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linac

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MOYBGM01 Global R&D Effort for the ILC Linac Technology cryogenics, linear-collider, acceleration, collider 12
 
  • A. Yamamoto
    KEK, Ibaraki
  The presentation will cover the ongoing ILC R&D program in the field of superconducting accelerating structures, accelerator modules and rf systems. In addition to technical/scientific aspects, a view of the organisational challenges of this global R&D programme and how they are addressed will be described.  
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MOZAG01 Simulations of the Emittance Compensation in Photoinjectors and Comparison with SPARC Measurements emittance, simulation, gun, space-charge 21
 
  • C. Ronsivalle, L. Giannessi, M. Quattromini
    ENEA C. R. Frascati, Frascati (Roma)
  • A. Bacci, A. R. Rossi, L. Serafini
    INFN-Milano, Milano
  • E. Chiadroni, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, B. Marchetti, M. Migliorati, A. Mostacci, L. Palumbo, C. Vaccarezza
    INFN/LNF, Frascati (Roma)
  • A. Cianchi
    INFN-Roma II, Roma
  FEL photoinjectors are based on the emittance compensation process, by which a high brightness beam can be accelerated without degradation. The experimental results obtained in the SPARC facility for which the beam dynamics has been extensively simulated confirm the theoretical predictions. The paper illustrates the most relevant beam dynamics results as well as a comparison between simulations and measurements.  
slides icon Slides  
 
MOZAM01 Review of Accelerators for Radioactive Beams cyclotron, ion, proton, target 41
 
  • Y. Blumenfeld
    IPN, Orsay
  The technical difficulties that have set up hurdles for the realisation of radioactive ion beam facilities have not discouraged the design of new high-performance accelerator systems. The talk should describe the state of accelerators for radioactive ion beams around the world.  
slides icon Slides  
 
MOZCM01 Commissioning and Operation of the 1.5 GeV Harmonic Double Sided Microtron at Mainz University dipole, injection, recirculation, microtron 51
 
  • A. Jankowiak, K. Aulenbacher, D. Bender, O. Chubarov, M. Dehn, H. Euteneuer, F. Fichtner, B. Gutheil, F. Hagenbuck, R. H. Herr, P. Jennewein, K.-H. Kaiser, W. Klag, H. J. Kreidel, U. Ludwig-Mertin, A. Nuck, J. R. Röthgen, B. Seckler, G. S. Stephan, V. Tioukine, G. Woell, Th. Zschocke
    IKP, Mainz
  In December 2006 the 4th stage of the Mainz Microtron MAMI has been succesfully set into operation expanding the 855MeV output energy of the existing three racetrack microtron cascade (MAMI B) to 1508MeV. This new recirculating cw electron accelerator is realised as a worldwide unique Harmonic Double Sided Microtron (HDSM, [*]). Since February 2006, after only 14 day of commissioning, the HDSM serves as part of the MAMI C accelerator cascade in routine 24h a day operation for nuclear physics experiments. We will give a brief overview of the design and construction of the HDSM and describe in detail the experiences gained during commissioning and the first year of operation.

[*] A. Jankowiak et al., "Status Report on the Harmonic Double Sided Microtron of MAMI C", Proceedings EPAC2006, Edinburgh, p. 834

 
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MOPC001 The Status of TAC Infrared Free Electron Laser (IR-FEL) Facility undulator, electron, laser, free-electron-laser 61
 
  • A. Aksoy, Ö. Karsli, B. Ketenoglu, O. Yavas
    Ankara University, Faculty of Engineering, Tandogan, Ankara
  • A. K. Ciftci, Z. Nergiz
    Ankara University, Faculty of Sciences, Tandogan/Ankara
  • E. Kasap
    Gazi University, Faculty of Science and Arts, Ankara
  Turkish Accelerator Complex (TAC) Infrared Free Electron Laser (IR-FEL) project was approved by State Planning Organization (DPT) as a first step of the national project. The facility will consist of 15 40 MeV superconducting electron linac and two different optical cavity systems with different undulator period length to obtain FEL in 2 185 microns wavelengths range. In this study, the results of optimization and current status of TAC IR FEL facility is presented. The facility will give opportunity to search applications in material science, biotechnology, nonlinear optics, semiconductors, medicine and chemistry using IR-FEL in Turkey and our region.  
 
MOPC006 Seeding of the Test FEL at MAX-lab laser, electron, gun, alignment 76
 
  • N. Cutic, F. Curbis, F. Lindau, S. Thorin, S. Werin
    MAX-lab, Lund
  The test FEL at MAX-lab has recently been completed. The system will be seeded at 263 nm by a tripled Ti:sapphire laser synchronized to the RF system and the gun laser. Issues important for the seeding will be presented, ranging from the laser system via the layout of photon and electron optics to timing/synchronization and the theoretical approach. Experimental results on the seeding operation will also be presented.  
 
MOPC007 Status and Upgrade Program of the FERMI@ELETTRA Linac laser, gun, klystron, controls 79
 
  • G. D'Auria, A. O. Borga, S. Di Mitri, O. Ferrando, G. C. Pappas, A. Rohlev, A. Rubino, C. Serpico, M. Trovo, A. Turchet, D. Wang
    ELETTRA, Basovizza, Trieste
  FERMI@ELETTRA is a seeded FEL user facility under construction at Sincrotrone Trieste, Italy. It will use the existing normal conducting S-band linac and with the installation of seven accelerating sections received from CERN after the LIL decommissioning, will be operated at 1.2 GeV. After the successful commissioning of the new injector system of ELETTRA, the linac has been disconnected from the storage ring and now is being revised and upgraded with the installation of new important subsystems, i.e., a new photoinjector, bunch compressors, laser heater, additional accelerating structures, etc. Here a description of the upgrade program as well as the ongoing activities on the main parts of the machine are reported and discussed.  
 
MOPC008 The Impact of PSK Timing on Energy Stability of e-Beam at FERMI@ELETTRA klystron, simulation, synchrotron, injection 82
 
  • G. D'Auria, P. Delgiusto, M. M. Milloch, C. Serpico, D. Wang
    ELETTRA, Basovizza, Trieste
  The existing linac sections S1-S7 at ELETTRA will be upgraded for the FERMI@ELETTRA FEL project. These seven sections are 3/4 π-mode backward traveling wave (BTW) constant-impedance structures, powered by 45-MW klystrons (Thales TH 2132A) and with a SLED system to increase the RF peak power. Because of the strict requirement on the pulse-to-pulse beam energy stability (<0.1%) of the FERMI@ELETTRA project, the impact of phase shift keying (PSK), the timing of phase flipping, on beam energy needs to be revisited and evaluated. Here the results obtained with a simulation model built up by use of MATLAB simulink are present and discussed.  
 
MOPC010 Injector System for X-ray FEL at SPring-8 emittance, gun, bunching, electron 85
 
  • H. Hanaki, T. Asaka, H. Ego, H. Kimura, T. Kobayashi, S. Suzuki
    JASRI/SPring-8, Hyogo-ken
  • T. Hara, A. Higashiya, T. Inagaki, N. Kumagai, H. Maesaka, Y. Otake, T. Shintake, H. Tanaka, K. Togawa
    RIKEN/SPring-8, Hyogo
  The SPring-8 X-FEL based on the SASE process has been developed to generate X-rays of 0.1 nm by the combination of an 8 GeV high gradient linac (400 m) and a mini-gap undulator of in-vacuum type (90 m). The design goals of the slice beam emittance and peak current at the end of the linac are 1 π mm mrad and 3 kA, respectively. The injector of the linac generates an electron beam of 1 nC, accelerates it up to 30 MeV, and compresses its bunch length down to 20 ps step by step. The injector has been designed on the basis of the SCSS test accelerator. We adopted the following keys to toward the goals:
  1. A 500 kV thermionic gun (CeB6) without a control grid ejecting a beam holding the low rms emittance of 1.1 π mm mrad,
  2. a beam deflector downstream gating the beam to form a bunch of a 1 ns length,
  3. multi-stage RF structures (238, 476 and 1428 MHz) bunching and accelerating the beam gradually to maintain the initial emittance, and
  4. extra RF cavities of 1428 and 5712 MHz linearizing the energy chirp of the beam bunch to achieve the bunch compression resulting the required peak current.
 
 
MOPC015 Start-to-End Simulations of the PSI 250 MeV Injector Test Facility gun, emittance, booster, simulation 100
 
  • Y. Kim, A. Adelmann, R. J. Bakker, M. Dehler, R. Ganter, T. Garvey, A. Oppelt, M. Pedrozzi, J.-Y. Raguin, L. Rivkin, A. Streun, F. Stulle, A. F. Wrulich
    PSI, Villigen
  From 2003, PSI has been investigating the advanced Low Emittance Gun (LEG) based 6 GeV PSI XFEL facility to supply coherent, ultra-bright, and ultra-fast XFEL photon beams covering from 0.1 nm to 10 nm. To build whole facility within a 800 m space, required beam parameters in front of undulators are challenging. For the first two FEL beamlines (FEL 1 and FEL 2), the required normalized slice emittance, slice energy spread, and peak current are about 0.2 mm.mrd, 0.6 MeV, and 1.5 kA, respectively. However, the required beam parameters for the third FEL beamline (FEL 3) covering 1 nm to 10 nm are somewhat flexible. Therefore PSI has been developing two different gun technologies. The 1 MV high gradient pulsed diode and field emission based advanced LEG will be used for first two FEL beamlines, while the CTF3 gun type V based conventional RF photoinjector will be used for the third FEL beamline. To test those two injector technologies, a dedicated 250 MeV injector test facility will be constructed at PSI from 2008. In this paper, we describe beam dynamics in two accelerator optimizations of the CTF3 RF gun based 250 MeV injector test facility for the PSI XFEL project.  
 
MOPC016 Status of the CUTE-FEL Project undulator, electron, klystron, gun 103
 
  • S. Krishnagopal, B. Biswas, S. K. Gupta, U. Kale, A. Kumar, V. Kumar, S. Lal, P. Nerpagar, K. K. Pant, A. Patel
    RRCAT, Indore (M. P.)
  We are building a Compact Ultrafast TErahertz Free-Electron Laser (CUTE-FEL), designed to lase around 80 microns, driven by a 10 MeV electron beam, and using a 5 cm period, 2.5 m long undulator. We present the latest status of the project, including acceleration and commissioning trials.  
 
MOPC026 Status of SPARX Project undulator, radiation, electron, laser 121
 
  • L. Palumbo
    Rome University La Sapienza, Roma
  The SPARX project consists in an X-ray-FEL facility jointly supported by MIUR (Research Department of Italian Government), Regione Lazio, CNR, ENEA, INFN and Rome University Tor Vergata. It is the natural extension of the ongoing activities of the SPARC collaboration. The aim is the generation of electron beams characterized by ultra-high peak brightness at the energy of 1.2 and 2.4 GeV, for the first and the second phase respectively. The beam is expected to drive a single pass FEL experiment in the range of 13.5-6 nm and 6-1.5 nm, at 1.2 GeV and 2.4 GeV respectively, both in SASE and Seeded FEL configurations.  
 
MOPC029 Longitudinal Structure of Electron Bunches at the Micrometer Scale from Spectroscopy of Coherent Transition Radiation radiation, electron, collective-effects, space-charge 130
 
  • B. Schmidt, C. Behrens, S. Wesch
    DESY, Hamburg
  • H. Delsim-Hashemi, J. Rossbach, P. Schmüser
    Uni HH, Hamburg
  At the free electron laser FLASH in Hamburg, a longitudinal bunch compression scheme is used resulting in a longitudinal current profile with a narrow leading spike. Part of this spike is responsible for producing high-intensity short FEL pulses via the SASE process. The width and the structure of the current spike, which are key parameters for the efficiency of the SASE process, are barely accessible to direct measurements in the time domain. Using an infrared multi-stage grating spectrometer, we have studied the spectral composition of coherent transition radiation from single electron bunches. The data show that the 'fundamental width' of the current spike is about 40 fs (fwhm) with prominent substructures down to the 10 fs scale. The intensity fluctuations of coherent radiation in the corresponding wavelength range are strongly correlated to the fluctuations of the FEL pulse energy. Extension of the method to the near infrared regime have revealed micro-structures with characteristic lengths from a few micrometers down to fractions of a micrometer. Their interrelation with the parameters of the electron beam and the compression system have been studied.  
 
MOPC030 Operation of FLASH at 6.5 nm Wavelength radiation, laser, gun, electron 133
 
  • S. Schreiber, B. Faatz, K. Honkavaara
    DESY, Hamburg
  FLASH, the Free-Electron-Laser at DESY, Germany has been upgraded in 2007. A 6th accelerating module with eight 9-cell superconducting cavities of the TESLA type has been installed. In addition, another module has been replaced and the tuners of a third module have been repaired. In September 2007, a beam energy of 1 GeV has been achieved for the first time, followed by lasing at 6.5 nm shortly after. With this remarkable achievement, the initial design goals of the FEL in terms of beam energy and wavelength have been reached.  
 
MOPC033 Sapphire - A High Peak Brightness X-Ray Source as a Possible Option for a Next Generation UK Light Source gun, emittance, klystron, undulator 142
 
  • R. P. Walker, C. Christou, J. H. Han, J. Kay
    Diamond, Oxfordshire
  • R. Bartolini
    JAI, Oxford
  In the UK there is increasing interest in a radiation source which would provide ultra-fast (from 100 fs down to a few fs and potentially below) multi-keV X-ray pulses with high peak brightness, in order to study rapid dynamical processes in electronic and molecular systems, complementary to the newly operational Diamond Light Source which has been designed principally for high time-averaged X-ray brightness. In this paper we present the results of our initial studies for one option for a cost-effective, staged, linac based source suitable as a national facility which can act additionally as a portal to larger X-ray free-electron laser facilities in Europe, the US and Japan.  
 
MOPC034 Collective Effects in a Short-Pulse FEL Driver emittance, electron, laser, space-charge 145
 
  • P. H. Williams, H. L. Owen
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Bassi
    Cockcroft Institute, Warrington, Cheshire
  • S. Thorin
    MAX-lab, Lund
  There is much interest in the provision of coherent, tunable VUV and soft X-ray pulses of duration less than 10fs. A 1.3 GHz linac driver concept has been developed, and in this paper we address collective effects in the short electron bunches using start-to-end modelling. In particular, we examine the limitations from coherent radiation and induced microbunching, and their impact on the design of the accelerator system.  
 
MOPC056 Challenges for Beams in an ERL Extension to CESR emittance, electron, undulator, scattering 190
 
  • G. Hoffstaetter, I. V. Bazarov, S. A. Belomestnykh, M. G. Billing, G. W. Codner, J. A. Crittenden, B. M. Dunham, M. P. Ehrlichman, M. J. Forster, S. Greenwald, V. O. Kostroun, Y. Li, M. Liepe, C. E. Mayes, H. Padamsee, S. B. Peck, D. H. Rice, D. Sagan, Ch. Spethmann, A. Temnykh, M. Tigner, Y. Xie
    CLASSE, Ithaca
  • D. H. Bilderback, K. Finkelstein, S. M. Gruner
    CHESS, Ithaca, New York
  Cornell University is planning to build an Energy-Recovery Linac (ERL) X-ray facility. In this ERL design, a 5 GeV superconducting linear accelerator extends the CESR ring. Currently CESR is used for the Cornell High Energy Synchrotron Source (CHESS). The very small electron-beam emittances would produce an x-ray source that is significantly better than any existing storage-ring light source. However, providing, preserving, and decelerating a beam with such small emittances has many issues. We describe our considerations for challenges such as optics, space charge, dark current, coupler kick, ion accumulation, electron cloud, intra beam scattering, gas scattering, radiation shielding, wake fields including the CSR wake, and beam stabilization.  
 
MOPC057 R&D Energy Recovery Linac at Brookhaven National Laboratory gun, electron, klystron, diagnostics 193
 
  • V. Litvinenko, D. Beavis, I. Ben-Zvi, M. Blaskiewicz, A. Burrill, R. Calaga, P. Cameron, X. Chang, K. A. Drees, G. Ganetis, D. M. Gassner, H. Hahn, L. R. Hammons, A. Hershcovitch, H.-C. Hseuh, A. K. Jain, A. Kayran, J. Kewisch, R. F. Lambiase, D. L. Lederle, G. J. Mahler, G. T. McIntyre, W. Meng, T. C. Nehring, B. Oerter, C. Pai, D. Pate, D. Phillips, E. Pozdeyev, T. Rao, J. Reich, T. Roser, T. Russo, K. Smith, J. E. Tuozzolo, D. Weiss, N. Williams, K. Yip, A. Zaltsman
    BNL, Upton, Long Island, New York
  • H. Bluem, M. D. Cole, A. J. Favale, D. Holmes, J. Rathke, T. Schultheiss
    AES, Medford, NY
  • J. R. Delayen, L. W. Funk, H. L. Phillips, J. P. Preble
    Jefferson Lab, Newport News, Virginia
  Collider Accelerator Department at BNL is in the final stages of developing the 20-MeV R&D energy recovery linac with super-conducting 2.5 MeV RF gun and single-mode super-conducting 5-cell RF linac. This unique facility aims to address many outstanding questions relevant for high current (up to 0.5 A of average current), high brightness energy-recovery linacs with novel Zigzag-type merger. We present the performance of the R&D ERL elements and detailed commissioning plan.  
 
MOPC059 BBU Limitations for ERLs dipole, beam-transport, recirculation, lattice 199
 
  • E. Wooldridge, C. D. Beard, P. A. McIntosh, B. D. Muratori, S. L. Smith
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The BBU threshold in ERLs is a limitation on the maximum beam current due to the interaction of the electron bunches and the Higher Order Modes (HOMs) contained within the RF cavities. Several factors are involved in determining the threshold current; from the cavity the Q, R/Q and degeneracy of the modes all play an important part. From the beam transport the values of the lattice functions α, β and μ have an effect. We will discuss the limits on these variables to provide a BBU current threshold greater than 100 mA for a multiple cavity machine and what will be required to provide higher currents. Also three different cavity profiles were investigated with the aim of reducing the BBU threshold. The TESLA 9-cell cavity was used as a baseline for comparison against possible 7-cell cavity designs, using the TESLA cell shape for their inner cells. The ends of the 7-cell cavities join to different sized beampipes, with radii of 39 mm and 54 mm, to allow the most of the HOMs to propagate to a broadband HOM absorber. Two different beampipe to cavity to transitions were investigated. The optimised 7-cell cavity will be shown to provide an increase in the BBU threshold.  
 
MOPC061 Progress in R&D Efforts on the Energy Recovery Linac in Japan laser, gun, electron, synchrotron 205
 
  • S. Sakanaka, T. A. Agoh, A. Enomoto, S. Fukuda, K. Furukawa, T. Furuya, K. Haga, K. Harada, S. Hiramatsu, T. Honda, Y. Honda, K. Hosoyama, M. Izawa, E. Kako, T. Kasuga, H. Kawata, M. Kikuchi, H. Kobayakawa, Y. Kobayashi, T. Matsumoto, S. Michizono, T. Mitsuhashi, T. Miura, T. Miyajima, T. Muto, S. Nagahashi, T. Naito, T. Nogami, S. Noguchi, T. Obina, S. Ohsawa, T. Ozaki, H. Sasaki, S. Sasaki, K. Satoh, M. Satoh, M. Shimada, T. Shioya, T. Shishido, T. Suwada, T. Takahashi, Y. Tanimoto, M. Tawada, M. Tobiyama, K. Tsuchiya, T. Uchiyama, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  • R. Hajima, H. Iijima, N. Kikuzawa, E. J. Minehara, R. Nagai, N. Nishimori, M. Sawamura
    JAEA/ERL, Ibaraki
  • H. Hanaki
    JASRI/SPring-8, Hyogo-ken
  • A. Ishii, I. Ito, T. Kawasaki, H. Kudo, N. Nakamura, H. Sakai, S. Shibuya, K. Shinoe, T. Shiraga, H. Takaki
    ISSP/SRL, Chiba
  • M. Katoh
    UVSOR, Okazaki
  • Y. Kobayashi, K. Torizuka, D. Yoshitomi
    AIST, Tsukuba
  • M. Kuriki
    HU/AdSM, Higashi-Hiroshima
  The future synchrotron light sources, based on the energy recovery linacs (ERL), are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The ERL-based light sources are under development at such institutes as the Cornell University, the Daresbury Laboratory, the Advanced Photon Source, and KEK/JAEA. The Japanese collaboration team, including KEK, JAEA, ISSP, and UVSOR, is working to realize the key technologies for the ERLs. Our R&D program includes the developments of ultra-low-emittance photocathode DC guns and of superconducting cavities, as well as proofs of accelerator-physics issues at a small test ERL (the Compact ERL). A 250-kV, 50-mA photo-cathode DC gun is under construction at JAEA. Two single-cell niobium cavities have been tested under high electric fields at KEK. The conceptual design of the Compact ERL has been carried out. We report recent progress in our R&D efforts.  
 
MOPC068 Preliminary Characterization of the Beam Properties of the SPARC Photoinjector emittance, quadrupole, cathode, gun 226
 
  • A. Cianchi
    INFN-Roma II, Roma
  • D. Alesini, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, G. Gatti, B. Marchetti, E. Pace, C. Vaccarezza, C. Vicario
    INFN/LNF, Frascati (Roma)
  • A. Mostacci
    Rome University La Sapienza, Roma
  • C. Ronsivalle
    ENEA C. R. Frascati, Frascati (Roma)
  The SPARC photoinjector is the test prototype of the recently approved SPARX project. It is used as R&D facility to perform accurate beam dynamics studies, comparing measurements and simulations. Emittance measurements at the gun exit and at the full energy has been performed and benchmarked with the simulations.  
 
MOPC086 IFMIF-EVEDA Accelerator: Beam Dump Design vacuum, quadrupole, rfq, shielding 259
 
  • B. Brañas, F. Arranz, G. Barrera, J. M. Gómez, A. Ibarra, D. Iglesias, C. Oliver
    CIEMAT, Madrid
  The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator prototype for verifying the validity of the accelerator design for IFMIF. A beam stop will be used for the RFQ and DTL commissioning as well as for the EVEDA accelerator tests. Therefore, this component must be designed to stop 5 MeV and 9 MeV deuteron beams with a maximum power of 1.12 MW. The first step of the design is the beam-facing material selection. The criteria used for this selection are low neutron production, low activation and good thermomechanical behavior. A thermomechanical analysis with ANSYS has been performed for a few materials which show good behavior from the radiological point of view. The input data are the expected beam shape and divergence at the beam dump entrance produced by the high energy beam line quadrupoles, a conical beam stop shape and the preliminary design of the cooling system. As a conclusion of the previous studies a conceptual design of the beam stop will be presented.  
 
MOPC093 Experimental Study of Radiation Damage in Carbon Composites and Graphite Considered as Targets in the Neutrino Super Beam proton, target, radiation, isotope-production 280
 
  • N. Simos, H. G. Kirk
    BNL, Upton, Long Island, New York
  • K. T. McDonald
    PU, Princeton, New Jersey
  Carbon composites have been of primary interest as materials of choice for a multi-MW neutrino superbeam which desires low-Z pion production target. Beam on target experiments conducted at BNL made the case stronger in their favor, as compared to graphite, by demonstrating their excellent shock resistance which is directly linked with their extremely low thermal expansion. Since target survivability also depends on resistance to prolonged radiation, a series of irradiation damage studies on carbon composites and graphite were launched. While carbon composites at moderate doses exhibited interesting behavior of damage reversal through thermal annealing, at higher dose levels of peak proton fluences >5x1020 protons/cm2 they exhibited serious structural degradation. The experimental study also showed that graphite suffered similar damage when subjected to same fluence level. The paper discusses the findings of the experimental studies focusing on these materials and attempts to explain their structural degradation observed under high proton fluences given the excellent survivability record, especially of graphite, under high neutron fluences in nuclear reactor settings.

Work performed under the auspices of the US DOE.

 
 
MOPC105 Activities of Hitachi Relating to Construction of J-PARC Accelerator power-supply, synchrotron, injection, rfq 310
 
  • Y. Chida, S. Koseki
    Hitachi Ltd., Ibaraki-ken
  • M. Abe
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • K. Nakamura, M. Watanabe, T. Watanabe, T. Watanuki
    Hitachi. Ltd., Hitachi Works, Hitachi-shi
  The Japan Proton Accelerator Research Complex (J-PARC) consists of a 330-m-long linac, a 3-GeV rapid cycle synchrotron with a circumference of 350 m, and a 50-GeV synchrotron with a circumference of 1,570 m. Owing to a collaboration between the Japan Atomic Energy Agency (JAEA) and the High Energy Accelerator Research Organization (KEK), the accelerators will be commencing operations at the site of JAEA Tokai Research and Development Center. The beam commissioning of the entire accelerator system is planned to take place before the end of 2008. Along with the JAEA and KEK, Hitachi has contributed to the construction of the system by manufacturing some major equipment with specifications that are of the highest level in the world.  
 
MOPC134 The Status of the J-PARC RF Systems synchrotron, acceleration, injection, controls 385
 
  • M. Yoshii, S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda
    KEK, Ibaraki
  • K. Haga, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The first acceleration of a proton beam at the J-PARC Rapid Cycling Synchrotron started in October 2007. The R&D for magnetic alloy (MA) loaded rf-systems to realize a high field gradient accelerating system for a rapid cycling machine has been initiated in 1996 with the aim of surpassing standard ferrite loaded cavities. The RCS RF system is broad-band and designed to cover both the RCS accelerating frequency range and the second harmonic for bunch shape manipulation. The optimum Q value of the RCS cavities is approximately 2. This is realized by combining a high-Q parallel inductor with an un-cut core configuration. The beam commissioning of the 50GeV Main Ring synchrotron will start in May 2008. Acceleration and slow-beam extraction are planned for December 2008. In case of the MR RF system, the accelerating frequency swing is small. The Q-value in the order of 20 has been selected to reduce transient beam loading due to the multiple-batch injection scheme. The MR RF cavities realize the Q-value by a cut-core configuration. The details of the RF systems and the results of beam accelerations are summarized.  
 
MOPC136 Beam Bunch Leakage and Control in the SNS Ring beam-losses, simulation, extraction, accumulation 391
 
  • Y. Zhang, J. Galambos
    ORNL, Oak Ridge, Tennessee
  In recent neutron production operations at SNS, beams contaminated the longitudinal extraction gap of the accumulator ring due to the limitation of the beam choppers. It caused significant beam loss and activation in the ring and in the extraction beam line. From simulations with computer models and in experimental measurements, properly utilizing the ring RF systems with additional storage turns after the beam accumulations in the ring effectively reduced beam loss in the SNS accelerator systems. Simulations and beam measurement results will be discussed  
 
MOPD009 Status of the Superconducting Cavity Development for ILC at MHI superconducting-RF, diagnostics 463
 
  • K. Sennyu, H. Hara, M. Matsuoka, T. Yanagisawa
    MHI, Kobe
  We report on the activities and achievements at MHI in the field of the superconducting cavity development for ILC. We describe especially the new procedures of cavity production for mass production.  
 
MOPD012 Half Wave Injector Design for WiFEL emittance, gun, cathode, space-charge 469
 
  • R. A. Legg
    UW-Madison/SRC, Madison, Wisconsin
  • W. Graves
    MIT, Cambridge, Massachusetts
  • T. L. Grimm
    Niowave, Inc., Lansing, Michigan
  • P. Piot
    Fermilab, Batavia, Illinois
  Seeded FELs will require exceptional beam quality. The Wisconsin FEL (WiFEL) requires peak currents of greater than 1 kA with less than 1 mm-mrad transverse slice emittance and 1·10-4 δp/p at the undulator. To perform the obligatory bunch compression after the injector without allowing micro-bunching will require very smooth bunch energy and density profiles and relatively low compression ratios. An injector which uses a low frequency, superconducting, half wave resonator gun combined with self-inflating, ellipsoidal bunches* to meet those requirements is described. The superconducting radio frequency TEM-class cavities have been in use for more than 25 years and because of their potential for flat field profiles, are desirable as electron gun structures. A Superfish model and field map of the specific gun cavity is presented. ASTRA** simulations from the cathode to 120MeV are provided. A description is given of the technique used to emittance compensate the space charge induced energy chirp while maintaining the peak bunch current.

* O. J.Luiten, et al., Phys. Rev. Lett. Vol 93, 094802 (2004)
** K. Floetmann, ASTRA, www.desy.de/~mpyflo

 
 
MOPD015 Current Status of Development in TETD of High-power Vacuum Microwave Devices klystron, electron, proton, power-supply 475
 
  • M. Niigaki
    Toshiba Electron Tubes & Devices Co., Ltd, Tokyo
  • K. Hayashi, M. Irikura, M. Sakamoto, H. Taoka
    TETD, Otawara
  • M. Y. Miyake, Y. Okubo, S. Sakamoto, Y. Yano
    Toshiba Electron Tubes & Devices Co., Ltd (TETD), Tochigi
  TETD (Toshiba Electron Tubes & Devices Co., LTD.) has been developing a wide variety of klystrons and input couplers in collaboration with some Japanese research institutes. This article presents recent results of the development including a C-band and an S-band pulsed klystrons for SPring-8 Joint Project for XFEL, 1.3-GHz horizontal MBK for DESY and a 1.3-GHz TTF-type input coupler for the European XFEL. As an application to fusion experimental devices, development of a 5-GHz, 500-kW CW klystron for KSTAR and a 170-GHz quasi CW gyrotron for ITER are also presented.  
 
MOPD022 New 1MW 704MHz RF Test Stand at CEA-Saclay klystron, cathode, proton, cryogenics 490
 
  • S. Chel, M. Desmons, A. Hamdi, F. Peauger
    CEA, Gif-sur-Yvette
  In the frame of the european CARE/HIPPI programme, superconducting accelerating cavities for pulsed proton injectors are developed. Qualification of these 704 MHz RF structures fully equipped (housed in a helium tank, with tuning system and power coupler), requires to perform high power tests in the existing horizontal cryostat CryHoLab. During the last years, CEA-Saclay built and ordered the necessary RF equipments to make such a platform for high power RF tests in a cryogenic environment available to the partners in HIPPI and later on to any other interested European teams. The main components of the RF test stand (95 kV-275kVA DC High Voltage Power Supply, 50Hz modulator and 1MW 704.4MHz RF klystron amplifier) are now installed and tested. In this paper, we present the different components with a focus on the new design of the hard tube modulator to match the new specifications and the compatibility with the floating HVPS, the results of the HV and RF measurements performed and we give a brief description of the PXI-based controller for the interlocks and klystron auxiliary controls.  
 
MOPD024 RF Power System for the IFMIF-EVEDA Prototype Accelerator power-supply, rfq, controls, radio-frequency 496
 
  • I. Kirpitchev, M-A. Falagán, A. Ibarra, P. Méndez, M. Weber
    CIEMAT, Madrid
  • M. Desmons, A. Mosnier
    CEA, Gif-sur-Yvette
  The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator prototype for verifying the validity of the accelerator design for IFMIF. The RFQ, matching section and DTL resonant cavities must be fed with continuous RF power at 175 MHz frequency with an accuracy of 1% in amplitude and ± 1° in phase. Currently two possible solutions for the DTL design are considered. The first option consists of normal conducting (NC) Alvarez type cavities and the second option consists of superconducting (SC) Half Wave Resonator cavities. Both options impose different demands on the RF system which are analyzed in this paper. The RF power system will be made of several amplification stages and will be based on vacuum tube amplifiers. The main characteristics of RF system including those of the high voltage power sources required to feed the anodes of the high power tubes will be presented in this paper.  
 
MOPD032 Neutronics Calculations to Support the SNS Accelerator Facility shielding, proton, radiation, target 520
 
  • I. I. Popova, G. W. Dodson, P. D. Ferguson, J. Galambos, F. X. Gallmeier
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS) is an accelerator driven neutron scattering facility for materials research that recently started operations. After commissioning, the facility started at low power and is presently in the process of a power ramp to reach the Megawatt power level within two years of operations, maintenance, and tuning cycles. Extensive neutronics work for shielding development and dose rate predictions was completed during design and construction for various operational and shut down scenarios. Now that the facility is successfully operating, there is still demand for neutronics analyses for radiation-protection support. This need arises from redesigning some parts of the facility, facility upgrades, designing additional structures, designing test stands for accelerator structures, and verification and code validation analyses on the basis of the measured data.  
 
MOPD041 The SSRF Radiation Safety Interlock System radiation, booster, controls, storage-ring 541
 
  • X. J. Xu, J. H. Cai, J. Cai, K. M. Fang, Z. D. Hua, X. Liu, J. H. Wang, J. Q. Xu
    SINAP, Shanghai
  Radiation Safety Interlock System (RSIS) for the Shanghai Synchrotron Radiation Facility (SSRF) is composed of two subsystems, the Access Control System (ACS) and the radiation containment system (RCS).The ACS prevents personnel from being exposed to the extremely high radiation inside the SSRF shielding tunnel (or called the interlock area) during machine operation. The RCS prevents personnel from being exposed to the high radiation outside a shielding tunnel during either normal or abnormal operation. The implementation of the ACS is based on the Programmable Logic Controllers, key transfer interlocking systems and IC card system. The RSIS is based on fail-safe, redundancy, multiplicity. Any violation of the RSIS will result in the inhibiting of redundant permission to the associated interlock systems, and cease the injection process and eliminate the entire stored electron beam in the SSRF. This paper describes the design philosophy, the logic, and the implementation of the RSIS at SSRF.  
 
MOPD042 Design and Testing of the Horizontal Version of the Multi Beam Klystron for European XFEL Project klystron, electron, cathode, gun 544
 
  • Y. Yano, M. Y. Miyake, Y. Okubo, S. Sakamoto
    Toshiba Electron Tubes & Devices Co., Ltd (TETD), Tochigi
  • Y. H. Chin
    KEK, Ibaraki
  • K. Hayashi, K. Tetsuka, H. Urakata
    TETD, Otawara
  Toshiba Electron Tubes & Devices (TETD) has been developing 10-MW L-band Multi-Beam Klystrons (MBKs) for the European XFEL project and possibly for future linear colliders. In order to allow horizontal installation in the XFEL tunnel, the horizontal version of MBK, MBK E3736H, has been designed, fabricated and tested by TETD. The MBK has six low-perveance beams operated at low voltage of less than 120 kV (for 10MW) and six ring-shaped cavities. In the successful acceptance testing at TETD in August 2007, the MBK achieved an output power of 10.3 MW at the beam voltage of 117 kV and at the RF pulse width of 1.5ms with efficiency of 67%. This test demonstrated that MBK E3736H fulfills all the requirements necessary as the RF power source of the XFEL linac.  
 
MOPP002 A Study of Failure Modes in the CLIC Decelerator quadrupole, lattice, simulation, power-supply 550
 
  • E. Adli, D. Schulte, I. Syratchev
    CERN, Geneva
  The CLIC Drive Beam decelerator is responsible for producing the RF power for the main linacs, using Power Extraction and Transfer Structures (PETS). To provide uniform power production, the beam must be transported with very small losses. In the paper failure modes for the operation of the decelerator are investigated, and the impact on beam stability, loss level and machine protection issues is presented. Quadrupole failure, PETS inhibition and PETS break down scenarios are being considered.  
 
MOPP010 Experimental Studies on Drive Beam Generation in CTF3 extraction, injection, quadrupole, optics 571
 
  • R. Corsini, S. Bettoni, S. Doebert, P. K. Skowronski, F. Tecker
    CERN, Geneva
  • C. Biscari, A. Ghigo
    INFN/LNF, Frascati (Roma)
  • Y.-C. Chao
    Jefferson Lab, Newport News, Virginia
  The objective of the CLIC Test Facility CTF3, built at CERN by an international collaboration, is to demonstrate the main feasibility issues of the CLIC two-beam technology by 2010. CTF3 consists of a 150 MeV electron linac followed by a 42 m long delay loop, an 84 m combiner ring and a two-beam test area. One key-issue studied in CTF3 is the efficient generation of a very high current drive beam, used in CLIC as the power source for the acceleration of the main beam to multi-TeV energies. The beam current is first doubled in the delay loop and then multiplied again by a factor four in the combiner ring by interleaving bunches using transverse deflecting RF cavities. The combiner ring and the connecting transfer line have been installed and put into operation in 2007. In this paper we give the status of the commissioning, illustrate the beam optics measurements, discuss the main issues and present the results of the combination tests.  
 
MOPP011 Fast Vertical Beam Instability in the CTF3 Combiner Ring injection, simulation, beam-losses, closed-orbit 574
 
  • R. Corsini, D. Schulte, P. K. Skowronski, F. Tecker
    CERN, Geneva
  • D. Alesini, C. Biscari, A. Ghigo
    INFN/LNF, Frascati (Roma)
  The CLIC Test Facility CTF3 is being built at CERN by an international collaboration, in order to demonstrate the main feasibility issues of the CLIC two-beam technology by 2010. The facility includes an 84 m combiner ring, which was installed and put into operation in 2007. High-current operation has shown a vertical beam break-up instability, leading to high beam losses over the four turns required for nominal operation of the CTF3 ring. Such instability is most likely due to the vertically polarized transverse mode in the RF deflectors used for beam injection and combination. In this paper we report the experimental data and compare them with simulations. Possible methods to eliminate the instability are also outlined.  
 
MOPP027 Placet Based Start-to-end Simulations of the ILC with Intra-train Fast Feedback System luminosity, simulation, emittance, feedback 604
 
  • J. Resta-López, P. Burrows, A. F. Hartin
    JAI, Oxford
  • A. Latina, D. Schulte
    CERN, Geneva
  Integrated simulations are important to assess the reliability of the luminosity performance of the future linear colliders. In this paper we present multi-bunch tracking simulation results for the International Linear Collider (ILC) from the start of the LINAC to the interaction point. The tracking along the LINAC and the beam delivery system is done using the code Placet. This code allows us to introduce cavity wakefield effects, element misalignment errors and ground motion. Static beam based alignment of the LINAC are also considered. The luminosity and beam-beam parameters are calculated using the code Guinea-Pig. In the framework of the Feedback On Nano-second Timescales (FONT) project, we describe and simulate an updated fast intra-train feedback system in order to correct for luminosity degradation mainly due to high frequency ground motion.  
 
MOPP028 Technical Specification for the CLIC Two-Beam Module quadrupole, alignment, vacuum, lattice 607
 
  • G. Riddone, H. Mainaud Durand, D. Schulte, I. Syratchev, W. Wuensch, R. Zennaro
    CERN, Geneva
  • R. Nousiainen
    HIP, University of Helsinki
  • A. Samoshkin
    JINR, Dubna, Moscow Region
  The 2-m long CLIC module comprises four decelerating structures and two quadrupoles forming a FODO cell. Each decelerating structure powers two accelerating structures. Some accelerating structures are removed at regular intervals to liberate space for a quadrupole of a FODO lattice. The present layout of the standard and special modules is presented as well as the status of the system integration. The main requirements for the different sub-systems (alignment, supporting, stabilization, cooling and vacuum) are introduced together with the major integration constraints. For the key components the specification on pre-alignment and beam-based alignment tolerances is also recalled as well as their influence on the requirements of other sub-systems. For example the required stable thermal behavior and the tight tolerances of accelerating structure (the requirements for the accelerating structure pre-alignment is 0.014 mm at 1? ) in the CLIC linac largely directly the sizing and integration of the cooling system. The paper also covers the main issues related to the module integration in the tunnel. In the last part, the critical issues and future activities are summarized.  
 
MOPP034 Large Scale Linac Simulations Using a Globalised Scattering Matrix Approach scattering, simulation, dipole, electromagnetic-fields 619
 
  • I. R.R. Shinton, R. M. Jones
    UMAN, Manchester
  A globalised cascaded scattering matrix scheme serves as practical method to simulate the electromagnetic (e.m.) fields in the groups of cavities which constitute the main accelerating structures of a linac. The cascaded scattering matrix technique is a well-proven method which allows realistic fabrication errors to be incorporated in an efficient manner without the necessity to re-mesh the entire geometry. Once the unit cell structures have been determined using a numerical scheme, such as finite element method utilized here, the overall cascaded scattering matrix calculation requires little in the way of computational resources or time and is consequently an efficient means of characterizing the e.m. field. Details of the e.m. field, shunt impedance and trapped modes for large scale linac simulations applied to the baseline and alternate high gradient cavities for the ILC and applications to XFEL are presented.  
 
MOPP036 Dark Current Model for ILC Main Linac simulation, electron, quadrupole, focusing 625
 
  • N. Solyak, N. V. Mokhov, G. V. Romanov
    Fermilab, Batavia, Illinois
  • Y. I. Eidelman
    BINP SB RAS, Novosibirsk
  • W. M. Tam
    IUCF, Bloomington, Indiana
  In the ILC Main Linac the dark current electrons, generated in SRF cavity can be accelerated to hundreds of MeV before being kicked out by quadrupoles and thus will originate electromagnetic cascade showers in the surrounding materials. Some of the shower secondaries can return back into vacuum and re-accelerated again. The results of simulation of the dark current dynamics and energy deposition along the linac are discussed in paper.  
 
MOPP042 RF Kick in the ILC Acceleration Structure emittance, acceleration, focusing, alignment 637
 
  • V. P. Yakovlev, I. G. Gonin, A. Latina, A. Lunin, K. Ranjan, N. Solyak
    Fermilab, Batavia, Illinois
  Detailed results of estimations and simulations for the RF kick caused by input and HOM couplers of the ILC acceleration structure are presented. Results of possible beam emittance dilution caused by RF kick are discussed for the main LINAC acceleration structure, and the RF structures of the ILC bunch compressors BC1 and BC2. Methods of the RF kick reduction are discussed.  
 
MOPP043 Transverse Wake Field Simulations for the ILC Acceleration Structure emittance, simulation, acceleration, linear-collider 640
 
  • V. P. Yakovlev, A. Lunin, N. Solyak
    Fermilab, Batavia, Illinois
  Details of wake potential simulation in the acceleration structure of ILC, including the RF cavities and input/HOM couplers are presented. Transverse wake potential dependence is described versus the bunch length. Beam emittance dilution caused by main and HOM couplers is estimated, followed by a discussion of possible structural modifications allowing a reduction of transverse wake potential.  
 
MOPP048 Fast Ion Instability in the CLIC Transfer Line and Main Linac ion, electron, vacuum, emittance 655
 
  • G. Rumolo, D. Schulte
    CERN, Geneva
  The Fast Ion Instability is believed to be a serious danger for bunch trains propagating in the CLIC electron transfer line and main linac, since it may strongly affect the bunches in the tail of the train if the vacuum pressure is not below a certain threshold. We have developed the FASTION code, which can track electrons through a FODO cell line and takes into account their interactions with the produced (and possibly trapped) ions. We describe how this tool can be used for setting tolerances on the vacuum pressure and for giving specifications for the design of a feedback system.  
 
MOPP091 Upgrade of Input Power Coupling System for the SNS RFQ rfq, vacuum, coupling, klystron 763
 
  • Y. W. Kang, A. V. Aleksandrov, P. E. Gibson, T. W. Hardek, C. Luck, R. C. Peglow, A. V. Vassioutchenko
    ORNL, Oak Ridge, Tennessee
  A RF input power coupler system has been developed for upgrade of input coupling to the RFQ in the SNS linac front-end. The design employs two coaxial loop couplers for 402.5 MHz operation. Two couplers are used in parallel to power the accelerating structure with up to 800 kW total peak power at 8% duty cycle. Each coupler loop has a coaxial ceramic window that is connected to each output of a magic-T waveguide hybrid splitter through a coaxial to waveguide transition. The coaxial loop couplers have been designed, manufactured, and high power processed. This paper presents the following: RF and mechanical designs of the couplers and system, procedure and result of high power RF conditioning, and test and operation results of the upgraded system.  
 
MOPP096 C-band Linac Optimization for a Race-track Microtron coupling, simulation, impedance, resonance 778
 
  • Yu. A. Kubyshin
    UPC, Barcelona
  • D. Carrillo, L. García-Tabarés, F. Toral
    CIEMAT, Madrid
  • A. V. Poseryaev, V. I. Shvedunov
    MSU, Moscow
  Optimization results of a C-band standing wave on-axis coupled linac for a miniature race-track microtron (RTM) are presented. The optimization procedure includes three steps: choice of the linac cells lengths and field strength following requirements of the RTM beam dynamics, 2D cells geometry optimization to maximize the shunt impedance and minimize the surface field strength and, finally, full scale 3D optimization. The 3D calculations were done independently with two codes: ANSYS and HFSS. Various methods of calculation of the coupling slots dimensions, including the waveguide-linac coupling slot, are described in detail.  
 
MOPP104 Possible Upgrade Scenario for J-PARC Ring RF impedance, synchrotron, acceleration, power-supply 799
 
  • C. Ohmori, K. Hara, A. Takagi, M. Toda, M. Yoshii
    KEK, Ibaraki
  • K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The whole J-PARC RCS RF system is operational and during beam commissioning in 2007 the beam in RCS was successfully accelerated to final energy and then extracted. The Main Ring RF system has been installed in the tunnel. Both Ring RF systems are based on the new technology using magnetic alloy loaded cavities and have achieved higher field gradient than existing ferrite base RF systems in this frequency region. For the future upgrade of the J-PARC Main Ring, a short accelerating cycle is required to increase the average beam current. In this paper, a possible upgrade scenario for RF cavities based on improvements of the magnetic alloy ring cores will be described.  
 
MOPP109 Status of the 100 MeV Preinjector for the ALBA Synchrotron gun, diagnostics, single-bunch, electron 811
 
  • A. Falone, D. Einfeld, M. Pont
    ALBA, Bellaterra
  • D. Jousse, J.-L. Pastre, F. Rodriguez, A. S. Setty
    THALES, Colombes
  • A. Sacharidis
    EuroMev, Buc
  A turn key 100 MeV linac has been constructed by THALES in order to inject electrons into the booster synchrotron of ALBA*. The linac will be commissioned in May 2008. This paper will remind the main features of the linac** and will give results obtained during the commissioning tests. The energy and emittance measurements will be done on the transfer line conceived and realized by CELLS.

* D. Einfeld "Status of ALBA", PAC07, Albuquerque, USA, June 2007.
** A. Setty "Beam dynamics of the 100 MeV preinjector for the spanish synchrotron ALBA", PAC07, Albuquerque, USA, June 2007.

 
 
MOPP110 The SNS Resonance Control Cooling System Control Valve Upgrade Performance controls, resonance, monitoring, feedback 814
 
  • D. C. Williams, J. P. Schubert, J. Y. Tang
    ORNL, Oak Ridge, Tennessee
  The normal-conducting linac of the Spallation Neutron Source (SNS) uses 10 separate Resonance Control Cooling System (RCCS) water skids to control the resonance of 6 Drift Tube Linac (DTL) and 4 Coupled Cavity Linac (CCL) accelerating structures. The RCCS water skids use 2 control valves; one to regulate the chilled water flow and the other is used to bypass water to a heat exchanger. These valves have hydraulic actuators that provide position and feedback to the control system. Frequency oscillations occur using these hydraulic actuators due to their coarse movement and control of the valves. New air actuator control positioners have been installed on the DTL3 RCCS water skid to give finer control and regulation of DTL3 cavity temperature. This paper shows a comparison of resonance control performance for two valve configurations.  
 
MOPP112 Status of the PEFP Superconducting RF Project superconducting-RF, damping, proton, controls 820
 
  • S. An, Y.-S. Cho, B. H. Choi, C. Gao, Y. M. Li, Y. Z. Tang, L. Zhang
    KAERI, Daejon
  Superconducting RF project of the Proton Engineering Frontier Project (PEFP) aims to develop a superconducting RF linac to accelerate a proton beam above 80 MeV at 700 MHz. The preliminary design of a low-beta cryomodule has been completed. A low-beta (β=0.42) cavity, a higher-mode coupler and a fundamental power coupler (FPC) for the PEFP cavities have also been designed. A FPC baking system and high power RF conditioning system are under construction. A helium vesel made of stainless steel has been designed. A new tuner has also been designed. Two prototype copper cavities have been produced and tested. The HOM coupler has been measured on the copper cavities. A cryostat for a SRF cavity vertical testing has been designed.  
 
MOPP113 PEFP Dumbbell Frequency and Length Tuning of a Low-beta SRF Cavity superconducting-RF, proton, target, controls 823
 
  • S. An, Y.-S. Cho, C. Gao, Y. M. Li, Y. Z. Tang
    KAERI, Daejon
  • L. Zhang
    Department of Mechanics, Chang’an University, Daejon
  Based on present technology, a dumbbell fabrication is a necessary mid-process for a cavity manufacting process. A dumbbell with a right length and frequency is necessary to build up a desired cavity. In order to obtain the exact frequencies of each individual half cell of a PEFP dumbbell, a new and confirmed measurement method has been established. In this paper, the dumbbell frequency measurement method and the frequency and length tuning practices for a PEFP low-beta cavity have been described.  
 
MOPP114 Design of the Prototypical Cryomodule for the EUROTRANS Superconducting Linac for Nuclear Waste Transmutation cryogenics, vacuum, radiation, alignment 826
 
  • S. Barbanotti, N. Panzeri, P. Pierini
    INFN/LASA, Segrate (MI)
  • J.-L. Biarrotte, P. Blache, C. Commeaux, P. Duthil, E. Rampnoux
    IPN, Orsay
  • M. Souli
    GANIL, Caen
  One task of the accelerator workpackage of the EUROTRANS program for the design of a nuclear waste transmutation system is dedicated to the engineering and realization of a prototype cryomodule of the high energy section of the linac, equipped with elliptical superconducting niobium cavities. We review here the present status of the design and the planned program that foresees the experimental characterization of the fully equipped cavity and RF system under its nominal operating conditions.  
 
MOPP116 Commissioning of the Cornell ERL Injector RF Systems klystron, controls, diagnostics, factory 832
 
  • S. A. Belomestnykh, J. Dobbins, R. P.K. Kaplan, M. Liepe, P. Quigley, J. J. Reilly, C. R. Strohman, V. Veshcherevich
    CLASSE, Ithaca
  Two high power 1300 MHz RF systems have been developed for the Cornell University ERL Injector. The first system, based on a 16 kWCW IOT transmitter, is to provide RF power to a buncher cavity. The second system employs five 120 kWCW klystrons to feed 2-cell superconducting cavities of the injector cryomodule. The sixth, spare klystron is used to power a deflecting cavity in a pulsed mode for beam diagnostics. A digital LLRF control stem was designed and implemented for precise regulation of the cavities’ field amplitudes and phases. All components of these systems have been recently installed and commissioned. The results from the first turn-on of the systems are presented.  
 
MOPP117 First Test of the Cornell Single-cavity Horizontal Cryomodule cryogenics, radiation, vacuum, resonance 835
 
  • S. A. Belomestnykh, E. P. Chojnacki, R. Ehrlich, R. P.K. Kaplan, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, P. Quigley, J. J. Reilly, D. M. Sabol, J. Sears, V. D. Shemelin, E. N. Smith, V. Veshcherevich, D. Widger
    CLASSE, Ithaca
  A single-cavity horizontal test cryomodule (HTC) has been designed and fabricated recently at Cornell University for ERL project. This cryomodule is a shortened version of the full injector cryomodule, which will house five superconducting cavities. It serves as a test bench for new design features and for testing fully dressed two-cell ERL injector cavities. The cryostat design has been optimized for precise cavity alignment, good magnetic shielding, and high cryogenic loads from the RF cavities, input couplers, and HOM loads. The HTC was made long enough so in the future it can accommodate longer, multicell cavities of the ERL main linac. In this paper we report on results from the first full test of the HTC, including RF system and superconducting cavity performance, cryomodule studies and operation of a new 1.8 K cryogenic system.  
 
MOPP123 Design and Fabrication of the Cornell ERL Injector Cryomodule vacuum, insertion, alignment, shielding 844
 
  • E. P. Chojnacki, S. A. Belomestnykh, Z. A. Conway, J. J. Kaufman, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, P. Quigley, J. Sears, V. D. Shemelin, V. Veshcherevich
    CLASSE, Ithaca
  The Energy Recovery Linac (ERL) development effort at Cornell will first produce an ERL beam source. The source will consist of a DC photo-gun, a buncher cavity, beam optics, and then an SRF Injector cryomodule to accelerate the 33-100 mA cw beam from 0.3-0.5 MeV to 5-15 MeV. The Injector cryomodule is based on TTF III technology with modifications to allow cw operation and the flexibility to accommodate the wide range of beam currents, bunch lengths, and beam energy. To deliver the 0.5 MWCW average power to the beam, the Injector cryomodule will contain five SRF 2-cell cavities, each cavity having two 50 kWCW coax couplers to deliver power from 100 kWCW klystrons, of which there are five for the Injector. Both the couplers and klystrons have been tested with 30% overhead in performance. Cold beamline HOM loads are placed between each cavity and outboard of the first and last cavities. Details of the Injector cryomodule design will be presented along with insight gained from the fabrication process, which will benefit the future ERL Linac cryomodule design and proto-typing.  
 
MOPP126 Experimental Characterization of a 700 MHz β=0.47 5 Cell Superconducting Cavity Prototype for Pulsed Proton Linac proton, simulation, electron, acceleration 853
 
  • G. Devanz, J.-P. Charrier, S. Chel, Y. Gasser, P. Hardy, J. Plouin, J. P. Poupeau, D. Roudier
    CEA, Gif-sur-Yvette
  A 700 MHz 5 cell elliptical cavity has been developed to accelerate a high intensity proton beam in the lower energy part of a superconducting linac, starting at 80 MeV. The cavity is stiffened in order to minimize the Lorentz detuning which limits high field pulsed operation of the flatter, low beta elliptical cavities. It is equipped with a stainless steel helium vessel. The RF tests of the cavity have been carried out at 1.8 K. Cavity performance is reported in this paper. Measurements of the RF response to mechanical excitations are also presented.  
 
MOPP127 Commissioning of Superconducting Linac at IUAC - Initial Challenges and Solutions acceleration, vacuum, damping, scattering 856
 
  • S. Ghosh, S. Babu, J. Chacko, A. Choudhury, G. K. Chowdhury, T. S. Datta, D. Kanjilal, S. Kar, M. Kumar, A. Mandal, D. S. Mathuria, R. S. Meena, R. Mehta, K. K. Mistri, A. Pandey, P. Patra, P. N. Prakash, A. Rai, A. Roy, B. K. Sahu, S. S. Sonti, J. Zacharias
    IUAC, New Delhi
  During initial acceleration of ion beam through the first module of linac having eight superconducting (SC) niobium quarter wave resonators (QWR), energy gains were found to be much lower. Major problem encountered was limitation of accelerating fields in the QWR achieved at much higher RF power (up to 300 W) leading to cable melting, metal coating on SC surface and increased cryogenic losses. Cold leaks in the niobium-stainless steel transition assemblies and niobium tuner bellows also posed a major challenge. A novel way of damping mechanical vibration was implemented to reduce RF power. Cooling was improved by installing a hemispherical structure on the resonator. The drive coupler was redesigned to eliminate metal coating. Design of the tuner/transition flange assemblies was modified to avoid cold leak. After incorporation of these modifications, on-line beam acceleration through Linac was accomplished. Pulsed (1.3 ns) Silicon beam of 130 MeV from Pelletron accelerator was further bunched to 250 ps by SC Superbuncher. After acceleration through the linac module and subsequent re-bunching using SC Rebuncher, 158 MeV Silicon beam having pulse width of 400 ps was delivered.  
 
MOPP129 Compensation of Lorentz Force Detuning for SC Linacs (with Piezo Tuners) controls, resonance, monitoring, radio-frequency 862
 
  • M. K. Grecki, J. Andryszczak, T. Pozniak, K. P. Przygoda, P. M.S. Sekalski
    TUL-DMCS, Łódź
  The superconducting linacs use niobium cavities working with extremely high quality factor. Therefore the bandwidth of the cavity is very narrow and even subtle deformation caused by Lorentz force detunes the cavity a lot. For high gradient operation (over 15MV/m) the mechanical deformation of the cavity should be compensated by piezo tuner*. The paper presents design of a piezo control system and the results of measurements of its efficiency. It was demonstrated in FLASH accelerator that an initial detuning of 300Hz can be compensated by single pulse excitation of the piezo. The described system consist of multichannel programmable pulse generator driving a 8 channel piezo amplifiers capable to supply piezos with pulses up to 1A and up to 80V. It can compensate for Lorentz force detuning in all three FLASH cryhomodules equipped with piezos (ACC3,5,6).

*Liepe et al. "Dynamic Lorentz Force Compensation with a Fast Piezoelectric Tuner," PAC2001, pp. 1074-1076.

 
 
MOPP131 Cryomodule Tests of the STF Baseline 9-cell Cavities at KEK radiation, electron, superconducting-RF, coupling 868
 
  • E. Kako, H. Hayano, S. Noguchi, N. Ohuchi, M. Sato, T. Shishido, K. Watanabe, Y. Yamamoto
    KEK, Ibaraki
  The STF-Baseline superconducting cavity system, which includes four TESLA-type 9-cell cavities, input couplers and frequency tuners, has been developed for the future ILC project. A 6m-cryomodule including one of four STF-Baseline cavities was assembled for the initial test called the STF Phase -0.5. The first cool-down of the cryomodule and high power tests of the STF-Baseline cavity had been successfully carried at 2 K. The maximum accelerating gradient (Eacc,max) of 19.3 MV/m was achieved in a specific pulse width of 1.5 msec and a repetition of 5 Hz, (23.4 MV/m in a shorter pulse of 0.6 msec). The onset of x-rays radiation was observed at higher field than 15 MV/m, and the measured Qo value was about 5 x 109 at 18 MV/m in accompanied with field emission. The detuning angle of about -13 degrees at 18 MV/m was successfully compensated to nearly zero by a combined operation with both an offset detuning and an optimised applied voltage in the piezo element. String assembly of four STF-Baseline cavities has been stated in Jan. 2008. The second cryomodule test for 4 cavities, called the STF Phase -1.0, is scheduled in this early summer.  
 
MOPP132 Progress Towards Development of an L-Band SC Traveling Wave Accelerating Structure with Feedback feedback, acceleration, coupling, resonance 871
 
  • A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio
  • P. V. Avrakhov
    LPI, Moscow
  • S. Kazakov
    KEK, Ibaraki
  • N. Solyak, V. P. Yakovlev
    Fermilab, Batavia, Illinois
  We describe an ongoing experimental program and progress towards development of a conceptual design for a superconducting traveling wave accelerating structure for the ILC. The accelerating gradient can be significantly improved by the use of an RF feedback system redirecting the accelerating wave that passed through the superconducting traveling wave accelerator (STWA) section back to the input of the accelerating structure. The conceptual design of the SC traveling wave accelerator has been considered by P. Avrakhov et al. [PAC07, pp.2538], where shape optimization, coupler cell design and tuning issues in the feedback loop were presented. The proposed TW structure design gives an overall 24% increase in gradient over the 1 m long standing wave structure and potentially can reach 46% if a longer structure is employed. Experimental investigation of the TW SC structure considers tests of a single cavity having the same shape as the regular cell of the full-sized STWA structure, and the same ratio of the RF fields. The details of the individual parts, joint configurations along with some developments on forming and welding of the proposed cavity shapes are discussed.  
 
MOPP138 First Test Results from the Cornell ERL Injector Cryomodule emittance, alignment, acceleration, booster 883
 
  • M. Liepe, S. A. Belomestnykh, E. P. Chojnacki, Z. A. Conway, R. Ehrlich, R. P.K. Kaplan, V. Medjidzade, H. Padamsee, P. Quigley, J. J. Reilly, D. M. Sabol, J. Sears, V. D. Shemelin, E. N. Smith, V. Veshcherevich, D. Widger
    CLASSE, Ithaca
  Cornell University has developed and fabricated a 5 cavity SRF injector cryomodule for the acceleration of a high current (100 mA), ultra low emittance beam. This cryomodule has been installed in the Cornell ERL prototype, and is presently under extensive test. The combination of a high beam current with emittance preservation of an ultra low emittance beam results in a multitude of challenges for the SRF system, pushing parameters well beyond present state of the art. Strong HOM damping and effective HOM power extraction is required to support the 100 mA beam current. This is achieved by placing HOM beam line absorbers between all cavities. Emittance preservation is addressed by a symmetric beam line with twin input couplers, tight cavity alignment and the option of fine alignment of cold cavities. In this paper we report on first results from the injector module test, including cavity performance tests, static heat load measurements and microphonic studies.  
 
MOPP141 Commissioning of the ERLP SRF Systems at Daresbury Laboratory booster, radiation, gun, shielding 889
 
  • P. A. McIntosh, R. Bate, R. K. Buckley, S. R. Buckley, P. A. Corlett, A. J. Moss, J. F. Orrett, S. M. Pattalwar, A. E. Wheelhouse
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • F. G. Gabriel
    FZD, Dresden
  • A. R. Goulden
    STFC/DL/SRD, Daresbury, Warrington, Cheshire
  • P. vom Stein
    ACCEL, Bergisch Gladbach
  The Energy Recovery Linac Prototype (ERLP) has been installed at Daresbury Laboratory and its baseline commissioning completed. The SRF systems for ERLP comprise two 9-cell, 1.3 GHz accelerating cavities in the injector (or Booster) cryomodule, which provide a nominal energy gain of 8 MeV for the injected 350 keV beam from the photo-injector. The beam is then accelerated in an identical two cavity cryomodule in the energy recovery main Linac, giving a final ERLP energy of 35 MeV. Each SRF accelerating cavity is powered by commercially available Inductive Output Tubes (IOTs) and the analog LLRF control system is identical to that employed on the ELBE facility at FZD Rossendorf. This paper details the commissioning experience gained for these systems and highlights the ultimate performance achieved.  
 
MOPP148 Design of a Magnetic Shield Internal to the Helium Vessel of SRF Cavities shielding, superconductivity, background, controls 898
 
  • P. Pierini, S. Barbanotti, L. Monaco, N. Panzeri
    INFN/LASA, Segrate (MI)
  The TRASCO elliptical cavities for intermediate velocity protons (β=0.47) employ a coaxial cold tuner of the blade type. To meet the perfomance goals of the 700 MHz cavities in the foreseen horizontal cryostat tests, the cavities are being equipped with a magnetic shield which lies internally to the cavity helium vessel and has a simple mechanical design and assembly procedure.  
 
MOPP149 Recent Developments of the Superconducting CH-Cavities simulation, cryogenics, beam-losses, resonance 901
 
  • H. Podlech, A. Bechtold, M. Busch, F. Dziuba, H. Liebermann, U. Ratzinger
    IAP, Frankfurt am Main
  The Crossbar-H-mode (CH)-structure which has been developed at the IAP in Frankfurt is a multi-cell drift tube structure for the efficient acceleration of low and medium energy protons and ions. The superconducting low energy CH-prototype cavity has reached gradients of up to 7 MV/m, corresponding to an effective voltage gain of 5.6 MV. This shows that high real estate gradients can be achieved in superconducting low energy multi-cell cavities. Additionally, microphonics and tuning measurements have been performed at room temperature and at 4K. Optimized cavity geometry for high power beam projects and plans for the construction of a new superconducting cavity will be presented.  
 
MOPP153 Cavity Diagnostics Using Rotating Mapping System for L-band ERL Superconducting Cavity radiation, electron, diagnostics, quadrupole 907
 
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • T. Furuya, T. Takahashi, K. Umemori
    KEK, Ibaraki
  • M. Sawamura
    JAEA/ERL, Ibaraki
  We are developing the L-band superconducting cavity for Energy Recovery Linac in Japan. In order to survey the electron emission and the heating spot of the cavity inner surface in detail, cavity diagnostics with the rotating mapping system was applied for the vertical tests of our cavities. Two types of sensor, one of which is the carbon resistor and the other is the Si PIN photo diode, was equipped to detect the temperature rise and electron emission. These two sensor arrays were arranged along the cavity axis and set on the rotating mechanics with servo motor. By rotating the sensor arrays around the cavity axis, a lot of information is obtained all over the cavity surface in detail. It is preferable that the number of sensors will be reduced compared with the usual cavity mapping system by using this rotating mapping system. We have already fabricated the Nb single cell cavities which is optimised for ERL operation and then performed the vertical test of Nb ERL single cell cavities. This paper reports the results of the mapping system with Nb single cell ERL-shape cavities.  
 
MOPP159 Results of Vertical Tests for the KEK-ERL Single Cell Superconducting Cavities acceleration, pick-up, insertion, superconductivity 925
 
  • K. Umemori, T. Furuya, T. Takahashi
    KEK, Ibaraki
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • M. Sawamura
    JAEA/ERL, Ibaraki
  The development of the superconducting cavities is indispensable for realizing the 5 GeV-class energy recovery linacs. The KEK-ERL cavity had been recently designed. Its features are the optimized cell shapes and adoption of the enlarged beampipes with eccentric-fluted structures. In order to confirm our cavity design, two types of single cell cavities had been fabricated. One is a center-cell type cavity, whose aim is a validation of the cell shape, and another is an end-cell type cavity, which has complex structure such as the eccentric-fluted beampipes. After applying a series of surface treatments, we had assembled the cavities and performed vertical tests at KEK D10 area. Promising results have been obtained. In this presentation, we will present the results of vertical tests for these cavities.  
 
MOPP168 Tests on the 1.3 GHz Low Loss Single-Cell RF Superconducting Large Grain Cavities of IHEP linear-collider, cryogenics, vacuum, collider 943
 
  • Z. G. Zong, J. Gao, M. Q. Ge, J. Gu, H. Sun, D. Wang, Q. J. Xu, J. Y. Zhai, F. C. Zhao
    IHEP Beijing, Beijing
  • F. Furuta, T. Saeki, K. Saito
    KEK, Ibaraki
  • L. Q. Liu
    Technical Institute of Physics and Chemistry, Beijing
  • L.-Y. Xiong, L. Zhang, T. X. Zhao, Z. G. Zong
    TIPC, BeiJing
  To contribute to the International Linear Collider (ILC) R&D on the 1.3 GHz low loss cavities has been carried out at IHEP since 2005. Six cavities had been fabricated by the standard technology and treated by some procedures of surface treatments, such as centrifugal barrel polishing, barrel chemical polishing, annealing, high pressure rinsing and baking at in-house IHEP. Because of the shortage of liquid helium in Beijing two large grain cavities with a fine grain one were sent to KEK for vertical tests. The large grain cavities was tested and treated at KEk and finally both reached the accelerating gradients of more than 35 MV/m with the maximum of 40.27 MV/m. This paper presents the testing and results of the large grain cavities.  
 
TUOCG01 The Heidelberg Ion Therapy (HIT) Accelerator Coming into Operation synchrotron, extraction, ion, proton 979
 
  • D. Ondreka, U. Weinrich
    GSI, Darmstadt
  The Heidelberg Ion Therapy Facility (HIT) is the first dedicated proton and carbon therapy facility in Europe. It uses full three dimensional intensity-controlled raster scanning as basic treatment technique. The commissioning of the accelerator with beam was successfully finished for two fixed-beam treatment places in December 2007. Therefore a library of 40000 combinations of beam properties (ion type, treatment place, energy, intensity, beam size) is now offered to the treatment technique teams preparing the treatment systems for the clinical use. The HIT facility also comprises a gantry with full scanning properties constituting the only carbon ion gantry worldwide. The gantry can be rotated by 360 degree, so that the beam may be aimed at the patient from arbitrary directions. Commissioning with beam of the gantry was started in January 2008 when the first beams were transported successfully into the treatment room. The talk will report on experiences and results of the commissioning of the accelerator sections. It puts special emphasis on the subject of preparing the enormous variety of beam properties in an efficient and reliable way.  
slides icon Slides  
 
TUOCG03 Proposal for a ½ MW Electron Linac for Rare Isotope and Materials Science proton, target, electron, site 985
 
  • S. R. Koscielniak, P. G. Bricault, B. Davids, J. Dilling, M. Dombsky
    TRIUMF, Vancouver
  • D. Karlen
    Victoria University, Victoria, B. C.
  TRIUMF, in collaboration with university partners, proposes to construct a megawatt-class electron linear accelerator (e-linac) as a driver for U(gamma,f) of actinide targets with rates up to 1013 - 1014 fissions/sec and for (gamma,p)8Li for materials science. The particular emphasis would be on neutron-rich species. The 50 MeV, 10 mA, c.w. linac is based on super-conducting radio-frequency (SRF) technology at 1.3 GHz. Though high power/current electron linacs are a mature technology proposed elsewhere for applications ranging from 4th generation light-sources to TeV-scale linear colliders, TRIUMF is in the vanguard for applying this technology to the copious production of isotopes for studies of (i) nuclear structure and astrophysics; and (ii) beta-NMR for materials science.  
slides icon Slides  
 
TUOAM01 Commissioning Status of the Shanghai Synchrotron Radiation Facility storage-ring, booster, injection, feedback 998
 
  • Z. T. Zhao, H. Ding, H. Xu
    SINAP, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF), an intermediate energy storage ring based third generation light source, is under commissioning at a site in Shanghai Zhang-Jiang Hi-Tech Park. The ground breaking of this project was made on Dec.25, 2004, and on Dec.24, 2007 electron beam was stored and accumulated in the SSRF storage ring. Since then the accelerator commissioning and beamline installation have been being continued toward the scheduled user operation from May 2009. This paper presents an overview of the SSRF status and its machine commissioning progress.  
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TUOAM02 The Status of the Daresbury Energy Recovery Linac Prototype gun, diagnostics, laser, radiation 1001
 
  • D. J. Holder, P. A. McIntosh, S. L. Smith
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • N. Bliss
    STFC/DL, Daresbury, Warrington, Cheshire
  • A. R. Goulden
    STFC/DL/SRD, Daresbury, Warrington, Cheshire
  This paper provides an update on the progress with the building and commissioning of the Energy Recovery Linac Prototype (ERLP). The past year has seen a number of notable achievements as well as a number of obstacles to overcome. The detailed results from the gun commissioning work are described elsewhere at this conference. ERLP is a 35 MeV technology demonstrator being built as part of the UK's R&D programme to develop its next-generation light source (NLS). It is based on a combination of a DC photocathode electron gun, a superconducting injector linac and a main linac operating in energy recovery mode. These drive an IR-FEL, an inverse Compton Back-Scattering (CBS) x-ray source and a terahertz beamline. The priorities for ERLP are to gain experience of operating a photoinjector gun and superconducting linacs; to produce and maintain high-brightness electron beams; to achieve energy recovery from an FEL-disrupted beam; the development of an electro-optic longitudinal profile monitor and to study challenging synchronisation issues. ERLP will also act as an injector for what will be the world's first non-scaling, Fixed-Field Alternating Gradient (FFAG) accelerator called EMMA.  
slides icon Slides  
 
TUPC001 Optics Calculation and Emittance Measurement toward Automatic Beam Tuning of Linac emittance, optics, gun, simulation 1035
 
  • T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo-ken
  • T. Watanabe
    SES, Hyogo-pref.
  The SPring-8 1-GeV linac has a total of 13 sets of 80MW klystron units. In usual operation, two klystron units are driven as the standby unit. If there's any problem with an arbitrary klystron unit, the beam operation is able to restart immediately by using the standby unit. In that case, the optimization of beam optics has carried out using beam screen monitors. This beam tuning spend about one hour. In order to reduce the beam tuning time, we are promoting the development of the automatic beam optics tuning system. Since the complete understanding of the beam envelope is important, the particles tracking simulation of the linac was carried out by using PARMELA and SAD. Five sets of beam size monitors were installed in the end of the linac for measurement of the real beam envelope. In a beam study applying the simulation results, the beam waist was actually formed at the 10-m long drift space after the 1-GeV chicane section as predicted by SAD. The values of the measured beam emittance were smaller than the simulation results.  
 
TUPC005 Simulation Study of Laser-wires as a Post-linac Diagnostic for CLIC and ILC background, dipole, electron, simulation 1047
 
  • G. A. Blair, L. Deacon, S. Malton
    Royal Holloway, University of London, Surrey
  • I. V. Agapov, A. Latina, D. Schulte
    CERN, Geneva
  Realistic CLIC and ILC bunch trains are simulated in the linac, including intra-train collective effects, and then analysed via a realistic simulation of a laser-wire system, including effects of laser-wire signal extraction, detection and deconvolution. Implications are drawn for the use of laser-wires as a post-linac machine diagnostic.  
 
TUPC014 SSRF Injector Diagnostics Commissioning Results booster, diagnostics, emittance, radiation 1074
 
  • Y. Z. Chen, J. Chen, Z. C. Chen, Y. B. Leng, Y. B. Yan, W. M. Zhou
    SINAP, Shanghai
  This paper presents Injector beam diagnostics layout of the Shanghai Synchrotron Radiation Facility(SSRF) which includes the 150MeV LINAC, booster(3.5GeV) and beam transport lines. The different beam diagnostics monitors for beam current, beam position and beam profile are briefly described. The beam diagnostics data acquisition architecture is introduced. Commissioning Results of the 150Mev LINAC are presented, as well as the commissioning status of the booster .  
 
TUPC017 Beam Instrumentation System Development and Commissioning in SSRF booster, storage-ring, feedback, diagnostics 1080
 
  • Y. B. Leng, J. Chen, Y. Z. Chen, Z. C. Chen, G. Q. Huang, D. K. Liu, Y. B. Yan, K. R. Ye, C. X. Yin, J. Yu, L. Y. Yu, R. Yuan, G. B. Zhao, L. Y. Zhao, W. M. Zhou, Y. Zou
    SINAP, Shanghai
  In recent months the first beams have been stored in the Storage Ring of the Shanghai Synchrotron Radiation Facility (SSRF). The brief introduction will be given of the beam diagnostics system development. The initial commissioning results including beam profile monitors, beam position monitors (BPMs), DC current monitors (DCCT), and synchrotron radiation monitor (SRM) will be reported in this paper.  
 
TUPC024 Video Profile Monitors Development for the CTF3 Probe Beam Linac laser, diagnostics, emittance, collider 1101
 
  • W. Farabolini, G. Adroit, P. Girardot, R. Granelli, F. Harrault, C. L.H. Lahonde-Hamdoun, T. Lerch, F. Orsini
    CEA, Gif-sur-Yvette
  The innovative CLIC concept is currently under study in the CLIC Test Facility (CTF3) at CERN where the acceleration of a probe beam will be demonstrated. This probe beam, delivered by a linac called CALIFES, is composed of short bunches (0.75 ps, 0.6 nC) at 170 MeV with normalized emittance lower than 20 mm.mrad. Measurements of longitudinal charges distribution, transverse emittance and energy spectrum rely on Video Profile Monitors (VPM) after appropriate manipulations of the beam (deflecting cavity, quad scan and analysis dipole). We report the design, development and tests of these new VPMs based on selectable YAG/OTR screens, optical line and CCD camera. Two selectable magnifications (1.75 and 0.33) are available via motorized lens mounts to comply both with resolution (20 μm) and field of view (10x10mm2). Study of optical line characteristics have been realised with Apilux software and Modulation Transfer Function (MTF) were measured. A grid pattern can be inserted at the screens position to check optical characteristics during operations. Tilt of the CCD plan in order to compensate the screen tilt of 15° has not proven to improve the depth of field and was not implemented.  
 
TUPC028 Design and Construction of an Inductive Pick-up for Beam Position Monitoring in the TBL Line of the CTF3 pick-up, vacuum, electron, monitoring 1110
 
  • J. J. Garcia-Garrigos, J. V. Civera-Navarrete, A. Faus-Golfe
    IFIC (CSIC-UV), Valencia
  In order to determine the beam position respect to the vacuum chamber, the IPU senses the azimuthal distribution of the beam image current flowing along its inner wall when a high frequency bunched beam passes through. The inner wall of the pick-up is divided into four electrodes, each of which forms the primary winding of a toroidal transformer. Therefore the beam image current component flowing through each electrode is transformed to a secondary winding connected to a pick-up output. The closer the beam is to the transformer electrode, the greater is the induced signal in its secondary winding. This basic sensing mechanism will allow to determine the beam position through the four transformers distributed orthogonally around the vacuum pipe. The bandwidth of the IPU and the amplifier is set above 200 MHz to let pass, with low distortion, the 20-140 ns pulse train signal induced from the beam. Also, its expected resolution at maximum current is 5μm. This paper reports on the design, construction as well as testing and calibration processes of two IPU prototypes. They will be installed in the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN by Spring 2008.  
 
TUPC034 Beam Instrumentations for the J-PARC RCS Commissioning injection, proton, synchrotron, diagnostics 1125
 
  • N. Hayashi, S. Hiroki, R. Saeki, K. Satou, R. Toyokawa, K. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • D. A. Arakawa, S. Hiramatsu, M. Tejima
    KEK, Ibaraki
  • S. Lee, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  A 3-GeV Rapid-Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has been commissioned recently. During its beam commissioning, various beam diagnostic instrumentation has been used. The multi-wire profile monitor (MWPM) is used to establish injection and H0 dump line, which transports un-stripped H- or H0 beam to the dump. The electron catcher confirms that the beam hits a charge exchange carbon foil and the specified current monitor limits the beam current to the H0 dump. Single pass BPMs which detect linac frequency (324MHz) and ionization profile monitors (IPM) help to check the one pass orbit without circulation of the beam. The beam position monitor (BPM) can measure both COD and turn-by-turn position. Tune monitor system consists of exciter and its own BPM. The exciter shakes the beam and coherent oscillation is measured at BPM. Dedicated BPMs, Fast CT (FCT) and Wall Current Monitor (WCM) are used for RF feedback or feedforward control. It will describe the performance of each instruments and how they are contributed to the successful beam commissioning.  
 
TUPC035 The Beam Position Monitor System of the J-PARC RCS injection, controls, pick-up, vacuum 1128
 
  • N. Hayashi, S. Hiroki, R. Saeki, K. Satou, R. Toyokawa, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • D. A. Arakawa, S. Hiramatsu, M. Tejima
    KEK, Ibaraki
  • S. Lee, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  The Beam Position Monitor (BPM) system of the J-PARC RCS has been fabricated, installed and operated successfully during the beam commissioning. There are 54 BPMs around the ring and most of them are placed inside steering magnets. The BPM is electro static type and it has four electrodes. A pair of electrode gives a linear response with diagonal cut shape and they were calibrated before their installation. The signal processing unit, which is equipped with 14-bit 14MSPS ADC and 600MHz DSP, has been developed for the system. In order to measure small signal, especially during the initial phase of the commissioning, careful design also done for cabling. The paper presents the current performance of the system.  
 
TUPC036 Multi-wire Profile Monitor for J-PARC 3GeV RCS injection, electron, radiation, superconductivity 1131
 
  • S. Hiroki, N. Hayashi, M. Kawase, F. Noda, P. K. Saha, H. Sako, H. Takahashi, A. Ueno
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Arakida, S. Lee, T. Toyama
    KEK, Ibaraki
  A set of six multi-wire profile monitors (MWPMs) has been installed in the injection line and the successive H0 dump line of the RCS (Rapid-Cycling Synchrotron), and contributed to the initial RCS commissioning for establishing an optimum injection orbit. The Au coated W wires (0.1 mm dia.) for the H- beam detection are fixed to a ceramic wind frame for two directions (horizontal and vertical with 17.7 o tilt, typically 51 wires with 2.9 mm or 9.5 mm distance), and the frame can be scanned for horizontal or vertical direction by using a stepping-motor driven actuator. A combination of the 17.7 o tilt wires and the precise scan function provides two step measurements, i.e. a rough profile is obtained only at one shot, and a detailed profile is measured for typically 101 shots (10 mm scan at 0.1 mm interval) thereafter. The beam induced charge signals are amplified by the instrumentation pre-amps located in a basement sub-tunnel at distances of 30-40 m from the frame through the shielded twisted pair cables. The signals are further transferred to the sample, hold and multiplex circuits at the ground floor. The digitized profile data are processed to the Gaussian fitting.  
 
TUPC046 Study on Longitudinal Phase-space of High-brightness Electron Beams at ISIR, Osaka University electron, vacuum, photon, radiation 1161
 
  • R. Kato, T. Igo, G. Isoyama, S. Kashiwagi, M. Morio
    ISIR, Osaka
  The performance of the free-electron laser based on self-amplified spontaneous emission strongly depends on characteristics of the electron beam, such as its transverse, longitudinal, and energy profiles as well as bunch charge. The longitudinal phase-space for the electron beam consists of the longitudinal position and energy of electrons, and several methods are extensively under study to evaluate the phase-space profile of the electron beam. We are developing a measurement system consisting of a profile monitor, a bending magnet and a streak camera. We first considered an optical transition radiation monitor as the profile monitor, but we could not get the efficient number of photons to obtain the phase-space images since the angular distribution of the transition radiation is too large to concentrate in the electron energy region of 10 – 20 MeV. In order to increase the number of photons, we have changed to a Cherenkov radiator using a hydrophobic silica aerogel. The Cherenkov radiator was installed in the beam transport line from the linac to the FEL system. We will present an outline of the phase-space measurement system and preliminary experimental results.  
 
TUPC048 Application of a 5 GSPS Analogue Ring Sampling Chip for Low-cost Single-shot BPM Systems pick-up, single-bunch, electron, undulator 1167
 
  • B. Keil, S. Lehner, S. Ritt
    PSI, Villigen
  In contrast to storage ring BPMs with continuously sampling ADCs, BPMs of single-bunch linear accelerators with typical repetition rates of 10-100Hz may also use waveform digitisers that sample just during a short interval when the bunch is passing the pickup. At PSI a 12-channel analogue sampling chip called "DRS" has been developed (*) that samples input signals in an array of 1024 capacitors per channel at up to 5GSPS. The acquisition can be stopped by a trigger signal and then the capacitor voltages of all 12 channels can be digitised with a single commercial external ADC at 33MSPS, achieving ~11 bit effective DC resolution and 450MHz max. bandwidth. The DRS chip was originally developed for low-cost digitization of 3000 detector signals of a particle physics experiment, using the PSI "VPC" VME64x FPGA board as digital back-end equipped with two PMC mezzanine modules with two DRS chips each. However, such DRS-based systems are also an attractive solution for inexpensive direct sampling and FPGA-based post-processing of suitable BPM pickup signals. This paper discusses BPM-related properties, limitations, possible improvements and measurement results of DRS-based electronics.

*S. Ritt. The DRS chip: Cheap waveform digitizing in the GHz range, Nucl. Instrum. Meth. A518: 470-471, 2004.

 
 
TUPC052 Beam Phase and RF Fields Monitoring System Using Lock-In Amplifier for RIBF monitoring, cyclotron, acceleration, ion 1173
 
  • R. Koyama, M. K. Fujimaki, N. Fukunishi, M. Hemmi, O. Kamigaito, M. Kase, Y. Kotaka, N. S. Sakamoto, K. Suda, T. Watanabe, K. Yamada, Y. Yano
    RIKEN, Saitama
  The accelerator complex of the RIKEN RI Beam Factory (RIBF) consists of two injectors - heavy ion linac (RILAC and CSM) and K78 MeV AVF cyclotron - and four cyclotrons from the upstream, RRC (K540 MeV), fRC (K570 MeV), IRC (K980 MeV), and SRC (K2600 MeV). In such a multi-stage acceleration system, one of the most important factors for stable operation is to maintain the matching of beam-phases between accelerators. However, drifts of beam-phases have been frequently observed, reasons of which might be the fluctuation of RF-fields, variation of magnetic field, and so on. Hence, it is important to monitor beam-phases constantly, and we have developed a monitoring system using the commercial RF lock-in amplifier model SR844 manufactured by Stanford Research Systems. In addition, the system for monitoring the RF-fields has also been developed to investigate its stability and the correlation with beam-phases. The beam-phases at eleven phase probes installed in the beam transport lines and RF-fields of 25 cavities are monitored in a uranium acceleration. In addition, lock-in amplifiers are also used to obtain good isochronous magnetic fields of three cyclotrons in the RIBF.  
 
TUPC061 Laser Wire Beam Profile Monitor at Spallation Neutron Source (SNS) laser, ion, electron, controls 1197
 
  • Y. Liu, S. Assadi, W. P. Grice, C. D. Long
    ORNL, Oak Ridge, Tennessee
  We report the first measurement of a hydrogen ion beam profile in the superconducting linear accelerator (SCL) at the Spallation Neutron Source (SNS) with a laser wire beam profile monitor. The advantage of the laser beam profile monitor includes non-invasive measurement, longitudinal beam scan and multiple station measurement capabilities. A Q-switched Nd:YAG laser at 1.06 μm is used to detach electrons from hydrogen ions. The laser has a repetition rate of 30 Hz and a pulse width of 7 ns. Typical pulse energies are 50 - 200 mJ. The laser is physically located outside the SCL tunnel and the ion beam profiles are measured at 9 different locations covering the entire SCL region (~ 200 m). At SNS the beam structure consists of 50 ps long micropulses separation by ~ 2.5 ns and gated into macropulses of up to 1 ms long. The firing of the laser flashlamps is synchronized to the macropulse timing. The collection magnet bends the photodetached electrons out of the beam and into a Faraday cup. Both horizontal and vertical beam profiles (typical width: 2 - 4 mm) can be measured with a resolution of 4 um. Transverse beam scans can be performed throughout the macropulse.  
 
TUPC073 A Real-time Bunch Length Terahertz Interferometer radiation, diagnostics, electron, optics 1218
 
  • G. Andonian, G. Travish
    UCLA, Los Angeles, California
  • S. Boucher, P. Frigola, A. Y. Murokh
    RadiaBeam, Marina del Rey
  With the recent development of advanced photoinjectors and next generation light sources, the progression towards high-current, ultra-short beams is very important. The measurement of these short pulses, with sub-picosecond resolution is essential for successful beam operation and optimization. This paper describes the development of a real-time, shot-to-shot bunch length diagnostic utilizing a novel beam auto-correlation technique.  
 
TUPC076 TTF HOM Data Analysis with Curve Fitting Method dipole, polarization, simulation, optics 1227
 
  • S. Pei, C. Adolphsen, K. L.F. Bane, Z. Li, J. C. Smith
    SLAC, Menlo Park, California
  To investigate the possibility of using HOM signal induced in SC cavities as beam and cavity diagnostics, experiments and analyses based on SVD have been done, which are very successful. In this paper, we described one new method based on curve fitting to analyze the HOM signal data, some results have been obtained. The new method can be used to extract the HOM mode frequency, Q and relative phase from the data. On the other hand, this method can also be used to find the HOM mode center, polarization axis, mode axis along the cavity, while careful handling of beam timing information need to be considered in analysis. Comparing with SVD, this method is more physical, and can also be used in the beam diagnostic data analysis to obtain the beam position and beam trajectory angle.  
 
TUPC080 Fermi Low-energy Transverse RF Deflector Cavity emittance, electron, coupling, RF-structure 1239
 
  • P. Craievich, S. Biedron, C. Bontoiu, S. Di Mitri, M. Ferianis, M. Veronese
    ELETTRA, Basovizza, Trieste
  • D. Alesini, L. Palumbo
    INFN/LNF, Frascati (Roma)
  • L. Ficcadenti
    Rome University La Sapienza, Roma
  • M. Petronio
    DEEI, Trieste
  The layout of FERMI@Elettra will include a transverse S-band RF deflector that will be located after the first bunch compressor (BC1) at 250 MeV. The deflector will operate in a vertical deflecting mode and coupled to a downstream dipole will be used to measure the electron bunch length and in particular to allow time-resolved beam quality measurements such as horizontal slice emittance and slice energy spread. In this paper we discuss the electron bunch deflection at 250 MeV taking into account the principal elements that dominate the selection of the transverse peak voltage specification: the finite transverse emittance, the resolution of OTR screens and the desired number of the slice divisions along the bunch that we wish to observe. The RF deflector proposed here is a frequency scaled version of the 5-cell standing wave SPARC structure.  
 
TUPC081 Single-shot Longitudinal Bunch Profile Measurements at FLASH Using Electro-optic Detection Techniques electron, laser, resonance, simulation 1242
 
  • P. J. Phillips, W. A. Gillespie
    University of Dundee, Nethergate, Dundee, Scotland
  • V. R. Arsov, H. Schlarb, B. Schmidt, P. Schmüser
    DESY, Hamburg
  • G. Berden, A. F.G. van der Meer
    FOM Rijnhuizen, Nieuwegein
  • S. P. Jamison
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • A. MacLeod
    UAD, Dundee
  • B. Steffen
    PSI, Villigen
  At the superconducting linac of FLASH at DESY, we have installed an electro-optic experiment for single-shot, non destructive measurements of the longitudinal electric charge distribution of individual electron bunches. The profile of the electron bunch field is electro-optically encoded onto a streched Ti:Sa laser pulse. In the decoding step, the profile is retrieved from a spectral measurement of the encoded pulse or from a cross-correlation of the encoded pulse with a 35 fs laser pulse , obtained from the same laser. At FLASH, sub-100 fs electron bunches have been measured during FEL operation with a resolution of better than 50 fs. The electro-optic measurements have been validated with a tranverse deflecting cavity measurements.  
 
TUPC092 An Application for Beam Profile Reconstruction with Multi-wire Profile Monitors at J-PARC RCS injection, controls, beam-transport, synchrotron 1272
 
  • H. Sako, S. Hiroki, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Ikeda
    Visual Information Center, Inc., Ibaraki-ken
  • H. Takahashi
    JAEA, Ibaraki-ken
  J-PARC RCS is commissioned since October 2007. In the early stage of RCS commissioning, Multi-Wire Profile Monitors (MWPM's) are most important beam monitors to measure positions and profiles of beam orbit in the injection line from LINAC. A MWPM consists of either a horizontal or a vertical wire plane. Each wire plane consists of several wires which has a tilt angle, and a wire scatters H- or proton beams and induced current in the wire is detected. A wire plane moves at a small step in the perpendicular direction to the wires and scans a beam profile. A complex analysis procedure and geometrical description is developed to reconstruct a beam profile from a MWPM. Beam profiles have been measured at MWPM's in the injection line and the H0 beam dump line.  
 
TUPC093 Beam Profile Monitor of the J-PARC 3GeV Rapid Cycling Synchrotron electron, ion, synchrotron, beam-losses 1275
 
  • K. Satou, N. Hayashi, R. Saeki, A. Ueno, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Harada
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima
  • S. Lee, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  • M. Tejima
    KEK, Ibaraki
  To obtain high intensity (1MW) and large emittance (214 π mm mrad) beam profiles of the 3GeV Rapid Cycling Synchrotron (RCS) of the J-PARC, we have developed the ionization profile monitors (IPMs) with wide active aperture and high dynamic range. It has three Microchannel Plates (MCPs) with active area of 81*41mm for signal multiplication and read out devices, and magnet system to generate guiding fields to collect electrons. The wide active aperture of ±116mm is obtained by arranging the three MCPs perpendicular to the beam axis. Furthermore, the dynamic range of 104 level can be obtained by adjusting each bias voltage of the MCPs. The IPMs are now collecting ions without the guiding fields. The beam commissioning of the RCS has been in progress since last year. The horizontal and vertical profiles are of great help, particularly to check injection errors. At the conference, the present status of the IPM system and the latest beam profiles will be reported.  
 
TUPC099 Wire Scanner for Transverse Beam Parameter Measurements in BEPCII electron, radiation, vacuum, simulation 1293
 
  • Y. F. Sui, J. Cao, L. Ma
    IHEP Beijing, Beijing
  The wire scanner has been installed in the linac injector of BEPCII (Beijing Electron-Positron Collider II) to provide the transverse beam parameters. In the several fellowing months, some experiments will be done. The result will be presented and the reason will be analysed.  
 
TUPC105 Slice Emittance Measurements at SPARC Photoinjector with a RF Deflector emittance, quadrupole, diagnostics, dipole 1305
 
  • C. Vaccarezza, D. Alesini, E. Chiadroni, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, G. Gatti, B. Marchetti, E. Pace
    INFN/LNF, Frascati (Roma)
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma
  • A. Mostacci
    Rome University La Sapienza, Roma
  The SPARC photoinjector is a R&D facility performing beam dynamics studies and driving a SASE-FEL. The RF deflector, completely designed and built by the SPARC team, allows measurements of the longitudinal properties of the beam bunch. Using it and the well know technique of the quadrupoles scan, the slice emittance has been measured in different conditions and benchmarked with the simulations.  
 
TUPC107 Feed-free Monitoring of Intense High-energy Bremsstrahlung electron, radiation, monitoring, simulation 1311
 
  • V. L. Uvarov, V. I. Nikiforov, V. A. Shevchenko, I. N. Shlyakhov, A. Eh. Tenishev
    NSC/KIPT, Kharkov
  High-intensity (>103 W/cm2) bremsstrahlung sources produced on the basis of electron linacs of energy E0 up to 100 MeV find use in accelerator-driven subcritical assemblies, in photonuclear isotope production, activation analysis, etc. These processes, as a rule, call for maintaining a stable bremsstrahlung flow for one or more days. Therefore the diagnostic means of the radiation must function reliably under conditions of high-absorbed doses (≥108 Gy). To solve the problem, it is proposed to use a direct charge detector (DCD). It consists of two vacuum gap-spaced metal plates of different thickness. The simulation method based on the software PENELOPE/2006 was used to investigate the conditions of equilibrium e, X-radiation formation in the area of detector location, the dependence of detector sensitivity in its standard geometry on the atomic number Z of the plate material and the gammas energy at E0 ranging from 20 to 100 MeV. The realization of the method has been demonstrated by experiment with the use of the DCD prototype. The proposed detector requires no external power supply, is easy to operate and has a high radiation resistance.  
 
TUPC138 Development of a New Low-Level RF-Control-System for the S-DALINAC controls, diagnostics, klystron, electron 1389
 
  • A. Araz, U. Bonnes, R. Eichhorn, M. Konrad, M. Platz, A. Richter
    TU Darmstadt, Darmstadt
  • U. Laier
    GSI, Darmstadt
  • R. Stassen
    FZJ, Jülich
  The Superconducting DArmstadt electron LINear ACcelerator S-DALINAC has a maximum energy of 130 MeV and beam currents of up to 60 μA. To reach this energy conveniently in cw, superconducting cavities with a high Q at a frequency of 3 GHz are used. In order to achieve minimal energy spread, the amplitude and phase the cavities have to be controlled strictly in order to compensat the impact of microphonic perturbations. The existing analog rf control system based on a self-exited loop, converts the 3 GHz signals down to the base band. This concept will also be followed by the new digital system currently under design. It is based on an FPGA in the low frequency part, giving a great flexibility in the control algorithm and providing additional diagnostics. For example it is possible to change the operational mode between self-exited loop and generator driven resonator within a second. We will report on the design concept, the status and the latest results measured with a prototype, including different control algorithms as well as beam loading effects.  
 
TUPC140 The Spallation Neutron Source Cryomodule Test Stand RF System controls, klystron, radio-frequency, monitoring 1395
 
  • M. T. Crofford, T. W. Hardek, D. Heidenreich, Y. W. Kang, K.-U. Kasemir, S.-H. Kim
    ORNL, Oak Ridge, Tennessee
  • J. A. Ball, T. L. Davidson
    ORNL RAD, Oak Ridge
  The Spallation Neutron Source (SNS) has recently commissioned a cryomodule test facility for the repair and testing of the super-conducting cryogenic cavities. This facility utilizes the original 402.5/805 MHz Radio Frequency (RF) Klystron Test Stand as its power source along with dual Low Level RF (LLRF) control systems. One control system is based on the standard SNS Linac LLRF controls with a second system for open-loop only control. The system is designed to allow simultaneous testing of devices in the test cave and other devices which can be tested outside of the enclosure. Initial tests have shown good results; some improvements are yet to be implemented. This paper will provide an overview of the RF systems, safety systems, and interlocks.  
 
TUPC145 FPGA Implementation of Multichannel Detuning Computation for SC Linacs controls, resonance, diagnostics, feedback 1410
 
  • K. P. Przygoda, J. Andryszczak, W. Jalmuzna, A. Napieralski, T. Pozniak
    TUL-DMCS, Łódź
  The paper presents a multi-cavity system for active compensation of SC cavities' deformations in linear accelerators like Free Electron Laser. Described system consists of digital controller, analog amplifiers and mechanical actuators. The previously developed control algorithms were implemented in SIMCON 3.1 board and allow online calculations of Lorentz force detuning only for one cavity. The recent development in the field is based on serial pipelined computations which allow a real time detuning measurements of 8 and more cavities. Moreover, the SIMCON DSP board was used for 10 ns latency computations. The new approach enables integrating the algorithm dedicated for cavity shape control with the LLRF control system using optical transmission. Furthermore the 8-channels amplifiers have been successfully added to the compensation system for driving the piezoelectric actuators. The system is tested in FLASH at DESY. The accelerating modules ACC 3, 5 and 6 with high operating gradients cavities have been taken into account. The multilayer piezostacks from PI and NOLIAC are used for the compensation purpose of cavities' deformations.  
 
TUPC151 Universal DOOCS Server Based on the Scripting Language controls 1425
 
  • J. Szewinski, K. Korzunowicz
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw
  This document describes the design and implementation of the universal DOOCS* server based on the script language for the FLASH accelerator in DESY (Hamburg, Germany). Server works with the DOOCS, which is used in FLASH for machine control. The typical usage of this application is to communicate with the measurement equipment and control small facilities of the accelerator. The aim of the project is to provide a tool which can make the server creation easy for non-programmer users (typically physicists). The heart of the server is the script language parser which has been done using well known UNIX tools: bison and flex. The complexity of designed language is comparable with complexity of the Matlab language. Application has additional features like possibility of attaching external dynamic libraries or possibility of defining the state machines (more sequencer like). Server has been tested at FLASH and currently is used by people who wish to control their equipment via DOOCS, with the minimal effort of software development.

*Distributed Object Oriented Control System.

 
 
TUPD002 Development of an Eddy Current Septum for LINAC4 septum, simulation, injection, extraction 1434
 
  • M. J. Barnes, B. Balhan, J. Borburgh, T. Fowler, B. Goddard, W. J.M. Weterings
    CERN, Geneva
  • A. Ueda
    KEK, Ibaraki
  The bump for the new PS Booster injection from the future Linac4 will be made up of a set of four pulsed dipole magnets; the first of these (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which the injected H- beam must pass. BS1 will provide a deflection of 66 mrad at 160 MeV; this will be achieved with a peak field of 630 mT and a length of 200 mm. The field must rise and fall in 40 microseconds and have a flattop of up to 120 microseconds. The ripple of the flattop should be below ±1%. This paper discusses the design of an eddy current septum for BS1.  
 
TUPD016 Grounding and Induced Voltage Issues of the Injection Bump Magnet System of the 3-GeV RCS in J-PARC power-supply, controls, proton, synchrotron 1461
 
  • T. Takayanagi, J. Kamiya, M. Kinsho, T. Ueno, M. Watanabe, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Irie
    KEK, Ibaraki
  The power supply of the injection shift bump magnets is required to rate a large current with high precision. The rating current is 20 kA and the pulse width is 1.3 ms. The power supply with the multiple connected two-quadrant IGBT choppers, which is controlled by the switching frequency over 48 kHz, realizes the tracking error less than 1.0 %. However, the switching noise due to the IGBT choppers caused damages to the control device and the measuring instrument. The ground cables were changed to copper sheets, so that the voltage due to the switching noise between the power supply board and the ground decreased from 800 V to 40 V. Furthermore, the output voltage of the RF shield was measured in connection with the several waveform patterns. These results showed the good agreement with the calculation and the experiment. The good performances of the shift bump magnet and power supply have been confirmed.  
 
TUPD032 RFQ Vacuum Brazing at CERN vacuum, rfq, alignment, radio-frequency 1494
 
  • S. J. Mathot
    CERN, Geneva
  The aim of this paper is to describe the vacuum brazing procedure used at CERN for the brazing of Radio Frequency Quadrupole (RFQ). The RFQ is made of high precision machined OFE copper pieces assembled together. Vacuum brazing is one of the most promising techniques used to join the individual components leading to vacuum tightness and high precision alignment. The RFQ's brazed at CERN are made of four 100 or 120 cm long vanes (two majors and two minor vanes). Our brazing procedure consists of two steps. The first step involves the brazing of the four vanes in a horizontal position. The second step consists of brazing the vacuum stainless steel flanges to the copper structure in a vertical position. The paper describes the problems encountered with the alignment and the vacuum tightness. The difficulties related to the stress relaxation of the machined copper pieces during the brazing heat treatment are discussed. In addition, the solutions developed to improve the alignment of the brazed RFQ's are also presented.  
 
TUPD037 Design and Development of Intercepting Devices at the Spallation Neutron Source radiation, vacuum, beam-transport, diagnostics 1508
 
  • R. T. Roseberry, S. Assadi, D. W. Crisp, K. R. Gawne
    ORNL, Oak Ridge, Tennessee
  Beam measurements in the LINAC and transport lines of the Spallation Neutron Source at Oak Ridge National Laboratory utilize a variety of intercepting instruments such as in-line emittance systems, wire scanners, scrapers and scintillation view screens. All of these devices require linear actuators with vacuum feedthroughs. The majority of the actuators acquired during the construction phase of the SNS were of commercial origin and have proven unable to meet long-term physics and engineering requirements. The predominant difficulties with these devices were lack of precision, reliability and longevity. Three new families of linear actuators have been developed at the SNS to address these deficiencies. The approach used in their development, has been to utilize a combination of commercially available linear motion components in custom built chassis to address the needs of a given set of applications. This approach has yielded devices that have met or exceeded expectations for accuracy, precision, radiation resistance, longevity and economy. Aspects of the underlying design of these actuators and their implementation will be presented at this conference.  
 
TUPP009 Implementation and Operation of the Elettra Booster Control System controls, booster, injection, power-supply 1544
 
  • M. Lonza, F. Asnicar, L. Battistello, S. Fontanini, V. Forchi', G. Gaio, F. Giacuzzo, E. Mariotti, R. Marizza, R. Passuello, L. Pivetta, C. Scafuri, G. Scalamera, G. Strangolino, D. Vittor, L. Zambon
    ELETTRA, Basovizza, Trieste
  A new injector based on a 100 MeV linac and a 2.5 GeV booster synchrotron has been built and commissioned at Elettra to provide full energy and top up injection into the storage ring. The booster replaces the 1.2 GeV linac that will be used for the new 4th generation light source FERMI@Elettra currently under construction at Elettra. A new architecture has been adopted for the booster control system based on the Tango control system software. The implementation of the control system and the tools developed to meet an aggressive commissioning time schedule are presented. The experience gained during the operation of the booster is also discussed.  
 
TUPP013 Synchronized Data Distribution and Acquisition System Using Reflective Memory for J-PARC 3GeV RCS monitoring, controls, acceleration, beam-losses 1553
 
  • H. Takahashi, N. Hayashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • M. Sugimoto
    Mitsubishi Electric Control Software Corp, Kobe
  J-PARC 3GeV RCS inject the different parameter beam to each facilities, which are MLF and MR. Therefore, 3GeV RCS Control System must realize the monitoring and the operation that are distinguished "MLF beam" from "MR beam". And, we have developed the data distribution and acquisition system for "synchronized data" which required the distinguished monitoring and operation. We have designed and developed distribution and acquisition system using Reflective Memory (RM) for BPM data, which is one of synchronized data. There are 54 BPM, and BPM signal is processed by each BPM signal circuit (total 54 circuits). Then, we have designed that RM have 54 virtual ring memories and for a few seconds BPM data pre one virtual ring memory is buffered. And we decide BPM data is written virtual ring memory position based on "beam tag", which distributed from RM of J-PARC Timing System. This "beam tag" is synchronized across J-PARC. Thereby, 54 BPM data that written same virtual ring memory position become BPM data for identical beam. The paper presents the current status of the synchronized data distribution and acquisition system using RM.  
 
TUPP019 Wakefield and RF Kicks due to Coupler Asymmetry in TESLA-type Accelerating Cavities emittance, impedance, coupling, collider 1571
 
  • K. L.F. Bane, C. Adolphsen, Z. Li
    SLAC, Menlo Park, California
  • M. Dohlus, I. Zagorodnov
    DESY, Hamburg
  • E. Gjonaj, T. Weiland
    TEMF, Darmstadt
  • I. G. Gonin, A. Lunin, N. Solyak, V. P. Yakovlev
    Fermilab, Batavia, Illinois
  In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate asymmetries in the fields that will kick the beam and tend to degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental and higher mode couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetries in) the fundamental RF fields and the other, due to transverse wakefields that are generated even when the beam is on axis. For the ILC configuration we numerically and analytically study both types of kicks and their effect on beam emittance. For the wakefield effect this is quite challenging since the bunches are very short (rms length of 300 microns), the cavity is very long (~1 m), and the distance to steady-state is even longer (~6 m). Finally, we study changes in the coupler design that can greatly reduce the effect.  
 
TUPP032 Trajectory Jitter and Single Bunch Beam Break Up Instability emittance, quadrupole, betatron, simulation 1607
 
  • S. Di Mitri, P. Craievich
    ELETTRA, Basovizza, Trieste
  • M. Borland
    ANL, Argonne, Illinois
  • A. Zholents
    LBNL, Berkeley, California
  This paper addresses stability issues related to control of the beam break up (BBU) instability in the FERMI@Elettra linac using local trajectory bumps. Analytical study and simulations using the Elegant code are presented. Three different parameters have been used to characterize the BBU, i.e. the projected emittance, the bunch head-to-tail deviation, and the Courant-Snyder invariant for the slice centroid. It is shown that shot-to-shot trajectory jitter in the injector affects the efficiency of the control of the BBU.  
 
TUPP033 Alternative Scheme of Bunch Length Compression in Linacs for Free Electron Lasers damping, simulation, bunching, laser 1610
 
  • S. Di Mitri, M. Cornacchia, S. V. Milton, S. Spampinati
    ELETTRA, Basovizza, Trieste
  The aim of this paper is to investigate the effect of an alternative scheme of bunch compression on the development of the microbunching instability. Two cases have been considered, one in the presence of a linear energy chirp at the compressor end and another without it. It is shown that after removing the linear energy chirp, a properly tuned R56 transport matrix element is able to dilute the initial energy modulation without affecting the bunch length and to damp the associated current spikes. A by-product of this study indicates that the global compression scheme can be further optimized in the direction of a double compression scheme in which the longitudinal Landau damping is enhanced by increasing the compression factor of the first compressor while reducing that of the second one. The limiting case of such a configuration is the single compression scheme at low energy. The study is based on analytical calculations and on the simulation code LiTrack.  
 
TUPP039 Wake-field Compensation in Energy Recovery Linacs acceleration, radiation, synchrotron, synchrotron-radiation 1628
 
  • G. Hoffstaetter, M. G. Billing, Y. H. Lau
    CLASSE, Ithaca
  Problems created by the correlated energy spread that wake fields can produce are strongly enhanced in Energy Recovery Linacs (ERLs), as compared to conventional linacs. This is due to the fact that in ERLs the spent beam is decelerated by a potentially large factor, which increases the relative energy spread proportionally. We show how severe this problem is for the impedance budget of the x-ray ERL that Cornell plans to build, and we analyze several different possibilities to compensate the correlated energy spread involving de-phasing linac components, linear and nonlinear time-of-flight terms in different accelerator sections, or high frequency accelerating cavities. Because of the particular design, which has a turn-around loop between two sections of the linac, there are many options for these techniques which we compare and evaluate.  
 
TUPP040 Intra Beam Scattering in Linear Accelerators, Especially ERLs scattering, simulation, lattice, radiation 1631
 
  • G. Hoffstaetter, M. P. Ehrlichman, A. Temnykh
    CLASSE, Ithaca
  The theories of beam loss and emittance growth by Touschek and Intra Beam Scattering have been formulated for beams in storage rings. It is there that these effects have hitherto been important because of their large currents. However, there are linear accelerators where these effects become important when considering loss rates and radiation damage. Prime examples are high current Energy Recovery Linacs (ERLs), managing these scattering effects can become challenging, and not only because of the large current, but also because the deceleration of the spent beam increases relative energy spread and transverse oscillation amplitudes. In this paper we describe two ways of simulating particle loss by these scattering affects, both implemented in BMAD. One that yields the places where scattering occurs, and another that yields loss rates along the chamber walls. BMAD includes nonlinear beam dynamics, wake effects, and more, which allows a rather complete propagation of scattered particle. For the example of the ERL x-ray facility that Cornell plans to build, we demonstrate that these capabilities are very important for designing a functional radiation protection system.  
 
TUPP046 Tunable Ferroelectric Based Technologies for Accelerator Components controls, insertion, luminosity, vacuum 1646
 
  • A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio
  • S. Kazakov
    KEK, Ibaraki
  • E. Nenasheva
    Ceramics Ltd., St. Petersburg
  • A. Tagantsev
    EPFL, Lausanne
  • V. P. Yakovlev
    Fermilab, Batavia, Illinois
  Low loss ferroelectric materials can be used as key elements in RF tuning and phase shifting components to provide fast, electronic control. These devices are under development for different accelerator applications in X, Ka and L - frequency bands. The exact design of these devices depends on the electrical parameters of the particular ferroelectric material to be used- its dielectric constant, loss tangent and tunability. BST based ferroelectric-oxide compounds have been found to be suitable materials for a fast electrically-controlled tuner for BNL and for high-power fast RF phase shifters to be used for SNS vector modulation applications. We present recent results on the development of BST based ferroelectric compositions synthesized for use in high power technology components. The BST(M) ferroelectrics have been tested using a transverse dc bias field. The tunability factor vs. dc field magnitude has been evaluated and the feasibility of transverse bias tuning for ferroelectric based accelerator components has been demonstrated.  
 
TUPP047 Simulation Studies on Coupler Wakefield and RF Kicks for the International Linear Collider with MERLIN emittance, simulation, higher-order-mode, linear-collider 1649
 
  • D. Kruecker, I. Melzer-Pellmann, F. Poirier, N. J. Walker
    DESY, Hamburg
  One of the critical issues in the design of the superconducting cavities or the International Linear Collider (ILC) is the influence of the RF and higher order mode (HOM) couplers on the beam dynamics. Both types of couplers break the rotational symmetry of the cavity and introduce non vanishing transverse wakefields even on the cavity axis. Furthermore the RF input coupler introduces an asymmetry into the accelerating RF field and thereby additional transverse field components. We have implemented both effects following the calculations presented previously* into the MERLIN C++ library**. This allows us to study the influence of wakefield and RF kicks on the beam dynamics, the bunch shape and the overall performance of the ILC for different proposed coupler designs.

*I. Zagorodnov and M. Dohlus, ILC Workshop, DESY 2007; K. Bane and I. Zagorodnov, Wake Fest 07, SLAC 2007.
**Merlin - A C++ Class Library for Accelerator Simulations; http://www.desy.de/~merlin.

 
 
TUPP112 The RADIOTHOMX Project electron, laser, photon, gun 1785
 
  • C. Bruni, F. Couchot, Y. Fedala, J. Haissinski, M. Lacroix, R. Roux, V. Variola, Z. F. Zomer
    LAL, Orsay
  • N. Artemiev
    LOA, Palaiseau
  • Ph. Balcou, E. Cormier, S. Montant, M. C. Nadeau
    CELIA, Talence
  • JP. Brasile, A. S. Chauchat, C. Simonboisson
    THALES, Colombes
  • R. Czarny
    Thales Laser SA, Orsay
  • P. Gladkikh
    NSC/KIPT, Kharkov
  The goal of this project is to develop a compact device, which could produce an intense flux of monochromatic X-rays for medical applications. It is based on Compton back-scattering resulting from collisions between laser pulses and relativistic electron bunches. Intense laser beams can be obtained with a high gain Fabry-Perot cavity coupled with a high average power fiber laser. Such a scheme is going to be developed by CELIA and LAL laboratories. The accelerator design to produce high repetition rate electron bunches at 50 MeV is under study. Two possibilities are being investigated: either a linear accelerator combined with a storage ring operating at an injection frequency high enough to preserve the electron beam characteristics or a high average current ERL. Both accelerator configurations aiming at producing X-ray fluxes higher than 1012 photons/s will be presented.  
 
TUPP113 Intensity Upgrade Programme for the HIT Injector Linac rfq, ion, ion-source, heavy-ion 1788
 
  • R. Cee, T. Haberer, A. Peters, S. Scheloske, T. Winkelmann
    HIT, Heidelberg
  The Heidelberg Ion Beam Therapy Centre (HIT) is a worldwide unique radiation therapy facility and the first installation of its kind in Europe. It is equipped with three treatment rooms and has the potential to irradiate over 1000 patients per year. To guarantee such a high patient throughput, i.e. based on short irradiation times, and in order to prepare upcoming clinical requirements the currently limited beam intensity (particles per spill) needs to be increased. In an endeavour to provide optimum conditions for the patient treatment an intensity upgrade programme for the injector linac has been initiated. It affects primarily the ion source and the RFQ but also other linac components. The largest influence on the linac transmission is expected by a new RFQ design with optimised electrodes, which is currently commissioned on a test bench. The update programme is accompanied by beam dynamics simulations and machine studies. First improvements are presented and the status of the programme is given.  
 
TUPP117 Review of Energy Variation Approaches in Medical Accelerators electron, coupling, radiation, photon 1797
 
  • S. M. Hanna
    MINA, Danville, California
  Most of cancer Radiation Therapy (RT) machines rely on a linac as the source of the treatment beam which can be an electron beam or an X-ray beam. In either case, an approach to vary the energy of the linac’s output beam may be needed to target cancer tumors of different depths. Over the last two decades, multiple approaches for medical linac energy variation were proposed and some of them have been developed and implemented clinically. The most direct and conventional technique is to vary the amount of the RF power delivered to the linac and hence the energy output as required by the treatment plan. A second approach involves keeping the RF power delivered to the linac fixed but varying the power delivered to different sections of the linac by utilizing a mechanical or an electronic switch that controls the power distribution inside the linac. A third approach is to use two separate linac sections. The first section receives a fixed amount of RF power while the RF power delivered to second section is controlled using conventional microwave power splitting techniques. In this paper we will review the above approaches and discuss the advantages and disadvantage of each technique.  
 
TUPP126 Advanced Concepts for Particle-therapy Accelerators ion, injection, proton, rfq 1821
 
  • Th. Strodl
    ATI, Wien
  • J. Murin, M. Pavlovic, R. Seemann
    STU, Bratislava
  Presently in Europe the first generation of particle-therapy accelerators is on the way from construction into operation. Each layout typically consists of two ion sources, a single injection line, a main synchrotron and beam transfer lines to several treatment rooms, one of them equipped with or foreseen for an ion gantry. The paper presents some possible enhancements for the next facility generation still based on existing layouts and design studies. The focus lies on an improved injection line and gantry concepts. A simplified injection line using a different configuration of ion sources and low-energy beam-transport line is described. It is based on combination of particle species with identical charge-to-mass ratio. Optimized gantry constructions are shown with mechanical designs driven by ion-optical demands, especially by the accuracy of the beam position at the isocentre. The enhancements presented in the paper may influence upgrades of existing centres or may be implemented in the design of newly developed next generation of particle- therapy accelerators.  
 
TUPP129 Accelerator Development for Advanced Particle Beam Therapy synchrotron, extraction, acceleration, proton 1827
 
  • K. Saito, K. Moriyama, H. Nihongi, H. Nishiuchi, H. Sakurabata, S. Totake, M. Umezawa
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  Particle beam therapy has become one of the most effective modalities of cancer treatment. High reliability, high throughput and high precision irradiation are strongly demanded for the therapy system. In order to meet the requirements, we have developed several key technologies of synchrotron-based accelerator system, such as multi-harmonic RF acceleration, extracted beam intensity feedback, respiration-synchronized operation and beam tuning for spot scanning irradiation. Almost all these technologies have already been applied to the proton beam therapy system at M. D. Anderson Cancer Center. Beam specifications required for the spot scanning irradiation have successfully been achieved. In this paper, present status of the accelerator development will be described.  
 
TUPP131 Status of the Linac Components for the Italian Hadrontherapy Centre CNAO rfq, vacuum, ion, controls 1833
 
  • H. Vormann, C. M. Kleffner, A. Reiter, B. Schlitt
    GSI, Darmstadt
  • G. Clemente, U. Ratzinger
    IAP, Frankfurt am Main
  The IH-DTL for the Linac in the Italian National Center for Hadron Therapy in Oncology CNAO will accelerate different ion species (C4+, O6+,3He+, H2+) to an energy of 7 MeV/u. The combined rebunching and accelerating beam dynamic concept ("KONUS", "Kombinierte Null Grad Struktur", combined zero degree structure) requires a real voltage distribution in all 56 accelerator gaps (distributed in 4 sections) matching very close to the design voltage distribution. The tuning of the mechanically finished and copper plated cavity started in January 2007, based on the experience from the similar IH-DTL for the HIT linac ("Heidelberger Ionenstrahl-Therapiezentrum", the Heidelberg ion beam therapy center). Very small differences in mechanical measures caused modified starting conditions, resulting in varying number and shape of fixed tuners, but nevertheless accurate field distribution. The CNAO Linac is at presently under commissioning, all linac components except the IH-DTL have been delivered to the center in November 2007.  
 
TUPP132 Design, Construction and Low Power RF Tests of the First Module of the ACLIP Linac proton, cyclotron, booster, coupling 1836
 
  • V. G. Vaccaro
    Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli
  • C. De Martinis
    Universita' degli Studi di Milano & INFN, Segrate
  • D. Giove
    INFN/LASA, Segrate (MI)
  • M. R. Masullo
    INFN-Napoli, Napoli
  • S. J. Mathot
    CERN, Geneva
  • A. C. Rainò, V. Variale
    INFN-Bari, Bari
  • R. J. Rush
    e2v, Chelmsford, Essex
  ACLIP is a 3 GHz proton SCL linac designed as a booster for a 30 MeV commercial cyclotron. The final energy is 62 MeV well suitable for the therapy of ocular tumours or for further acceleration (up to 230 MeV) by a second linac in order to treat deep seated tumours. The possibility of using magnetrons as the source of RF power, to reduce the overall cost of the machine, is under investigation within a collaboration with the company e2v (Chelmsford, UK). ACLIP is a 5 modules structure coupled together. The first one (able to accelerate proton from 30 to 35 MeV) has been machined and completely the brazed. We plan to have the high power test by early fall 2008. In this paper we will review the main features of the linac and discuss the results of the RF measurements carried out on this prototype.  
 
TUPP139 Variable Energy 2-MeV S-Band Linac for X-ray and Other Applications electron, emittance, target, simulation 1845
 
  • H. Bender, D. D. Schwellenbach, R. Sturgess, C. P. Trainham
    NSTec, Los Alamos, New Mexico
  • J. M. Potter
    JP Accelerator Works, Los Alamos, New Mexico
  We will describe the design and operation of a compact, 2-MeV, S-band linear accelerator (linac) with variable energy tuning and short-pulse operation down to 15 ps with 100-A peak current. The design consists of a buncher cavity for short-pulse operation and two coupled resonator sections for acceleration. Single-pulse operation is accomplished through a fast injector system with a 219-MHz subharmonic buncher. The machine is intended to support a variety of applications, such as X-ray and electron beam diagnostic development and, recently, electron diffraction studies of phase transitions in shocked materials.  
 
TUPP151 A High Intensity Positron Source at Saclay: The SOPHI Project positron, target, electron, ion 1863
 
  • O. Delferriere, V. Blideanu, M. Carty, A. Curtoni, L. Liszkay, P. Perez, J. M. Rey, N. Ruiz, Y. Sauce
    CEA, Gif-sur-Yvette
  • F. Forest, J. L. Lancelot, D. Neuveglise
    Sigmaphi, Vannes
  One of the fundamental questions of todays physics concerns the action of gravity upon antimatter. No experimental direct measurement has ever been successfully performed with antimatter particles. An R&D program has been launched at IRFU (CEA/Saclay) to demonstrate the feasibility of the production of antihydrogen (H) with the use of a target of positronium (Ps) atoms. This target, when bombarded with antiprotons, should allow combining its positrons with the incoming antiprotons and create H atoms and H+ ions. This experiment needs a large amount of Ps atoms, thus an intense source of positrons is necessary. We are building the SOPHI experiment in Saclay, based on a small 5 MeV electron linac to produce positrons via pair production on a tungsten target. This device should provide 108 slow e+/s, i.e. a factor 300 greater than the strongest activity Na22 based setups. The SOPHI system has been finalized in 2006 and the main components have been studied and built during 2007. The experiment is currently assembled and first results are expected in June 2008. The Linac, beam production and transport system will be presented, and first positron production rate measurements reported.  
 
TUPP158 Development of Laser System for Compact Laser Compton Scattering X-ray Source laser, electron, gun, scattering 1878
 
  • R. Kuroda, M. K. Koike, H. Toyokawa, K. Y. Yamada
    AIST, Tsukuba, Ibaraki
  • T. Gowa, A. Masuda, K. Sakaue, M. Washio
    RISE, Tokyo
  • S. Kashiwagi
    ISIR, Osaka
  • T. Nakajyo, F. Sakai
    SHI, Tokyo
  A compact X-ray source via laser Compton scattering is required for biological, medical and industrial science because it has many benefits about generated X-rays such as short pulse, quasi-monochromatic, energy tunability and good directivity. Our X-ray source is conventionally the single collision system between an electron pulse and a laser pulse. To increase X-ray yield, we have developed a multi-collision system with a multi-bunch electron beam and a laser optical cavity. The multi-bunch beam will be generated from a Cs-Te photocathode rf gun sytem using a multi-pulse UV laser system. The laser optical cavity will be built like the regenerative amplification including the collision point between the electron pulse and the laser pulse to enhance the laser peak power per 1 collision on laser Compton scattering. In this conference, we will describe the results of preliminary experiments for the multi-collision system and future plans.  
 
TUPP159 Dual Energy Material Recognition: Preliminary Results Obtained with the Radio-tomographic System Hosted in Messina simulation, electron, photon, target 1881
 
  • D. Loria, L. Auditore, R. C. Barnà, U. Emanuele, E. Morgana, A. Trifirò, M. Trimarchi
    INFN - Gruppo Messina, S. Agata, Messina
  • M. Carpinelli
    INFN-Cagliari, Monserrato (Cagliari)
  • A. Franconieri, M. Gambaccini
    INFN-Ferrara, Ferrara
  Dual Energy technique is a very powerful tool for material recognition. It typically involves X-ray energy below 1 MeV, thus limiting to few mm the thickness of the inspected heavy materials. However, it would be interesting to investigate the chance to extend this technique to higher energies, to allow recognition of thick heavy samples too. Encouraging preliminary tests performed by means of the radio-tomographic system based on a 5 MeV electron linac have suggested to develop a dual energy technique for high energy x-ray beams. This can be done because first experimental tests have confirmed the chance to vary the electron beam energy in a continuous way. As a consequence, bremsstrahlung beams with different end points can be produced, thus allowing to work with different x-ray transmissions. The composition of two different energies X-ray transmission results, allows to perform material recognition. By means of the MCNP4C2 code, simulations have been performed to evaluate the theoretical x-ray transmission in different materials and thickness. These results allow us to choose two x-ray energies providing the best results in order to perform material recognition.  
 
WEOBG01 CLIC RF High Power Production Testing Program damping, recirculation, target, beam-losses 1909
 
  • I. Syratchev, G. Riddone
    CERN, Geneva
  • S. G. Tantawi
    SLAC, Menlo Park, California
  The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production (~ 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses make the PETS design rather unique and the operation very challenging. In coming years the intensive PETS testing program will be implemented. The target is to demonstrate full performance of the PETS operation. The testing program overview and test results available to date will be presented.  
slides icon Slides  
 
WEOCG03 RF Reference Signal Distribution System for FAIR target, controls, antiproton, ion 1935
 
  • M. Bousonville
    GSI, Darmstadt
  • P. Meissner
    TU Darmstadt, Darmstadt
  For the synchronisation of RF systems in the FAIR (Facility for Antiproton and Ion Research) synchrotrons and storage rings, an RF Reference Signal Distribution System is being developed. The FAIR RF cavities need signals with different phases and frequencies. Furthermore, frequency ramps with RF frequency ratios of up to 7 have to be realized in all rings. To enable this functionality, the distribution system provides two different clock signals to several locations within the facility that will be up to 1 km apart. By means of these clock signals, frequency generators can be synchronised that generate the RF signals needed for the cavities. For the transmission of the clock signals, an optical network based on the DWDM method (Dense Wavelength Division Multiplex) will be used. The delay will permanently be measured and by means of the delay data, a clock regenerator produces a phase synchronous and stable reference signal at the end of each transmission line. A delay measurement accuracy of better than 100 fs has been achieved. The presentation focuses on the design of the system as well as the performance of the prototype.  
slides icon Slides  
 
WEXM02 Status of the Linac Coherent Light Source undulator, electron, laser, radiation 1939
 
  • J. N. Galayda
    SLAC, Menlo Park, California
  The Linac Coherent Light Source (LCLS) is a free-electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor were commissioned in 2007*. Accelerator commissioning activities are presently devoted to the achievement of performance goals for the completed linac.

*R. Akre, et al., "Commissioning the LCLS Injector", submitted to PRSTAB, 2007

 
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WEOAM02 A Scheme for Stabilization of Output Power of an X-ray SASE FEL undulator, laser, radiation, electron 1947
 
  • E. Schneidmiller, G. Geloni, E. Saldin, M. V. Yurkov
    DESY, Hamburg
  Stability of XFEL radiation is naturally linked to stability of the linac RF system through bunch compression, leading to very tight requirements on RF amplitude and phase. We propose a new scheme that allows to relax these requirements by a large factor.  
slides icon Slides  
 
WEOBM03 Development of a High Resolution Camera and Observations of Superconducting Cavities superconductivity, electron, superconducting-RF 1956
 
  • Y. Iwashita, Y. Tajima
    Kyoto ICR, Uji, Kyoto
  • H. Hayano
    KEK, Ibaraki
  An inspection system of the interior surface of superconducting RF cavities is developed in order to study the relation between the achievable field gradient and the defects of the interior surface. The achieved resolution is about 7 microns/pixel. So far there are good correlations between locations identified by a thermometry measurements and positions of defects found by this system. The heights or depths can be also estimated by measuring wall gradients for some well-conditioned defects. The detailed system and the data obtained from the system will be described.  
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WEIM03 Industrialization of Superconducting Accelerator Module Production vacuum, alignment, collider, free-electron-laser 1964
 
  • B. Petersen
    DESY, Hamburg
  As part of the EUROFEL Design Study, two industrial partners recently took part in the assembly of superconducting TESLA modules for FLASH. The aim was to transfer the module assembly knowledge to industry and to analyse the assembly sequence to perpare for industrial production for future projects such as the XFEL. This talk should discuss the conclusions of this study and identify issues that must be considered when transferring SRF technology to industry.  
slides icon Slides  
 
WEIM04 Highly Customized Industrialized Linacs for Applications in Scientific Research electron, proton, vacuum, RF-structure 1967
 
  • C. Piel
    ACCEL, Bergisch Gladbach
  Industrial capabilities and experience in linac design and manufacturing shall be given for the various types of scientific applications. Furthermore the process from linac contracting through establishing a project team and adequate human and machine ressources for fulfilling the technical, schedule and pricing requirements shall be described.  
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WEIM05 Institutional and Industrial Partnerships synchrotron, controls, feedback, instrumentation 1972
 
  • C. J. Bocchetta
    Instrumentation Technologies, Solkan
  To be successful, accelerator projects require close interaction with industry for design, engineering and construction. Partnership and cooperation between institutes and industry is a means to transfer knowledge and foster innovation in the private sector, while the public sector benefits from best practices, efficient use of resources and pooled knowledge. An overview of partnerships between institutions and industry is given with examples from active projects.  
slides icon Slides  
 
WEPC005 Design Considerations of the TPS Linac-to-booster Transfer Line booster, injection, kicker, septum 1989
 
  • H.-P. Chang, H. C. Chao, K. T. Hsu, S. Y. Hsu, D.-G. Huang, C.-C. Kuo, K.-K. Lin, W. T. Liu, Y.-C. Liu
    NSRRC, Hsinchu
  Design considerations of the linac to booster (LTB) transfer line for Taiwan Photon Source (TPS) project is described in this report. Electron beam from the linac with 150 MeV, 50 π-mm-mrad normalized emittance and 0.5% energy spread will be transferred to a booster synchrotron of 489.6 m. This LTB transfer line is designed with the flexible tuning capability and the diagnostics are included. Matching of transverse beam parameters from linac to booster is deliberated. The on-axis injection scheme with repetition rate around 2 or 3 Hz and efficiency with beta-mismatch for top-up operation is also studied.  
 
WEPC009 Progress of ALBA storage-ring, vacuum, booster, quadrupole 2001
 
  • D. Einfeld
    ALBA, Bellaterra
  The construction of the ALBA Synchrotron Light Source in Barcelona (Spain) is well advanced. In spring of this year the 100 MeV Linac will be installed and results from the commissioning will be reported on this conference. The different components for the accelerators have successfully completed the prototyping phase and the different series are now under production. Installation of Booster and Storage Ring should start in summer of this year and commissioning is planned for spring 2009. The construction status will be presented.  
 
WEPC015 Baseline Design of HLS Linac Upgrade klystron, electron, quadrupole, gun 2019
 
  • G. Feng, W. Li, L. Shang, L. Wang, C.-F. Wu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  The existing 200MeV linac of Hefei Light Source (HLS) mainly consists of electron gun, prebuncher, buncher, one 3m S-band linac section, and four 6m S-band linac sections. Energy gain of electron beam at the end of the linac is 200MeV and energy spread is ±0.8%. In order to improve the electron beam quality, An upgrade project is required. Four 80MW klystrons will be used to instead the old ones, which can improve the beam energy stability. This upgrade can also make it possible to increase the linac energy from 200 MeV to 400 MeV without changing the accelerating structure. In the meantime, New operation modes of HLS linac has been found by extensive computer modelling and optimization. Electron beam dynamics simulation from electron gun to the end of linac has been given, which considering space charge effects and wakefields.  
 
WEPC039 PLS Upgrade Plan lattice, emittance, insertion, booster 2070
 
  • T.-Y. Lee
    PAL, Pohang, Kyungbuk
  Pohang Light Source (PLS) has operated for 14 year successfully. To meet the request of the increasing user community, an upgrade plan of PLS is under consideration. The design goal is to achieve an emittance as low as 5 nm rad and to install as many insertion devices as possible. To minimize the necessary relocation of existing beamlines, the new lattice will still be a TBA. But, adopting combined function magnets, it is possible to achieve low emittance while the insertion straight is as long as 8.8 m where two insertion devices will be installed. The PLS upgrade plan and the lattice design will be presented in this paper.  
 
WEPC040 Commissioning of the SSRF Booster booster, dipole, electron, synchrotron 2073
 
  • H. H. Li, Q. Gu, D. M. Li, L. G. Liu, D. Wang, Z. T. Zhao
    SINAP, Shanghai
  The SSRF Booster, designed to accelerate the electrons from 150MeV to 3.5GeV, is a FODO structure synchrotron with 180m circumference and 2Hz repetition rate. The commissioning of the SSRF booster from the LTB transfer line started on Sept. 30th evening, 2007, the first turns of beam in the booster was obtained in 20 hours. With about 60 hours effective commissioning effort, the electrons were accelerated to 3.5GeV on October 5th morning, 2007. And then the first 3.5GeV beam was extracted to BTS transfer line on October 30th, 2007. In this paper, the SSRF booster is introduced and its commissioning results are presented.  
 
WEPC069 A Possible THz Radiation Source with a Train of Short Pulses in the SPARC High Brightness Photoinjector radiation, electron, cathode, simulation 2154
 
  • M. Boscolo, M. Castellano, E. Chiadroni, M. Ferrario, A. Stella, C. Vaccarezza
    INFN/LNF, Frascati (Roma)
  • V. Petrillo
    Universita' degli Studi di Milano, Milano
  A radiofrequency electron gun followed by a compressor can generate trains of THz sub-picosecond electron pulses by illuminating the photocathode with a comb laser pulse. This structure of the beam can be used to produce coherent radiation. A feasibility study for a possible experiment at SPARC to be realized with the addition of a dedicated magnetic chicane is discussed. An optimization study of a magnetic chicane with a negative and variable R56 is studied, together with a set of parameters relative to the SPARC machine with the intent of demonstrating the feasibility of this experiment. The dynamics is studied within the SPARC system with the PARMELA code and with the RETAR code for the evaluation of the radiation.  
 
WEPC070 Further Optimisation of the Diamond Light Source Injector booster, injection, klystron, storage-ring 2157
 
  • C. Christou, J. A. Dobbing, V. C. Kempson, A. F.D. Morgan, B. Singh, S. J. Singleton
    Diamond, Oxfordshire
  The Diamond Light Source injector consists of a 100MeV linac and a 3GeV full-energy booster, and has been providing beam to the storage ring since September 2006. System optimisation has continued throughout the first year of user operation at Diamond. Beam losses on injection into both the booster and storage ring have been minimised by optimisation of operating parameters and the stabilisation of injection elements, particularly the elimination of a linac energy beat. High level software has been developed to monitor turn-by-turn BPM data, allowing booster chromaticity to be measured. The same software generates an automatic log of storage ring frequency spectra on injection, enabling the parasitic measurement of storage ring tune, and can be used to provide information on storage ring impedance and chromaticity. Further optimisation of single bunch injection has been carried out in preparation for top-up operation, and top-up capability has been extended to provide a single bunch filling mode for the storage ring. Injection into the booster at low energy has been demonstrated, providing a mode of operation for the injection system in the event of a linac klystron failure.  
 
WEPC071 Installation and Commissioning of the 100 MeV Preinjector Linac of the New Elettra Injector gun, booster, klystron, electron 2160
 
  • G. D'Auria, P. Borsi, A. Carniel, P. Delgiusto, O. Ferrando, A. Franceschinis, M. M. Milloch, A. Milocco, F. Pribaz, N. Sodomaco, M. Stefanutti, L. Veljak, D. Wang
    ELETTRA, Basovizza, Trieste
  • L. Picardi, C. Ronsivalle
    ENEA C. R. Frascati, Frascati (Roma)
  A new full energy injector has been installed and commissioned at Sincrotrone Trieste, the Italian Synchrotron Light Source Facility in Trieste. It consists of a 100 MeV Preinjector Linac (PL) followed by a 2.5 GeV Booster Synchrotron (BS), that will fill the Elettra Storage Ring (SR) with 2.0 GeV and 2.4 GeV electrons. Here a complete description of the preinjector linac and its characterization in terms of beam parameters will be presented and discussed.  
 
WEPC073 Layout of the Beam Switchyard at the European XFEL kicker, septum, undulator, collimation 2163
 
  • W. Decking, F. Obier
    DESY, Hamburg
  A unique feature of the European XFEL will be the possibility to distribute electron bunches of one beam pulse to different FEL beam lines. This is achieved by using a combination of fast kickers and a DC septum. Integration of a beam abortion dump allows a flexible selection of the bunch pattern at the FEL experiment, while the superconducting linear accelerator operates with constant beam-loading. We describe the principal scheme, the geometrical and optical layout and deal with stability and technical issues like the fast kicker development.  
 
WEPC075 Recent Results and Future Perspectives of the SPARC Project emittance, undulator, laser, radiation 2169
 
  • M. Ferrario, D. Alesini, M. Bellaveglia, R. Boni, M. Boscolo, M. Castellano, E. Chiadroni, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, B. Marchetti, A. Marinelli, C. Marrelli, E. Pace, L. Palumbo, L. Pellegrino, R. Ricci, U. Rotundo, C. Sanelli, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario
    INFN/LNF, Frascati (Roma)
  • A. Bacci, I. Boscolo, F. Broggi, F. Castelli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, A. R. Rossi, L. Serafini
    INFN-Milano, Milano
  • M. Bougeard, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Salieres, O. Tchebakoff
    CEA, Gif-sur-Yvette
  • L. Catani
    INFN-Roma II, Roma
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma
  • F. Ciocci, G. Dattoli, A. Dipace, A. Doria, G. P. Gallerano, L. Giannessi, E. Giovenale, G. L. Orlandi, S. Pagnutti, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I. P. Spassovsky, V. Surrenti
    ENEA C. R. Frascati, Frascati (Roma)
  • M.-E. Couprie
    SOLEIL, Gif-sur-Yvette
  • M. Mattioli, M. Serluca
    INFN-Roma, Roma
  • M. Migliorati, A. Mostacci
    Rome University La Sapienza, Roma
  • M. Petrarca
    Università di Roma I La Sapienza, Roma
  • J. B. Rosenzweig
    UCLA, Los Angeles, California
  The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive 500 nm FEL experiments in various configurations, a Thomson backscattering source and a plasma accelerator experiment. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. As a first stage of the commissioning a complete characterization of the photoinjector has been accomplished with a detailed study of the emittance compensation process downstream the gun-solenoid system and the demonstration of the emittance oscillation in the drift. The second stage of the commissioning, that is currently underway, foresees a detailed analysis of the beam matching with the linac in order to confirm the theoretically prediction of emittance compensation based on the “invariant envelope” matching and the demonstration of the “velocity bunching” technique in the linac. In this paper we report the experimental results obtained so far and the scientific program for the near future.  
 
WEPC082 Technical Considerations of the TPS Linac electron, controls, synchrotron, bunching 2186
 
  • A. P. Lee, H.-P. Chang, J. Chen, C.-S. Fann, K. T. Hsu, S. Y. Hsu, W. K. Lau, K.-K. Lin, K.-B. Liu, Y.-C. Liu, C. Y. Wu
    NSRRC, Hsinchu
  The technical considerations of the TPS (Taiwan Photon Source) linac will be presented in this report. A 150 MeV turn-key linac is chosen in this case in order to provide the ease of injection into the booster in which the electron energy will be raised up to 3 GeV. This linac will be similar to that equipping at recently commissioned synchrotron light sources. The major beam parameters are derived from the booster and storage ring injection requirements. The beam diagnostics arrangement for linac commissioning purpose will be briefly described.  
 
WEPC089 Status of the NSLS-II Injection System Design injection, booster, storage-ring, lattice 2198
 
  • T. V. Shaftan, A. Blednykh, G. Ganetis, W. Guo, R. Heese, H.-C. Hseuh, E. D. Johnson, S. Krinsky, Y. J. Li, R. Meier, S. Ozaki, I. Pinayev, M. Rehak, J. Rose, S. Sharma, O. Singh, J. Skaritka, N. Tsoupas, F. J. Willeke, L.-H. Yu
    BNL, Upton, New York
  NSLS-II is a new ultra-bright 3rd generation 3GeV light source planned to be built at Brookhaven National Laboratory. The design of this facility is well under way. The requirement for the compact injector complex which has to continuously provide 3GeV electrons for top off injection into the storage ring is very demanding: high reliability, low loss, relatively high charge (10nC). The injector consists of linear accelerator, a full-energy booster, as well as transport lines and injection straight section. A large three dimensional dynamic aperture through the entire acceleration cycle in the booster synchrotron is required. Tolerances on pulsed magnets for the beam transfer are very tight in order to minimize injection losses and disturbance of the stored beam in the main ring. The components of the injector are optimized for high reliability and availability. In this paper we give an overview of the NSLS-II injector, discuss status, specifications and design challenges.  
 
WEPC090 Overview of the Status of the Elettra Booster Project booster, injection, storage-ring, extraction 2201
 
  • M. Svandrlik
    ELETTRA, Basovizza, Trieste
  The Elettra Booster Project is in its final phase. The 100 MeV linac pre-injector and the 2.5 GeV booster were constructed and installed on schedule and within the foreseen budget. Elettra was shut down during the last autumn to switch from the old linac injector to the new booster. The new 2.5 GeV transfer line was successfully connected to the storage ring by December 2007. During the same period the booster commissioning was started. Operation for users of the light source, with the booster as injector, is scheduled in March 2008. An overview of the booster systems and of the current status of its commissioning and operation is presented and discussed here.  
 
WEPC095 Progress in Raising the Energy of the CAMD Linac to 300 MeV injection, klystron, simulation, controls 2216
 
  • Y. Wang, K. J. Morris, V. P. Suller, S. Wang
    LSU/CAMD, Baton Rouge, Louisiana
  The possibilities and methods for higher energy injection at CAMD have been discussed previously. All components of the former HELIOS 1 linac have now been transferred to CAMD from Jefferson Laboratory. It is planned to reconfigure the CAMD injector linac by installing one of the HELIOS accelerating sections in addition to the two existing CAMD sections, thereby increasing the energy to 300MeV. The optimum arrangement for installing the 300 MeV linac in the existing tunnel has been established. Meanwhile, the arrangements and upgrades of sub-systems are being prepared, simulations of the electron beam trajectory by MATLAB based linear accelerator program are being made, and recommissioning the major HELIOS linac components is underway. In the paper, the detailed technical design of the 300 MeV linac is proposed, the key parameters of the linac are presented, and the benefits of 300 MeV injection to the CAMD synchrotron radiation light source are mentioned.  
 
WEPC138 Transient Electromagnetic Analysis and Thermal Design on the Magnet of 3-GeV Synchrotron magnet-design, synchrotron, proton, quadrupole 2332
 
  • M. Abe, S. Tounos
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • T. Adachi
    KEK, Ibaraki
  • Y. Chida
    Hitachi Ltd., Ibaraki-ken
  • K. Nakamura, T. Watanabe
    Hitachi. Ltd., Hitachi Works, Hitachi-shi
  • T. Takayanagi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • N. Tani
    JAEA/LINAC, Ibaraki-ken
  J-PARC 3GeV synchrotron is operated at 25Hz alternatively, which can generate eddy currents and heat. They can disturb continuous operations. We prepared a design technique to analyze them and manage the temperature rises of the magnets. Eddy current and hysteresis heat generations were calculated with 3D models then temperature rises were evaluated with natural convection cooling from surfaces. The technique was applied on the dipole, quadrupole and bump magnets. Slits on intense eddy current position can decrease the heat generation, however deep slits can disturb magnetic field distribution. Their depth and positions were optimized for the temperature rise reduction. So far, the synchrotron operation is fair with reasonable temperature rises.  
 
WEPC141 Septa and Distributor Developments for H- Injection into the Booster from Linac4 vacuum, injection, septum, booster 2338
 
  • J. Borburgh, B. Balhan, T. Fowler, M. Hourican, W. J.M. Weterings
    CERN, Geneva
  The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented.  
 
WEPC145 A Fast-sampling, Planar Array for Measuring the AC Field of Fermilab Pulsed Extraction Magnets extraction, pick-up, dipole, booster 2350
 
  • J. DiMarco, C. Johnstone, O. Kiemschies, S. Kotelnikov, M. J. Lamm, A. Makulski, R. Nehring, D. F. Orris, A. D. Russell, M. Tartaglia, G. Velev, D. G.C. Walbridge, A. Yuan
    Fermilab, Batavia, Illinois
  A system employing a planar array of inductive pick-up coils has been developed for measurements of the rapidly changing dipole field in pulsed extraction magnets of the Fermilab MuCool project. The magnets are of C-type design, and have a peak field of 0.65 T during 8.33 millisecond half-sine pulse with 15 Hz repetition rate. The coils of the measurement system are fabricated on a single, 97.5 mm wide, 2-layer circuit board. The top layer of the circuit board has 15 unbucked coils distributed over its width. The bottom layer has a similar arrangement of coils, except each is bucked against the central winding to suppress the main dipole field and allow for more sensitive measurements of higher-order harmonics across the magnet mid-plane. The array of coils is simultaneously sampled at data rates of up to 100kHz with 10kHz bandwidth using 24-bit ADC’s. A detailed overview of the system and data analysis is presented, along with a characterization of results and system performance.  
 
WEPC159 Compact Design of Race-track Microtron Magnets focusing, microtron, induction, electron 2380
 
  • J. P. Rigla, Yu. A. Kubyshin
    UPC, Barcelona
  • S. Ferrer
    ALBA, Bellaterra
  • A. V. Poseryaev, V. I. Shvedunov
    MSU, Moscow
  A novel design of the end magnets for race-track microtrons (RTMs) is proposed. It consists of four-poles with the REPM material being used as a source of the magnetic field. For a proper choice of parameters of such magnetic system it can provide both the closure of the first orbit after beam reflection and required focusing properties. It is shown that such end magnet can be made quite compact thus allowing to build miniature RTMs. The procedure of design of the four-pole magnetic system and its optimization using the ANSYS code is described in detail.  
 
WEPP028 Flexible Momentum Compaction Return Arcs for RLAs acceleration, focusing, lattice, quadrupole 2578
 
  • D. Trbojevic
    BNL, Upton, Long Island, New York
  • S. A. Bogacz
    Jefferson Lab, Newport News, Virginia
  • R. P. Johnson
    Muons, Inc, Batavia
  • M. Popovic
    Fermilab, Batavia, Illinois
  Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity and the cost of the return arcs is appropriate. Flexible Momentum Compaction (FMC) lattice designs for the teardrop return arcs provide sufficient momentum acceptance to allow multiple passes of each sign of muon in one string of magnets to improve cost-effectiveness.  
 
WEPP048 Recirculating Linear Muon Accelerator with Ramped Quadrupoles optics, focusing, quadrupole, acceleration 2629
 
  • S. A. Bogacz
    Jefferson Lab, Newport News, Virginia
  • R. P. Johnson
    Muons, Inc, Batavia
  Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We are developing the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed Linac quadrupoles to allow the maximum number of passes.

Supported in part by DOE STTR grant DE-FG02-05ER86253

 
 
WEPP051 QCD Explorer Based eA and γA Colliders collider, ion, luminosity, electron 2635
 
  • H. Karadeniz
    Turkish Atomic Energy Authority, Ankara
  • E. Recepoglu
    SNRTC, Ankara
  • S. Sultansoy
    TOBB ETU, Ankara
  TeV scale lepton-hadron and photon-hadron colliders are necessary both to clarify fundamental aspects of strong interactions and for adequate interpretation of the LHC data. Today, there are two realistic proposals for the post-HERA era, namely, QCD Explorer (QCD-E) and Large Hadron electron Collider (LHeC). Both QCD-E and LHeC can operate as eA colliders, whereas γp and γA options are unique for QCD-E. Another advantage of QCD-E is the possibility to increase the center of mass energy by lengthening of electron linac. In this presentation main parameters of the QCD-E nucleus options are discussed.  
 
WEPP075 Effects of the Cryogenic Operational Conditions on the Mechanical Stability of the FLASH Linear Accelerator Modules quadrupole, electron, cryogenics, controls 2692
 
  • R. Amirikas, A. Bertolini, J. Eschke, M. Lomperski
    DESY, Hamburg
  The Free electron LASer in Hamburg (FLASH) accelerating modules have been instrumented with vertical geophones on their corresponding quadrupoles and their vacuum vessels. The signals from these geophones are constantly monitored and the data are integrated into the control system of the accelerator. Therefore, vibration stability studies of a string of superconducting accelerating modules, in various cryogenic conditions, are now possible for the first time. The results of this experiment will be an important reference for both the European X-ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) linear accelerators which are expected to take advantage from the separation between the feed lines of the 4.5 K shield and of the quadrupole, which will operate in a 2 K Helium-II bath.  
 
WEPP079 Beam Dynamics Layout and Loss Studies for the FAIR P-Injector quadrupole, emittance, proton, beam-losses 2701
 
  • G. Clemente, L. Groening
    GSI, Darmstadt
  • S. Minaev
    ITEP, Moscow
  • U. Ratzinger, R. Tiede
    IAP, Frankfurt am Main
  The development of coupled CH-DTL cavities represents a major achievement in the development of the 325 MHz, 70 MeV FAIR P-Injector. This coupled-cavity solution has important consequencies on the beam dynamics design which has to be adapted to this new kind of resonator. In combination with the KONUS beam dynamics, this solution allows to achieve all the requirements of the FAIR project in terms of beam intensity and quality reducing at the same time the number of focusing elements along the machine. A layout based on 6 CH coupled modules is presented and compared with a solution composed of three coupled modules up to 35 MeV followed by three long single resonators up to the energy of 70 MeV. A redesigned 35 MeV intertank section became necessary to avoid beam losses and emittance growth. Finally, the effect of random mistakes such as quadrupole misalignments and phase as well as voltage setting errors have been investigated to determine the tolerances of mechanical construction and rf controls during operation.  
 
WEPP080 Baseline Design of the ESS Bilbao Linac proton, ion, ion-source, target 2704
 
  • R. Enparantza, L. Uriarte
    Fundación TEKNIKER, Eibar (Gipuzkoa)
  • F. J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao
  • J. Lucas
    Elytt Energy, Madrid
  The baseline design for the ESS-B accelerator adheres to suggestions made by ESS-I, and seeks to enter a design phase for a machine based upon a 150 mA +H proton beam. Such intensity was to be delivered, as stated in the 2003 Technical Report by a tandem of two proton ion sources of some 85 mA each funnelled after the two beams are accelerated up to about 20 MeV. Current activities developed during the last few years within the CARE and EUROTRANS efforts have resulted in significant advances in both ion source and low-energy acceleration technologies which will surely have a relevant impact on the proposed accelerator design. More into specifics, our current activities are being directed towards the exploration of:
  1. The use of a single proton source capable to deliver proton currents of 150 mA or above. Proton sources such as SILHI at CEA have already produced currents of 130 mA at low duty factors.
  2. The use of superconducting cavities (spokes, quarter-wave etc.) for medium energy (40 - 100 MeV) acceleration (IFMIF and SPIRAL2).
  3. The behaviour of beams extracted from present day proton ECR sources at medium and high energies.
 
 
WEPP081 Wake-fields and Beam Dynamics Simulations for ILC ACD Accelerating Cavities emittance, damping, simulation, higher-order-mode 2707
 
  • C. J. Glasman, R. M. Jones
    UMAN, Manchester
  The ILC aims at colliding bunches of electrons and positrons at a centre of mass energy of 0.5 TeV and in a proposed upgrade to 1 TeV. These bunches of charged particle are accelerated in superconducting linacs. The baseline design for the ILC relies on the relatively mature TESLA-style cavities, with a proposed gradient of more than 30 MV/m and is known as the baseline configuration document (BCD). However, here we investigate electromagnetic fields in superconducting cavities, with the potential to reach accelerating gradients in excess of 50 MV/m, and these are the subject of the alternative configuration document (ACD). We analyse the band structure and necessary damping requirement of the wake-fields in two design configurations: Cornell's re-entrant cavity and KEK's Ichiro cavity. The emittance dilution arising from beams subjected to injection offsets and from cavity misalignments are studied in beam dynamics simulations.  
 
WEPP083 Development of an X-band Hybrid Dielectric-iris-loaded Accelerator electron, impedance, gun, longitudinal-dynamics 2713
 
  • X. D. He, S. Dong, G. Feng, Y. J. Pei, C.-F. Wu
    USTC/NSRL, Hefei, Anhui
  A compact x-band hybrid dielectric-iris-loaded travelling-wave linac with constant impendence structure has been designed. By adjusting the values of and the numbers of cells, the beam energy of 29 MeV, the capture efficiency about 50% and the energy spread about with the beam current being 70 mA and the electric gun voltage being 50KeV are obtained through longitudinal dynamics calculation. The length of accelerator tube is 1.12m . The maximum accelerating gradient is less than 45MV/m. By using electromagnetic code such as MAFIA, the attenuation per unit length of structure , the shunt impedance , the quality factor Q, the group velocity and the phase velocity are got by optimizing the dimensions of the cavities.  
 
WEPP085 RF Coupler Kicks and Wake-fields in SC Accelerating Cavities simulation, dipole, coupling, higher-order-mode 2719
 
  • N. Juntong, R. M. Jones, I. R.R. Shinton
    UMAN, Manchester
  • C. D. Beard
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Burt
    Cockcroft Institute, Warrington, Cheshire
  The main accelerating cavities of the ILC provide acceleration of both positron and electron beams to 250 GeV per beam and 500 GeV per beam in a proposed upgrade. The wake-field excited by each ultra-relativistic beam in the accelerating cavities can seriously dilute the emittance of the particles within the beams. Each cavity is supplied with both fundamental and higher order mode couplers. The geometrical configuration of these RF couplers results in an asymmetrical field and this gives rise to both an RF kick being applied to the beam and transverse wake-field. Detailed e.m. fields are simulated in the vicinity of the couplers in order to assess the impact on the beam dynamics. We investigate modified geometries with a view to alleviating the emittance dilution resulting from the e.m. field associated with the RF couplers.  
 
WEPP087 Observation and Mitigation of Multipass BBU in CEBAF dipole, damping, recirculation, optics 2722
 
  • R. Kazimi, A. Freyberger, C. Hovater, G. A. Krafft, F. Marhauser, T. E. Plawski, C. E. Reece, J. S. Sekutowicz, C. Tennant, M. G. Tiefenback, H. Wang
    Jefferson Lab, Newport News, Virginia
  The CEBAF recirculating accelerator at Jefferson Lab consists of two linacs carrying beam for up to five passes of acceleration. The Beam Break-Up (BBU) phenomenon was anticipated during design of the accelerator. The threshold beam current to induce BBU was calculated to be approximately 20 milliamperes, far above operational current. No sign of BBU was ever seen in more than a decade of operation. A specially designed acceleration cavity in a recently installed cryomodule was found to cause a BBU instability under special conditions with as low as 40 uA of injected beam current. This presented an opportunity to study BBU in a five-pass accelerator. In this paper we will discuss multipass BBU, show observational data, and discuss the ways we have developed to maintain the instability threshold current to values above those required for operation.  
 
WEPP090 Accelerator Design for a 1/2 MW Electron Linac for Rare Isotope Beam Production electron, klystron, target, gun 2728
 
  • S. R. Koscielniak, F. Ames, I. V. Bylinskii, R. E. Laxdal, M. Marchetto, A. K. Mitra, I. Sekachev, V. A. Verzilov
    TRIUMF, Vancouver
  TRIUMF, in collaboration with university partners, proposes to construct a megawatt-class electron linear accelerator (linac) as a photo-fission driver for radioactive ion beam production (RIB) for nuclear astrophysics studies and materials science. The design strategy, including upgrade path, for this cost-effective facility is elaborated. The 50 MeV, 10 mA, c.w. linac is based on TESLA/ILC super-conducting radio-frequency (SRF) technology at 1.3 GHz and 2K; and consists of an electron gun, buncher and capture sections, followed by 10 MeV and 40 MeV cryomodules containing one and four 9-cell cavities, respectively. Preliminary results from PARMELA beam dynamics simulations are presented. C. W. operation leads to challenges of large cryogenic heat load, input coupler power handling and beam loss mitigation similar to those encountered in ERL-based light sources. Unlike those sources there is no need for high beam brilliance, and a triode thermionic gun modulated at 1.3 GHz is employed; nor are short bunches required, and so the HOM excitation is modest. Many of the major sub-system components have been identified and where possible existing designs will be adopted.  
 
WEPP091 Injector Upgrade for the S-DALINAC vacuum, coupling, acceleration, electron 2731
 
  • T. Kuerzeder, A. Araz, M. Brunken, J. Conrad, R. Eichhorn, H.-D. Gräf, M. Hertling, F. Hug, M. Konrad, M. Platz, A. Richter, S. Sievers, T. Weilbach
    TU Darmstadt, Darmstadt
  • W. Ackermann, W. F.O. Müller, B. Steiner, T. Weiland
    TEMF, Darmstadt
  • J. D. Fuerst
    ANL, Argonne, Illinois
  Since 1991 the superconducting Darmstadt linear accelerator S-DALINAC provides an electron beam of up to 130 MeV for nuclear and astrophysical experiments. Currently its injector delivers beams of up to 10 MeV with a current of up to 60 μA. The upgrade aims to increase both parameters to 14 MeV and 150 μA in order to allow more demanding astrophysical experiments. Therefore, a modified cryostat module equipped with two new cavities is required. Due to an increase in RF power to 2 kW the old coaxial RF input couplers, being designed for a maximum power of 500 W, have to be replaced by new waveguide couplers. We review the design principles and report on the fabrication of the coupler and the whole module.  
 
WEPP092 Tuning of Waveguide to Cavity Coupling Coefficient Beta for a PWT Linac and a Photocathode Gun coupling, gun, simulation, electromagnetic-fields 2734
 
  • S. Krishnagopal
    BARC, Mumbai
  • U. Kale, S. Lal, K. K. Pant
    RRCAT, Indore (M. P.)
  The waveguide to cavity coupling coefficient beta for two types of accelerating structures: a Plane Wave Transformer (PWT) linac and a 1.6 cell photocathode gun has been tuned to obtain critical coupling in both. Analytical calculation of the dimensions of slot required for critical coupling have been done using Gao’s formulation based on Bethe’s theory for hole coupling. While the PWT linac structure, with high inter-cell coupling, shows good agreement between measured and predicted slot dimensions for different values of beta, the agreement is not so good in the photocathode gun on account of poor inter-cell coupling. This paper discusses details of the analytical calculation of slot dimensions for the two structures, their comparison with experimentally measured results, and the procedure adopted for tuning the two structures to critical coupling.  
 
WEPP093 Prototype of Parallel Coupled Accelerating Structure coupling, focusing, resonance, controls 2737
 
  • A. E. Levichev, V. M. Pavlov
    BINP SB RAS, Novosibirsk
  • Y. D. Chernousov
    ICKC, Novosibirsk
  • V. Ivannikov, I. V. Shebolaev
    ICKC SB RAS, Novosibirsk
  The prototype of parallel coupled accelerating structure is developed. It consists of five accelerating cavities, common excitation cavity and RF power waveguide feeder. The excitation cavity is a segment of rectangular waveguide loaded by cupper pins. The excitation cavity operate mode is TE105. Connection between excitation cavity and accelerating cavities is performed by magnetic field. The expressions for coupled factor excitation cavity to accelerating cavities and coefficient of efficiency for RF power transmission from generator to accelerating cavities are obtained using coupled cavities theory. The parallel coupled accelerating structure electrodynamic characteristics are measured.  
 
WEPP096 Nextef: The 100MW X-band Test Facility in KEK klystron, linear-collider, collider, controls 2740
 
  • S. Matsumoto, M. Akemoto, S. Fukuda, T. Higo, N. Kudoh, H. Matsushita, H. Nakajima, T. Shidara, K. Yokoyama, M. Yoshida
    KEK, Ibaraki
  Nextef is a new X-band test facility in KEK. By combining the power from two klystrons, 100MW-class X-band RF power will be available. The facility is for researches on future high gradient linear accelerators. The commissioning operation of the whole facility was started in November 2007. It is planed to conduct high power testing of X-band accelerator structures as well as the fundamental researches such as the RF breakdown experiment with specially designed waveguides.  
 
WEPP097 Simulation of Wakefield Effect in ILC IR Chamber simulation, impedance, luminosity, collider 2743
 
  • S. Pei, T. O. Raubenheimer, A. Seryi, J. C. Smith
    SLAC, Menlo Park, California
  To achieve super high luminosity, high current beams with very short bunch length are needed, which carry high intensity EM fields. For ILC, two bunch trains with bunch length of 300μm and bunch charge of 3.2nC are needed to collide at the IR to achieve the ILC luminosity goals. When the 300μm bunches pass through the IR chamber, wakefields will be excited, which will cause HOM power flowing through the IR chamber beam pipe to the final doublets due to the high frequency characteristic of the induced wakefields. Since superconducting technology is adopted for the final doublets of ILC BDS, whose operation stability might be affected by the HOM power produced at the IR chamber, quench might happen. In this paper, we did some analytical estimation and numerical simulation on the wakefield effects in ILC IR chamber.  
 
WEPP098 Efficient Traveling-wave Accelerating Structure for Linear Accelerators electron, coupling, bunching, acceleration 2746
 
  • V. M. Pirozhenko
    MRTI RAS, Moscow
  The shaped traveling-wave (STW) structure contains periodic structure of cavities with optimal shape and magnetic coupling operating in the forward traveling-wave mode. The structure combines the advantages of conventional standing-wave (SW) and traveling-wave (TW) structures. It ensures high efficiency of the use of radio-frequency (RF) power for the particle acceleration inherent in the SW structures. Also it gives a possibility to vary output energy of the particles by changing the beam loading and provides for good matching with RF generator without application of special matching devices that is inherent in the TW structures. The STW structure is well suited for compact variable-energy electron linear accelerators used for radiation technologies.  
 
WEPP119 The International Design Study for a Neutrino Factory target, proton, acceleration, factory 2773
 
  • C. R. Prior
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. S. Berg
    BNL, Upton, Long Island, New York
  • M. Meddahi
    CERN, Geneva
  • Y. Mori
    KURRI, Osaka
  The International Design Study (IDS) is the successor to the International Scoping Study (ISS), which identified a baseline scenario for a Neutrino Factory. IDS was launched in August 2007, with the aim of developing the baseline to the point where a full, technical design report can be written. The accelerator complex starts with a 4 MW proton driver operating at 50 Hz producing three to five, 1-2 ns bunches per pulse. The proton beam impacts on a liquid mercury jet target; pions are generated and are captured in a solenoid channel; they decay to muons which are phase rotated and formed into trains of interleaved bunches alternating in sign. The muon bunches then undergo ionisation cooling so as to be accepted by a linac, two dogbone recirculating linacs and finally an FFAG for acceleration to 25GeV. The muons are transferred to purpose-built storage rings, with long production straights, where they decay to neutrinos which are directed to detectors at distances of about 3000 km and 7500 km. IDS will be developing this baseline design, identifying its strengths and weaknesses, and progressing the whole towards a self-consistent scenario for the final technical design report stage.  
 
WEPP124 The Status of Turkish Accelerator Complex Project factory, electron, positron, synchrotron 2788
 
  • A. Aksoy, Ö. Karsli, B. Ketenoglu, O. Yavas
    Ankara University, Faculty of Engineering, Tandogan, Ankara
  • A. K. Ciftci
    Ankara University, Faculty of Sciences, Tandogan/Ankara
  • S. Sultansoy
    TOBB ETU, Ankara
  The Turkish Accelerator Complex (TAC) is proposed as a regional facility for accelerator based fundamental and applied research in 1997 with support of Turkish State Planning Organization (DPT). The feasibility and conceptual design phases of TAC proposal were completed in 2001 and 2005, respectively. Again with support of DPT, the technical design phase of TAC was started at the beginning of 2006. The complex will include 1 GeV electron linac and 3.56 GeV positron ring for linac on ring type electron-positron collider as a charm factory and a few GeV proton linac. Besides the particle factory, it is also planned to produce SASE FEL from electron linac and synchrotron radiation from positron ring. It is planed that the TDR of TAC Project will be completed in 2011 and the construction will be performed during following ten years .  
 
WEPP154 Linac-LHC ep Collider Options proton, electron, luminosity, emittance 2847
 
  • F. Zimmermann, F. Bordry, H.-H. Braun, O. S. Brüning, H. Burkhardt, R. Garoby, T. P.R. Linnecar, K. H. Mess, J. A. Osborne, L. Rinolfi, D. Schulte, R. Tomas, J. Tuckmantel, A. de Roeck
    CERN, Geneva
  • H. Aksakal
    N. U, Nigde
  • S. Chattopadhyay
    Cockcroft Institute, Warrington, Cheshire
  • A. K. Ciftci
    Ankara University, Faculty of Sciences, Tandogan/Ankara
  • J. B. Dainton
    Liverpool University, Science Faculty, Liverpool
  • A. Eide
    EPFL, Lausanne
  • B. J. Holzer
    DESY, Hamburg
  • M. Klein
    University of Liverpool, Liverpool
  • S. Sultansoy
    TOBB ETU, Ankara
  • A. Vivoli
    LAL, Orsay
  • F. J. Willeke
    BNL, Upton, New York
  We describe various parameter scenarios for a ring-linac ep collider based on LHC and an independent s.c. electron linac. Luminosities of order 1032/cm2/s can be achieved with a standard ILC-like linac, operated either in pulsed or cw mode, with acceptable beam power. Reaching much higher luminosities, up to 1034/cm2/s and beyond, would require the use of two linacs and the implementation of energy recovery. Advantages and challenges of a ring-linac ep collider vis-a-vis an alternative ring-ring collider are discussed.  
 
THXG01 SNS Progress, Challenges and Upgrade Options target, injection, beam-losses, beam-transport 2892
 
  • S. Henderson
    ORNL, Oak Ridge, Tennessee
  The talk describes the progress of SNS towards 1 MW, includes discussion of the challenges of successfully running high power superconducting pulsed proton linacs, and also looks forward to upgrade programmes.  
slides icon Slides  
 
THXG02 J-PARC Progress and Challenges of Proton Synchrotrons proton, injection, beam-losses, acceleration 2897
 
  • M. Kinsho
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  After briefly outlining the status of the J-PARC linac, the talk should concentrate on describing the outcome of the 3 GeV J-PARC synchrotron commissioning programme, and also include discussion of the challenges of successfully running high power proton synchrotrons.  
slides icon Slides  
 
THYG02 Results from the CLIC Test Facility CTF3 and Update on the CLIC Design acceleration, electron, luminosity, beam-loading 2912
 
  • G. Geschonke
    CERN, Geneva
  The CLIC Test Facility CTF3 is being built and commissioned in stages. Up to now the facility consists of an electron linac, a magnetic chicane for changing bunch length, the Delay Loop and the Combiner Ring. Recent experience and commissioning results will be presented together with plans for the next steps which should lead to feasibility demonstration of CLIC technology by the year 2010. The CLIC design has been reviewed in detail. The resulting changes in parameters will be presented.  
slides icon Slides  
 
THXM01 CLIC Accelerating Structure Development damping, site, collider, simulation 2922
 
  • W. Wuensch
    CERN, Geneva
  One of the most important objectives of the CLIC (Compact Linear Collider) study is to demonstrate the design accelerating gradient of 100 MV/m in a fully featured accelerating structure under nominal operating conditions including pulse length and breakdown rate. The development and testing program which has been put into place to achieve this objective is described. Recent advances in understanding and quantifying the effects which limit the accelerating gradient are presented.  
slides icon Slides  
 
THYM03 Advanced Computing Tools and Models for Accelerator Physics simulation, space-charge, electron, collider 2947
 
  • R. D. Ryne
    LBNL, Berkeley, California
  The design of the next generation of accelerators will require a new level of simulation capability to perform high resolution, multi-physics modelling of beam dynamics phenomena and to design complex 3D electromagnetic structures. Thanks to the availability of computational resources that will soon reach the petascale, we will be able to perform simulations involving unprecedented size, complexity, and physical realism. This paper will review the state-of-the-art in scientific computing for accelerator physics.  
slides icon Slides  
 
THPPGM02 EPS-AG 2008 Frank Sacherer Prize Presentation: First Steps Toward Laser Stripping Implementation laser, ion, polarization, proton 2955
 
  • V. V. Danilov
    ORNL, Oak Ridge, Tennessee
  Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping foils become radioactive and produce uncontrolled beam loss, which is one of the main factors limiting beam power in high intensity proton rings. Recently, the first laser-assisted high efficiency conversion of H- beam into protons was successfully demonstrated for a short laser pulse at Spallation Neutron Source project in Oak Ridge, Tennessee. The next step will be to build stripping device to make 1-10 μsec pulses stripping. The associated problems and possible solutions for projects with large ranges of H- beam energies are described.  
slides icon Slides  
 
THPPGM03 EPS-AG 2008 Gersh Budker Prize Presentation: The Successful Construction and Commissioning of the Spallation Neutron Source target, proton, site, beam-transport 2960
 
  • N. R. Holtkamp
    ITER, St Paul lez Durance
  • N. R. Holtkamp
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source collaboration between six Department of Energy laboratories was a unique arrangement in its mission to build a large science facility, with equally distributed responsibility for design, construction, project management and budget. The Oak Ridge National Laboratory, with no previous experience in large accelerator construction, was selected as the project site, the team was recruited worldwide, and the management team was exchanged several times during the construction period. The constraints of such a collaboration, a new team having to work together on a complex project, facing demanding scientific and technical challenges, is a cocktail that can easily lead to failure, but also to success, as proven. Was it luck or good management that decided the fate of the project? Can the weakness of such a situation simultaneously become its strength? In hindsight, it is interesting to reflect on how it was done and what became of some of the key players. Certainly this experience in many ways provided the author with a key to face a much larger challenge, namely the management of an international science project shared between seven Countries, called ITER. A project that takes the concepts tried at SNS to another extreme. Comparisons will be provided and some of the unique features will be discussed.  
slides icon Slides  
 
THPC004 Chromatic and Wakefield Effects in PSI-XFEL Linac emittance, quadrupole, electron, injection 2978
 
  • B. Grigoryan, G. A. Amatuni, V. M. Tsakanov
    CANDLE, Yerevan
  • R. J. Bakker, Y. Kim, M. Pedrozzi, J.-Y. Raguin
    PSI, Villigen
  Detailed knowledge about the wakefield and chromatic effects on electron beam emittance is an important issue to preserve the natural emittance of the beam in linear accelerators for FEL. The study of these two effects for beam and accelerator components imperfections in PSI-XFEL S-Band linear accelerator is presented. Emittance dilution caused by the beam coherent oscillations, accelerating section and quadrupole misalignments is analysed. The residual chromatic emittance dilution of the corrected trajectory is evaluated.  
 
THPC010 Trajectory Correction in the Fermi@Elettra Linac quadrupole, electron, simulation, lattice 2993
 
  • S. Di Mitri
    ELETTRA, Basovizza, Trieste
  • A. Zholents
    LBNL, Berkeley, California
  The effect of the static magnetic field errors and misalignment of the magnetic elements and linac modules on the beam trajectory in the Fermi@elettra linac [1] has been studied. Analytical description has been used to guide simulations of the trajectory correction using three different techniques. A control over the residual R56 transfer matrix element along the linac lattice has been applied. The importance of the linac structural transverse wake field for a reliable prediction of the bunch centroid dynamics has been demonstrated. Transverse deviations of bunch slices along the electron bunch induced by the wake fields have been calculated.

[1] S. Di Mitri, ST/M–07/01 (2007)

 
 
THPC012 Longitudinal Beam Dynamics Studies for the FERMI@ELETTRA Linac klystron, electron, emittance, space-charge 2999
 
  • O. Ferrando, G. D'Auria
    ELETTRA, Basovizza, Trieste
  FERMI is a single-pass FEL project under construction at Sincrotrone Trieste Laboratory. It will be driven by the present warm S-band linac, upgraded by the addition of seven accelerating sections to bring its working energy up to 1.2 GeV. The goal of the project is to have an X-ray user facility covering the wavelength region between 100 -10 nm. The stringent constraints on the electron beam parameters required by FERMI, such as emittance, pulse to pulse energy and current stabilities, and time of arrival of the bunch at the input of the undulator chain, impose very stringent requirements on the parameters and operating conditions of the linac accelerating sections. To address the problem, i.e. evaluating the operating conditions of the machine and the flexibility of the adopted layout, beam dynamics studies with the LiTrack code have been performed. Here the results of different linac settings as well as the allowed variations in terms of RF phase and amplitude of the accelerating field are presented and discussed.  
 
THPC016 Beam Optics of the PEFP Modified Beam Lines proton, quadrupole, optics, dipole 3011
 
  • J.-H. Jang, Y.-S. Cho, B. Chung, H.-J. Kwon
    KAERI, Daejon
  The 100 MeV Linac of the Proton Engineering Frontier Project (PEFP) is designed to supply 20 MeV and 100 MeV proton beams to user groups. In order to extract 20 MeV proton beams, a 45 degrees bending magnet is installed after 20 MeV DTL tank. The extracted proton beams are separated into five target rooms via a AC bending magnets. For 100 MeV beams, we use the same distribution schemes. Recently, the layout of the beam lines are modified to be short and compact. The work summaries the beam optics calculation of the modified beam lines.  
 
THPC027 Pulsed RF Accelerator of Electrons with Beam Recirculation electron, simulation, acceleration, dipole 3038
 
  • V. V. Mytrochenko, M. I. Ayzatskiy, P. Gladkikh, V. A. Kushnir, A. Opanasenko, A. Y. Zelinsky
    NSC/KIPT, Kharkov
  • S. Chemerisov, D. Ehst
    ANL, Argonne, Illinois
  We discuss the project of upgrading existent 20 MeV L-band electron linac at Argonne National Laboratory aimed at electron energy increasing. It is shown that the proposed beam recirculation will provide on the accelerator output an electron beam with a pulse current 0.5 A and energy of particles 45 MeV. Problems of stability of recirculating beam are discussed.  
 
THPC030 Simulation Studies of Correlated Misalignments in the ILC Main Linac and the Influence of Ground Motion emittance, alignment, simulation, survey 3044
 
  • F. Poirier, D. Kruecker, I. Melzer-Pellmann, N. J. Walker
    DESY, Hamburg
  Component misalignments are an important source of emittance dilution in the main linac of the International Linear Collider (ILC). The impact of static uncorrelated alignment errors has been widely studied with various simulation codes and several beam based alignment algorithms. For a realistic scenario one has to take into account that the survey and alignment process will introduce correlations between the component errors. In the present paper we study the performance of the Dispersion Matched Steering (DMS) technique for the case of such correlated misalignments. Different models for the correlations are investigated including a proposed alignment strategy for the ILC main linac* which has been implemented into the Merlin C++ library**. In addition to the initial static errors, dynamic errors due to ground motion will produce an emittance growth with time. For this case we have also investigated the stability of DMS tuning over time.

* Kiyoshi Kubo, private communication
** Merlin - A C++ Class Library for Accelerator Simulations; http://www.desy.de/~merlin.

 
 
THPC036 Model Based Orbit Correction in a Diagnostics Deficient Region controls, dipole, beam-losses, diagnostics 3056
 
  • A. P. Shishlo, A. V. Aleksandrov
    ORNL, Oak Ridge, Tennessee
  A method is presented for an orbit correction in a region where the number of beam position monitors is much less than the number of possible trajectory distortions points (quads). The method was developed for the Coupled Cavities Linac (CCL) part of the Spallation Neutron Source (SNS) linac. The orbit correction is very important in this region to minimize losses and activation, but the usual orbit correction method did not work here. The new method is based on a usage of a realistic online model. The parameters of the model were defined by multidimensional fitting procedure with a substantial array of measured trajectories in CCL. The procedure of parameters finding, model, and results are discussed.  
 
THPC037 Studies of Orthogonal Bumps for ILC Main Linac emittance, alignment, coupling, simulation 3059
 
  • N. Solyak
    Fermilab, Batavia, Illinois
  • S. A. Glukhov
    BINP SB RAS, Novosibirsk
  To preserve small vertical emittance of the beam in ILC main linac a few beam-based alignment techniques were proposed and studied in recent years. Dispersion and wakefield bumps are one of the effective tool for final tuning of the machine. One of the modifications of bumps is so called orthogonal (or SVD) bumps, proposed for CLIC. In paper we present study of orthogonal bumps performances for final alignment of the ILC main linac.  
 
THPC038 Beam Dynamic Simulations of the New Polarized Electron Injector of the S-DALINAC simulation, electron, gun, emittance 3062
 
  • B. Steiner, W. Ackermann, S. S. Franke, W. F.O. Müller, T. Weiland
    TEMF, Darmstadt
  • R. Barday, C. Eckardt, R. Eichhorn, J. Enders, C. Hessler, Y. Poltoratska, A. Richter, M. Roth
    TU Darmstadt, Darmstadt
  Aiming at an extension of the experimental possibilities at the Superconducting Darmstadt electron linear accelerator S-DALINAC, a polarized gun is going to be constructed at the moment. The new injector will be able to supply polarized electrons with kinetic energy in the 100 keV range and should add to the present unpolarized thermionic 250 keV source. The design requirements include a polarization degree of at least 80%, a mean current intensity of 60 μA and a 3 GHz cw time structure. The gun part is simulated in CST MAFIA whereas subsequent beam dynamics simulations are performed in V-Code. Initial conditions for the V-Code’s moment approach are extracted from the CST MAFIA simulations. The injector consists of short triplets, an alpha magnet, a Wien filter, a Mott polarimeter, a chopper/prebuncher system and beam diagnostic elements. For the simulations, the 3D electromagnetic fields of the beam line elements are used by means of a Taylor series expansion of variable order. All components except the chopper and a collimator is represented in the simulations. Recent beam dynamic results will be presented.  
 
THPC069 Impact of Magnet Misalignment in an ERL for Electron Cooling in RHIC emittance, electron, dipole, space-charge 3146
 
  • V. H. Ranjbar, D. T. Abell, K. Paul
    Tech-X, Boulder, Colorado
  • I. Ben-Zvi, J. Kewisch
    BNL, Upton, Long Island, New York
  • R. D. Ryne
    LBNL, Berkeley, California
  The MaryLie/IMPACT code was recently upgraded to include magnet errors. We have used the code to assess the sensitivity of final emittance of an ERL injector for the proposed RHIC electron cooler to up-stream magnetic element misalignments. This calculation will help determine the error tolerance for the construction of the ERL.  
 
THPC088 Beam Dynamics Simulation of Superconducting HWR Option for the IFMIF Linac simulation, rfq, beam-losses, emittance 3194
 
  • N. Chauvin, A. Mosnier, P. A.P. Nghiem, D. Uriot
    CEA, Gif-sur-Yvette
  One of the requirements of the International Fusion Materials Irradiation Facility (IFMIF) is a 250 mA, 40 MeV cw deuteron beam provided by two 125 mA linacs. In this paper, a design based on superconducting half-wave resonators (HWR) for the 5 to 40 MeV section of the IFMIF driver accelerator is presented. Multi particle beam dynamics simulations have been performed in order to validate the linac design in such a high charge space regime. A Monte Carlo error analysis has been carried out to study the effects of misalignments or field variations. The results of the simulations are presented and the final specifications of the HWR linac are summarized.  
 
THPC111 Simulation ofμBunching Instability Regimes in the FLASH Bunch Compressors bunching, simulation, space-charge, gun 3236
 
  • M. Vogt, T. Limberg
    DESY, Hamburg
  • D. H. Kuk
    The University of Texas at Austin, Austin, Texas
  The bunch compression scheme for the European XFEL will operate in a regime in which, at least without additional energy spread introduced by a laser heater, theμbunching effect proposed in the literature may severely degrade the performance of the FEL. However, clear, unambiguous signals of theμbunching effect have not yet been seen neither in simulation nor experiment. The proposedμbunching effect amplifies initial current modulations by interleaved application of longitudinal collective energy kicks and transformations of energy modulation into current modulation in magnetic chicanes. In order to establish a parameter regime for experimental verification ofμbunching at the FLASH VUV-FEL at DESY, we have scanned the relevant part of the parameter space using a linear, quasi-analytic, noise-free gain-model and complemented this with particle tracking simulations. The tracking was performed using interleaved runs of ASTRA for acceleration modules and CSRTrack for the chicanes, automatically linked by the start-to-end simulation tool box Gluetrack.  
 
THPC112 KONUS Dynamics and H-mode DTL Structures for EUROTRANS and IFMIF focusing, beam-losses, simulation, rfq 3239
 
  • C. Zhang, M. Busch, H. Klein, H. Podlech, U. Ratzinger, R. Tiede
    IAP, Frankfurt am Main
  During the last two decades, the combination of the KONUS beam dynamics and H-mode DTL structures has been developed as an efficient solution for accelerating low- and medium-energy proton and ion beams. EUROTRANS is a EUROpean Research Programme for the TRANSmutation of High Level Nuclear Waste in an Accelerator Driven System. IFMIF is a planned International Fusion Material Irradiation Facility to test materials for fusion reactors. For the driver linacs of both projects, two H-DTLs have been proposed to cover the energy ranges of 3–17MeV and 5–40MeV, respectively. The beam dynamics designs as well as the error studies of the H-DTLs are presented in this paper.  
 
THPC142 The Operation Event Logging System of the SLS feedback, controls, beam-losses, radio-frequency 3318
 
  • A. Luedeke
    PSI, Villigen
  Modern 3rd generation synchrotron light sources aim for 100% availability. No single beam interruption is acceptable and every distortion of operation should be investigated: What caused the interruption? Can it be avoided in the future? If it can't be avoided, how can the recovery be accelerated? An automated event recording system has been implemented at the Swiss Light Source (SLS) in order to simplify this investigations. The system identifies distortions of the user operation and records automatically type and duration of the event. All relevant information connected to the event, from control system archive data to shift protocols, is linked to the event and presented in web pages. Additional information can be added manually. Each event will be assigned to a failure cause and area. Means to filter the events are provided. The paper will describe the concept and implementation of the even logging system at the SLS and the experiences with the system.  
 
THPC143 A Wide Range Electrons, Photons, Neutrons Beam Facility electron, photon, positron, diagnostics 3321
 
  • B. Buonomo, G. Mazzitelli, F. Murtas, L. Quintieri
    INFN/LNF, Frascati (Roma)
  • P. Valente
    INFN-Roma, Roma
  The DAΦNE Beam Test Facility is in operation since the 2003 and has been continuously improved and upgraded in order to take into account the many different requests coming from the high energy and accelerator community. The facility was initially optimized to produce single electron and positron in the 25-750 MeV energy rage, manly for high energy detector calibration and testing; it can now provide beam in a wider range of intensity, up to 1010 electrons/pulse, typically needed for accelerator diagnostic tests. In the last two years the facility has also been modified in order to produce tagged photons, and the possibility to deliver tagged neutrons in the MeV energy range is under study. The main results obtained, the performance and the most significant characteristics of the facility diagnostics and operation are presented, as well as the users experience collected during these years of operation.  
 
THPC152 Electro-optic Bunch Arrival Time Measurement at FLASH laser, electron, diagnostics, acceleration 3348
 
  • V. R. Arsov, M. Felber, E.-A. Knabbe, F. Loehl, B. Lorbeer, F. Ludwig, K.-H. Matthiesen, H. Schlarb, B. Schmidt, P. Schmüser, S. Schulz, B. Steffen, A. Winter, J. Zemella
    DESY, Hamburg
  The operation of the next generation free electron lasers such as FLASH and the planned European XFEL requires drift free synchronization and femto-second stability. For this purpose an optical synchronization system has been developed, based on a mode-locked erbium-doped fiber laser, whose pulses are distributed over length stabilized fiber links. In order to evaluate the performance of the optical distribution system and the bunch arrival time monitors (BAM) an independent reference is needed. The measurement of the electro-optic (EO) response in a GaP crystal offers such a possibility. The method is destruction free and allows simultaneous determination of the peak current and the charge center of mass arrival time with femto-second precision. The measurements are performed with a 0.175 mm thick GaP crystal using 3 ps linearly chirped pulses from a Ti:Sa oscillator. The EO signal is encoded to the chirped pulse and spectrally resolved near crossed polarizers. Comparison of the EO and BAM timings provides a check of the relative accuracy of both methods, including the accuracy of the optical timing distribution system.  
 
THPC156 Performances of the SPARC Laser and RF Synchronization Systems laser, klystron, feedback, radiation 3354
 
  • A. Gallo, D. Alesini, M. Bellaveglia, G. Gatti, C. Vicario
    INFN/LNF, Frascati (Roma)
  The SPARC project consists in a 150 MeV S-band, high-brilliance linac followed by 6 undulators for FEL radiation production at 530 nm. The linac assembly has been completed and the SPARC scientific program is presently in progress. The low level RF control electronics to monitor and synchronize the RF phase of the accelerating structures along the linac and the laser shot on the photocathode has been commissioned and it is now fully operative. The laser synchronization is routinely monitored and slow drifts are automatically corrected by a dedicated shot-to-shot feedback system. A similar slow automatic regulation is implemented on each linac accelerating section acting either on low level or high power sliding lines. The phase noise in the 2 RF power stations is counteracted by fast intra-pulse phase feedback systems that have been developed and put in operation. Phase stability measurements taken over the whole synchronization system are reported, and performances of different synchronization architectures, micro-wave based or laser based, are compared.  
 
THPC159 Timing and Event Distribution for FERMI@ELETTRA controls 3363
 
  • A. Rohlev, A. O. Borga, G. D'Auria
    ELETTRA, Basovizza, Trieste
  • L. R. Doolittle, A. Ratti
    LBNL, Berkeley, California
  • J. Serrano, M. W. Stettler
    CERN, Geneva
  FERMI@ELETTRA is a 4th generation light source under construction at Sincrotrone Trieste. It will be operated as a seeded FEL driven by a warm S-band Linac which places very stringent specifications on control of the amplitude and phase of the RF stations. The local clock generation and distribution system at each station will not be based on the phase reference distribution but rather on a separate frequency reference distribution which has significantly less stringent phase stability requirements. This frequency reference will be embedded in the serial data link to each station and has the further advantage of being able to broadcast synchronous machine timing signals with sub-nanosecond temporal accuracy. The phase and amplitude of the phase reference line is measured for each pulse and used to calibrate the other measurements. This paper describes the architecture used to distribute the frequency reference along with the precision machine timing and clocking signals.  
 
THPC162 The SSRF Timing System booster, controls, injection, storage-ring 3369
 
  • L. Y. Zhao, D. K. Liu, C. X. Yin
    SINAP, Shanghai
  In the Shanghai Synchrotron Radiation Facility (SSRF), various equipment in the 150MeV linac, the full energy booster and the 3.5GeV storage ring need to be triggered and synchronized by a low jitter timing system. An event system based on distribution network is implemented in the SSRF timing system. In this paper, the software and hardware structure of the SSRF timing system are described and the system performance is presented.  
 
THPP003 RF System Design for the EMMA FFAG controls, power-supply, coupling, acceleration 3377
 
  • C. D. Beard, S. A. Griffiths, C. Hill, P. A. McIntosh, A. E. Wheelhouse
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • N. Bliss, A. J. Moss, C. J. White
    STFC/DL, Daresbury, Warrington, Cheshire
  • D. Teytelman
    Dimtel, San Jose
  In this report the RF system design for EMMA is described. The power source options, power supplies, waveguide distribution scheme and control system is discussed. The architecture necessary to meet the operation specifications requires a large degree of adjustment. To simplify commissioning and enhance the versatility of the machine a complex RF system is desired. This report details the RF "knobs" included to meet this.  
 
THPP020 Progress in the ALPI -PIAVE Low-beta Section Upgrade heavy-ion, acceleration, ion, controls 3413
 
  • A. Facco, F. Scarpa, D. Zenere
    INFN/LNL, Legnaro, Padova
  The low-b section of the PIAVE-ALPI superconducting linac is being upgraded in order to increase its energy gain from approximately 10 to about 20 MeV/q. This large increase of the accelerating voltage will be obtained by increasing by 20% the number of low-beta bulk niobium quarter-wave resonators and by upgrading the old rf system, underdimensioned in comparison with the resonator performance. This will lead to a significant enhancement of the linac capabilities, including the possibility of acceleration well above the Coulomb barrier heavy ions with any mass number. Status and technical details of the upgrade program will be described.  
 
THPP022 IH Linac with Higher-order Modes acceleration, ion, resonance, heavy-ion 3419
 
  • N. Hayashizaki, T. Hattori
    RLNR, Tokyo
  As one of a drift tube type linac, an Interdigital H-type (IH) linac has been applied for ion acceleration in low beta range. It can realize a resonant cavity of convenient size at low frequency band and higher shunt impedance at low velocity range. These characteristics are advantageous especially for heavy ion acceleration; therefore, this structure has been applied for heavy ion cancer therapy. The RF field is resonated in TE111 mode and the electric field does not have the axial field component. The accelerating field is excited by using the electrode of Interdigital shape. In order to apply this structure to intermediate beta range, we propose a IH linac with the TE11n mode of the higher-order mode (HOM). Although the operating frequency becomes higher by using HOM, it is convenient to accelerate ion beam of intermediate energy. The design of the cavity structure and the possibility are presented.  
 
THPP025 Fabrication Status of the PEFP DTL II alignment, proton, laser, vacuum 3425
 
  • H. S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, B.-S. Park
    KAERI, Daejon
  The DTL II as a main part of the PEFP proton linac is under development. Following the DTL I which accelerates the proton beam up to 20 MeV, DTL II increases the proton energy from 20 MeV to 100 MeV. The DTL II consists of 7 tanks and each tank is composed of 3 sections whose length is about 2.2 m. The tank is made of seamless carbon steel and inside surface is electroplated with copper. Each drift tube contains an electroquadrupole magnet which is made of hollow conductor and iron yoke with epoxy molding. The status of development and test results of the fabricated parts are reported in this paper.  
 
THPP027 Heating and Stress in the LANSCE Side-coupled Linac RF Cavities coupling, impedance 3431
 
  • S. S. Kurennoy, S. Konecni, J. F. O'Hara, L. Rybarcyk
    LANL, Los Alamos, New Mexico
  RF heating and related temperature distribution and stress are important problems in room-temperature accelerating cavities operating at high duty factors. To evaluate feasibility of higher duty operations of the Los Alamos Neutron Science Center (LANSCE) side-coupled linac (SCL), we have performed a combined 3-D electromagnetic (EM) and thermal-stress analysis of the SCL RF cavities. In the process, we have developed a procedure and interface for data exchange between the electromagnetic (MicroWave Studio) and engineering (COSMOS) codes for the combined EM-engineering analysis. This interface can be useful for other applications involving room-temperature accelerating cavities.  
 
THPP029 Status of the RAL Front End Test Stand ion, rfq, ion-source, diagnostics 3437
 
  • A. P. Letchford, M. A. Clarke-Gayther, D. C. Faircloth, D. J.S. Findlay, S. R. Lawrie, P. Romano, P. Wise
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • S. M.H. Al Sari, S. Jolly, A. Kurup, D. A. Lee, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  • J. Alonso, R. Enparantza
    Fundación Tekniker, Elbr (Guipuzkoa)
  • J. J. Back
    University of Warwick, Coventry
  • F. J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao
  • C. Gabor, D. C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. Lucas
    Elytt Energy, Madrid
  • J. Pasternak, J. K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon
  High power proton accelerators (HPPAs) with beam powers in the several megawatt range have many applications including drivers for spallation neutron sources, neutrino factories, waste transmuters and tritium production facilities. The UK's commitment to the development of the next generation of HPPAs is demonstrated by a test stand being constructed in collaboration between RAL, Imperial College London, the University of Warwick and the Universidad del Pais Vasco, Bilbao. The aim of the RAL Front End Test Stand is to demonstrate that chopped low energy beams of high quality can be produced and is intended to allow generic experiments exploring a variety of operational conditions. This paper describes the current status of the RAL Front End Test Stand.  
 
THPP031 Upgrade of the ISAC DTL Tuning Procedure at TRIUMF simulation, diagnostics, acceleration, ion 3440
 
  • M. Marchetto, J. Berring, R. E. Laxdal
    TRIUMF, Vancouver
  The TRIUMF ISAC facility has two variable energy heavy ion linacs as post accelerators for radioactive ion beams. The ISAC I linac is a warm IH-DTL with five accelerating tanks and three bunchers, the ISAC II one uses twenty independently phased superconducting cavities. The first linac operates between 150 keV/u and 1.8 MeV/u; the second boosts the 1.5 MeV/u injected beam by 20 MV. The DTL is tuned based on the energy beam profile given by an analysing magnet. The SC linac is tuned on energy and time profiles with a diagnostic based on a gold foil scattering ions to a silicon detector (SID). The SID requires lower beam intensity. Furthermore the tuning time is reduced and streamlined by means of a MATLAB graphical user interface (GUI). This GUI uses a simple cosine model to characterize the energy gain versus RF phase of each cavity. Based on this we have pursued a new tuning procedure for the DTL using a gold foil/SID diagnostic. The more complex RF structures of the DTL require measurements and beam dynamics simulations (with LANA code) to produce a model for a dedicated GUI. In the paper we describe the two existing tuning methods and present new DTL procedure and interface.  
 
THPP034 Design Study of Alternate Injector at Pelletron Accelerator Facility rfq, ion, ion-source, simulation 3443
 
  • N. Mehrotra, P. V. Bhagwat, R. K. Choudhury, A. K. Gupta, S. Kailas, S. Krishnagopal
    BARC, Mumbai
  • R. G. Pillay
    TIFR, Mumbai
  An alternate injector system is contrived under the AIDNP project in the Xth plan to utilize the 150MHz supercond. LINAC to its full capability. This injection system consists of ECR ion source, RFQ Linac and supercond. QWR cavities. This configuration can deliver high current and wider mass range(1/7≤ q/m≤1/2) beam into the S-LINAC with the required velocity acceptance which otherwise is not possible from pelletron. The design study from ion source to exit of RFQ is presented in this paper. Prior to injection to s-linac,the beam needs to be accelerated to an equivalent of 12-14MV/q. Beam from a high frequency(18GHz) ECRsource producing Au30+,U34+ and pre accelerated to 10keV/u will be injected into heavy ion RFQ. The RFQ operating at f/2 i.e.75MHz of the linac frequency, will accept beams with β=0.46% and accelerate upto β=3.5%.These beams would then go through two sets of superconductiong cavities with β=5.0% and β=7.0% respectively. This acceleration is expected to bring all ion beams from carbon to uranium, in the velocity range β=8%-10% which is suitable for linac. After further acceleration in Linac~12 MeV/u light ions and 7 MeV/u uranium beams would be available.  
 
THPP037 A Decelerator for Heavy Highly Charge Ions at HITRAP emittance, ion, background, heavy-ion 3449
 
  • J. Pfister, B. Hofmann, U. Ratzinger, A. Schempp
    IAP, Frankfurt am Main
  • W. Barth, L. A. Dahl, P. Gerhard, O. K. Kester, W. Quint, T. Stoehlker
    GSI, Darmstadt
  The heavy highly charged ion trap (HITRAP) project at GSI is in the commissioning phase. Highly charged ions up to U92+ provided by the GSI accelerator facility will be decelerated and subsequently injected into a large Penning trap for further cooling almost to rest. A combination of an IH- and an RFQ-structure decelerates the ions from 4 MeV/u down to 6 keV/u. In front of the decelerator a double drift-buncher-system provides for phase focusing and a final de-buncher integrated in the RFQ-tank reduces the energy spread in order to improve the efficiency for beam capture in the cooler trap. This contribution concentrates on the beam dynamics simulations and corresponding measurements in the first commissioning beam times.  
 
THPP040 Choice of Accelerating System for Undulator Linear Accelerator simulation, undulator, ion, rfq 3455
 
  • E. S. Masunov, N. V. Avreline, V. S. Dyubkov, S. M. Polozov
    MEPhI, Moscow
  • A. L. Sitnikov
    ITEP, Moscow
  The undulator linear accelerators (UNDULAC) were suggested as a new type of high intensity low energy ion linac. Such accelerators can be realized in periodical IH structure. The RF field in UNDULAC has no spatial harmonics in synchronism with the beam*. An accelerating force is to be driven by a combination of two non-synchronous space harmonics. The ratio of first to zero RF field harmonics amplitude must be equal to 0.25-0.4. The effective beam bunching and focusing could be provided in this case. The construction of UNDULAC accelerating channel is discussed to realize such ratio. The first results of IH resonator type choice are also presented.

*E. S. Masunov, Technical Physics, V. 46, 11, 2001, pp. 1433-1436.

 
 
THPP041 Beam Dynamics Simulation of the 1.5 MeV/u Proton/Deuteron Beams Measured at the SARAF RFQ Exit rfq, simulation, proton, ion 3458
 
  • J. Rodnizki, B. Bazak, D. Berkovits, G. Feinberg, A. Shor, Y. Yanay
    Soreq NRC, Yavne
  • K. Dunkel, C. Piel
    ACCEL, Bergisch Gladbach
  The Soreq Applied Research Accelerator Facility (SARAF) accelerator's front-end is composed of a 20 keV/u protons and deuterons ECR ion source, a 5 mA low energy beam transport and a 1.5 MeV/u, 4 mA, 176 MHz, 4-rod RFQ. In this work, beam dynamics simulations of the SARAF accelerator front-end is compared to the first beam measurements taken during commissioning. Beam transmission, ion energy and bunch width as a function of the RFQ power have been measured in the medium energy beam transport diagnostics and using a dedicated diagnostic plate. The simulations and measurements show similar trends. This agreement allows calibrating the RFQ power to its electrodes voltage, in the low electric field range, where the common x-ray measurement method is not feasible. The benchmark between simulation and measurement shows that the RFQ model in our simulation can well predict the measured values. The simulation is covering the beam tail as well and is used to find the optimal operating voltage by minimizing the low energy tail and hence the beam loss downstream the accelerator.  
 
THPP044 Experience with the SNS SC Linac beam-losses, emittance, focusing, beam-transport 3461
 
  • Y. Zhang, A. V. Aleksandrov, C. K. Allen, I. E. Campisi, S. M. Cousineau, V. V. Danilov, J. Galambos, J. A. Holmes, D.-O. Jeon, S.-H. Kim, T. A. Pelaia, A. P. Shishlo
    ORNL, Oak Ridge, Tennessee
  The SNS SC linac (SCL) is designed to deliver 1 GeV, up to 1.56 MW pulsed H- beams for neutron production. Beam commissioning of the SNS accelerator systems completed in June 2006 with the maximum linac output beam energy approximately 952 MeV. In 2007, we successfully tuned the SCL for 1 GeV beams during a test run, and the SNS linac achieved its design energy for the first time. During the linac tune-up, phase scan signature matching, drifting beam measurement as well as linac RF cavity phase scaling was applied. In this paper, we will introduce the experiences with the SCL, and we will also briefly discuss beam parameter measurements.


 
 
THPP073 Performance of the SNS Front End and Warm Linac target, beam-losses, kicker, radiation 3530
 
  • A. V. Aleksandrov, C. K. Allen, S. M. Cousineau, V. V. Danilov, J. Galambos, J. A. Holmes, D.-O. Jeon, T. A. Pelaia, M. A. Plum, A. P. Shishlo, M. P. Stockli, Y. Zhang
    ORNL, Oak Ridge, Tennessee
  The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H- injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The 2.5 MeV beam from the Front End is accelerated to 86 MeV in the Drift Tube Linac, then to 185 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. With the completion of beam commissioning, the accelerator complex began operation in June 2006 and beam power is being gradually ramped up toward the design goal. Operational experience with the injector and linac will be presented including chopper performance, longitudinal beam dynamics study, and the results of a beam loss study.  
 
THPP077 The IFMIF-EVEDA Accelerator Activities rfq, emittance, diagnostics, simulation 3539
 
  • A. Mosnier
    CEA, Gif-sur-Yvette
  • A. Facco
    INFN/LNL, Legnaro, Padova
  • A. Ibarra
    CIEMAT, Madrid
  The International Fusion Materials Irradiation Facility (IFMIF) aims at producing an intense flux of 14 MeV neutrons, in order to characterize materials envisaged for future fusion reactors. This facility is based on two high power CW accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV to the common lithium target. In the framework of the EU-JA Bilateral Agreement for the Broader Approach for Fusion, the Engineering Validation and Engineering Design Activities (EVEDA) phase of IFMIF has been launched in the middle of 2007. The objectives of EVEDA are to produce the detailed design of the entire IFMIF facility, as well as to build and test a number of prototypes, including a high-intensity CW deuteron accelerator (125 mA @ 9 MeV). The major components and subsystems will be designed and developed in Europe, and will be then assembled and operated at Rokkasho in Japan. The individual components are developed in Spain, Italy and France and an european accelerator team has been settled for the coordination of the accelerator activities. The design and the layout of the accelerator are presented as well as the development schedule.  
 
THPP079 Design of the High Current Linac of SPES Project rfq, target, klystron, beam-transport 3545
 
  • A. Pisent, M. Comunian, E. Fagotti, A. Palmieri, P. A. Posocco
    INFN/LNL, Legnaro, Padova
  • F. Grespan
    Università degli Studi di Milano, Milano
  The proposed driver, composed by a four vanes RFQ and an Alvarez DTL, generates a high intensity beam, for an average current of 1.5 mA and an energy of 43 MeV, upgradable to 95 MeV. The high rep rate (50 Hz) is necessary for the correct mechanical behavior of the target. The accelerator is composed by the source TRIPS, built at LNS and now in operation at LNL, by the RFQ of TRASCO research program (5 MeV 30 mA), very advanced in the construction, and by a normal conducting Drift Tube Linac (DTL). This last accelerating structure is the same proposed for LINAC4 at CERN. A prototype of this structure, of interest for both projects, is in construction in Italy with the joint effort of CERN and LNL. The RFQ and the two tanks of the DTL are fed by 3 klystrons; the first one, with a power of 1.3 MW, is already at LNL, while the other two with a power of 2.5 MW each are the same adopted for LINAC4. The power supply of the RF system (50 Hz 0.6 ms) has been evaluated in details on the bases of the system in operation for the Japanese project JPARC. This paper illustrates the physical design and beam dynamics studies of this linac.  
 
THPP080 A Superconducting CH-Linac for IFMIF rfq, acceleration, focusing, beam-losses 3548
 
  • H. Podlech, A. Bechtold, M. Busch, F. Dziuba, H. Klein, H. Liebermann, U. Ratzinger, R. Tiede, C. Zhang
    IAP, Frankfurt am Main
  The IFMIF accelerator which has to provide a 40 MeV 250 mA Deuteron beam requires a duty cycle of 100%. The IAP Frankfurt has proposed 175 MHz H-type drift tube linac consisting of an IH-cavity and a chain of superconducting CH-cavities. A superconducting CH-prototype cavity has been tested very successfully and reached effective gradients of 7 MV/m. Two rf power couplers are necessary to feed one CH-cavity. The maximum rf power per cavity is approximately 500 kW. As amplifiers the originally foreseen 1 MW tubes or 300 kW tubes can be used. The focusing scheme in the CH-linac is based on superconducting solenoids. Beam dynamics simulations have been performed with an error analysis using the LORASR code based on the KONUS dynamics. An updated and improved linac design will be presented. A contribution of IAP for the EVEDA phase could consists of the construction and the test of the room temperature IH-cavity and the first complete CH cryo-module. A study together with industry has been already performed regarding the production process and the system integration of auxiliary equipment like couplers and tuner.  
 
THPP083 Megawatt Upgrades for the ISIS Facility synchrotron, injection, target, space-charge 3554
 
  • J. W.G. Thomason, D. J. Adams, D. J.S. Findlay, I. S.K. Gardner, B. Jones, A. P. Letchford, S. J. Payne, B. G. Pine, A. Seville, C. M. Warsop, R. E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • D. C. Plostinar, C. R. Prior, G. H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Presently, it runs at beam powers of 0.2 MW, with upgrades in place to supply increased powers for the new Second Target Station due to start operation in autumn 2008. This paper outlines schemes for major upgrades to the facility in the megawatt regime, with options for 1, 2 and 5 MW. The ideas centre around new 3.2 GeV RCS designs that can be employed to increase the energy of the existing ISIS beam to provide powers of ~1 MW or, possibly as a second upgrade stage, accumulate and accelerate beam from a new 0.8 GeV linac for 2-5 MW beams. Summaries of ring designs are presented, along with studies and simulations to assess the key loss mechanisms that will impose intensity limitations. Important factors include injection, RF systems, instabilities, longitudinal and transverse space charge.  
 
THPP084 Discussion on RCS versus AR on the Basis of J-PARC Beam Commissioning for Pulsed Spallation Neutron Source injection, beam-losses, proton, space-charge 3557
 
  • Y. Yamazaki
    KEK/JAEA, Ibaraki-Ken
  • M. Kinsho
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  Over a decade it is one of the most controversial issues regarding the accelerator scheme choice whether RCS or AR should be chosen for the pulsed spallation neutron source. In order to simplify the discussion, we compare 3-GeV RCS with 1-GeV AR. The former is J-PARC scheme while the latter is SNS scheme. To summarize the discussion, RCS technology is much more difficult than AR technology, although RCS has many advantages over AR arising from its low beam current for the same beam power. Now, the J-PARC 3-GeV RCS was actually commissioned. On the basis of its experience, the discussion will be resumed.  
 
THPP085 Status of the SNS Ring Power Ramp Up target, beam-losses, injection, extraction 3560
 
  • M. A. Plum, A. V. Aleksandrov, C. K. Allen, S. M. Cousineau, V. V. Danilov, J. Galambos, J. A. Holmes, D.-O. Jeon, T. A. Pelaia, A. P. Shishlo, Y. Zhang
    ORNL, Oak Ridge, Tennessee
  Beam was first circulated in the SNS ring in January 2006. Since that time we have been working to raise the beam power to the design value of 1.4 MW. In general the power ramp up has been proceeding very well, but several issues have been uncovered. Examples include poor transmission of the waste beams in the injection dump beam line, cross-plane coupling in the ring to target beam transport line, and higher-than-expected peak densities in the ring to target transport. In this paper we will discuss these issues and present an overall status of the ring and the transport beam lines.  
 
THPP091 One Nano-second Bunch Compressor for High Intense Proton Beam dipole, proton, kicker, target 3578
 
  • L. P. Chau, M. Droba, N. S. Joshi, O. Meusel, U. Ratzinger, C. Wiesner
    IAP, Frankfurt am Main
  About ten bunches of 2MeV proton rf-linac with an average current of 150mA at 175 MHz will be deflected by kicker on different paths into a magnetic bending system. Passing this optimized geometry they approach each other longitudinaly (βλ = 0.114m) and arrive at the same time at the focus of the dipole system. For longitudinal focussing of the merged bunches a rebuncher cavity is included in the bending system. The motivation and the layout of the whole project, "Frankfurter Neutronen Quelle am Stern-Gerlach Zentrum" (FRANZ), were presented in details in previous conferences*,**. More accurate investigation results in a revision of the preliminary concept. For a theoretical proof of principle one trajectory with the biggest path length of a new geometry is calculated by a multi particle beam dynamics program (LORASR). Preliminary investigations showed, that magnetic fringing fields and bunch-bunch interactions have to be included as detailed as posible in the beam simulations. In this paper the beam dynamics results from LORASR-simulations, the new geometry and the code development for the bunch compressor are discussed in details.

*L. P. Chau et al. Proc. of the Eur. Part. Acc. Conf., Edinburgh (2006), 1690-1692.
**O. Meusel et al. Proc. of the Lin. Acc. Conf., Knoxville (2006), MOPO51, 159-161.

 
 
THPP093 Conceptual Design of the PEFP Beam Line target, proton, vacuum, shielding 3581
 
  • I.-S. Hong, Y.-S. Cho, B. H. Choi, B. Chung, J.-H. Jang, H. S. Kim, K. R. Kim, H.-J. Kwon, B.-S. Park, S. P. Yun
    KAERI, Daejon
  In the Proton Engineering Frontier Project (PEFP), 20MeV and 100MeV proton beams from a 100MeV proton liner accelerator will be supplied to users for proton beam applications. Switch magnets will share the beam to three directions, two fixed beam lines and one AC magnet. The two fixed beam lines will be used for isotope production and power semiconductor production. An AC magnet will distribute the beams to three targets simultaneously. To provide flexibilities of irradiation conditions for users from many application fields, we designed beam lines to the targets with wide or focused, external or in-vacuum, and horizontal or vertical beams. As far as possible we designed the simple beam lines to reduce the construction cost. The details of the beam line conceptual design will be reported.  
 
THPP094 The Development of a Fast Beam Chopper for Next Generation High Power Proton Drivers proton, rfq, factory, ion 3584
 
  • M. A. Clarke-Gayther
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  The Front End Test Stand (FETS) project at RAL will test a fast beam chopper, designed to address the requirements of high-power proton drivers for next generation pulsed spallation sources and neutrino factories. The RAL ‘Fast-Slow’ chopping scheme for the 2.5 MeV, 280 MHz, ESS Medium Energy Drift Space (MEBT)* is evolving to address the requirements of the 3.0 MeV, 324 MHz, FETS project. The recent adoption of a more efficient optical design for the FETS MEBT** will result in a useful increase in beam aperture and permit an important reduction in the amplitude of the chopper E-fields. A description is given of a 'state of the art' high voltage pulse generator designed to address the FETS 'Slow' chopper requirement. Measurements of output waveform and timing stability are presented.

*M. Clarke-Gayther, "A Fast Beam Chopper for Next Generation High Power Proton Drivers," EPAC04.
**M. Clarke-Gayther et al. "A fast beam chopper for the RAL Front-End Test Stand," EPAC06.

 
 
THPP108 Temperature Measurements of Carbon Stripper Foil by Pulsed 650keV H- Ion Beam target, ion, ion-source, synchrotron 3620
 
  • A. Takagi, Y. Irie, I. Sugai, Y. Takeda
    KEK, Ibaraki
  Thick carbon foils (>300 mg/cm2) has been used for stripping of H- ion beam at the 3 GeV Rapid Cycling Synchrotron　(3GeV-RCS) of the J-PARC. The carbon stripper foils with long lifetime against high temperature >1800 °K are strongly required. We have recently developed a new irradiation system for lifetime measurement using the KEK 650keV Cockcroft-Walton accelerator with high current pulsed and dc H- beams, which can simulate the high-energy deposition upon foils in the RCS. The experimental results from the measured temperature of carbon stripper foil by the pulsed 650keV H- ion beam (-6mApeak, 0.3ms, 25Hz) and the observed time structure in the beam spot by a photo-transistor are described.  
 
THPP124 Commissioning of the 150 MeV SSRF Linac controls, electron, bunching, gun 3649
 
  • M. H. Zhao, G. Q. Lin, W. H. Liu, B. L. Wang, J. Q. Zhang, S. P. Zhong, W. M. Zhou
    SINAP, Shanghai
  The 150 MeV SSRF linac has been integrated and commissioned from late 2006 to middle of 2007. This paper presents the design, installation, commissioning and status of this linac.  
 
THPP150 LANSCE Vacuum System Refurbishment Plan and Vacuum Alert System Improvements for Predictive Maintenance vacuum, ion, power-supply, monitoring 3717
 
  • T. Tajima, M. J. Borden, A. Canabal, J. P. Chamberlin, S. Harrison, F. R. Olivas, M. A. Oothoudt
    LANL, Los Alamos, New Mexico
  The Los Alamos Neutron Science Center (LANSCE) accelerator, an 800-MeV H+/H- LINAC with a storage ring, has been operated over 30 years since early 1970s. A refurbishment project named LANSCE-R was approved and started in 2007. This paper describes our plan for vacuum system refurbishment as well as an update on the ongoing vacuum email alert system improvement project, which will eventually notify workers of the need for predictive maintenance of particular devices like ion pumps.  
 
FRYAGM01 Upgrade Issues for the CERN Accelerator Complex luminosity, proton, injection, synchrotron 3734
 
  • R. Garoby
    CERN, Geneva
  The Large Hadron Collider at CERN is at a very advanced stage of construction and the first beam collisions in the experiments are expected during the year 2008. Work has now started for maximizing its physics reach and for preparing for other foreseeable needs. Beyond upgrades in the LHC itself, mainly in the optics of the insertions, the injector complex has to be renewed to deliver beam with upgraded characteristics with a high reliability. In a first phase, a new 160 MeV H- linac (“Linac4”) will be built to replace the present 50 MeV proton linac (Linac2) and extensive consolidation will be made. In a second phase, the present 26 GeV PS and its set of injectors (Linac2 + PSB) are planned to be replaced with a ~50 GeV synchrotron (“PS2”) using a 4 GeV superconducting proton linac (“SPL”) as injector. The SPS itself will also be the subject of major improvements, to be able to cope with a 50 GeV injection energy and with beams of much higher brightness. These proposals are described as well as their potential to evolve and fit the needs of future facilities for radioactive ions and/or neutrinos.  
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