.  
 
TUPB100 Recovery and Status Report of DTL/SDTL for the J-PARC After Earthquake DTL, cavity, alignment, target 693
 
  • T. Ito, K. Hirano
    JAEA/LINAC, Ibaraki-ken, Japan
  • F. Naito, K. Nanmo
    KEK, Ibaraki, Japan
 
  The J-PARC facilities had big damages because of the earthquake on March 11, 2011. The J-PARC linac in the tunnel had also damages. For instance the alignment of the cavity was deformed more than 40 mm and there had been observed about 0.2 mm in horizontal direction for a few DTs in the DTL. However, as the result of the recovery work which includes the re-alignment and re-conditioning of whole cavities, we were able to restart the beam acceleration of the linac. The stability of the DTL and SDTL has returned to the state before the earthquake except for a few tanks of SDTL. In this paper, we will present the recovery works from the earthquake and the operating status of the DTL and the SDTL.  
 
TUPB101 Beam Loss Occurred at DTL Cavity in J-PARC Linac DTL, radiation, cavity, drift-tube-linac 696
 
  • A. Miura, K. Hirano, T. Ito, T. Maruta
    JAEA/J-PARC, Tokai-mura, Japan
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • T. Miyao, F. Naito, K. Nanmo
    KEK, Ibaraki, Japan
 
  The beam operation of J-PARC linac was suspended until December 2011 due to the damage by the Tohoku earthquake in March 2011. After resumed the operations, we measured the residual radiation along with the beam line during a short interval. Because the higher residual radiation was detected at the surface of drift tube linac (DTL) cavity by radiation survey, we installed the scintillation beam loss monitors (BLM) at the points where the higher radiation was detected to understand the cause of the radiation. Even the DTL section is low energy part of the linac, fine structure of the beam loss was observed by the scintillation BLM. And we measured the beam loss occurred at the DTL with the parameters of beam orbit and cavity settings. Also, the BLM is employed for the linac tuning. In this paper, the result of the radiation measurement and beam loss signals obtained by the scintillation BLMs are presented.  
 
TUPB102 Design and Performances of Phase Monitor in J-PARC Linac acceleration, pick-up, vacuum, impedance 699
 
  • A. Miura
    JAEA/J-PARC, Tokai-mura, Japan
  • Z. Igarashi, T. Miyao
    KEK, Ibaraki, Japan
 
  J-PARC linac employs a fast current transformer (FCT) as a beam phase monitor to calculate the beam energy by time-of-flight method. We have installed and used 61 FCTs in the current beam line. Because the phase measurements at additional 41 points in the future ACS sections are required for the energy upgrade project with adding 21 ACS (Annular Coupled Structure) cavities, we stared the design and fabrication of FCTs as the phase measurement devices. In addition, J-PARC linac employs the 4-stripline beam position monitors (BPMs) for the beam position measurement. It has been considered that the signals from striplines of BPM would be useful for a phase measurement. A phase measurement using a BPM has been successfully conducted. In order to evaluate the performances of the FCT, the signal sensitivity and cut-off frequency of newly fabricated FCT are measured. Also, these data of the BPM are also measured to be compared with the data of FCT. Based on the results of the comparing both measurements, the superiority of both monitors for beam phase measurement is discussed.  
 
TUPB103 CSNS DTL Prototyping and RF Tuning DTL, cavity, vacuum, quadrupole 702
 
  • H.C. Liu, Q. Chen, S. Fu, K.Y. Gong, A.H. Li, J. Peng, Y.C. Xiao, X. Yin
    IHEP, Beijing, People's Republic of China
 
  The 324 MHz Alvarez-type Drift Tube Linac (DTL) for the China spallation neutron source will be used to accelerate the H ion beam of up to 15 mA peak current from 3 to 80 MeV. It consists of four independent tanks, of which the average length is about 8.6 m. Each tank is divided into three short unit tanks about 2.8 m in length for easy manufacture. A full-scale prototype of the first unit tank with 28 drift tubes containing electromagnetic quadrupoles has been constructed to validate the design and to demonstrate the technology. The overall features of the prototype in both key technology and RF tuning are presented. In particular, the influence of the post couplers was studied in the ramped field DTL.  
 
TUPB104 Study of the Beam Dynamics in the RISP Driver Linac solenoid, quadrupole, lattice, cryomodule 705
 
  • H.J. Kim, J.G. Hwang, D. Jeon
    IBS, Daejeon, Republic of Korea
 
  Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.3 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control.  
 
TUPB108 Uppsala High Power Test Stand for ESS Spoke Cavities rf-amplifier, power-supply, cryomodule, controls 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.  
 
WE1A01 ERL-Based Light Source Challenges gun, electron, laser, emittance 714
 
  • Y. Kobayashi
    KEK, Ibaraki, Japan
 
  The challenges of the design and technology for the future Energy Recovery Liancs will be reviewed: electron sources, injector, SCRF cavities and cryomodules, commissioning.  
 
WE1A02 Status and Future of the CLIC Study luminosity, emittance, target, damping 719
 
  • R. Corsini
    CERN, Geneva, Switzerland
 
  The Compact Linear Collider (CLIC) International Collaboration is carrying out an extensive R&D program towards a multi-TeV electron-positron collider. The CLIC concept is based on the use of high-gradient normal-conducting accelerating structures in conjunction with a novel two-beam acceleration scheme, where the RF power needed to accelerate the colliding beams is extracted from a high-current drive beam running parallel to the main linac. In order to establish the feasibility of such concept a number of key issues were addressed, both experimentally and theoretically, and the results of the study were documented in the recently completed CLIC Conceptual Design Report (CDR). The conclusions reached in the CDR constitute also an important contribution to the European strategy group. A short summary of the present status with will be given, together with an outlook on the program for the next period, aimed at the preparation of an implementation plan.  
 
WE1A03 Application of X-band Linacs FEL, emittance, gun, collider 724
 
  • G. D'Auria
    ELETTRA, Basovizza, Italy
 
  Since the late 80’s the development of Normal Conducting (NC) X-band technology for particle accelerators has made significant progress and has witnessed tremendous growth. The driving force behind this technological development has been, and is, the interest of the scientific community in the construction of a Multi-TeV e+e Linear Collider at a reasonable size and cost. The use of the X-band frequency allows for a much higher accelerating gradient per meter, when compared to the S and C bands. SLAC, with a major contribution from KEK, has been pioneering this development since the late 80’s in the framework of the NLC/JLC projects. Later, in 2007, the same technology was chosen by CERN for CLIC, the 12 GHz Linear Collider based on the Two-Beam Acceleration (TBA) concept. In addition to these applications, X-band technology is also rapidly expanding in the field of X-ray FELs and other photon sources where it shows great potential. Here, a selection of X-band projects as well as the main applications of this technology at different international laboratories, is reported. The paper also includes a brief report on X-band medical and industrial applications.  
slides icon Slides WE1A03 [5.826 MB]  
 
WE1A04 The ARIEL Superconducting Electron Linac cryomodule, cavity, gun, TRIUMF 729
 
  • S.R. Koscielniak, F. Ames, R.A. Baartman, I.V. Bylinskii, Y.-C. Chao, D. Dale, R.J. Dawson, E.R. Guetre, N. Khan, A. Koveshnikov, A. Laxdal, R.E. Laxdal, F. Mammarella, M. Marchetto, L. Merminga, A.K. Mitra, T. Planche, Y.-N. Rao, A. Sitnikov, V.A. Verzilov, D. Yosifov, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
  • D. Karlen, R.R. Langstaff
    Victoria University, Victoria, B.C., Canada
 
  The TRIUMF Advanced Rare Isotope Laboratory (ARIEL) is funded since 2010 June by federal and BC Provincial governments. In collaboration with the University of Victoria, TRIUMF is proceeding with construction of a new target building, connecting tunnel, rehabilitation of an existing vault to contain the electron linear accelerator, and a cryogenic compressor building. TRIUMF starts construction of a 300 keV thermionic gun, and 10 MeV Injector cryomodule (EINJ) in 2012; the designs being complete. The 25 MeV Accelerator Cryomodule (EACA) follows in autumn 2013. TRIUMF is embarking on major equipment purchases and has signed contracts for 4K cryogenic plant and four sub-atmospheric pumps, a 290 kW c.w. klystron and high-voltage power supply, 80 quadrupole magnets, EINJ tank and lid, and four 1.3 GHz niobium 9-cell cavities from a local Canadian supplier. The low energy beam transport and beam diagnotics are being installed at the ISAC-II/VECC test facility. Procurement is anticipated October 2012 for the liquid He distribution system.  
slides icon Slides WE1A04 [4.305 MB]  
 
WE1A05 Linac-Based Laser Compton Scattering X-Ray and Gamma-Ray Sources photon, laser, electron, brightness 734
 
  • R. Hajima
    JAEA, Ibaraki-ken, Japan
 
  Laser Compton scattering (LCS) light sources can provide high-energy photons from keV to MeV range. Many research and development projects of linac-based LCS sources are carried on. For the photon energies of tens keV, linac-based LCS sources realize laboratory-size X-ray sources, of which performance can be comparable to synchrotron light sources. Linac-based LCS also realizes unprecedented gamma-ray sources with better monochromaticity than ring-based LCS sources. This talk will review linac-based LCS source in the world.  
slides icon Slides WE1A05 [2.881 MB]  
 
WE2A02 Solid State Marx Modulators for Emerging Applications klystron, high-voltage, diagnostics, linear-collider 743
 
  • M.A. Kemp
    SLAC, Menlo Park, California, USA
 
  A class of intelligent, Marx-topology modulators are under development at SLAC. These modulators combine numerous advanced features that could be employed in any significant new HPRF installation. The talk will describe the design features and operational experience.  
slides icon Slides WE2A02 [1.117 MB]  
 
TH1A03 Superconducting Spoke Cavities for Electron and High-Velocity Proton Linacs cavity, impedance, SRF, electron 758
 
  • J.R. Delayen
    ODU, Norfolk, Virginia, USA
 
  Spoke resonantors are currently under development for many proton machines but these structures are also considered for high beta electron linacs as well. These structures compare well to traditional elliptical cavities.  
slides icon Slides TH1A03 [3.570 MB]  
 
TH1A04 Superconducting Linac and Associated Developments at IUAC Delhi ion, rfq, ECR, cavity 763
 
  • A. Roy
    IUAC, New Delhi, India
 
  A superconducting linear accelerator system consisting of a series of independently phase locked niobium quarter wave resonators has been developed as a booster of heavy ion beams available from the existing 15UD Pelletron accelerator. Two superconducting linac booster modules having eight niobium quarter wave resonators (QWRs) each have been installed and are fully operational for regular scheduled experiments. The third module is being added to the system. A new high current injector has been planned to couple to the superconducting linac. For this a high temperature superconducting electron cyclotron resonance ion source (HTS-ECRIS) was designed, fabricated and installed successfully. A radio frequency quadrupole (RFQ) accelerator is being developed for accelerating accelerate ions from the ECR (A/Q ~ 6) to an energy to of about 180 keV/A. The beams will then be accelerated further by drift tube linacs (DTL) to the required velocity to inject them to the existing superconducting linac booster. Prototypes of both these have been tested for power and thermal studies. Details of these developments and associated systems will be presented.  
slides icon Slides TH1A04 [7.830 MB]  
 
TH2A01 The ESS Linac Design klystron, cryomodule, cavity, proton 768
 
  • M. Lindroos, H. Danared, C. Darve, D.P. McGinnis, S. Molloy
    ESS, Lund, Sweden
 
  The European Spallation Source (ESS) is a 5 MW, 2.5 MeV long pulse proton machine. It represents a big jump in power compare to the existing spallation facilities. The design phase is well under way, with the delivery of a Conceptual Design Report expected in 2012, and a Technical Design Report in 2013. Why and how the 5 MW goal influences the parameter choice will be describe.  
slides icon Slides TH2A01 [5.667 MB]  
 
TH2A02 SPIRAL2 Accelerator Construction Progress rfq, ion, ECR, cryomodule 773
 
  • P. Bertrand, R. Ferdinand
    GANIL, Caen, France
 
  The SPIRAL2 superconducting accelerator installation starts in 2012. The major components have been tested in the various partner laboratories, and the building construction is well engaged. The management of the interfaces between process and buildings is a strategic point in an underground project with strong space constraints. This contribution will describe the performances of the various components of the SPIRAL2 accelerator, and the methodology put in place in order to insure the integration of the process inside the buildings.  
slides icon Slides TH2A02 [5.441 MB]  
 
TH2A03 Design and Construction of the Linac4 Accelerating Structures DTL, rfq, cavity, vacuum 778
 
  • F. Gerigk, Y. Cuvet, A. Dallocchio, G. Favre, J.-M. Geisser, L. Gentini, J.-M. Giguet, S.J. Mathot, M. Polini, S. Ramberger, B. Riffaud, C. Rossi, P. Ugena Tirado, M. Vretenar, R. Wegner
    CERN, Geneva, Switzerland
  • E. Kendjebulatov, Ya.G. Kruchkov, A.G. Tribendis
    BINP SB RAS, Novosibirsk, Russia
  • M.Y. Naumenko
    RFNC-VNIITF, Snezhinsk, Chelyabinsk region, Russia
 
  The Linac4 project at CERN is at an advanced state of construction. Prototypes of the different types of accelerating structures (RFQ, DTL, CCDTL and pi-mode structures) have been built and are presently tested. This paper gives the status of the cavity production and reviews the RF and mechanical design of the various structure types. Furthermore the production and the first test results shall be presented.  
slides icon Slides TH2A03 [2.675 MB]  
 
TH2A004 Computational Model Analysis for Experimental Observation of Optical Current Noise Suppression Below the Shot-noise Limit plasma, electron, simulation, beam-transport 783
 
  • A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
  • A. Nause
    University of Tel Aviv, Tel Aviv, Israel
 
  Funding: We acknowledge support of the Israel Science Foundation grant
We report first demonstration of optical frequency current shot-noise suppression in a relativistic e-beam. This process is made possible by collective Coulomb interaction between the electrons of a cold intense beam during beam drift, and is essentially a process of longitudinal beam-plasma oscillation.[1] Suppression of beam current noise below the classical “shot-noise” level has been known in the microwave tubes art [2]. This is the first time that it is demonstrated in the optical regime. We predict that the scheme can be extended to the XUV and possibly to shorter wavelengths with further development of technology. The fundamental current shot-noise determines the level of incoherent spontaneous radiation emission from electron-beam optical radiation sources and SASE-FELs [3]. Suppressing shot-noise would make it possible to attain spontaneous emission sub-radiance [4] and surpass the classical coherence limits of seed-injected FELs. The effect was demonstrated by measuring sub-linear growth as a function of current of the OTR Radiation. This finding indicates that the beam charge homogenizes due to the collective interaction, and its distribution becomes sub-Poissonian.
[1] A. Gover, E. Dyunin, PRL, 102, 154801, 2009
[2] H. Haus, N. Robinson, Proc. IRE, 43, 981 (1955)
[3] P. Emma, et al , Nature Photonics 4, 641 (2010)
[4] A. Dicke, Phys. Rev. 93, 99 (1954)
 
 
TH3A01 Status of ILC cavity, cryomodule, HLRF, linear-collider 787
 
  • A. Yamamoto
    KEK, Ibaraki, Japan
  • M.C. Ross
    SLAC, Menlo Park, California, USA
  • N.J. Walker
    DESY, Hamburg, Germany
 
  A review of the ILC project with emphasis on the changes in the technical progress report.  
slides icon Slides TH3A01 [5.396 MB]  
 
TH3A02 The 12 GeV Energy Upgrade at Jefferson Laboratory cryomodule, cavity, collider, electron 792
 
  • F.C. Pilat
    JLAB, Newport News, Virginia, USA
 
  Two new cryomodules and an extensive upgrade of the bending magnets at Jefferson Lab has been recently completed in preparation for the full energy upgrade in about one year.  
slides icon Slides TH3A02 [3.482 MB]  
 
TH3A03 ERL-Based Lepton-Hadron Colliders: eRHIC and LHeC electron, hadron, ion, proton 797
 
  • F. Zimmermann
    CERN, Geneva, Switzerland
 
  This talk will review hadron-ERL collider projects. The LHeC is a plan to collide the LHC beam with electrons or positrons. One scheme for this facility is based on a superconducting recirculating linac with energy recovery. The electron hadron collider eRHIC will collide polarized and unpolarized electrons with a current of 50 mA and energy in the range of 5 GeV to 30 GeV with hadron beams, including heavy ions or polarized light ions of the RHIC storage ring. The electron beam will be generated in an energy recovery linac contained inside the RHIC tunnel, comprising six passes through two linac section of about 2.5 GeV each.  
slides icon Slides TH3A03 [3.286 MB]  
 
TH3A04 Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET plasma, electron, radiation, acceleration 802
 
  • C.I. Clarke, E. Adli, S. Corde, F.-J. Decker, R.J. England, R.A. Erickson, A.S. Fisher, S.J. Gessner, C. Hast, M.J. Hogan, S.Z. Li, N. Lipkowitz, M.D. Litos, Y. Nosochkov, J.T. Seeman, J. Sheppard, I. Tudosa, G.R. White, U. Wienands, M. Woodley, Z. Wu, G. Yocky
    SLAC, Menlo Park, California, USA
  • C.E. Clayton, C. Joshi, W. Lu, K.A. Marsh, N. Vafaei
    UCLA, Los Angeles, California, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515.
FACET (Facility for Advanced Accelerator and Experimental Tests) is an accelerator R&D test facility that has been recently constructed at SLAC National Accelerator Laboratory. The facility provides 20 GeV, 3 nC electron beams, short (20 um) bunches and small (20 um wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. FACET is also a source of THz radiation for material studies. We present the FACET design, initial operating experience and first science from the facility.
 
slides icon Slides TH3A04 [3.091 MB]  
 
THPLB01 Linac Construction for China Spallation Neutron Source DTL, rfq, neutron, cavity 807
 
  • S. Fu, J. Li, H.C. Liu, H.F. Ouyang, X. Yin
    IHEP, Beijing, People's Republic of China
 
  Construction of China Spallation Neutron Source(CSNS) has been launched in September 2011. CSNS accelerator will provide 100kW proton beam on a target at beam energy of 1.6GeV. It consists of an 80MeV H linac and 1.6GeV rapid cycling synchrotron. Based on the prototyping experience, CSNS linac, including the front end and four DTL tanks, has finalized the design and started procurement. In this paper, we will first present an outline of the CSNS accelerator in its design and construction plan. Then the major prototyping results of the linac will be presented. Finally the linac construction progress in recent will be updated.  
slides icon Slides THPLB01 [1.969 MB]  
 
THPLB03 Front-End Linac Design and Beam Dynamics Simulations for MYRRHA rfq, DTL, simulation, emittance 813
 
  • C. Zhang, H. Klein, D. Mäder, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede, M. Vossberg
    IAP, Frankfurt am Main, Germany
 
  Funding: Funded by the European Atomic Energy Community’s (Euratom) 7th Framework Programme under Grant Agreement n°269565.
A 17MeV, 176MHz, and CW (Continuous Wave) proton linac is being developed as the front end of the driver accelerator for the MYRRHA facility in Mol, Belgium. Based on the promising preliminary design, further simulation and optimization studies have been performed with respect to code benchmarking, RFQ simulation using realistic LEBT output distributions, and an updated CH-DTL design with more detailed inter-tank configurations. This paper summarizes the new results.
 
slides icon Slides THPLB03 [1.292 MB]  
 
THPLB05 R&D Activities on High Intensity Superconducting Proton Linac at RRCAT cavity, SRF, ion, niobium 819
 
  • S.C. Joshi, J. Dwivedi, P.D. Gupta, P.R. Hannurkar, P. Khare, P.K. Kush, G. Mundra, A. Puntambekar, S.B. Roy, P. Shrivastava
    RRCAT, Indore (M.P.), India
 
  Raja Ramanna Centre for Advanced Technology (RRCAT), Indore has taken up a program on development of 1 GeV high intensity superconducting proton linac for Spallation Neutron Source. This will require several multi-cell superconducting cavities operating at different RF frequencies. To start with, a number of single-cell prototype cavities at 1.3 GHz have been developed in high RRR bulk niobium. These single-cell cavities have exhibited high quality factor and accelerating gradients. Superconducting properties of niobium are being studied for varying composition of impurities and different processing conditions. Development activity on solid state RF amplifiers to power the SCRF cavities at various RF frequencies is being pursued. A building has been constructed to house the SCRF cavity fabrication and processing facility. To characterize SCRF cavity, a 2 K Vertical Test Stand is being set up including a 2 K cryostat, RF power supply and data acquisition system. Design activities for cryomodule and large 2 K cryostat for Horizontal Test Stand are also under progress. The paper will discuss the status of above R&D activities and infrastructure development at RRCAT.  
slides icon Slides THPLB05 [1.614 MB]  
 
THPLB06 The New Option for a Front End of Ion Linac rfq, ion, DTL, proton 822
 
  • A.D. Kovalenko
    JINR, Dubna, Moscow Region, Russia
  • A. Kolomiets
    ITEP, Moscow, Russia
 
  The standard ion linac front-end consisting of RFQ, two tanks of accelerating IH-structures, MEBTs with matching and focusing elements is modified to achieve better performances. Special vane section that provides the same beam transformation as debuncher and quadrupole triplet is added within the RFQ tank, whereas superconducting focusing elements, solenoids, for example, are used between the IH - structure tanks. Test frond end was designed to provide the output beam energy up to 4 MeV/u for the particles with charge-to-mass ratio of 0.16 < q/m ≤ 1. Results of beam dynamics simulation are presented. Possible application of the considered scheme for the NICA facility at JINR (Dubna, Russia) is discussed.  
slides icon Slides THPLB06 [0.482 MB]  
 
THPLB07 Experience with a 4-Rod CW Radio Frequency Quadrupole rfq, ion, damping, resonance 825
 
  • P. Gerhard, W.A. Barth, L.A. Dahl, W. Hartmann, G. Schreiber, W. Vinzenz, H. Vormann
    GSI, Darmstadt, Germany
 
  Since 1991 the High Charge State Injector (HLI) provides heavy ion beams for the linear accelerator UNILAC at GSI*. It is equipped with an ECR ion source and an RFQ-IH linac which accelerates highly charged ion beams with high duty factor of up to 30% to 1.4 MeV/u for further acceleration in the Alvarez DTL of the UNILAC. Main user of these beams is the Super Heavy Element (SHE) research, one of the outstanding projects at GSI**. Experiments like TASCA and SHIP strongly benefit from the high average beam intensities. After two decades of successful operation the four-rod Radio Frequency Quadrupole (RFQ) accelerator was replaced in 2010 by a newly designed RFQ of the same type**. Besides higher beam transmission, the principal intention of this upgrade was to raise the duty factor up to 100%, since the HLI is foreseen as injector for the upcoming cw linac dedicated to the SHE program**. Commissioning and operational experience from the first years revealed that this goal could not be reached easily. In this paper we present the RFQ design, commissioning results, operational experience and future activities.
* N. Angert et al., EPAC92, Berlin, Germany (1992), p. 167
** L. Dahl et al., LINAC10, Tsukuba, Japan (2010), MOP042, and references therein
 
slides icon Slides THPLB07 [0.986 MB]  
 
THPB003 R&D Activities on High Intensity Superconducting Proton Linac at RRCAT cavity, SRF, ion, niobium 843
 
  • S.C. Joshi, J. Dwivedi, P.D. Gupta, P.R. Hannurkar, P. Khare, P.K. Kush, G. Mundra, A. Puntambekar, S.B. Roy, P. Shrivastava
    RRCAT, Indore (M.P.), India
 
  Raja Ramanna Centre for Advanced Technology (RRCAT), Indore has taken up a program on development of 1 GeV high intensity superconducting proton linac for Spallation Neutron Source. This will require several multi-cell superconducting cavities operating at different RF frequencies. To start with, a number of single-cell prototype cavities at 1.3 GHz have been developed in high RRR bulk niobium. These single-cell cavities have exhibited high quality factor and accelerating gradients. Superconducting properties of niobium are being studied for varying composition of impurities and different processing conditions. Development activity on solid state RF amplifiers to power the SCRF cavities at various RF frequencies is being pursued. A building has been constructed to house the SCRF cavity fabrication and processing facility. To characterize SCRF cavity, a 2 K Vertical Test Stand is being set up including a 2 K cryostat, RF power supply and data acquisition system. Design activities for cryomodule and large 2 K cryostat for Horizontal Test Stand are also under progress. The paper will discuss the status of above R&D activities and infrastructure development at RRCAT.  
 
THPB005 Front-End Linac Design and Beam Dynamics Simulations for MYRRHA rfq, DTL, simulation, emittance 849
 
  • C. Zhang, H. Klein, D. Mäder, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede, M. Vossberg
    IAP, Frankfurt am Main, Germany
 
  Funding: Funded by the European Atomic Energy Community’s (Euratom) 7th Framework Programme under Grant Agreement n°269565.
A 17MeV, 176MHz, and CW (Continuous Wave) proton linac is being developed as the front end of the driver accelerator for the MYRRHA facility in Mol, Belgium. Based on the promising preliminary design, further simulation and optimization studies have been performed with respect to code benchmarking, RFQ simulation using realistic LEBT output distributions, and an updated CH-DTL design with more detailed inter-tank configurations. This paper summarizes the new results.
 
 
THPB006 Post Acceleration of Laser-generated Proton Bunches by a CH-DTL proton, laser, DTL, cavity 852
 
  • A. Almomani, M. Droba, I. Hofmann, U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  Laser driven proton beam sources applying the TNSA process show interesting features in terms of energy and proton number per bunch. This makes them attractive as injectors into RF linacs at energies as high as 10 MeV or beyond. The combination shows attractive features like a very high particle number in a single bunch from the source and the flexibility and reliability of the rf linac to match the needs of a specified application. The approach aims on a very short matching section from the source target into the rf linac by one pulsed solenoid lens only. A crossbar H-type (CH - structure) is suggested because of its high acceleration gradient and efficiency at these beam energies. It is intended to realize the first cavity of the proposed CH - linac and to demonstrate the acceleration of a laser generated proton bunch within the LIGHT collaboration at GSI Darmstadt. Detailed beam and field simulations will be presented.  
 
THPB007 A Pulsed Linac Front-end for ADS Applications proton, rfq, emittance, simulation 855
 
  • U. Ratzinger, H. Podlech, A. Schempp, K. Volk
    IAP, Frankfurt am Main, Germany
  • U. Hagen, O. Heid, T.J.S. Hughes
    Siemens AG, Erlangen, Germany
  • H. Hoeltermann
    BEVATECH OHG, Offenbach/Main, Germany
 
  Quite a number of projects worldwide develop proton driver linacs for neutron sources and other accelerator driven systems. One trend is to use a high duty factor and superconducting cavities as much as possible. Alternatively, one can aim on short duty factor and count on a continuing rapid development of pulsed rf amplifiers based on power transistor technology. A 500 mA, 5 % duty factor layout of a proton injector is presented, consisting of a filament driven volume ion source, of a 150 keV transport section and of a 4 m long 162 MHz RFQ up to 2 MeV beam energy. Beam dynamics results as well as the technical design will be shown.  
 
THPB010 Progress in the Construction of Linac4 at CERN injection, rfq, klystron, DTL 864
 
  • M. Vretenar, L. Arnaudon, P. Baudrenghien, G. Bellodi, C. Bertone, Y. Body, J.C. Broere, O. Brunner, M.C.L. Buzio, C. Carli, J.-P. Corso, J. Coupard, A. Dallocchio, N. Dos Santos, J.-F. Fuchs, A. Funken, R. Garoby, F. Gerigk, L. Hammouti, K. Hanke, J. Hansen, I. Kozsar, J.-B. Lallement, J. Lettry, A.M. Lombardi, L.A. Lopez Hernandez, C. Maglioni, S.J. Mathot, B. Mikulec, D. Nisbet, M.M. Paoluzzi, B. Puccio, U. Raich, S. Ramberger, F. Roncarolo, C. Rossi, N. Schwerg, R. Scrivens, G. Vandoni, J. Vollaire, R. Wegner, S. Weisz, Th. Zickler
    CERN, Geneva, Switzerland
 
  As first step of the LHC luminosity upgrade program CERN is building a new 160 MeV H¯ linear accelerator, Linac4, to replace the ageing 50 MeV Linac2 as injector to the PS Booster (PSB). Linac4 is an 86-m long normal-conducting linac made of a 3 MeV injector followed by 22 accelerating cavities of three different types. The general service infrastructure has been installed in the new tunnel and surface building and its commissioning is progressing; high power RF equipment is being installed in the hall and installations in the tunnel will start soon. Construction of the accelerator parts is in full swing involving industry, the CERN workshops and a network of international collaborations. The injector section including a newly designed and built H¯ source, a 3-m long RFQ and a chopping line is being commissioned in a dedicated test stand. Beam commissioning of the linac will take place in steps of increasing energy between 2013 and 2014. From end of 2014 Linac4 could deliver 50 MeV protons in case of Linac2 failure, while 160 MeV H¯ could be injected into the PSB from end of 2015; the exact start of the LHC shut-down required for connection will be coordinated with its experiments.  
 
THPB011 Linac4 45 keV Proton Beam Measurements rfq, solenoid, simulation, proton 867
 
  • G. Bellodi, V.A. Dimov, L.M. Hein, J.-B. Lallement, A.M. Lombardi, O. Midttun, R. Scrivens
    CERN, Geneva, Switzerland
  • P.A. Posocco
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Linac4 is a 160 MeV normal-conducting H linear accelerator, which will replace the 50 MeV proton Linac (Linac2) as injector for the CERN proton complex. Commissioning of the low energy part - H source, a 45 keV Low Energy Beam Transport line (LEBT), a 3 MeV RFQ and a Medium Energy Beam Transport (MEBT) line - will start in fall 2012 on a dedicated test stand installation. In preparation to this, preliminary measurements were taken in the past few months using a 45 keV proton source and a temporary LEBT setup, with the aim of characterising the output beam by comparison with simulations. This also allowed a first verification of the diagnostics instrumentation and acquisition software tools. Measurements of beam profile, emittance and intensity were taken after the source, after the first and after the second LEBT solenoids respectively. Particle distributions were reconstructed from emittance scans and used as input to simulation studies of the beam transport through the line. Comparison of the results with the measurements allowed an experimental validation of the LEBT (in terms of misalignments and calibration points) and qualification of the beam at the source output.  
 
THPB012 High Resolution Emittance Measurements at SNS Front End emittance, coupling, DTL, target 870
 
  • A.P. Zhukov, A.V. Aleksandrov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
Spallation Neutron Source (SNS) linac accelerates an H beam from 2.5MeV up to 1GeV. Recently the emittance scanner in the MEBT (2.5 MeV) was upgraded. In addition to the slit - harp measurement we now can use a slit installed on the same actuator as the harp. In combination with a faraday cup located downstream in DTL part of the linac it represents a classical slit-slit emittance measurement device. While a slit – slit scan takes much longer time, it is immune to harp related problems such as wire cross talk and thus looks promising for accurate halo measurements. Time resolution of the new device seems to be sufficient to estimate amount of the beam in the chopper gap (the scanner is downstream of the chopper) and probably measure its emittance. The paper describes initial measurements with new device and some model validation data.
 
 
THPB013 Diagnostics Tools for Beam Halo Investigation in SNS Linac emittance, laser, diagnostics, background 873
 
  • A.V. Aleksandrov, W. Blokland, Y. Liu, C.D. Long, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Uncontrolled beam loss is the major concern in operation of a high intensity hadron linac. A low density cloud of particles with large oscillation amplitudes, so called halo, can form around the dense regular beam core. This halo can be direct or indirect cause of beam loss. There is an experimental evidence of halo growing in SNS linac and limiting further reduction of beam loss. A set of tools is being developed for detecting of the halo and investigating its origin and dynamics. The set includes high resolution emittance measurements in the injector, laser based emittance measurements at 1 GeV, and high resolution profile measurements along the linac. We will present our experience with useful measurement techniques and data analysis algorithms as well as current understanding of the halo dynamics in SNS linac.
 
 
THPB014 Lattice Design and Beam Dynamics Studies for Project X cryomodule, lattice, rfq, emittance 876
 
  • N. Solyak, J.-P. Carneiro, V.A. Lebedev, J.-F. Ostiguy, A. Saini
    Fermilab, Batavia, USA
 
  Fermilab is developing Project-X, a high intensity superconducting H machine for high energy physics experiments. The first stage is 1 mA average, 3 GeV linac operating in CW mode. Its front-end comprises a LEBT section with magnetic focusing and pre-chopping, a 162.5 MHz RFQ and ~10 m long MEBT section which includes a high bandwidth, bunch-by-bunch capable chopper. The latter extracts, out of a nominal 5 mA peak 162.5 MHz train, and arbitrary bunch structure able to meet the requirements of different experiments. Acceleration from 2.1 MeV to 3 GeV is accomplished through five families of SRF cavities operating at three frequencies: Half-wave resonators (162.5 MHz), spoke cavities (two families at 325 MHz) and elliptical cavities (two families at 650 MHz). In this contribution, we present the status of the CW linac lattice design and results from recent beam physics studies.  
 
THPB016 Concept: Low Energy, Low Intensity NF from ProjectX target, proton, accumulation, extraction 882
 
  • M. Popovic
    Fermilab, Batavia, USA
 
  This note describes the concept of a Low Luminosity Low Energy Neutrino Factory (L3ENF) using a Project X pulsed, or CW, Linac at 8GeV. By collecting pis and mus with energy ~1 GeV, and accelerating them to 10 GeV, it is possible to store ~1020 mus per year. Most of the concepts suggested here can be tested using the Booster beam, Recycler, Antiproton Target Station, the Main Injector and the Tevatron. Once the VLENF Muon Storage Ring is built, components needed for L3ENF could be used in experiments before Project X completion.  
 
THPB017 A Concept: 8GeV CW Linac, Staged Approach booster, rfq, injection, proton 885
 
  • M. Popovic, J.-F. Ostiguy
    Fermilab, Batavia, USA
 
  This note describes a concept of CW Proton Linac on the Fermilab site. With exception of RFQ the linac is based on superconducting technology. Based on the output, energy is segmented in three parts, 1GeV, 3GeV and 8GeV. It is located near existing Fermilab Proton Source with the intention that each section of the linac can be used as soon as it is commissioned. The whole design is based on the designs suggested for the Proton Driver and ProjectX. The suggested site and linac segmentation allows for the construction to start immediately. Additional benefits come from the fact that the present linac (the oldest machine in Fermilab complex) is replaced and existing Proton Source’s functionality is preserved for the future.  
 
THPB020 Annular-ring Coupled Structure for the Energy Upgrade of the J-PARC Linac vacuum, cavity, coupling, target 888
 
  • H. Ao, H. Asano, N. Ouchi, J. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  • F. Naito, K. Takata
    KEK, Ibaraki, Japan
 
  The linac of Japan Proton Accelerator Research Complex (J-PARC), which is an injector to the synchrotron, comprises a 3-MeV RFQ, 50-MeV DTLs and the 181-MeV Separated-type DTLs. In order to increase the beam power of the synchrotron, the task of the 400-MeV energy upgrade of the linac started from March 2009. The tanks of the Annular-ring Coupled Structure (ACS) linac, RF sources, beam monitors and utilities are in production. Although some peripheral components of the ACS linac are prepared previously, the all ACS tanks will be installed and conditioned for 4 months from July 2013. Beam commissioning of the 400-MeV linac is scheduled to begin in October and expected to finish at the end of November 2013. In this paper, we present the current status of the energy upgrade and some R&D results for new equipment for ACS linac.  
 
THPB021 Recovery Efforts from the Tohoku Earthquake and Energy Upgrade Preparation of the Beam Transport from the J-PARC Linac to the 3-GeV Synchrotron radiation, beam-transport, synchrotron, vacuum 891
 
  • J. Tamura, H. Ao, H. Asano, T. Morishita, N. Ouchi
    JAEA/J-PARC, Tokai-mura, Japan
  • Y. Sawabe
    MELCO SC, Tsukuba, Japan
 
  In 2013, the beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac is going to be increased from 181-MeV to 400-MeV by adding the annular-ring coupled structure (ACS) at the downstream of the 191-MeV drift tube linac. To install and operate all the ACS cavities in only five months of the energy upgrade shutdown in 2013, we decided to replace and upgrade all the related component of the beam line (cables, magnet power supplies and vacuum control systems) for the 400-MeV operation, in the period of the recovery from the Tohoku Earthquake which caused not negligible damage to the J-PARC accelerator facilities. The present beam line is operated by using some part of the 400-MeV componets. In this paper, the recovery of the beam transport, the present status and the future tasks of the beam energy upgrade will be presented.  
 
THPB022 Beam Phase Measurement for PEFP Linear Accelerator DTL, simulation, LLRF, proton 894
 
  • H.S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, J.Y. Ryu, K.T. Seol, Y.-G. Song
    KAERI, Daejon, Republic of Korea
 
  Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government.
According to the commissioning plan of the PEFP proton linac, an accurate measurement of beam phase is essential, especially for setting up the RF operating parameters of DTL. Beam position monitors (BPMs) installed between DTL tanks can provide information about the beam phase as well as about the beam transverse position. By using a BPM as a beam phase monitor, beam phase can be measured without additional devices on the linac or the beam line. The signals from 4 electrodes in the BPM can be summed by using a 4-way RF combiner, by which the effect of the transverse beam offset on the phase measurement can be eliminated. The combined BPM signal (350 MHz) is mixed with LO signal (300 MHz) and down-converted to IF signal (50 MHz), then fed into the signal processing unit, where the phase information is extracted by using IQ demodulation method with a sampling frequency of 40 MHz. In this paper, the beam phase measurement system and signal processing scheme will be presented.
 
 
THPB023 Linac Construction for China Spallation Neutron Source DTL, rfq, neutron, cavity 897
 
  • S. Fu, J. Li, H.C. Liu, H.F. Ouyang, X. Yin
    IHEP, Beijing, People's Republic of China
 
  Construction of China Spallation Neutron Source(CSNS) has been launched in September 2011. CSNS accelerator will provide 100kW proton beam on a target at beam energy of 1.6GeV. It consists of an 80MeV H linac and 1.6GeV rapid cycling synchrotron. Based on the prototyping experience, CSNS linac, including the front end and four DTL tanks, has finalized the design and started procurement. In this paper, we will first present an outline of the CSNS accelerator in its design and construction plan. Then the major prototyping results of the linac will be presented. Finally the linac construction progress in recent will be updated.  
 
THPB024 Main Linac Physics Design Study of the C-ADS Project emittance, cavity, solenoid, lattice 900
 
  • F. Yan, Z. Li, C. Meng, J.Y. Tang
    IHEP, Beijing, People's Republic of China
 
  Funding: The pilot special funds of Chinese Academy of Science
The Chinese ADS project is proposed to build a 1000MW Accelerator Driven sub-critical System before 2032. The accelerator will be operating on CW mode with 10mA average current and the final energy is 1.5GeV. The whole linac are composed of two major sections: the Injector section and the main linac section. There are two different schemes for the Injector section. InjectorI is basing on 325MHz RFQ and superconducting spoke cavities and Injector II is basing on 162.5MHz RFQ and superconducting HWR cavities. The main linac design will be different for different Injector choice. If Injector II scheme is adopted, the main linac bunch current will be doubled. In this paper we studied the main linac design basing on InjectorII scheme. The design principles and the priliminary design results is presented.
 
 
THPB027 Progress of one of 10 MeV superconducting proton linear Injectors for C-ADS rfq, proton, cavity, niobium 909
 
  • Y. He, J. Meng, A. Shi, Z.J. Wang, J.X. Wu, W. Wu, H.S. Xu, Z. Xu, B. Zhang, J.H. Zhang, S.H. Zhang, Z.M. Zhang, H.W. Zhao, Z.Z. Zhou
    IMP, Lanzhou, People's Republic of China
  • D. Li
    LBNL, Berkeley, California, USA
 
  A 10 MeV superconducting proton linac is being design and constructing at Institute of Modern Physics (IMP) of Chinese Academy of Sciences (CAS). This proton linac is one of two injectors for Chinese ADS project. It is to validate one of concepts for C-ADS front end, to demonstrate the low beta acceleration, to minimize the risk of key technoledges within the Reference Design. It consists of a 2.1 MeV RFQ and two cryomodules hosting 8 HWR cavities. The basic frequecy is 162.5 MHz. The physical design of linac and the progess of prototypes for solid state amplifiers, superconducting solenoids, supercondecting HWRs, ion source, and RFQ are presented in the paper.  
 
THPB028 The ESS Low Energy Beam Transport Line Design rfq, solenoid, ion, emittance 912
 
  • L. Neri, L. Calabretta, A.C. Caruso, L. Celona, S. Gammino, A. Longhitano, D. Mascali
    INFN/LNS, Catania, Italy
  • B. Cheymol, A. Ponton
    ESS, Lund, Sweden
 
  The linear accelerator of the European Spallation Source (ESS) will deliver proton beams of 50 mA and 2.5 GeV onto the 5 MW neutron production target. The Proton Source for ESS (PS-ESS) [1] is based on the experience of TRIPS and VIS developed at LNS Catania [2,3]. A two solenoid Low Energy Beam Transport (LEBT) is foreseen to match the beam into the first acceleration stage, the Radio-Frequency Quadrupole (RFQ) [4]. Beam production means also detailed characterization of produced beam, with this scope the LEBT houses many instrumentation devices and use different techniques that will be described in this work. The LEBT will be also equipped with an electrostatic chopper in order to remove the unwanted part of the beam pulse during the natural rise and fall times of the ion source. Beam dynamics calculations of the LEBT have been carried out considering also the Space Charge Compensation (SCC) produced by the interaction of the beam with the residual gas, and its effect on beam transport and chopping. Particular emphasis has been put on the evaluation of the beam transient behavior, due to the chopping process, at the entrance of the RFQ, results of the study are presented in this paper.  
 
THPB029 The ESS RFQ Beam Dynamics Design rfq, proton, emittance, DTL 915
 
  • A. Ponton
    ESS, Lund, Sweden
 
  to be added  
 
THPB030 DTL Design for ESS DTL, simulation, proton, drift-tube-linac 918
 
  • M. Comunian, F. Grespan, A. Pisent
    INFN/LNL, Legnaro (PD), Italy
  • R. De Prisco
    Lund University, Lund, Sweden
  • M. Eshraqi
    ESS, Lund, Sweden
  • P. Mereu
    INFN-Torino, Torino, Italy
 
  In the present design of the European Spallation Source (ESS) accelerator, the Drift Tube Linac (DTL) will accelerate a proton beam of 50 mA pulse peak current from 3 to 80 MeV. It is designed to operate at 352.2 MHz, with a duty cycle of 4% (3 ms pulse length, 14 Hz repetition period). Permanent magnet quadrupoles (PMQs) are used as focusing elements in a FODO lattice scheme, which leaves space for steerers and diagnostics . In this paper beam dynamics studies and preliminary RF design are shown, including constraints in terms of quadrupole dimensions, total length, field stability, RF power, peak electric field.  
 
THPB032 Beam Dynamics Design Aspects for a Proposed 800 MeV H ISIS Linac cavity, DTL, quadrupole, rfq 924
 
  • D.C. Plostinar, C.R. Prior, G.H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  Several schemes have been proposed to upgrade the ISIS Spallation Neutron Source at Rutherford Appleton Laboratory (RAL). One scenario is to develop a new 800 MeV, H linac and a ~3 GeV synchrotron, opening the possibility of achieving several MW of beam power. In this paper the design of the 800 MeV linac is outlined with an emphasis on the beam dynamics design philosophy. The linac consists of a 3 MeV Front End similar to the one now under construction at RAL (the Front End Test Stand -FETS). Above 3 MeV, a 324 MHz DTL will be used to accelerate the beam up to ~75 MeV. At this stage a novel collimation system will be added to remove the halo and the far off-momentum particles. To achieve the final energy, a 648 MHz superconducting linac will be employed using three families of elliptical cavities with transition energies at ~196 MeV and ~412 MeV.  
 
THPB034 Status of the FAIR 70 MeV Proton Linac proton, rfq, cavity, DTL 927
 
  • L. Groening, W.A. Barth, R. Berezov, G. Clemente, P. Forck, R. Hollinger, A. Krämer, C. Mühle, J. Pfister, G. Schreiber, J. Trüller, W. Vinzenz, C. Will
    GSI, Darmstadt, Germany
  • N. Chauvin, O. Delferrière, O. Tuske
    CEA/IRFU, Gif-sur-Yvette, France
  • B. Koubek, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
  • B. Launé, J. Lesrel
    IPN, Orsay, France
  • C.S. Simon
    CEA/DSM/IRFU, France
 
  To provide the primary proton beam for the FAIR anti-proton research program, a 70 MeV, 70 mA linac is currently under design & construction at GSI. The nc machine comprises an ECR source, a 3 MeV RFQ, and a DTL based on CH-cavities. Up to 36 MeV pairs of rf-coupled cavities (CCH) are used. A prototype cavity has been built and is prepared for high power rf-testing. An overview of the status as well as on the perspectives of the project is given.  
 
THPB035 Experience with a 4-Rod CW Radio Frequency Quadrupole rfq, ion, damping, resonance 930
 
  • P. Gerhard, W.A. Barth, L.A. Dahl, W. Hartmann, G. Schreiber, W. Vinzenz, H. Vormann
    GSI, Darmstadt, Germany
 
  Since 1991 the High Charge State Injector (HLI) provides heavy ion beams for the linear accelerator UNILAC at GSI*. It is equipped with an ECR ion source and an RFQ-IH linac which accelerates highly charged ion beams with high duty factor of up to 30% to 1.4 MeV/u for further acceleration in the Alvarez DTL of the UNILAC. Main user of these beams is the Super Heavy Element (SHE) research, one of the outstanding projects at GSI**. Experiments like TASCA and SHIP strongly benefit from the high average beam intensities. After two decades of successful operation the four-rod Radio Frequency Quadrupole (RFQ) accelerator was replaced in 2010 by a newly designed RFQ of the same type**. Besides higher beam transmission, the principal intention of this upgrade was to raise the duty factor up to 100%, since the HLI is foreseen as injector for the upcoming cw linac dedicated to the SHE program**. Commissioning and operational experience from the first years revealed that this goal could not be reached easily. In this paper we present the RFQ design, commissioning results, operational experience and future activities.
* N. Angert et al., EPAC92, Berlin, Germany (1992), p. 167
** L. Dahl et al., LINAC10, Tsukuba, Japan (2010), MOP042, and references therein
 
 
THPB036 The New Option for a Front End of Ion Linac rfq, ion, DTL, proton 933
 
  • A.D. Kovalenko
    JINR, Dubna, Moscow Region, Russia
  • A. Kolomiets
    ITEP, Moscow, Russia
 
  The standard ion linac front-end consisting of RFQ, two tanks of accelerating IH-structures, MEBTs with matching and focusing elements is modified to achieve better performances. Special vane section that provides the same beam transformation as debuncher and quadrupole triplet is added within the RFQ tank, whereas superconducting focusing elements, solenoids, for example, are used between the IH - structure tanks. Test frond end was designed to provide the output beam energy up to 4 MeV/u for the particles with charge-to-mass ratio of 0.16 < q/m ≤ 1. Results of beam dynamics simulation are presented. Possible application of the considered scheme for the NICA facility at JINR (Dubna, Russia) is discussed.  
 
THPB038 Assembly and RF Tuning of the Linac4 RFQ at CERN rfq, quadrupole, dipole, cavity 939
 
  • C. Rossi, A. Dallocchio, J. Hansen, J.-B. Lallement, A.M. Lombardi, S.J. Mathot, D. Pugnat, M.A. Timmins, G. Vandoni, M. Vretenar
    CERN, Geneva, Switzerland
  • M. Desmons, A. France, Y. Le Noa, J. Novo, O. Piquet
    CEA/DSM/IRFU, France
 
  The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.  
 
THPB043 The RFQ injector for the Radioactive Ion Beam of SPES Project rfq, ion, emittance, injection 951
 
  • M. Comunian, F. Grespan, A. Palmieri, A. Pisent
    INFN/LNL, Legnaro (PD), Italy
 
  A Continous Wave Radio Frequency Quadrupole Accelerator has been designed for the Radioactive Ion Beam of SPES Project to be used as an Injector of the ALPI Linac. The RFQ frequency is 80 MHz for an input energy of 40 keV, with output energy of 5 MeV and ion ratio q/A<= 1/7. Particular care has been put in the design phase to include an internal bunching section able to reduce the longitudinal output emittance. The details of the RF study of such a cavity are included as well.  
 
THPB047 Test RFQ for the MAX Project rfq, simulation, cavity, proton 960
 
  • M. Vossberg, H. Klein, H. Podlech, A. Schempp, C. Zhang
    IAP, Frankfurt am Main, Germany
  • A. Bechtold
    NTG Neue Technologien GmbH & Co KG, Gelnhausen, Germany
 
  As a part of the MAX project it will be demonstrated by simulations and thermal measurements, that a 4-rod-RFQ is the right choice even at cw-operation. A 4-rod Test-RFQ with a resonance frequency of 175 MHz has been designed and built for the MAX-Project. But the RFQ had to be modified to solve the cooling problem at cw-operation, the geometrical precision had to be improved as well as the rf-contacts. The developments led to a new layout and a sophisticated production procedure of the stems and the electrodes. Calculations show an improved Rp-value leading to powerlosses of ca. 25 kW/m only, which is about half of the powerlosses which could be achieved safely at cw-operation of the similar Saraf-RFQ. Thermal measurements and simulations with the single components are in progress. The temperature distribution in cw-operation will be measured and the rf-performance checked.  
 
THPB049 Tuning Studies on 4-Rod-RFQs rfq, simulation, resonance, coupling 963
 
  • J.S. Schmidt, B. Klump, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  A NI LabVIEW based Tuning Software has been devel- oped to structure the tuning process of 4-rod Radio Fre- quency Quadrupole s (RFQs). Its results are compared to measurement data of 4-rod RFQs in different frequency ranges. For the optimization of RFQ design parameters, a certain voltage distribution along the electrodes of an RFQ is assumed. Therefore an accurate tuning of the voltage distribution is very important for the beam dynamic prop- erties of an RFQ. A variation can lead to particle losses and reduced beam quality especially at higher frequencies. Our electrode design usually implies a constant longitudi- nal voltage distribution. For its adjustment tuning plates are used between the stems of the 4-rod-RFQ. These pre- dictions are based, in contrast to other simulations, on mea- surements to define the characteristics of the RFQ as it was build - not depending on assumptions of the design. This will lead to a totally new structured process of tuning 4- rod-RFQs in a broad range of frequencies by using the pre- dictions of a software. The results of these studies are pre- sented in this paper.  
 
THPB051 Improvements at the BNL 200 MeV Linac rfq, solenoid, emittance, beam-transport 969
 
  • D. Raparia, J.G. Alessi, B. Briscoe, J.M. Fite, O. Gould, V. LoDestro, M. Okamura, J. Ritter, A. Zelenski
    BNL, Upton, Long Island, New York, USA
 
  After reconfiguration of the low energy (35 keV) and the medium energy (750 keV) transport lines in 2009-10, the Brookhaven linac delivered the highest intensity beam since it was built in 1970 (~120 μA average current of H to the Brookhaven Linac Isotope Producer). It also delivered lower emittance polarized H ion beam for the polarized program at RHIC. To increase the intensity further, the match into the RFQ was improved by reducing the distance from the fnal focusing solenoid to the RFQ and replacing the buncher in the 750 keV line with one with higher Q value, to allow operation at higher power. We also found that drift –tube linac tank number 7 was operating with about 1 MW lower power than design. The transmission efficiencies and beam quality will be discussed in the paper.  
 
THPB052 Recent Progress with the J-PARC RFQs rfq, emittance, vacuum, simulation 972
 
  • Y. Kondo, K. Hasegawa, T. Morishita
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
 
  In this paper, we will report recent topics about J-PARC RFQs. First, the operating RFQ (RFQ I) have been recovered from the long shutdown due to the earthquake. This RFQ have been suffered from breakdown problem since 2008, therefore we have been developing a back-up RFQ (RFQ II). In April 2012, the high power test was successfully performed. Finally, we are fabricating a new RFQ for the beam-current upgrade of the J-PARC linac (RFQ III). The status of these RFQs are described.  
 
THPB055 Numerical Simulations of ProjectX/PXIE RFQ rfq, emittance, simulation, space-charge 975
 
  • J.-F. Ostiguy, A. Saini, N. Solyak
    Fermilab, Batavia, USA
 
  Funding: Fermi Research Alliance, LLC under DOE Contract No. De-AC02-07CH11359
Project-X is a proposed superconducting linac-based high intensity proton source at Fermilab. The machine first stages operate in CW mode from 2.1 to 3 GeV and a high bandwidth chopper is used to produce the required bunch patterns. A 162.5 MHz CW RFQ accelerates the beam from 30 keV to 2.1 MeV. A concern with CW operation is that losses either within the RFQ or in the dowstream modules should be well-understood and remain very low to ensure safe and/or reliable operation. In this contribution, we investigate the suitability of existing RFQ codes and model the PXIE RFQ (ProjectX test facility) designed constructed by LBNL to make useful predictions of loss patterns and phase space distribution.
 
 
THPB064 Beam Dynamics Tools for Linacs Design electron, simulation, beam-loading, synchrotron 987
 
  • A.S. Setty
    THALES, Colombes, France
 
  In the last 25 years, we have been using our in house 3D code PRODYN * for electron beam simulations. We have also been using our in house code SECTION for the design of the travelling wave accelerating structures and the beam loading compensation. PRODYN follows in time, the most complicated electron trajectories with relativistic space-charge effects. This code includes backward as well as forwards movements. This paper will describe those two codes and will give some simulations and measurements results.
* D. Tronc and A. Setty, Electrons RF auto-focusing and capture in bunchers, Linear Accelerator Conference 1988, Virginia.
 
 
THPB079 Development of a Superconducting Focusing Solenoid for CADS solenoid, focusing, cavity, dipole 1011
 
  • W. Wu, S.F. Han, Y. He, L.Z. Ma, D.S. Ni, Z.J. Wang, B.M. Wu, W.J. Yang, X.L. Yang, S.J. Zheng, L. Zhu
    IMP, Lanzhou, People's Republic of China
 
  A superconducting focusing solenoid has been designed and developed for the China Accelerator Driven System (CADS). In order to meet the requirement of focusing strength and fringe field while minimizing physical size of the solenoid, the novel optimizing design method based on linear programming method was employed. In this report, we will introduce the design of the solenoid including magnetic field optimization, mechanical design and quench protection. The fabrication and the test results of the solenoid will also be introduced in this report.  
 
THPB091 Machine Protection Issues and Solutions for Linear Accelerator Complexes beam-losses, instrumentation, controls, radiation 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.  
 
THPB092 Recent Improvements in SPring-8 Linac for Early Recovery from Beam Interruption klystron, gun, electron, power-supply 1035
 
  • S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo-ken, Japan
 
  The 1GeV SPring-8 linac is an injector for the SPring-8 synchrotron radiation storage ring with 8GeV booster synchrotron. In recent years, backup systems were installed to eliminate long-time interruption of the beam injections: The main gun system is usually operated, and the second gun is always pre-heated and can inject electron beams into a buncher section with an interval of several minutes in case the main gun failed. The first klystron, that feeds RF powers to the buncher system and the downstream klystrons, can be relieved by the next klystron with an interval of about 20 minutes by switching the waveguide circuit. When one of the eleven working klystrons faults, one of standby klystrons, which are kept for hot spares on line, is automatically activated to accelerate beams instead of the failed one without beam interruption. The total downtime in FY2012 was 0.12% in top-up operation user time. The averaged fault frequency was 0.2 times per day.  
 
THPB097 FRIB Front End Design Status rfq, ion, ECR, ion-source 1047
 
  • E. Pozdeyev, N.K. Bultman, G. Machicoane, G. Morgan, X. Rao, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  • V.L. Smirnov, S.B. Vorozhtsov
    JINR, Dubna, Moscow Region, Russia
  • J. Stovall
    CERN, Geneva, Switzerland
  • L.T. Sun
    IMP, Lanzhou, People's Republic of China
  • L.M. Young
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams (FRIB) will provide a wide range of primary ion beams for nuclear physics research with rare isotope beams. The FRIB SRF linac will be capable of accelerating medium and heavy ion beams to energies beyond 200 MeV/u with a power of 400 kW on the fragmentation target. This paper presents the status of the FRIB Front End designed to produce uranium and other medium and heavy mass ion beams at world-record intensities. The paper describes the FRIB high performance superconducting ECR ion source, the beam transport designed to transport two-charge state ion beams and prepare them for the injection in to the SRF linac, and the design of a 4-vane 80.5 MHz RFQ. The paper also describes the integration of the front end with other accelerator and experimental systems.
 
 
FR1A04 In Flight Ion Separation using a Linac Chain rfq, DTL, ISAC, TRIUMF 1059
 
  • M. Marchetto, F. Ames, B. Davids, R.E. Laxdal, A.C. Morton
    TRIUMF, Vancouver, Canada
 
  The ISAC accelerator complex now can accelerate radioactive heavy ion beams to above the Coulomb Barrier. Recently an ECR type charge state booster has been added to allow the acceleration of radioactive beams with masses A>30. A characteristic of the ECR source is the efficient ionization of background species that can overwhelm the low intensity RIB beam. The long linac chain at ISAC can be used to provide some in flight separation both in time domain and in spatial domain analogous to fragment separators at in-flight fragmentation facilities. The talk will summarize the work done at TRIUMF to develop tools to aid in the filtration and diagnosis of beam purity in the post acceleration of charge bred beams. Marco Marchetto has been leading this effort.  
slides icon Slides FR1A04 [24.174 MB]  
 
FR1A05 SARAF Phase II P/D 40 MeV Linac Design Studies rfq, cryomodule, proton, emittance 1064
 
  • P.N. Ostroumov, Z.A. Conway, M.P. Kelly, A. Kolomiets, S.V. Kutsaev, B. Mustapha
    ANL, Argonne, USA
  • J. Rodnizki
    Soreq NRC, Yavne, Israel
 
  Funding: This work was supported by the ANL WFO No. 85Y47
The Soreq NRC initiated the establishment of SARAF – Soreq Applied Research Accelerator Facility. SARAF will be a multi-user facility for basic research, e.g., nuclear astrophysics, radioactive beams, medical and biological research; neutron based non-destructive testing (using a thermal neutron camera and a neutron diffractometer) and radio-pharmaceuticals research, development and production. The SARAF continuous wave (CW) accelerator is planned to produce variable energy (5-40 MeV) proton and deuteron beam currents (0.04-5 mA). Phase I of SARAF (ion source, radio-frequency quadrupole (RFQ), and one cryomodule housing 6 half-wave resonators (HWR) was installed and being operated at Soreq NRC delivering CW 1mA 3.5 MeV proton beams and low-duty cycle (0.0001) 0.3 mA 4.7 MeV deuteron beams. SARAF is designed to enable hands-on maintenance, which implies very low beam losses for the entire accelerator. The physics design of two options is explored to subsequently develop a conceptual design for selected option for extending the linac to its planned beam parameters (SARAF Phase-II: 40 MeV, 5 mA protons and deuterons).
 
slides icon Slides FR1A05 [3.459 MB]  
 
FR2A01 Recovery of the J-PARC Linac from the Earthquake DTL, vacuum, ion, rfq 1069
 
  • K. Hasegawa
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  Following the amazingly quick recovery from the disastrous earthquake in March 2011, and in the interests of promoting robust designs of linacs, it would be interesting to learn what the J-PARC team reckons are the key features of accelerator design and construction that lead to strong and reliable hardware.  
slides icon Slides FR2A01 [3.928 MB]