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MOPKF003 Design of 2 T Wiggler Vacuum Chamber for the LNLS Storage Ring wiggler, simulation, insertion, insertion-device 300
 
  • M.J. Ferreira, R.O. Ferraz, H.G. Filho, M.B. Silva
    LNLS, Campinas
  A 2 T wiggler with 2.8 m long and a gap of 22 mm will be installed at LNLS storage ring. The main requirements of the chamber design are short conditioning time and low mechanical deformation. Two different designs in stainless steel are proposed for the prototypes, an elliptical tube and a machined sheet. A pressure profile simulation with and without a NEG coating were made for evaluating the life-time influence and the time necessary for conditioning. A simulation with finite element of mechanical deformation for both case show equivalent results. The first prototype was made with the elliptical tube and a NEG coating deposition will be made at ESRF. The second prototype with machined parts is under construction and will be TIG welded. Descriptions of mounting structure for the prototype are show and the evaluation the dimension tolerance of the chambers.  
 
MOPKF012 A 7T Multipole Wiggler in BESSY II: Implementation and Commissioning Results wiggler, radiation, optics, dynamic-aperture 324
 
  • E. Weihreter, J. Feikes, P. Kuske, R. Müller, G. Wustefeld
    BESSY GmbH, Berlin
  • D. Berger
    HMI, Berlin
  • N.A. Mezentsev, V. Shkaruba
    BINP SB RAS, Novosibirsk
  To generate hard X-ray beams for residual stress analysis and for magnetic scattering with the BESSY II SR source, a 7T wiggler with 17 poles has been implemented. Several problems had to be solved. Wake fields induced by smaller steps in the geometry of the radiation shield inside the beam chamber led to intolerable LHe consumption, which have been analysed numerically and then cured by improving the shield geometry. Much of the routine operation procedures are influenced by the unusually high radiation power level of max. 55 kW. For system protection an interlock system dumps the electron beam automatically in case of relevant error events. This wiggler is by far the strongest perturbation of the linear beam optics, breaking seriously the symmetry of the ring. Beam optical parameters including tune shift and beta beat have been measured to quantify these perturbations and develop efficient cures to limit the negative effects on beam lifetime and dynamic aperture. So far the wiggler is operated at 2.8 T and max. currents up to 250 mA in normal user shifts.  
 
MOPKF021 Properties of Cathodes Used in the Photoinjector RF Gun at the DESY VUV-FEL cathode, gun, laser, insertion 348
 
  • S. Schreiber
    DESY, Hamburg
  • J.H. Han
    DESY Zeuthen, Zeuthen
  • P. Michelato, L. Monaco, D. Sertore
    INFN/LASA, Segrate (MI)
  The new injector of the DESY VUV-FEL is being commissioned in spring 2004. Several cathodes have been tested in the photoinjector RF Gun. We report on quantum efficiency, dark current, and the overall appearance of the cathodes after their use.  
 
MOPKF025 Planar and Planar Helical Superconductive Undulators for Storage Rings, State of the Art undulator, polarization, storage-ring, synchrotron 354
 
  • R. Rossmanith, A. Bernhard, B.K. Kostka
    FZK-ISS-ANKA, Karlsruhe
  • D. Dölling, A. Hobl, D. Krischel, S. Kubsky
    ACCEL, Bergisch Gladbach
  • U. Schindler, E. Steffens
    Erlangen University, Erlangen
  • T. Schneider
    FZ Karlsruhe, Karlsruhe
  Planar superconductive undulators for low beam currents were successfully tested in the past. In a next step devices suitable for small gaps in storage rings are in preparation. The tests will clarify experimentally the heat load generated by the beam in the cold bore and will allow to optimize the control system of such devices. In addition, the layout of the next generation of planar superconductive undulators with electrically variable polarization direction are introduced in this paper.  
 
MOPKF026 Conditioning and High Power Test of the RF Guns at PITZ gun, cathode, electron, klystron 357
 
  • J.H. Han, K. Abrahamyan, J. Bähr, H.-J. Grabosch, M. Krasilnikov, D. Lipka, V. Miltchev, A. Oppelt, B. Petrosyan, D. Pose, L. Staykov, F. Stephan
    DESY Zeuthen, Zeuthen
  • I. Bohnet, J.-P. Carneiro, K. Floettmann, S. Schreiber
    DESY, Hamburg
  • M.V. Hartrott, R. Richter
    BESSY GmbH, Berlin
  • P. Michelato, L. Monaco, D. Sertore
    INFN/LASA, Segrate (MI)
  This paper describes the recent results of conditioning and high power tests of the photocathode RF guns at the Photo Injector Test Facility at DESY Zeuthen (PITZ). For successful operation of high gain SASE FELs, high phase space density of the electron beam is required. A high gradient in the gun has to be applied to improve the quality of the space charge dominated beams. In addition, long RF pulses and high repetition rate should be achieved to provide a high average power of FEL radiation. The first PITZ RF gun has been successfully tested at a mean power of 27 kW (900μseconds, 10 Hz, and 3 MW) and has been installed at the VUV-FEL at DESY Hamburg. Another RF gun has been installed at PITZ in January 2004 and is being conditioned for high power tests. The dark current behavior for various cathodes and for all operating schemes is also presented.  
 
MOPKF034 Status of the Development of Superconducting Undulators at the ESRF undulator, storage-ring, synchrotron, radiation 378
 
  • E.J. Wallén, J. Chavanne, P. Elleaume
    ESRF, Grenoble
  This note describes the present status of the development of superconducting undulators at the ESRF. Magnetic models of superconducting undulators suitable for the ESRF storage ring have been developed and evaluated. The superconducting undulators studied are horizontally polarizing undulators with a flat field profile and the vertical physical aperture of the undulator is 6 mm. Both 2D models of the local field in a period of the undulator and 3D models of the complete superconducting undulator, including the end sections and current leads, have been evaluated. The practical limit for the obtainable magnetic field has been estimated from the known performance of superconducting wire available from the cabling industry. This note also describes the conceptual design of the cryostat of the superconducting undulator and estimations of the expected heat load to the cryostat at different filling modes of the storage ring.  
 
MOPKF036 Wideband Infrared FEL undulator, electron, laser, simulation 384
 
  • J.-M. Ortega, F. Glotin, R. Prazeres
    LURE, Orsay
  The infrared free-electron laser offers the advantage of a potential large tunability since the FEL gain itself remains subtantially high throughout the infrared spectral range, provided that the electron beam quality remains sufficient at low energy. Moreover, the reflectivity of metal mirrors used in the optical cavity remains close to unity from the near infrared up to the microwave range. The main limitation comes from the diffraction of the optical beam due to the finite size of the vacuum chamber of the undulator and other optical cavity elements. The undulator magnetic gap, and thus magnetic chamber inner heigth, cannot be made arbitrarily large since one needs a K parameter sufficiently large to produce a large wavength tunability (typically K > 2). The diffraction losses can however be further reduced by using an elliptical vacuum chamber inside the undulator and elliptical, instead of spherical, mirrors. Then the optical beam is partially guided inside the chamber. Working in this regime at CLIO, we have obtained an FEL tunable from 3 to 120 μm by operating the accelerator between 50 and 14 MeV. This is the largest spectral range ever obtained with a single optical cavity. We plan to use larger mirrors to further reduce the diffraction produced at the edges of the undulator chambers in order to increase the maximum wavelength to approximately 200 μm  
 
MOPKF052 Design of an In Archromatic Superconducting Wiggler at NSRRC wiggler, synchrotron, storage-ring, multipole 425
 
  • C.-H. Chang, H.-H. Chen, T.-C. Fan, G.-Y. Hsiung, M.-H. Huang, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  A 15-pole superconducting wiggler with period length of 6 cm is designed for National Synchrotron Research Center (NSRRC) in Taiwan. The compact superconducting wiggler will be installed near the second bending magnet of the triple bend achromat section in the 1.5 GeV storage ring. This wiggler magnet with maximum peak field of 3.2 T at pole gap width of 19 mm is operated in 4.2 K liquid helium vessel. A 5-pole prototype magnet is tested and measured to verify the magnetic field performance in the testing dewar. Furthermore, the cryogenic considerations and thermal analysis in the 4.2 K wiggler magnet and the 77 K vacuum chamber are also presented in this work.  
 
MOPKF058 Construction of an APPLE-II Type Undulator at Daresbury Laboratory for the SRS undulator, radiation, insertion-device, coupling 440
 
  • F.E. Hannon, J.A. Clarke, C. Hill, A.A. Muir, D.J. Scott, B.J.A. Shepherd
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A new variable polarisation undulator of the APPLE-II type has been designed and constructed at Daresbury Laboratory. Testing of the 56mm period device has recently started in the new Magnet Test Facility at Daresbury Laboratory. This paper presents the magnetic and mechanical design of the undulator, and the first magnetic measurement results.  
 
MOPKF068 Experimental Study of the Stability Margin with Beam Heating in a Short-Period Superconducting Undulator for the APS undulator, photon, storage-ring, synchrotron 470
 
  • S.H. Kim, C. Doose, R. Kustom, E.R. Moog, K.M. Thompson
    ANL/APS, Argonne, Illinois
  A superconducting undulator with a period of 15 mm is under development at the Advanced Photon Source (APS). The undulator is designed to achieve a peak field on the beam axis of 0.8 T with an 8 mm pole tip gap and an NbTi coilpack current density of 1 kA/mm2. Because of the high current density in the coilpack, the superconducting magnet operates at about 75% of the short sample limit at 4.2K. Additional heat load to the coilpack, mainly due to the image currents and synchrotron radiation from the electron beam in the storage ring, will reduce the stability margin. An experiment was conducted to measure the reduction in the stability margin of the coilpack due to heat load on the beam chamber. The heat load was deposited in a 12-period prototype undulator using thin-film heaters attached to the inner surface of a simulated vacuum chamber. Evaluation of the stability margin based on the experiment and calculations of the beam heating and thermal conduction between the undulator and beam chamber will be discussed.  
 
MOPKF069 Engineering Design of the LUX Photoinjector klystron, coupling, impedance, emittance 473
 
  • J.W.  Staples, S.P. Virostek
    LBNL, Berkeley, California
  • S.M. Lidia
    LBNL/AFR, Berkeley, California
  The photoinjector for the LBNL LUX project, a femtosecond-regime X-ray source, is a room-temperature 1.3 GHz 4-cell structure producing a 10 MeV, nominal 30 psec, 1 nanocoulomb electron bunch at a 10 kHz rate. The first cell is of reentrant geometry, with a peak field of 64 MV/m at the photocathode surface, the geometry of which will be optimized for minimum beam emittance. The high repetition rate and high peak power results in a high average surface power density. The design of the cavity, its cooling structure and power couplers, is coordinated with the configuration of the RF system, including a short, high-power driving pulse and active removal of stored energy after the beam pulse to reduce the average power dissipated in the cavity. An RF and thermal analysis will be presented, along with plans for a high average and peak power test of the first cell.  
 
MOPLT001 Acceleration of Electrons by Spatially Modulated Laser Wave electron, acceleration, laser, injection 527
 
  • R.A. Melikian, M.L. Petrosyan, V.S. Pogosyan
    YerPhI, Yerevan
  We study the acceleration of electrons in a system of linearly polarized laser wave, propagating at small angles to the direction of electron motion. The parameters of electron bunch and laser wave are chosen so, that during driving electrons in a band of a wave, the electric field of a wave has not changed the direction. The requirements of deriving of maximum rate of acceleration are found depending on parameters of electronic bunch and laser wave. It is shown, that the dependence of growth of electrons energy from number of light bands has nonlinear character. The influence of light diffraction on process of acceleration is considered. It is shown, that the discussed scheme of acceleration allows a possibility of deriving of high acceleration rate owing to existence of modern powerful lasers.  
 
MOPLT006 The New Layout of the LHC Cleaning Insertions collimation, insertion, impedance, optics 539
 
  • R.W. Assmann, O. Aberle, O.S. Brüning, S. Chemli, D. Gasser, J.-B. Jeanneret, J.M. Jimenez, V. Kain, E. Métral, G. Peon, S. Ramberger, C. Rathjen, T. Risselada, F. Ruggiero, L. Vos
    CERN, Geneva
  • D. Kaltchev
    TRIUMF, Vancouver
  The improved LHC collimation system required significant changes in the layout and design of the warm insertion IR7. Requirements for collimation, optics, impedance, vacuum, and additional infrastructure are described and the adopted layout is discussed. Various design principles have been explored during the re-design, ranging from a regular 90 degree lattice and special low impedance lattices to an option with additional warm quadrupole units that could have extended the usable space for collimator installations in the insertion. The various constraints for the optics and cleaning design in the LHC cleaning insertions are summarized. Magnet positions and collimators were moved significantly, such that a good cleaning efficiency was maintained while impedance was reduced by a factor of two. Metallic phase 2 collimators allow a better efficiency than originally achievable and additional scrapers were allocated. The required infrastructure was specified, including a powerful cooling system for the collimators.  
 
MOPLT008 The Mechanical Design for the LHC Collimators alignment, simulation, collimation, beam-losses 545
 
  • A. Bertarelli, O. Aberle, R.W. Assmann, E. Chiaveri, T. Kurtyka, M. Mayer, R. Perret, P. Sievers
    CERN, Geneva
  The design of the LHC collimators must comply with the very demanding specifications entailed by the highly energetic beam handled in the LHC: these requirements impose a temperature on the collimating jaws not exceeding 50°C in steady operations and an unparalleled overall geometrical stability of 25micro-m on a 1200 mm span. At the same time, the design phase must meet the challenging deadlines required by the general time schedule. To respond to these tough and sometimes conflicting constraints, the chosen design appeals to a mixture of traditional and innovative technologies, largely drawing from LEP collimator experience. The specifications impose a low-Z material for the collimator jaws, directing the design towards graphite or such novel materials as 3-d Carbon/Carbon composites. An accurate mechanical design has allowed to considerably reduce mechanical play and optimize geometrical stability. Finally, all mechanical studies were supported by in-depth thermo-mechanical analysis concerning temperature distribution, mechanical strength and cooling efficiency.  
 
MOPLT013 Fatigue Testing of Materials by UV Pulsed Laser Irradiation laser, linac, simulation, radiation 557
 
  • S. Calatroni, H. Neupert, M. Taborelli
    CERN, Geneva
  The energy dissipated by the RF currents in the cavities of high-power pulsed linacs induces cycles of the surface temperature. In the case of the CLIC main linac the expected amplitude of the thermal cycles is about hundred degrees, for a total number of pulses reaching 10e11. The differential thermal expansion due to the temperature gradient in the material creates a cyclic stress that can result in surface break-up by fatigue. The materials for cavity fabrication must therefore be selected in order to withstand such constraints whilst maintaining an acceptable surface state. The fatigue behaviour of Cu and CuZr alloy has been tested by inducing larger surface peak temperatures, thus reducing the number of cycles to failure, irradiating the surface with 50 ns pulses of UV light (308 nm) from an excimer laser. Surface break-up is observed after different number of laser shots as a function of the peak temperature. CuZr appears to withstand a much larger number of cycles than Cu, for equal peak temperature. The characterization of the surface states and possible means of extrapolating the measured behaviour to the expected number of pulses of CLIC are discussed in detail.  
 
MOPLT018 Aperture and Delivery Precision of the LHC Injection System injection, extraction, quadrupole, kicker 572
 
  • B. Goddard, M. Gyr, J.-B. Jeanneret, V. Kain, M. Lamont, V. Maire, V. Mertens, J. Wenninger
    CERN, Geneva
  The main LHC injection elements in interaction regions 2 and 8 comprise the injection septa (MSI), the injection kicker (MKI), together with three families of passive protection devices (TDI, TCDD and TCLI). The apertures of the injection septa for the injected and two circulating beams are detailed with a new enlarged vacuum chamber and final septum alignment. The circulating beam aperture of the TDI is detailed with a new TDI support design and modified vacuum tank alignment. A modified TCDD shape is also presented and the implications for the aperture and protection level discussed. The various errors in the SPS, the transfer lines and the injection system, which contribute to injection errors, are analysed, and the expected performance of the system is derived, in terms of the expected delivery precision of the injected beam.  
 
MOPLT027 Cold Beam Vacuum Interconnects for the LHC Insertion Regions impedance, insertion, undulator, synchrotron 599
 
  • D.R. Ramos, D. Chauville, J. Knaster, R. Veness
    CERN, Geneva
  The LHC machine is composed of arcs and insertion regions where superconducting magnets, working at temperatures of 1.9 K and 4.5 K, have flexibly interconnected beam vacuum chambers. These interconnects must respect strict requirements in terms of impedance, aperture, space optimization and reliability. A complete interconnect design was first developed for the arc regions, and from which a total of 20 variants have been created according to the different functional requirements of each pair of cryostats along the machine. All design features and manufacture processes were validated through extensive testing. Manufacture and assembly cost was minimised by using a modular interconnect design, with common components shared among different design variants. A detailed quality assurance structure was implemented in order to achieve the high level of reliability required. This paper presents the layout of cold beam vacuum interconnects along with details of development and testing performed to validate design and integration.  
 
MOPLT032 Breakdown Resistance of Refractory Metals Compared to Copper site, cathode, collider, instrumentation 614
 
  • M. Taborelli, S. Calatroni, M. Kildemo
    CERN, Geneva
  The behaviour of Mo, W and Cu with respect to electrical breakdown in ultra high vacuum has been investigated by means of a capacitor discharge method. The maximum stable electric field and the field enhancement factor, beta, have been measured between electrodes of the same material in a sphere/plane geometry for anode and cathode, respectively. The maximum stable field increases as a function of the number of breakdown events for W and Mo. In contrast, no systematic increase is observed for Cu. The highest values obtained are typically 500 MV/m for W, 350 MV/m for Mo and only 180 MV/m for Cu. This conditioning, found for the refractory metals, corresponds to a simultaneous decrease of beta and is therefore related to the field emission properties of the surface and their modification upon sparking. Accordingly, high beta values and no applicable field increase occur for Cu even after repeated breakdown. The results are in agreement with rf breakdown experiments [*] performed on prototype 30 GHz accelerating structures for the CLIC accelerator.

* W. Wuensch, C. Achard, S. Döbert, H. H. Braun, I. Syratchev, M. Taborelli, I. Wilson, "A Demonstration of High Gradient Acceleration", CERN-AB-2003-048-RF; CLIC-Note-569, Proc. PAC2003.

 
 
MOPLT035 Beam Induced Heating of the SPS Fast Pulsed Magnets impedance, kicker, extraction, injection 623
 
  • J.A. Uythoven, G. Arduini, T. Bohl, F. Caspers, E.H.R. Gaxiola, T. Kroyer, M. Timmins, L. Vos
    CERN, Geneva
  Fast pulsed magnets with ferrite yokes are used in CERN?s SPS accelerator for beam injection, extraction and excitation for tune measurements. The impedance of the ferrite structures can provoke significant beam induced heating, especially for beams with high peak currents as for LHC operation, even beyond the Curie temperature. The expected heating in the different kicker systems for various operational modes is compared with beam measurements. Estimates of the beam induced power have been derived from measured beam spectra. A fast extraction kicker system has recently been equipped with a cooling system. The measured cooling performance is compared with data from laboratory setups and numerical simulations.  
 
MOPLT038 Conceptual Design of the LHC Beam Dumping Protection Elements TCDS and TCDQ proton, extraction, dumping, instrumentation 629
 
  • W.J.M. Weterings, B. Goddard, B. Riffaud, M. Sans Merce
    CERN, Geneva
  The Beam Dumping System for the Large Hadron Collider, presently under construction at CERN, consists, per ring, of a set of horizontally deflecting extraction kicker magnets, vertically deflecting steel septa, dilution kickers and finally, a couple of hundred metres further downstream, an absorber block. A fixed diluter (TCDS) will protect the septa in the event of a beam dump that is not synchronised with the particle free gap or a spontaneous firing of the extraction kickers which will cause the beam to sweep over the septum. A mobile diluter block (TCDQ) will protect the superconducting quadrupole immediate downstream of the extraction as well as the arc at injection energy and the triplet aperture at top energy from bunches with small impact parameters. The conceptual design of the protection elements will be described, together with the status of the mechanical engineering.  
 
MOPLT040 Test Results of Superconducting Cavities Produced and Prepared Completely in Industry pick-up, superconductivity, cathode, linac 635
 
  • M. Pekeler, S. Bauer, B. Griep, H.P. Vogel, P. vom Stein
    ACCEL, Bergisch Gladbach
  Superconducting cavities for a variety of recent projects are produced and prepared for operation in industry. We report on test results of those cavities produced and prepared at ACCEL. The preparation of the cavities includes chemical treatment (BCP), rinsing with high pressure water and assembly in a clean room. The following cavity types were treated: 400 MHz single cell cavities for LHC, 500 MHz single cell cavities of the Cornell CESR design for our superconducting accelerating modules, 1300 MHz TESLA type cavities, 176 MHz and 160 MHz halfwave resonators and a 352 MHz CH-mode cavity for ion accelaration.  
 
MOPLT041 Production of Superconducting Accelerator Modules for High Current Electron Storage Rings storage-ring, instrumentation, electron, damping 638
 
  • M. Pekeler, S. Bauer, B. Griep, M. Knaak, H.P. Vogel, P. vom Stein
    ACCEL, Bergisch Gladbach
  For Diamond Light Source, ACCEL was awarded to produce three more superconducting 500 MHz accelerator modules of the Cornell CESR design. With the already 6 modules produced for Cornell, NSRRC and CLS, this module can now be considered as a kind of standard product. In this paper we describe the basic parameters and guaranteed values of this module and will also report on the performance of delivered modules.  
 
MOPLT045 Vacuum Induced Backgrounds in the New HERA Interaction Regions proton, background, interaction-region, radiation 647
 
  • M. Seidel, M.G. Hoffmann
    DESY, Hamburg
  After the rebuild of the HERA interaction regions the experimental detectors were limited by beam induced backgrounds. Four types of background mechanisms were observed and identified - proton gas scattering, lepton gas scattering, synchrotron radiation and proton beam-halo losses. With some refined beam steering methods it was possible to tune the synchrotron radiation background to acceptable limits. The remaining most important effect was the scattering of the beam particles, mostly the protons, at the residual gas. In this contribution we describe our systematic attempts to investigate the complex behavior of the beam gas background and the measures taken to improve the situation. This includes dynamic pressure profile simulations and measurements, experimental determination of the background sensitivity profile along the beamline, the pressure development with current and time, and residual gas analysis. The background conditions were finally improved due to long term conditioning with beam, modifications of internal masks which were heated by higher order mode losses and moderate improvements of the pumping speed at strategic locations.  
 
MOPLT058 Status of CTF3 Stretcher-compressor and Transfer Line dipole, synchrotron, linac, synchrotron-radiation 686
 
  • A. Ghigo, D. Alesini, C. Biscari, A. Clozza, A. Drago, A. Gallo, F. Marcellini, C. Milardi, B. Preger, M.A. Preger, C. Sanelli, M. Serio, F. Sgamma, A. Stecchi, A. Stella, M. Zobov
    INFN/LNF, Frascati (Roma)
  • R. Corsini, G. Geschonke
    CERN, Geneva
  The first part of the CTF3 transfer line is under installation. It includes a chicane which, because of its very flexible lattice and large aperture vacuum chamber, can change the bunch length in a wide range. The chicane can be used as a stretcher to lengthen the pulses coming from the linac in order to reduce the coherent synchrotron radiation (CSR) in the recombination rings. A possible use as a bunch compressor is also foreseen in order to make CSR experiments and to characterize beam instrumentation. This paper describes the final design of the vacuum chambers, including beam diagnostics components, and their laboratory tests. The installation status of the magnetic and vacuum chamber components together with the ancillary systems is reported.  
 
MOPLT067 KEKB Performance luminosity, injection, electron, positron 707
 
  • Y. Funakoshi, K. Akai, K. Ebihara, K. Egawa, A. Enomoto, J. Flanagan, H. Fukuma, K.  Furukawa, T. Furuya, J. Haba, S. Hiramatsu, T. Ieiri, N. Iida, H. Ikeda, T. Kageyama, S. Kamada, T. Kamitani, S. Kato, M. Kikuchi, E. Kikutani, H. Koiso, M. Masuzawa, T. Mimashi, A. Morita, T. Nakamura, H. Nakayama, Y. Ogawa, K. Ohmi, Y. Ohnishi, N. Ohuchi, K. Oide, M. Shimada, S. Stanic, M. Suetake, Y. Suetsugu, T. Sugimura, T. Suwada, M. Tawada, M. Tejima, M. Tobiyama, S. Uehara, S. Uno, S.S. Win, N. Yamamoto, Y. Yamamoto, Y. Yano, K. Yokoyama, M. Yoshida, M. Yoshida, S.I. Yoshimoto
    KEK, Ibaraki
  • F. Zimmermann
    CERN, Geneva
  The KEKB B-Factory is an electron-positron double ring collider working at KEK. Its peak luminosity surpassed 1034 /cm2/sec in May 2003 for the first time in the history of colliders. In this report, we summarize the history of KEKB with an emphasis of recent progress.  
 
MOPLT071 EPICS Based Control System for the KOMAC RF System proton, rfq, feedback, linac 716
 
  • J.C. Yoon, J. Choi, K.M. Ha, J.H. Kim, J.M. Kim, J.-W. Lee
    PAL, Pohang
  This paper presents the RF control system for Korea Multi-purpose Accelerator Complex (KOMAC). KAERI (Korea Atomic Energy Research Institute) has been performing the project named KOMAC. As the 3nd phase of the project, 20MeV proton accelerating structure is under development. The new design is based on the use of VME based Multi-function modules connected to the specific low level RF Controllers(LLRF) via distributed I/O modules and Serial communication modules. The control system was based on EPICS (Experimental Physics and Industrial Control System) from the end of 2003. Installation and commissioning of the RF module is scheduled on 2004. Control system to integrated the RF System to the KOMAC control system is implemented. Hardware, software and various applications are developed to support the operation of RF Control system. This paper EPICS based control system for KOMAC RF  
 
MOPLT086 Upgrading the Control System at KCSR monitoring, radiation, power-supply, storage-ring 734
 
  • I.V. Krylov, V. Korchuganov, L.A. Moseiko, N.I. Moseiko, V.A. Novikov, A.G. Valentinov, Y.L. Yupinov
    RRC Kurchatov Institute, Moscow
  Till now Kurchatov Centre of Synchrotron Radiation facility control system is based on a CAMAC-oriented computers network. In this paper the project of upgrading and results of prototyping of the new equipment is submitted. Upgrading includes two levels. First, it is possible to create the modern CAMAC crate-controller, connected with standard network. More advanced variant will consist in replacement of CAMAC modules with the embedded controllers of equipment. Second level is a creation of a local managing network of personal computers, as consoles of the control system. The control system is functionally divided into four levels: 1) the controllers managing in a real-time mode by the executive equipment; 2) the workstations which are supporting the link with controllers by CAN-network; 3) the server of applications containing a dynamic database; 4) the PCs network for users applications. Examples of realisation of the software are presented.  
 
MOPLT097 Co-sourcing Development of Accelerator Controls controls, synchrotron, booster, power-supply 758
 
  • K. Zagar, R. Sabjan, I. Verstovsek
    JSI, Ljubljana
  • M. Plesko
    Cosylab, Ljubljana
  Frequently, accelerator facilities make use of products and services offered by the industry. This paper's focus is on such outsourcing of control system hardware and software. Firstly, an attempt is made to explain the facility's motivation for seeking outside help, which is typically due to lack of resources, technology or knowledge. Then, the risks of outsourcing are enumerated. To mitigate them, the industrial partner should have not only the adequate technical expertise, but also a reliable, yet agile management and quality assurance process that meets the facility's expectations, schedule, budget constraints, maintenance and support needs. Finally, Cosylab's business model is presented, designed to provide lasting open-source solutions that help not only a single facility, but the entire community.  
 
MOPLT105 Implementation of MICE at RAL emittance, synchrotron, target, shielding 779
 
  • P. Drumm
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The Muon Ionisation Cooling Experiment (MICE) is motivated by the vision of the neutrino factory (NF). The cost and practicality of the NF depends on an early control of the emittance of the muon beam that will be accelerated and stored to produce the neutrino beams. A number of possibilities for transverse cooling of the emittance have been proposed including ionisation cooling. In such a concept, the muon beam is alternatively slowed down in cryogenic absorbers (energy loss by ionisation) and then re-accelerated in RF cavities to replace the lost energy. This process reduces the transverse momentum of the beam while maintaining the average momentum in the z-direction. The energy absorbing material should be characterised by a high stopping power and low multiple scattering: The material of choice is liquid hydrogen. MICE will replicate a piece of the NF cooling channel. The engineering of a safe system with thin windows for the containment of the liquid hydrogen and other features needed to safely operate will test the practical application of the cooling scheme and its performance. MICE is proof of principle for this untried technology. The paper reviews progress in MICE and the plans for its implementation at RAL.

The MICE Collaboration

 
 
MOPLT111 On using NEA Cathodes in an RF Gun gun, electron, ion, cathode 797
 
  • M. Huening
    Fermilab, Batavia, Illinois
  RF guns have been proven to deliver high brightness beams and therefore appear attractive as electron source for a linear collider. Only so far no polarized beams have been produced. To create a polarized electron beam GaAs NEA cathodes are used. Operating rf guns with a NEA cathode poses concerns in three areas, oxidation by residual gas, ion bombardment, and electron bombardment. In this paper we report about an attempt to reduce the vacuum pressure inside the gun by cooling it to cryogenic temperatures. Furthermore the energy deposition by ions and electrons will be quantified.  
 
MOPLT119 Fabrication of X-band Accelerating Structures at FERMILAB RF-structure, factory, alignment, simulation 815
 
  • T.T. Arkan, C. Boffo, E. Borissov, H. Carter, D. Finley, I. Gonin, T. Khabibouline, S.C. Mishra, G. Romanov, N. Solyak
    Fermilab, Batavia, Illinois
  The RF Technology Development group at Fermilab is working together with the NLC and GLC groups at SLAC and KEK on developing technology for room temperature X-band accelerating structures for a future linear collider. We built seven 60cm long, high phase advance, detuned structures (HDS or FXB series). These structures have 150 degrees phase advance per cell, and are intended for high gradient tests. The structures were brazed in a vacuum furnace with a partial pressure of argon, rather than in a hydrogen atmosphere. We have also begun to build 60cm long, damped and detuned structures (HDDS or FXC / FXD series). So far, we have built 3 FXC structures. Our goal is to build 4 FXC and 2 FXD structures for the 8-pack test at SLAC by the end of March 2004, as part of the GLC/NLC effort to demonstrate the readiness of room temperature RF technology for a linear collider. This poster describes the RF structure factory infrastructure (clean rooms, vacuum furnaces, vacuum equipment, RF equipment etc.), and the fabrication techniques utilized (the machining of copper cells / couplers, quality control, etching, vacuum brazing, cleanliness requirements etc.) for the production of FXB and FXC structures.  
 
MOPLT135 Damping the High Order Modes in the Pumping Chamber of the PEP-II Low Energy Ring positron, damping, impedance, electromagnetic-fields 854
 
  • A. Novokhatski, S. Debarger, F.-J. Decker, A. Kulikov, J. Langton, M. Petree, J. Seeman, M.K. Sullivan
    SLAC, Menlo Park, California
  The Low Energy Ring of the PEP-II B-factory operates with extremely high currents and short positron bunches. Any discontinuity in the vacuum chamber can excite a broad-band spectrum of the High Order Modes. A temperature rise has been found in the vacuum chamber elements in one transition from straight section to arc. The power in the wake fields was high enough to char beyond use the feed-through for the Titanium Sublimation Pump. This pumping section consists of the beam chamber and an ante-chamber. Fields, excited in the beam chamber penetrate to the ante-chamber and then through the heater wires of the TSP come out. A small ceramic tile was placed near the TSP feed-through to absorb these fields. A short wire antenna was also placed there. HOM measurements show a wide spectrum with a maximum in the 2-3 GHz region. A special water cooled HOM absorber was designed and put inside the ante-chamber part of the section. As a result, the HOM power in the section decreased and the temperature rise went down. The power loss is 750 W for a beam current of 2 A. Measurements of the HOM impedance for different bunch patterns, bunch length and transverse beam position will be presented.  
 
MOPLT151 Study of Arc-related RF Faults in the CEBAF Cryomodules ion, linac, laser, electron 890
 
  • E. Daly, D. Curry, J. Musson, G. Myneni, T. Powers, H. Wang, T.E. Whitlatch
    Jefferson Lab, Newport News, Virginia
  • I.E. Campisi
    ORNL/SNS, Oak Ridge, Tennessee
  A series of measurements has been conducted on two superconducting radio-frequency cavity pairs, installed in cryomodules and routinely operated in the Continuous Electron Beam Accelerator Facility, in order to study the RF-vacuum interaction during an RF fault. These arc-related fault rates increase with increasing machine energy, contribute to system downtime and directly affect the accelerator?s availability. For this study, the fundamental power coupler waveguides have been instrumented with vacuum gauges, additional arc detectors, additional infrared sensors and temperature sensors in order to measure the system response during both steady-state operations and RF fault conditions. Residual gas analyzers have been installed on the waveguide vacuum manifolds to monitor the gas species present during cooldown, RF processing and operation. Simultaneous measurements of the signals are presented, a comparison with analysis is shown and results are discussed. The goal of this study is to characterize the RF-vacuum interaction during normal operations. With a better understanding of the installed system response, methods for reducing the fault rate may be devised, ultimately leading to improvements in availability.  
 
MOPLT164 Bunch Patterns and Pressure Rise in RHIC electron, simulation, injection, background 914
 
  • W. Fischer, U. Iriso
    BNL, Upton, Long Island, New York
  The RHIC luminosity is limited by pressure rises with high intensity beams. At injection, the dominating cause for the pressure rise was shown to be electron clouds. We discuss the distributions of bunches along the circumference that minimize the electron cloud effect in RHIC. Experimental data are compared with simulation results, and experiences at the B-factories.  
 
MOPLT165 Luminosity Increases in Gold-gold Operation in RHIC luminosity, power-supply, background, electron 917
 
  • W. Fischer, L. Ahrens, J. Alessi, M. Bai, D. Barton, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, D. Bruno, J. Butler, R. Calaga, P. Cameron, R. Connolly, T. D'Ottavio, J. DeLong, K.A. Drees, W. Fu, G. Ganetis, J. Glenn, T. Hayes, P. He, H.-C. Hseuh, H. Huang, P. Ingrassia, U. Iriso, R. Lee, Y. Luo, W.W. MacKay, G. Marr, A. Marusic, R. Michnoff, C. Montag, J. Morris, T. Nicoletti, B. Oerter, C. Pearson, S. Peggs, A. Pendzick, F.C. Pilat, V. Ptitsyn, T. Roser, J. Sandberg, T. Satogata, C. Schultheiss, A. Sidi-Yekhlef, L. Smart, S. Tepikian, R. Tomas, D. Trbojevic, N. Tsoupas, J. Tuozzolo, J. Van Zeijts, K. Vetter, K. Yip, A. Zaltsman, S.Y. Zhang, W. Zhang
    BNL, Upton, Long Island, New York
  After an exploratory phase, during which a number of beam parameters were varied, the RHIC experiments now demand high luminosity to study heavy ion collisions in detail. Presently RHIC operates routinely above its design luminosity. In the first 4 weeks of its current operating period (Run-4) the machine has delivered more integrated luminosity that during the 14 weeks of the last gold-gold operating period (Run-2). We give an overview of the changes that increased the instantaneous luminosity and luminosity lifetime, raised the reliability, and improved the operational efficiency.  
 
TUYBCH01 Design Criteria and Technology Challenges for the Undulators of the Future undulator, radiation, electron, synchrotron 59
 
  • H. Kitamura, T. Hara, X. Maréchal, T. Tanaka
    RIKEN Spring-8 Harima, Hyogo
  • T. Bizen, T. Seike
    JASRI/SPring-8, Hyogo
  Nowadays, undulators are essential devices for synchrotron radiation (SR) facilities since they generate a quasi-monochromatic radiation with various features, high brightness , high energy and special polarization characteristics. Particularly, demands for high-energy radiation in the X-ray region have become much stronger in many research fields. Accordingly, a short-period undulator design has been developed, because they increase the number of periods in a unit undulator length and as a consequence, they generate brilliant synchrotron radiation. Also, short undulator periodicity enables emission of high-energy photons, and it opens the way for X-ray beamline operation in medium size synchrotron radiation facilities, such as SLS, NSLS, PLS, CLS, ALS, SOLEIL, DIAMOND, SPEAR-III and so on. From the same reason, a short-period undulator is very attractive for SASE-FEL or ERL facilities, since it lowers the electron beam energy necessary for X-ray operation. As a result this design makes a whole facility design compact and economic. In the talk, I will review the status of the development on short-period undulators of various types (in-vacuum, superconducting and cryogenic types) and describe the future direction.  
Video of talk
Transparencies
 
TUYBCH02 Technological Challenges for High Brightness Photo-injectors laser, electron, gun, brightness 64
 
  • G. Suberlucq
    CERN, Geneva
  Many applications, from linear colliders to free-electron lasers, passing through light sources and many other electron sources, require high brightness electron beams, usually produced by photo-injectors. Because certain parameters of these applications differ by several orders of magnitude, various solutions were implemented for the design and construction of the three main parts of the photo-injectors: lasers, photocathodes and guns. This paper summarizes the different requirements, how they lead to technological challenges and how R&D programs try to overcome these challenges. Some examples of state-of-the-art parts are presented.  
Video of talk
Transparencies
 
TUPKF003 Industrial Production of the Eight Normal-conducting 200 MHz ACN Cavities for the LHC simulation, beam-losses, electron, controls 956
 
  • R. Losito, E. Chiaveri, R. Hanni, T.P.R. Linnecar, S. Marque, J. Tuckmantel
    CERN, Geneva
  The LHC-ACN RF system consists of 8 normal-conducting cavities and is designed to reduce beam losses in the LHC when injecting beams with longitudinal emittance > 0.7 eVs from the CERN SPS. The cavity design took into account the possibility of recuperating all the "ancillary" equipment (tuners, fundamental mode damper, High Order Mode (HOM) couplers) from the old CERN SPS 200MHz system. The cavities are made from OFE copper. The original ingots, procured in Austria, have been forged and pre-formed by pressing them with a 20 tons press, following a procedure defined and adapted for the unusual dimensions of these pieces. The raw components thus obtained were machined and then welded together with an electron beam. In order to get a good repeatability of the fundamental mode frequency across the eight cavities, a procedure has been established with the contractor for the final machining and welding leading to a spread in frequencies below ±20 kHz (< 0.01%). The cavities will be installed in the LHC when losses at high intensities become significant. In the meantime they are undergoing a surface treatment to clean the RF surface and will be stored.  
 
TUPKF007 Series Fabrication Technologies for Normalconducting Linac and Storage Ring Cavities linac, alignment, coupling, RF-structure 968
 
  • P. vom Stein, K. Dunkel, B. Griep, C. Piel, H.P. Vogel
    ACCEL, Bergisch Gladbach
  Twelve HOM damped 476 MHz single cell cavities have been delivered for PEP II and the production of several 805 MHz CCL modules for SNS has recently been finalised by ACCEL Instruments. Based on those two examples, required key technologies for cavity production will be introduced. Final prove of successful manufacturing is given by low level rf measurements. Results of those measurements for above mentioned projects will be presented within this paper.  
 
TUPKF008 Status of the HoBiCaT Superconducting Cavity Test Facility at BESSY linac, superconductivity, radiation, power-supply 970
 
  • J. Knobloch, W. Anders, J. Borninkhof, S. Jung, M. Martin, A. Neumann, D. Pflückhahn, M. Schuster
    BESSY GmbH, Berlin
  BESSY has recently constructed the HoBiCaT cryogenic test facility for superconducting TESLA cavity units, including all ancillary devices (helium tank, input coupler, tuner, magnetic shielding). It is designed to house two such units in a configuration similar to that envisaged for the superconducting CW linac of the BESSY FEL. These units are presently being fabricated, prepared and assembled by industry. HoBiCaT will be used to address many of the issues that must be considered prior to finalizing the design of the proposed linac. Rapid turn-around-tests permit the investigation of items such as RF regulation, microphonic detuning and cryogenic parameters/achievable pressure stability. These test will also serve as the first step towards qualifying the industrial production of assembled cavity units. The commissioning of HoBiCaT is scheduled for Spring 2004 and the current status is presented here.  
 
TUPKF011 First Tests of a HOM-Damped High Power 500MHz Cavity impedance, damping, simulation, coupling 979
 
  • F. Marhauser, E. Weihreter
    BESSY GmbH, Berlin
  A prototype high power 500 MHz copper cavity with three tapered circular waveguides for broadband higher order mode (HOM) damping has been fabricated especially for the use in 3rd generation synchrotron radiation sources. Low power impedance measurements are presented and compared with theoretical simulations to verify the expected HOM damping efficiency as well as the fundamental mode shunt impedance. After a careful cleaning and baking process to reduce the vacuum pressure the cavity has been conditioned at high power. All relevant parameters of the cavity are reported.  
 
TUPKF019 Recent Developments on Superconducting b035 and b015 Spoke Cavities at IPN for Low and Medium Energy Sections of Proton Linear Accelerators. linac, proton, pick-up, tandem-accelerator 1003
 
  • G. Olry, J.-L. Biarrotte, S. Blivet, S. Bousson, F. Chatelet, D. Gardès, N. Hammoudi, T. Junquera, J. Lesrel, C. Miélot, A.C. Müller, D. Ruffier, H. Saugnac, P. Szott, J.P. Thermeau
    IPN, Orsay
  Spoke cavities studies leaded by IPN-Orsay, for both XADS and EURISOL projects, are fully integrated within the 5th and 6th European Framework Programs. During 2003, several tests have been performed on the first b035 spoke cavity prototype. They have demonstrated the great potential of this type of cavity in term of RF performances (Eacc max=12.5 MV/m at T=4.2 K) and mechanical behavior (very low sensitivity to errors fabrication, good stiffness…). Following the upgrade of our cryogenic facility, we have tested, this spring, the cavity at 2 K. These new results will be presented in this paper. In parallel, the fabrication of a new spoke cavity (2-gap, 352 MHz, b015) has begun in January. While keeping the same geometry than that of the b035 cavity, we carried out significant changes on the coupler port and stiffening system designs. We report here in particular, RF calculations concerning the new location of the coupler port (in order to minimize losses due to magnetic field) and also, mechanical calculations about the new stiffening ring. Finally, we will present the preliminary thought on modular cryomodule which are based on the ?short? cryomodule concept used with the Quarter Wave Resonators for the SPIRAL-2 project.  
 
TUPKF020 Numerical Investigation on the ELETTRA 500 MHz Power Coupler coupling, simulation, electron, storage-ring 1006
 
  • C. Pasotti, P. Craievich, A. Fabris, G. Penco, M. Svandrlik
    ELETTRA, Basovizza, Trieste
  • B. B. Baricevic
    DEEI, Trieste
  Due to the high input power required to feed a resonant cavity, the RF input coupler is a critical component for the reliability of an RF system. The 500 MHz RF input coupler for the ELETTRA cavities was specified for 150 kW input power. It is important to investigate the performance limits of the coupler in view of increasing RF power requirements. The coupler's maximum peak field and dissipation versus the input power have been studied by means of the numerical simulator HFSS. Possible improvements to the existing design have been investigated. The optimization has to take into consideration the following requirements: convenient power transmission efficiency, RF matching, suitable coupling coefficient, negligible perturbation on cavity voltage, moderate operating temperature and stress.  
 
TUPKF021 First Year of Operation of SUPER-3HC at ELETTRA damping, storage-ring, electron, synchrotron 1009
 
  • G. Penco, P. Craievich, A. Fabris, C. Pasotti, M. Svandrlik
    ELETTRA, Basovizza, Trieste
  Since July 2003 a superconducting third harmonic cavity has been in routine operation at ELETTRA. When the cavity is activated the stored electron bunches are lengthened by about a factor of three. The related longitudinal Landau damping has allowed first time operation at 320 mA, 2.0 GeV with a beam completely free of longitudinal coupled bunch instabilities. With the cavity active the lifetime at 320 mA, 2.0 GeV is three times the theoretical value for nominal bunch length. The increase in beam stability and lifetime contributed significantly to enhance the brightness and the integrated flux of the source. We will further discuss the operating experience with the superconducting cavity and the cryogenic system, analyzing the impact of the new system on machine operation and uptime. Finally we will also report on the characterization of the cavity performance for different filling patterns of the storage ring and relate the results to preliminary beam-cavity interaction studies.  
 
TUPKF022 Constructionand Testing of the Beta=0.31, 352 MHz Superconducting Half-wave Resonator for the SPES Project linac, quadrupole, coupling, proton 1012
 
  • A. Facco, W. Lu, F. Scarpa
    INFN/LNL, Legnaro, Padova
  • E. Chiaveri, R. Losito
    CERN, Geneva
  • V. Zviagintsev
    TRIUMF, Vancouver
  The interest in low- and medium- beta superconducting cavities is presently focused to future high intensity proton, deuteron and heavy ion linacs. A particular application is acceleration of cw and pulsed beams of variable q/A, which requires cavities with a small number of gaps and excellent mechanical stability. We have designed and constructed a 2 gap, 352 MHz SC half wave cavity aiming to similar characteristics and fitting the requirements of the intermediate-beta section of the LNL-SPES driver. The status of the project and the first test results will be presented.  
 
TUPKF023 Construction of a 161 MHz, beta=0.16 Superconducting QWR with Steering Correction for RIA linac, ion, superconductivity, light-ion 1015
 
  • A. Facco, W. Lu, F. Scarpa
    INFN/LNL, Legnaro, Padova
  • E. Chiaveri, R. Losito
    CERN, Geneva
  • T.L. Grimm, W. Hartung, F. Marti, R.C. York
    NSCL, East Lansing, Michigan
  • V. Zviagintsev
    TRIUMF, Vancouver
  We have built a 161 MHz, b=0.16 superconducting Quarter Wave Resonator with steering correction for the low beta section of RIA. This bulk niobium, double wall cavity, compatible with both separate vacuum between beam line and cryostats or unified one, was designed in collaboration between MSU-NSCL and LNL. The design is suitable for extension to other frequencies, e.g. to obtain the 80 MHz, beta=0.085 cavity required in RIA. The shaped drift tube allows correction of the residual QWR steering that can cause emittance growth especially in light ions; this could make this resonator a good alternative to Half-Wave resonators in high intensity proton-deuteron linacs, like the SPES injector project at LNL. First test results will be presented.  
 
TUPKF025 Superconducting Niobium Film for RF Applications cathode, plasma, electron, laser 1021
 
  • A. Cianchi, L. Catani, A. Cianchi, S. Tazzari
    INFN-Roma II, Roma
  • Y.H. Akhmadeev
    Institute of High Current Electronics, Tomsk
  • A. Andreone, G. Cifariello, E. Di Gennaro, G. Lamura
    Naples University Federico II, Napoli
  • J.L. Langner
    The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock
  • R.R. Russo
    Università di Roma II Tor Vergata, Roma
  Thin niobium film coated copper RF cavities are an interesting possible alternative to bulk-Nb cavities since copper is much cheaper than niobium, it has higher thermal conductivity and a better mechanical stability. Unfortunately, the observed degradation of the quality factor with increased cavity voltage of sputtered accelerating cavities restricts their usage in future large linear accelerators needing gradients higher than 15MV/m. We are developing an alternate deposition technology, based on a cathodic arc system working in UHV conditions. Its main advantages compared to standard sputtering are the ionized state of the evaporated material, the absence of gases to sustain the discharge, the much higher energy of atoms reaching the substrate surface and the possibility of higher deposition rates. To ignite the arc we use a Nd-YAG pulsed laser focused on the cathode surface that provides a reliable and ultraclean trigger. Recent results on the characterization of niobium film samples produced under different conditions are presented showing that the technique can produce bulk-like films suitable for RF superconducting applications.  
 
TUPKF026 RF Tests of the Beta=0.5 Five Cell TRASCO Cavities electron, pick-up, linac, superconductivity 1024
 
  • A. Bosotti, C. Pagani, P. Pierini
    INFN/LASA, Segrate (MI)
  • J.P. Charrier, B. Visentin
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • G. Ciovati, P. Kneisel
    Jefferson Lab, Newport News, Virginia
  Two complete 5 cell superconducting cavities at b=0.5 have been designed and fabricated. The cavities have been designed to minimize peak electric and magnetic fields, with a goal of 8.5 MV/m of accelerating gradient, at a Q > 5E9. The cavities are currently in the testing stage and the results of the vertical tests will be presented at this conference.  
 
TUPKF036 RF Property of the Prototype Cryomodule for ADS Superconducting Linac linac, coupling, simulation, proton 1042
 
  • E. Kako, S. Noguchi, N. Ohuchi, T. Shishido
    KEK, Ibaraki
  • N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno
    JAERI/LINAC, Ibaraki-ken
  • H. Hara, M. Matsuoka, K. Sennyu
    MHI, Kobe
  A prototype cryomodule containing two 9-cell superconducting cavities of beta=0.725 and frequency=972MHz is being constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Design and performance of RF components will be reported.  
 
TUPKF041 Quasi-optic RF Power Transmission Line from a FEM Oscillator to the Model of the CLIC Accelerating Structure radiation, diagnostics, insertion, alignment 1054
 
  • A. Kaminsky, A.V. Elzhov, E.A. Perelstein, N.V. Pilyar, T.V. Rukoyatkina, S. Sedykh, A.P. Sergeev, A. Sidorov
    JINR, Dubna, Moscow Region
  • N.S. Ginzburg, S.V. Kuzikov, N.Yu. Peskov, M.I. Petelin, A. Sergeev, N.I. Zaitsev
    IAP/RAS, Nizhny Novgorod
  Experimental investigation of a copper resonator lifetime under multiple action of 30 GHz power pulses is now carried out by the collaboration of CLIC team (CERN), FEM group of JINR (Dubna) and IAP RAS (Nizhny Novgorod). A quasi-optic two-mirror transmission line is used between the FEM oscillator and test cavity. An oversized FEM output waveguide based on the wavebeam transformation (Talbot effect) provides the optimal transverse distribution of the radiation, eliminates the output window breakdown and decrease the influence of the reflected wave on the FEM oscillator regime.  
 
TUPKF048 Studies of Electron Multipacting in CESR Type Rectangular Waveguide Couplers electron, simulation, diagnostics, insertion 1057
 
  • P. Goudket, M. Dykes
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • S.A. Belomestnykh, R. Geng
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • R.G. Carter
    Microwave Research Group, Lancaster University, Lancaster
  • H. Padamsee
    Cornell University, Ithaca, New York
  The latest results from an experimental waveguide section, as well as simulations from a model of electron multipacting using the MAGIC PIC code, are discussed. Tests were carried out on a new waveguide section that included enhanced diagnostics and the possibility of changing surface materials and temperature. Those tests evaluated grooves, ridges and surface coatings, such as TiN and a TiZrV NEG coating, as methods of multipactor suppression. The conclusion remains that the most effective method to achieve complete multipactor suppression remains the application of a static magnetic bias of approximately 10G. The experiments also provided good data sets that can be used to verify the accuracy of simulations. Simulations of the waveguide multipacting have been carried out and have offered better understanding of electronic behaviour.  
 
TUPKF049 Combining Cavity for RF Power Sources: Computer Simulation and Low Power Model simulation, klystron 1060
 
  • E. Wooldridge, S.C. Appleton, B. Todd
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A combining cavity for RF power sources has been investigated as a way of saving space, in comparison to waveguides, and as a way of combining power with graceful degradation if one or more component were to fail. The cavity has been investigated as the maximum power output of an Inductive Output Tube (IOT) for CW is 80KW at 500MHz and a proposed output of 20KW at 1.3GHz and most RF systems for particle accelerators require much more than this. Although 1.3GHz klystrons do exist they are vastly more expensive to purchase and maintain. Also the down time could be minimised to minutes in the even of a single IOT failure where as a klystron has a minimum downtime of several days in the event of a failure. Initially the cavity and its inputs were simulated in CSTs? Microwave studio. After optimising the cavity to ensure the minimum reflection at the input ports and maximum transmission at the output port, a low power model was then created from aluminium. Signal generators were used to power the model and a network analyser was used to check the output. The model was used to compare the results gained from the computer simulation and to obtain results from asymmetric positioning of the ports, which was not possible in the simulation.  
 
TUPKF053 New Waveguide-type HOM Damper for the ALS Storage Ring RF Cavities storage-ring, damping, radiation, synchrotron 1069
 
  • S. Kwiatkowski, K.M. Baptiste, J. Julian
    LBNL/ALS, Berkeley, California
  The ALS storage ring 500 MHz RF system uses two re-entrant accelerating cavities powered by a single 320kW PHILLIPS YK1305 klystron. During several years of initial operation, the RF cavities were not equipped with effective passive HOM damper systems. Longitudinal beam stability was achieved through cavity temperature control and the longitudinal feedback system (LFB), which was often operating at the edge of its capabilities. As a result, longitudinal beam stability was a significant operations issue at the ALS. During two consecutive shutdown periods (April 2002 and 2003) we installed E-type HOM dampers on the main and third harmonic cavities. These devices dramatically decreased the Q-values of the longitudinal anti-symmetric HOM modes. The next step is to damp the rest of the longitudinal HOM modes in the main cavities below the synchrotron radiation damping level. This will hopefully eliminate the need for the LFB and set the stage for a possible increase in beam current. The ?waveguide? type of HOM damper was the only option that didn?t significantly compromise the vacuum performance of the RF cavity. The design process and the results of the low level measurements of the new waveguide dampers are presented in this paper.  
 
TUPKF059 Simulation of Dark Currents in X-band Accelerator Structures simulation, electron, linac, emittance 1081
 
  • K.L.F. Bane, V.A. Dolgashev, G.V. Stupakov
    SLAC, Menlo Park, California
  In high gradient accelerator structures, such as those used in the main linac of the GLC/NLC, electrons are emitted spontaneously from the structure walls and then move under the influence of the rf fields. In this report we study the behavior of this "dark current" in X-band accelerator structures using a simple particle tracking program and also the particle-in-cell program MAGIC. We address questions such as what is the sensitivity to emission parameters, what fraction of dark current is trapped and reaches to the end of a structure, and what are the temporal, spatial, and spectral distributions of dark current as functions of accelerating gradient.  
 
TUPKF063 Current Status of the Next Linear Collider X-band Klystron Development Program klystron, gun, focusing, collider 1090
 
  • D.W. Sprehn, G. Caryotakis, A.A. Haase, E.N. Jongewaard, C. Pearson
    SLAC, Menlo Park, California
  Klystrons capable of driving accelerator sections in the Next Linear Collider have been developed at SLAC during the last decade. In addition to fourteen 50 MW solenoid-focused devices and a 50 MW Periodic Permanent Magnet focused (PPM) klystron, a 500 kV 75 MW PPM klystron was tested in 1999 to 80 MW with 3-microsecond pulses, but very low duty. Subsequent 75 MW prototypes aimed for low-cost manufacture by employing reusable focusing structures external to the vacuum, similar to a solenoid electromagnet. During the PPM klystron development, several partners (CPI, EEV and Toshiba) have participated by constructing partial or complete PPM klystrons. After early failures during testing of the first two devices, SLAC has recently tested this design (XP3-3) to the full NLC specifications of 75 MW, 1.6 microseconds pulse length, and 120 Hz. This 14.4 kW operation came with a tube efficiency of 50%. The XP3 3 average and peak output power, together with the focusing method, arguably makes it the most advanced high power klystron ever built anywhere in the world. Design considerations and the latest testing results for these latest prototypes will be presented.  
 
TUPKF065 Comparison of Klystron and Inductive Output Tubes (IOT) Vacuum-electron Devices for RF Amplifier Service in Free-electron Laser klystron, electron, cathode, laser 1093
 
  • A. Zolfaghari, P. MacGibbon, W. North
    MIT/BLAC, Middleton, Massachusetts
  The MIT X-Ray Laser project, conceived to produce output in the 0.3 to 100 nanometer range, is based on a super-conducting 4-GEV linear accelerator, using 24 multi-cavity cryo-modules, each with its own dedicated RF amplifier, operating at 1.3 GHz. The continuous output of each amplifier is nominally 15 kW, with an optional repetitive pulse-modulation mode of 0.1 second pulse duration at one pulse per second. Although there are no fundamental restraints which preclude the consideration of any RF amplifier type, including solid-state or conventional triode or tetrode, the most appropriate current technology includes the Klystron and the IOT (Inductive Output Tube), also known by the CPI trade-name, Klystrode. The mechanisms by which the devices convert DC input power into RF output power are discussed. The devices are then compared with regard to availability (developmental or off-the-shelf), conversion efficiency, means of pulse-modulation, RF power gain, phase and amplitude stability (pushing factors), and acquisition and life-cycle costs.  
 
TUPKF068 JLAB Hurricane Recovery linac, site, cryogenics, superconductivity 1102
 
  • A. Hutton, D. Arenius, F.J. Benesch, S. Chattopadhyay, E. Daly, V. Ganni, O. Garza, R. Kazimi, R. Lauze, L. Merminga, W. Merz, R. Nelson, W. Oren, M. Poelker, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, M. Spata, S. Suhring
    Jefferson Lab, Newport News, Virginia
  Hurricane Isabel, originally a Category 5 storm, arrived at Jefferson Lab on September 18 with winds of only 75 mph creating little direct damage to the infrastructure. However, electric power was lost for four days allowing the superconducting cryomodules to warm up and causing a total loss of the liquid helium. The subsequent recovery of the cryomodules and the impact of the considerable amount of opportunistic preventive maintenance provides important lessons for all accelerators complexes, not only those with superconducting elements. The details of how the recovery process was structured and the resulting improvement in accelerator availability will be discussed in detail.  
 
TUPKF072 Production and Performance of the CEBAF Upgrade Cryomodule Intermediate Prototypes linac, damping, controls, synchrotron 1105
 
  • A-M. Valente, E. Daly, J.R. Delayen, M. Drury, R. Hicks, C. Hovater, J. Mammosser, H.L. Phillips, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, H. Wang
    Jefferson Lab, Newport News, Virginia
  • C. Thomas-Madec
    SOLEIL, Gif-sur-Yvette
  We have installed two new cryomodules, one in the nuclear physics accelerator (CEBAF) and the other in the Free Electron Laser (FEL) of Jefferson Lab. The new cryomodules consist of 7-cell cavities with the original CEBAF cell shape and were designed to deliver gradients of 70 MV/module. Several significant design innovations were demonstrated in these cryomodules. This paper describes the production procedures, the performance characteristics of these cavities in vertical tests, results of tests in the new cryomodule test facility (CMTF) as well as the commissioning in the CEBAF tunnel and FEL. Performances and limitations after installation in the accelerators are discussed in this paper along with improvements proposed for future cryomodules.  
 
TUPKF074 Niobium Thin Film Cavity Deposition by ECR Plasma plasma, ion, electron, superconductivity 1108
 
  • A-M. Valente, H.L. Phillips, H. Wang, A. Wu, G. Wu
    Jefferson Lab, Newport News, Virginia
  Nb/Cu technology for superconducting cavities has proven to be over the years a viable alternative to bulk niobium. Energetic vacuum deposition is a very unique alternative method to grow niobium thin film on copper. Single crystal growth of niobium on sapphire substrate has been achieved as well as good surface morphology of niobium on small copper samples. The design of a cavity deposition system is in development. This paper presents the exploratory studies of the influence of the deposition energy on the Nb thin film properties. Several possible venues to achieve Nb/Cu cavity deposition with this technique are also discussed along with the design of the cavity deposition setup under development.  
 
TUPKF080 Photoemission Properties of Lead cathode, laser, electron, heavy-ion 1126
 
  • J. Smedley, T. Srinivasan-Rao, J. Warren
    BNL, Upton, Long Island, New York
  • R.S. Lefferts, A.R. Lipski
    SBUNSL, Stony Brook, New York
  • J. Sekutowicz
    Jefferson Lab, Newport News, Virginia
  There is significant interest in the possibility of building a super-conducting injector for high average current accelerator applications. One candidate for such a cavity design is superconducting lead. Such an injector would be made considerably simpler if it could be designed to use lead as the photocathode, eliminating the need for Cesiated materials in the injector. In this paper we present a study of the photoemission properties of lead at several UV wavelengths, including a study of the damage threshold of electroplated lead under laser cleaning. A quantum efficiency in excess of 0.1% has been achieved for a laser cleaned, electroplated lead sample with a laser wavelength of 193 nm.  
 
TUPLT002 The Small-gap Undulator Impedance Study impedance, undulator, resonance, synchrotron 1132
 
  • M. Ivanyan, V.M. Tsakanov
    CANDLE, Yerevan
  The small gap undulator vacuum chamber resistive impedance model is developed. The vacuum chamber is considered as equal-radii tubes with the different wall materials (stainless steel "copper" stainless steel). The complete impedance was calculated as a sum of tubes and transitions impedances. The modal expansion method for transition impedance calculation is presented.  
 
TUPLT007 The CERN-SPL Chopper Concept and Final Layout quadrupole, linac, proton, antiproton 1141
 
  • F. Caspers, Y. Cuvet, J. Genest, M. Haase, M. Paoluzzi, A. Teixeira
    CERN, Geneva
  The fast chopper for the CERN SPL (Superconducting Proton Linac) consists of a double meander structure with a beta (v/c) value of 8 % printed on an alumina substrate for the deflecting plates. Each chopper unit is 50 cm long and housed in a quadrupole magnet surrounding the vacuum chamber. The deflecting plates are operated simultaneously in a dual mode, namely traveling wave mode for frequencies above about 10 MHz and as quasi electro-static deflectors below. The deflecting structures are water-cooled to handle heating from beam losses as well as from the deflecting signal. A detailed mechanical layout is presented including the tri-axial feeding and termination technique as well as a discussion of the drive amplifier  
 
TUPLT011 The LHC Lead Ion Injector Chain ion, electron, injection, linac 1153
 
  • K. Schindl, A. Beuret, A. Blas, J. Borburgh, H. Burkhardt, C. Carli, M. Chanel, T. Fowler, M. Gourber-Pace, S. Hancock, C.E. Hill, M. Hourican, J.M. Jowett, K. Kahle, D. Kuchler, A.M. Lombardi, E. Mahner, D. Manglunki, M. Martini, S. Maury, F. Pedersen, U. Raich, C. Rossi, J.-P. Royer, R. Scrivens, L. Sermeus, E.N. Shaposhnikova, G. Tranquille, M. Vretenar, T. Zickler
    CERN, Geneva
  A sizeable part of the LHC physics programme foresees heavy ion (lead-lead) collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines. Each LHC ring will be filled in ~10 minutes with ~600 bunches, each of 7 107 Pb ions. Central to the scheme is the Low Energy Ion Ring (LEIR), which transforms long pulses from Linac3 to high-brilliance bunches by means of 6D multi-turn injection and accumulation via electron cooling. Major limitations along the chain, including space charge, intra-beam scattering, vacuum issues, and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR includes new magnets and power converters, high-current electron cooling, broad-band RF cavities, upgraded beam diagnostics, and UHV vacuum equipment relying on beam scrubbing to achieve a few 10-12 mbar. Major hardware changes in Linac3 (Electron Cyclotron Resonance source, repetition rate, energy ramping cavity), PS (new injection hardware, elaborate RF gymnastics, stripping insertion), and SPS (100 MHz system) are described. An early beam scenario, using fewer bunches but the same bunch intensity to deliver a lower luminosity, reduces the work required for LHC ion operation in spring 2008.  
 
TUPLT015 The Bunch Compressor System for SIS18 at GSI ion, synchrotron, heavy-ion, impedance 1165
 
  • P. Hülsmann, G. Hutter, W. Vinzenz
    GSI, Darmstadt
  For bunch compression down to pulse durations of 50 ns, a dedicated rf system is under development for the SIS12/18 heavy ion synchrotron upgrade and will be described in this paper. Due to space restrictions in SIS12/18 the rf system consists of very short cavities which provide a very large voltage gradient (50 kV/m) at a very low frequency of approximately 800 kHz and rf final stages which provide a short rise time. The only possibilty to meet the requirements is the application of a cavity heavily inductively loaded by metallic alloy (MA) ring cores. This new rf system will be a prototype for the advanced acceleration and compression system needed in SIS100, which is the most important part for the proposed International Acceleration Facility at GSI. In order to gain experience with different MA ring core materials two of the four compressor cavities are loaded differently, which gives us an opportunity to learn the operational advantages of both materials. It is expected that the experimental results will support the final judgement for the future rf system in SIS100.  
 
TUPLT033 RF Design of the MAFF IH-RFQ Power Resonator ion, rfq, impedance, alignment 1216
 
  • M. Pasini, D. Habs, O. Kester
    LMU, München
  • T. Sieber
    CERN, Geneva
  The low energy part of the LINAC of the MAFF facility will be an IH-RFQ cavity with 101.28 MHz resonance frequency. The RF design of the cavity has been completed, including design calculations and model measurements. The RFQ is designed to deliver ions of A/q = 6.5 up to 300 keV/u to be injected into the following LINAC. The structure chosen was an IH type of resonator since it was demontrated to have a better shunt impedance. The required voltage between the electrodes is 70kV and the operation mode is pulsed with a duty cycle of 10%. The structure will be made out from bulk copper in order to improve the shunt impedance and hence to allow not direct cooling on the electrodes. The optimizazion of the several parameters of the structure, and the technique for tuning the voltage distribution are presented in this paper. Measurements with a short model will be shown as well.  
 
TUPLT040 CSR - a Cryogenic Storage Ring at MPI-K ion, electron, quadrupole, storage-ring 1237
 
  • C.P. Welsch, J. Crespo López-Urrutia, M. Grieser, D. Orlov, C.D. Schroeter, D. Schwalm, J. Ullrich, A. Wolf, R. von Hahn
    MPI-K, Heidelberg
  • X. Urbain
    UCL CRC, Louvain-la-Neuve
  • D. Zajfman
    Weizmann Institute of Science, Physics, Rehovot
  A small cryogenic storage ring is planned to be developed at MPI-K, Heidelberg. The energy in the machine will be variable from 300 keV > down to 20 keV. Electron cooling will be applied to produce a high quality ion beam. The ring shall accommodate slow, vibrationally and rotationally cooled molecular ions and highly charged ions from the EBIT ion source. Moreover, it will serve as a test facility for the low-energy antiproton ring planned within the FLAIR collaboration to be installed at the future GSI facility. A number of technological challenges have to be handled: Especially highly charged ions require a vacuum in the order below 10-13 mbar to achieve reasonable lifetimes. Therefore - and for enabling experiments with rotationally cold molecules - the complete machine will be cooled down to below 10 K. Moreover, experiments with reaction microscopes to determine the full kinematics of ion- (antiproton-) atom or molecule collisions require a bunched operation with a bunch length below 2 ns. The optical elements of the machine and the lattice functions are given and first ideas about the vacuum chamber design are described in this paper.  
 
TUPLT047 First Results of Pulsed Superconducting Half-wave Resonators linac, synchrotron, resonance, coupling 1258
 
  • R. Stassen, R. Eichhorn, F.M. Esser, B. Laatsch, R. Maier, G. Schug, R. Tölle
    FZJ/IKP, Jülich
  A pulsed linac for the cooler synchrotron COSY was projected based on superconductive half-wave resonators (HWRs). The concept of single phased resonators is a great challenge related to the requirement of accelerating protons and deuterons up to a similar energy. A cryomodule, which houses four cavities was designed in Cooperation with FZJ-ZAT, taking into account the restricted space and the special requirements of a linear accelerator. Two prototypes of the 160MHz Half-Wave Resonators (HWRs) were built at different companies. The fabrication differs slightly concerning the top and bottom parts of the cavity as well as the welding of the inner and outer conductor. First results of warm and cold measurements will be presented. The behaviour of the adjustable 4kW main coupler as well as the mechanical tuner can be tested together with the HWR in a new vertical test-cryostat.  
 
TUPLT049 Triple-spoke Cavities in FZJ simulation, resonance, coupling, proton 1261
 
  • E. Zaplatin, W. Braeutigam, R. Maier, M. Pap, M. Skrobucha, R. Stassen, R. Tölle
    FZJ/IKP, Jülich
  We report the situation with superconducting triple-spoke cavity activities at the research center FZJ in Juelich. The Nb prototype of the 700 MHz, beta=0.2 cavity is already in fabrication and should be tested this year. This work has been initiated for the European Spallation Source project. In the frames of the new European project of High Intensity Pulsed Proton Injector the 352 MHz, beta=0.48 cavity is under developments. This cavity should be designed, built and tested in the Lab within next few years.  
 
TUPLT053 Recent Evolutions in the Design of the French High Intensity Proton Injector (IPHI) rfq, diagnostics, linac, proton 1273
 
  • P.-Y. Beauvais
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In 1997, the two French National Research Agencies (CEA and CNRS) decided to collaborate in order to study and construct a prototype of the low energy part of a High Power Proton Accelerator (HPPA). The main objective of this project (the IPHI project), is to allow the French team to master the complex technologies used and the control concepts of the HPPAs. Recently, a collaboration agreement was signed with the CERN and led to some evolutions in the design and in the schedule. The IPHI design current was maintained at 100 mA in Continuous Wave mode. This choice should allow to produce a high reliability beam at reduced intensity (typically 30 mA) tending to fulfill the Accelerator Driven System requirements. The output energy of the Radio Frequency Quadrupole (RFQ), originally set to 5 MeV, was reduced to 3 MeV, allowing then the adjunction and the test in pulsed mode of a chopper line developed by the CERN for the Superconducting Proton Linac (SPL). In a final step, the IPHI RFQ and the chopper line should become parts of the SPL injector. In this paper, the IPHI project evolutions are reported as well as the construction and operation schedule.  
 
TUPLT054 Design of the Low-beta, Quarter-wave Resonator and its Cryomodule for the SPIRAL 2 Project resonance, alignment, coupling, simulation 1276
 
  • P.-E. Bernaudin, P. Bosland, S. Chel, G. Devanz, P. Hardy, F. Michel, P. de Girolamo
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  The SPIRAL 2 project, to be built in GANIL, consists of a 40 MeV linear accelerator for 5 mA of deuterons and a target-source complex for the production of exotic isotopes. The accelerator is also optimised to accelerate q/A = 1/3 ion up to 14.4 MeV/u. The three stages of the linac are a RFQ (up to 0.75 MeV/A), a low beta (0.007) and a high beta (0.12) sections consisting of quarter-wave, 88 MHz superconducting resonators. This paper focuses on the low beta cavity and its cryomodule. The cavity nominal accelerating gradient is at least 6.5 MV/m in operation conditions. RF properties of the cavities are dealt with, as well as the mechanical ones: helium pressure effects, tunability, vibrations. The cryomodule is designed so as to save longitudinal space and therefore is partly assembled in clean room.  
 
TUPLT075 Improvements of SPring-8 Linac towards Top-up Operation linac, injection, synchrotron, power-supply 1327
 
  • S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Masuda, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo
  The top-up operation of the SPring-8 storage ring will start in May, 2004. In order to realize alternative injection into the booster synchrotron in the top-up operation and the NewSUBARU, an AC bending magnet replaced the DC bending magnet in the beam transport line to the booster synchrotron. This magnet operates at 1 Hz with a trapezoid current pattern. The 1-GeV electron beam goes at the bottom of the current pattern to the NewSUBARU or at the top of the pattern to the booster synchrotron. In order to obtain the higher reliability of the linac for the top-up operation, reinforcement of the beam monitor systems, further improvement of RF phase stability and upgrade of the control system were required. BPM?s has been newly installed in energy dispersion sections, and beam transport feedback control is in development. The phase variation in the RF system was reduced by the regulation of the gas pressure in the waveguide of the klystrons drive system. We re-engineered the VME systems to maximize availability of the linac operation considering its reliability, usability, expandability and flexibility.  
 
TUPLT078 Study of Impedances and Instabilities in J-PARC kicker, impedance, resonance, synchrotron 1336
 
  • T. Toyama, K. Ohmi
    KEK, Ibaraki
  • Y. Shobuda
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  J-PARC consists of two high intensity proton rings with energies of 3 GeV and 50 GeV. Longitudinal impedances and instabilities, which are caused by beam chamber, cavities, kicker magnets and others, are mainly discussed in this paper.  
 
TUPLT079 Opposite Field Septum Magnet System for the J-PARC 50GeV Ring Injection septum, injection, synchrotron, proton 1339
 
  • I. Sakai, Y. Arakaki, K. Fan, Y. Mori, M. Muto, Y. Saitou, Y. Shirakabe, M. Tomizawa, M. Uota
    KEK, Ibaraki
  • K. Gotou, Y. Morigaki, A. Nishikawa, M. Takahashi
    IHI/Yokohama, Kanagawa
  • H. Mori, A. Tokuchi
    NICHICON, Shiga
  For the injection/extraction system of the high energy high intensity proton synchrotrons, high field wide aperture thin septum magnets are required. To solve these tight problems, new design concept of opposite-field septum magnet system has been invented. The same grade of opposite magnetic field is produced both inside and outside of the septum. The electromagnetic force and leakage flux around the septum conductor are cancelled out each other. The magnetic field of the circulating beam side is compensated by two sub-bending magnets set on the up-stream and down-stream of the opposite fields septum magnet. The beam-separation angle per magnet length is twice as large as normal septum magnet and the two sub-bending magnets also have a role to extend the injection/extraction angle. The newly developed method of the opposite field septum magnets system.is applied to the injection septum magnets for the J-PARC 50-GeV proton synchrotron to get the sufficient injection angle and clearance for low loss injection. The thin septum thickness and larger kick angle at the septum magnet can be obtained by the new system, which is applicable to many accelerators.  
 
TUPLT089 Status of PEFP 3MeV RFQ Development rfq, proton, klystron, scattering 1363
 
  • Y.-S. Cho, B.-H. Choi, S.-H. Han, J.-H. Jang, Y.H. Kim, H.-J. Kwon, C.-B. Shim
    KAERI, Daejon
  In the PEFP (Proton Engineering Frontier Project), a 350MHz, 3MeV RFQ (Radio Frequency Quadrupole) has been developed and tested. The tuning results showed that the resonant frequency is somewhat higher than 350MHz and other methods in addition to slug tuners should be used to tune the cavity correctly. To check the cavity characteristics, high power RF test has been done. The required peak RF power is 600kW and pulse width, repetition rate for initial test are 100 micro-s, 10Hz respectively. To solve the problems in PEFP RFQ, the upgrade design of 3MeV RFQ has been decided. The main concept of this upgrade design is constant vane voltage profile with the same length of RFQ. The other parameters (350MHz, 3MeV, 20mA) are the same with the previous RFQ. With constant vane voltage profile, fabrication of RFQ can be easier, and with the same mechanical dimension, other parts such as vacuum pumping station can be re-used. In this paper, the test results of the PEFP RFQ, and the details of beam dynamics design/engineering design of upgrade RFQ will be presented.  
 
TUPLT091 Fabrication Status of the PEFP 20 MeV DTL quadrupole, proton, site, pick-up 1369
 
  • M.-Y. Park, Y.-S. Cho, J.-H. Jang, Y.H. Kim, H.-J. Kwon
    KAERI, Daejon
  The PEFP (Proton Engineering Frontier Project) 20 MeV DTL have been constructed in KAERI site. The fabrication of the first tank is finished and the DT installation is in the process. We choose the pool-type electromagnets as the focusing magnet and 50 DTs will be installed on first tank. We tested the winding schemes of copper coils on the iron core and measured the magnetic field saturation.In this paper, the results of the tank fabrication and quadrupole magnet test are presented.  
 
TUPLT112 Radiation Damage to the Elements of the Nuclotron-type Dipole of SIS100 ion, dipole, beam-losses, proton 1408
 
  • E. Mustafin, G. Moritz, G. Walter
    GSI, Darmstadt
  • L. Latysheva, N. Sobolevskiy
    RAS/INR, Moscow
  Radiation damage to various elements of the Nuclotron-type dipole of SIS100 sensitive to irradiation was calculated. Among the elements of consideration were the superconducting cables, insulating materials, ceramic insertions and high-current by-pass diodes. The Monte-Carlo particle transport code SHIELD was used to simulate propagation of the lost ions and protons together with the products of nuclear interactions in the material of the elements. The results for the proton projectiles were cross-checked using the particle transport code MARS, and a good agreement between the codes were found. It was found that the lifetime of the organic materials under irradiation are much more restrictive limit for the tolerable level of beam particle losses than the danger of the quench events.  
 
TUPLT113 Technicalities for a Novel Medium Energy Ion Accelerator ion, positron, proton, heavy-ion 1411
 
  • V. Gorev
    RRC Kurchatov Institute, Moscow
  Transmutation of radioactive waste,high-intensity pulsed sources of fast neutrons,problem of inertially-confined fusion and a lot of different problems of science and technology put increased demands on the linear high power medium energy proton and heavy ion accelerators.But these accelerators are presently massive,huge and very expansive,which restrict now and in a near future their wide use and motivates the study of altenetive methods to achieve the design current,power and economic characteristics.This report decribes the present reseach on attaining high power medium energy ion beams,using novel idea for accelerator design.Theoretical proposal and preliminary conceptual design for the accelerator,based on a principle of free flying ion emitter("ballistic anode"),were discussed first a few years ago.The principle involves a high potencial difference generated only for a short time in the special vacuum chamber,but not steady-state conditions.Now,we would like to discuss next problems:1.technicalities of the ballistic anode design,both for proton and heavy ion beams generation.2 pulse power multiplication.3.high current sources for charge pumping of the ballistic anode.4 experimental modelling.  
 
TUPLT117 Test of Materials for the High Temperature Intense Neutron Target Converter target, radiation, electron, diagnostics 1413
 
  • K. Gubin, M. Avilov, S. Fadeev, A. Korchagin, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, S.N. Morozov, S. Shiyankov
    BINP SB RAS, Novosibirsk
  • J. Esposito, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Nowadays in LNL INFN (Italy) the project for gain and study of short-lived radioactive isotopes is in progress [1]. The intense neutron target is required for these goals. In BINP, Russia, the design of high temperature target cooled by radiation is proposed. Presented paper describes the results of preliminary test of materials for the target converter: MPG6-brand graphite, graphite material on the basis of 13C, boron carbide, glassy carbon. Test included the distributed heating over volume of samples with the electron beam up to conditions, simulating the converter working regime (heating power density up to 1300 W/cm2, temperature up to 20000C, temperature gradient up to 1000C/mm). Graphite materials show its adaptability under conditions specified.  
 
TUPLT118 Test of Construction for High Temperature Intense Neutron Target Prototype target, simulation, electron, radiation 1416
 
  • K. Gubin, M. Avilov, D. Bolkhovityanov, S. Fadeev, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, A.A. Starostenko
    BINP SB RAS, Novosibirsk
  • O. Alyakrinsky, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Within the framework of the creation of the high temperature intense neutron target prototype, the thermal tests of the preliminary design were done in BINP. Tests were aimed at experimental definition of temperature and heat flux distribution over the construction, heat transfer via the contact areas between materials selected, specifying the properties of these materials. This paper presents the experimental test results as well as the comparison of experimental data with the results of numerical simulation of the working regimes of the construction.  
 
TUPLT120 Commissioning of Electron Cooler EC-300 electron, gun, ion, cathode 1419
 
  • V.B. Reva, E.A. Bekhtenev, V.N. Bocharov, A.V. Bubley, Y. Evtushenko, A.D. Goncharov, A.V. Ivanov, V.I. Kokoulin, V.V. Kolmogorov, M.N. Kondaurov, S.G. Konstantinov, V.R. Kozak, G.S. Krainov, Ya.G. Kruchkov, E.A. Kuper, A.S. Medvedko, L.A. Mironenko, V.M. Panasyuk, V.V. Parkhomchuk, K.K. Schreiner, B.A. Skarbo, A.N. Skrinsky, B.M. Smirnov, M.A. Vedenev, R. Voskoboinikov, M.N. Zakhvatkin, N.P. Zapiatkin
    BINP SB RAS, Novosibirsk
  • J. Li, W. Lu, L.J. Mao, Z.X. Wang, X.B. Yan, X.D. Yang, J.H. Zhang, W. Zhang, H.W. Zhao
    IMP, Lanzhou
  The article deals with the commissioning of electron cooler EC-300. It was designed and manufactured for CSR experiment (IMP, Lanzhou, China) by BINP, Russia. The energy of electron beam is up to 300 keV, the electron current is up to 3 A, the magnetic field in the cooling section is up to 1.5 kG. The major innovation of the cooler is the variable profile of electron beam, the electrostatic bends of the electron beam and the system of the magnetic field correction. During commissioning the linearity of the magnetic field 10-6 was obtained, the recuperation efficiency was observed up 10-6 , the pressure of residual gas in the vacuum chamber was 5? 10-11 torr during operation with the electron beam. The CSRe cooler for IMP is a new step at cooling technique and the first results achieved during commissioning are very interesting for accelerator physics.  
 
TUPLT121 Compact Tandem Accelerator Based Neutron Source for the Medicine ion, tandem-accelerator, target, ion-source 1422
 
  • V.V. Shirokov, A.A. Babkin, P.V. Bykov, G.S. Kraynov, G. Silvestrov, Y. Tokarev
    BINP SB RAS, Novosibirsk
  • M.V. Bokhovko, O.E. Kononov, V.N. Kononov
    IPPE, Kaluga Region
  Status of original heavy hydrogen ion electrostatic accelerator-tandem is described. Potential electrodes with vacuum insulation organize tract for accelerating ion beam before and after gas stripper, located inside the high voltage electrode. There are no accelerating tubes in the tandem proposed. 20 kHz, 10 kW, 500 kV compact sectioned rectifier is a high voltage source. Both the geometry of neutron source and results of the rectifier testing are presented. Estimation of yield and space-energy distribution of neutron, as a result of nuclear reactions produced by heavy hydrogen ion in beryllium or carbon targets are given. Result of Monte-Carlo simulation of neutron and photon transferring for these sources of neutron is the distribution of the absorbed dose incide phantom. Result of the simulation are compared with result of the experiment. The possibility of use of this neutron source for the neutron or neutron capture therapy is discussed too.  
 
TUPLT124 DESIREE - A Double Electrostatic Storage Ring ion, quadrupole, ion-source, storage-ring 1425
 
  • K.-G. Rensfelt, G. Andler, L. Bagge, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, P. Löfgren, A. Paal, A. Simonsson, Ö. Skeppstedt
    MSL, Stockholm
  • H. Cederquist, M. Larsson, H. Schmidt, K. Schmidt
    Stockholm University, Department of Physics, Stockholm
  The advantages of storage rings with only electrostatic elements were first demonstrated by ELISA in Aarhus and later in other places. At MSL and Fysikum at Stockholm University the ideas have been developed further in the Double Electrostatic Storage Ion Ring ExpEriment, DESIREE. Beams of negative and positive ions will be merged in a common straight section of the rings so that low energy collisions can be studied. Furthermore the rings will be cooled to 10 - 20 K in order to relax internal excitations in circulating molecules. A design report can be found at www.msl.se. The project is now (January 2004) almost fully financed and the final design work has recently been started. The paper will shortly review the physics programme and describe the status of the design work.  
 
TUPLT132 Investigation of Injection through Bending Magnet Fringe Fields in X-rays Source NESTOR injection, dipole, storage-ring, linac 1434
 
  • A. Mytsykov, P. Gladkikh, A.V. Rezaev, A.Y. Zelinsky
    NSC/KIPT, Kharkov
  In paper injection in the X-rays source NESTOR through fringe fields of a bending magnet is considered. The simulation of a motion of a beam of charged particles through 3-d fields of magnetic devices of the injection channel, which ones is located on a ring, are performed. The focusing properties of the injection channel are determined.  
 
TUPLT151 Status of the Fermilab Electron Cooling Project electron, recirculation, acceleration, antiproton 1485
 
  • J.R. Leibfritz, D.R. Broemmelsiek, A.V. Burov, K. Carlson, B. Kramper, T. Kroc, M. McGee, S. Nagaitsev, L. Nobrega, G. Saewert, C.W. Schmidt, A.V. Shemyakin, M. Sutherland, V. Tupikov, A. Warner
    Fermilab, Batavia, Illinois
  • G. Kazakevich
    BINP SB RAS, Novosibirsk
  • S. Seletsky
    Rochester University, Rochester, New York
  Fermilab has constructed and commissioned a full-scale prototype of a multi-MV electron cooling system to be installed in the 8.9 GeV/c Fermilab Recycler ring. This prototype was used to test all of the electron beam properties needed for cooling. However, because the prototype is not located within proximity of the Recycler ring, the actual electron cooling of antiprotons can not be demonstrated until it is relocated. The Fermilab electron cooling R&D project is scheduled to be completed in May, 2004 at which time it will be disassembled and relocated to a newly constructed facility where it will be installed in the Recycler. This paper describes the experimental results obtained with the prototype cooler system, gives an overview of the new electron cooling facility, and discusses the overall status of the project.  
 
TUPLT167 Installation of the Spallation Neutron Source (SNS) Warm Linac alignment, linac, site, quadrupole 1521
 
  • P.E. Gibson, C. Deibele, J.J. Error, G.A.J. Johnson, P. Ladd
    ORNL/SNS, Oak Ridge, Tennessee
  • N.K. Bultman
    LANL, Los Alamos, New Mexico
  The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built at Oak Ridge National Laboratory. The SNS project design and construction is a partnership involving six DOE national laboratories including Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Oak Ridge, and Los Alamos. When completed in 2006, the SNS will provide the most intense, pulsed neutron beams in the world for scientific research and industrial development. At the present time we are installing and commissioning the warm linac system, designed by Los Alamos, and have to date had good success. The warm linac is comprised of six Drift Tube Linac (DTL) tanks and four Coupled Cavity Linac (CCL) modules. These accept an incoming negative hydrogen ion beam from the Front End injector at 2.5 MeV, and accelerate to a final energy of 185 MeV. At this time we have installed and commissioned DTL tanks 1-3 and installed CCL module 1 . Experience and information gained during installation will be presented. The performance in terms of alignment, vacuum and field tuning will be described.  
 
TUPLT186 Managing System Parameters for SNS Magnets and Power Supplies power-supply, target, controls, linac 1565
 
  • W.J. McGahern, S. Badea, F.M. Hemmer, H.-C. Hseuh, J.W. Jackson, A.K. Jain, F.X. Karl, R.F. Lambiase, Y.Y. Lee, C.J. Liaw, H. Ludewig, G.J. Mahler, W. Meng, C. Pai, C. Pearson, J. Rank, D. Raparia, J. Sandberg, S. Tepikian, N. Tsoupas, J. Tuozzolo, P. Wanderer, J. Wei, W.-T. Weng
    BNL, Upton, Long Island, New York
  • R. Cutler, J.J. Error, J. Galambos, M.P. Hechler, S. Henderson, P.S. Hokik, T. Hunter, G.R. Murdoch, K. Rust, J.P. Schubert
    ORNL/SNS, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort of six U.S. Department of Energy partner laboratories. With over 312 magnets and 251 power supplies that comprise the beam transport lines and the accumulator ring, it is a challenge to maintain a closed loop on the variable parameters that are integral to these two major systems. This paper addresses the input variables, responsibilities and design parameters used to define the SNS magnet and power supply systems.  
 
WEOACH02 Gas Condensates onto a LHC Type Cryogenic Vacuum System Subjected to Electron Cloud electron, proton, synchrotron, injection 126
 
  • V. Baglin, B.J. Jenninger
    CERN, Geneva
  In the Large Hadron Collider (LHC), the gas desorbed via photon stimulated molecular desorption or electron stimulated molecular desorption will be physisorbed onto the beam screen held between 5 and 20 K. Studies of the effects of the electron cloud onto a LHC type cryogenic vacuum chamber have been performed with the cold bore experiment (COLDEX) installed in the CERN Super Proton Synchrotron (SPS). Experiments performed with gas condensates such as H2, H2O, CO and CO2 are described. Implications to the LHC design and operation are discussed.  
Video of talk
Transparencies
 
WEYCH02 Technical Issues for Large Accelerators based on High Gradient SC Cavities electron, collider, linac, radiation 137
 
  • C. Pagani, C. Pagani
    DESY, Hamburg
  The perspective to build large accelerators based on high gradient superconducting cavities is posing a number of new problems that have been addressed in the preparation of the TESLA project. Starting from the experience gained with the past large installations, such as LEP2 at CERN and CEBAF at JLab, in this paper I discuss the new demands and the solution envisaged. Industrial production issues are focussed in terms of large scale production, reviewed quality control criteria and cost reduction. The impact on component design and engineering together with the expected improvements in term of performances and reliability are also outlined.  
Video of talk
Transparencies
 
WEOCCH02 Construction Status and Issues of the Spallation Neutron Source Ring injection, extraction, dipole, kicker 156
 
  • J. Wei
    BNL, Upton, Long Island, New York
  (For the Spallation Neutron Source collaboration) The Spallation Neutron Source (SNS) accelerator complex is now in its sixth year of a seven-year construction cycle. The design, fabrication, test, and assembly of the accumulator ring and its transport lines is approaching the final stage. In order to reach the design goal of this high-power ring to deliver 1.5 MW beam power (1.5$× 1014 protons of 1 GeV kinetic energy at a repetition rate of 60 Hz), stringent measures have been implemented to ensure the quality of the accelerator systems. This paper reviews the progress of the ring and transport systems with emphasis on the challenging technical issues and their solutions inccurred during the construction period.  
Video of talk
Transparencies
 
WEILH00 Industrial Involvement in EC Supported Accelerator R&D in the 6th Framework Programme and in Preparing Large Scale Accelerator Projects linac, electron, proton, klystron 194
 
  • D. Proch
    DESY, Hamburg
  The presentation will cover industrial involvement in EC supported accelerator R&D in the 6th framework programme and in preparing large scale accelerator projects (TESLA).  
Video of talk
Transparencies
 
WEILH04 Industrial Involvement in the Construction of Synchrotron Light Sources storage-ring, synchrotron, booster, insertion 206
 
  • M.S. de Jong
    CLS, Saskatoon, Saskatchewan
  The design, construction and commissioning of a modern third-generation synchrotron light source facility is a major project, costing hundreds of millions of dollars. The delivery of these new facilities, usually on a fixed budget and schedule, requires an effective working relationship with all suppliers providing equipment and services to the project. This talk will examine some of the key issues in developing and maintaining such a relationship with industry during the construction of a third-generation synchrotron light facility. These issues include project planning, the contract specification, the tendering process, communication techniques over the contract term, and other aspects of contract control. Examples, primarily from our experience constructing the Canadian Light Source but also from other new facilities planned or under construction, will be used to examine the effectiveness of various approaches to working with industry.  
Video of talk
Transparencies
 
WEPKF001 Diffusion Welding of Heterogeneous Materials in Accelerator Technique induction, lattice, radiation 1586
 
  • V.S. Avagyan
    CANDLE, Yerevan
  • A. Babayan, N.M. Dobrovolski, I.V. Tunyan
    YerPhI, Yerevan
  The results of the joining of heterogeneous materials, such as titanium with stainless steel (serviceable at 4.2 K), copper with aluminum, titanium with niobium (this work has been carried out for TESLA project), stainless steel with aluminum, copper with stainless steel are presented in this work.  
 
WEPKF002 Magnets for the CANDLE Booster Synchrotron, Design and Prototyping dipole, booster, simulation, synchrotron 1588
 
  • V.G. Khachatryan, Y.L. Martirosyan, A. Petrosyan
    CANDLE, Yerevan
  CANDLE booster synchrotron magnetic lattice contains 48 dipoles of H-shape. Detailed magnetic and mechanical design of those magnets is performed within the framework of the project. In this report, the design considerations of the dipole magnet, including the magnetic field simulation is presented. The main features of the fabricated first prototype dipole magnet are discussed.  
 
WEPKF004 Magnetic Quadrupole Lenses for the IFUSP Microtron quadrupole, microtron, beam-transport, simulation 1594
 
  • T.F. Silva, M.L. Lopes, A.A. Malafronte, M.N. Martins, P.B. Rios, J. Takahashi
    USP/LAL, Bairro Butantan
  The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work, we describe the design of the magnetic quadrupole lenses for the IFUSP microtron. The design consists of a laminar structure divided in four equal pieces. Because each piece corresponds to an individual pole, it eases the assembling of the coils and the installation of the quadrupole on the beam transport line without breaking the vacuum. Due to the fact that the quadrupole is laminated along the longitudinal axis, it is possible to change the length of a given lens by adding or subtracting foils. We also present the magnetic field distribution calculated using the POISSON code. A prototype presented good mechanical rigidity and thermal performance, showing that a refrigeration system is not necessary. The magnetic measurements show that the field distribution within the region of interest agrees with the POISSON simulation.  
 
WEPKF005 Pressure Field Distribution in a Cylindrical Geometry with Arbitrary Cross Section electron, storage-ring 1597
 
  • F.T. Degasperi
    FATEC-SP, Sao Paulo, SP
  • M.N. Martins, J. Takahashi
    USP/LAL, Bairro Butantan
  • L.L. Verardi
    IBILCE - UNESP, Sao Jose do Rio Preto, SP
  This work presents analytical and numerical results for the pressure field distribution along the axis of tubular geometries with arbitrary axisymmetric cross sections with an arbitrary time- and position-dependent gas source. Several areas of applied physics deal with problems in high-vacuum and ultra high-vacuum technology that present tubular form. In many cases one finds tubes with non uniform cross sections, like parts of particle accelerators, colliders, storage rings, gravitational antennas, and electron devices, like klystrons, electron microscopes, and also parts of vacuum systems in general, for instance, bellows, conical pipes and others. In this work one can get the detailed pressure distribution is not determined. This work presents and describes in detail the pressure field in tubes with arbitrary axisymetric cross sections. Details of the mathematical and physical formulations and modeling are given; specific conductance and specific throughput are defined; and a detailed discussion about the boundary conditions is given. These concepts and approach are applied to usual realistic cases, like conical tubes and bellows, with typical laboratory dimensions.  
 
WEPKF007 Vacuum Characterisation of a Woven Carbon Fiber Cryosorber in Presence of H2 electron, injection, scattering, collider 1603
 
  • V. Baglin, H. Dupont, T. Garcin
    CERN, Geneva
  Some of the cryogenic components in the Large Hadron Collider (LHC) will operate at 4.5 K. The H2 desorption will rapidly increase to the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications to the LHC are discussed.  
 
WEPKF015 The Design of Cold to Warm Transitions of the LHC electron, insertion, collider, impedance 1624
 
  • J. Knaster, B.J. Jenninger, D.R. Ramos, G. Ratcliffe, R. Veness
    CERN, Geneva
  The Large Hadron Collider (LHC) is the next accelerator being constructed on the CERN site to be operational in 2007. It will accelerate and collide 7 TeV protons and heavier ions up to lead. More than 2000 cryomagnets working at 1.9 or 4.5 k will form part of the magnetic lattice of the LHC. The transitions from cryogenic temperatures to room temperature zones will be achieved by 200 cold to warm transitions (CWTs). The CWTs will compensate for longitudinal and transversal displacements between beam screens and cold bores, ensuring vacuum continuity without limiting the aperture for the beam. The transverse impedance contribution is kept below the assigned total budget of 1 MΩ/m by means of a 5 μm thick Cu coating that also minimises the dynamic heat load through image currents. Tests have been performed that confirm that the static heat load per CWT to the cryomagnets remains below 2.5 W, hence validating the design.  
 
WEPKF018 Beam-loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u In49+ Ions at the CERN SPS ion, heavy-ion, linac, beam-losses 1633
 
  • E. Mahner, I. Efthymiopoulos, J. Hansen, E. Page, H. Vincke
    CERN, Geneva
  During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.  
 
WEPKF020 The Design of the Special Magnets for PIMMS/TERA injection, septum, extraction, power-supply 1639
 
  • L. Sermeus, J. Borburgh, T. Fowler, M. Hourican, K.D. Metzmacher
    CERN, Geneva
  • M. Crescenti
    TERA, Novara
  In the framework of a collaboration agreement with the TERA Foundation CERN provided the design, drawings and engineering specifications for 2 kickers, 1 chopper and 3 bumper magnets as well as 3 magnetic and 2 electrostatic septa, power supplies for the electrostatic septa, kickers and bumpers including control electronics for the PIMMS/TERA proton and carbon ion medical synchrotron. The first application will be in the Italian National Centre for Hadron Therapy, to be constructed in Pavia. The main features of the devices are described along with the strategic design choices, directed by the demand for very high reliability and minimum maintenance.  
 
WEPKF027 R&D Vacuum Issues of the Future GSI Accelerator Facilities ion, target, dipole, synchrotron 1657
 
  • H.R. Sprenger, M.C. Bellachioma, M. Bender, H. Kollmus, A. Kraemer, J. Kurdal, P.J. Spiller
    GSI, Darmstadt
  The new GSI accelerator facilities are planned to deliver heavy ion beams of increased energy and highest intensity. Whereas the energy is planned to be increased roughly by a factor of 10, the ion beam intensities are planned to be enlarged by three orders of magnitude. To achieve highest beam intensities, medium charged heavy ions (e.g. U28+) are accelerated. Since the ionization cross sections for these ions are comparably high, a UHV-accelerator system with a base pressure in the low 10-12mbar regime is required, even under the influence of ion beam loss induced desorption processes. An intensive program was started to upgrade the UHV system of the existing synchrotron SIS18 (bakeable) and to design and lay out the UHV systems of the future synchrotron SIS100 and SIS300 (mainly cryogenic). The strategy of this program includes basic research on the physics of the ion induced desorption effects as well as technical developments, design and prototyping on bakeable UHV components (vacuum chambers, diagnostics, bakeout-control, pumping speed), collimator for controlled ion beam loss, NEG coating and cryogenic vacuum components.  
 
WEPKF029 The Vacuum System of the Australian Synchrotron dipole, synchrotron, storage-ring, synchrotron-radiation 1663
 
  • E. Huttel
    FZK-ISS-ANKA, Karlsruhe
  • B. Barg, A. Jackson, B. Mountford
    ASP, Melbourne
  A 3 GeV Synchrotron Radiation Source is being built in Melbourne, Australia. The storage ring has a circumference of 216 m and has a 14 fold DBA structure. The vacuum chambers of the storage ring will be made from stainless steel. They consist of a beam chamber (width 70, height 32mm ) connected to an ante chamber, where lumped absorbers and lumped ion pumps are installed. No distributed absorber and pumps are foreseen. The nominal pumping speed of the complete ring is 31 000 l/s. The vacuum chamber of an achromat will be baked ex situ and installed under vacuum. The design of the chamber, the pump configuration and the expected vacuum behaviour will be presented.  
 
WEPKF035 Analysis of the Cold Mass Displacements at the TTF quadrupole, alignment, monitoring, linac 1681
 
  • A. Bosotti, C. Pagani, P. Pierini
    INFN/LASA, Segrate (MI)
  • R. De Monte, M. Ferianis
    ELETTRA, Basovizza, Trieste
  • R. Lange
    DESY, Hamburg
  Few of the TTF cryomodules have been equipped with wire position monitors (WPM) in order to monitor on line the displacements of the cold mass to verify alignment stability and reproducibility . Based on the operation experience of the first prototypical cryomodules, equipped with up to 36 WPMs distributed in two strings, on the last generation cryomodules a single string of 7 sensors has been installed. Here we review and analyze the data collected so far to prove that the the proposed cryomodule design is consistent with the TESLA alignment requirements.  
 
WEPKF037 Structural Analysis of an Integrated Model of Short Straight Section, Service Module, Jumper Connection and Magnet Interconnects for the Large Hadron Collider alignment, collider, hadron, ground-motion 1684
 
  • S. Dutta, J. Dwivedi, A. Kumar, H.C. Soni
    CAT, Indore (M.P.)
  • B. Skoczen
    CERN, Geneva
  The Short Straight Section (SSS) of the Large Hadron Collider (LHC) houses a twin quadrupole.The cryogens are fed to the SSS through a Jumper Connection between service modules of Cryogenic Distribution Line (QRL) and SSS.A Finite Element analysis has been performed in collaboration with CERN for the unified model of SSS of LHC,consisting of cold mass, cold supports,vacuum vessel and its bellows, interconnects, jumper connection and alignment jacks. The model has been developed to understand coupling between the quadrupole magnet and the service module due to ground motion and during the realignment or global smoothening of the LHC arc. The model incorporates experimental stiffness values for support posts, internal pipes and jacks and calculated stiffness for magnet-to-magnet interconnects. The computation space and time has been reduced by executing a two step linear static analycal approach with an initial trial analytical approach cycle in which the program estimates the behavior of the flexibles. A special routine is developed within ANSYS,using APDL which selects the correct secant stiffness of flexibles(by applying a user interactive logical algorithm)from their non-linear force displacement characteristics.  
 
WEPKF038 The Alignment Jacks of the LHC Cryomagnets alignment, radiation, quadrupole, collider 1687
 
  • J. Dwivedi, S.G. Goswami, A. Kumar, V. Madhumurthy, H.C. Soni
    CAT, Indore (M.P.)
  • V. Parma
    CERN, Geneva
  The precise alignment of the some 1700 cryomagnets of the LHC collider, requires the use of some 7000 jacks. The specific requirements and the need for an cost-effective solution for this large production, justified the development and industrialisation of a dedicated mechanical jack which was developed, and is now being produced, in the framework of a collaboration between CERN and the Center for Advanced Technology in India. Three jacks support each of the 32-ton heavy, 15-meter long cryo-dipoles of LHC, and provide the required alignment features. The main requirements are a setting resolution of 0.05 mm, and a range of movement of 20 mm in the horizontal and 40 mm in the vertical direction. Each jack has two degrees of controlled movement in the horizontal and vertical direction, whereas the remaining horizontal movement is left free. By a suitable choice of the layout of the three jacks, the full range of alignment of a cryo-magnet can be obtained. The design of the jacks evolved from a preliminary value analysis between various concepts, towards the complete engineering of the retained concept, selection of the most appropriate and cost-effective industrial production processes and setting-up of an effective quality assurance policy. Building and testing of 36 prototype jacks allowed an extensive experimental validation of their performance at CERN, where they were operated in the String 2 facility, and yielded an improved understanding for cost-effective steering of the production processes before launching the series production. Presently, the mass production of the jacks is in progress with two Indian manufacturers, and some 1500 jacks have already been delivered to CERN. Considering the successful performance of the jacks, it is now envisaged to extend the use of the same type of jacks to provide the even higher-demanding alignment of the low-beta quadrupoles of LHC.  
 
WEPKF039 The Vacuum System of Super SOR synchrotron, radiation, synchrotron-radiation, insertion 1690
 
  • H. Sakai, M. Fujisawa, A. Kakizaki, T. Kinishita, H. Kudo, N. Nakamura, O. Okuda, S. Shibuya, K. Shinoe, H. Takaki
    ISSP/SRL, Chiba
  • K. Kobayashi
    KEK, Ibaraki
  • T. Koseki
    RIKEN/RARF/BPEL, Saitama
  • H. Ohkuma
    JASRI/SPring-8, Hyogo
  • S. Suzuki
    LNS, Sendai
  The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which consists of 1.8GeV storage ring and injector. The beam current is circulated up to 400mA. These accelerators are designed so as to fully meet requirements for top-up injection. In order to realize these operation modes, our vacuum system are required on following conditions. One is to obtain the long lifetime. The other is not to melt the vacuum chamber by irradiating the high flux synchrotron radiation. Finally beam instability is not occurred by large wake fields. We describe the design of the vaccum chamber of Super-SOR and present the recent R&D concerning this system.  
 
WEPKF046 Gradient Field Generation in a Uniform Gapped Magnet synchrotron, proton, lattice, power-supply 1705
 
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • Y. Arimoto, A. Sato
    Osaka University, Osaka
  Magnets with gradient field (indexed magnets) usually have different gap distances with the different entrance positions. This situation will break a uniformity of the effective length. Trim coils, which are usually used in Cyclotron, are not practical to modify a field distribution when a large gradient is required such as FFAG. In order to generate a gradient field in a constant gapped magnet, a novel method with use of inter-pole is devised. This magnet has not only constant gap but also smaller fringing field compared with a conventional one. This technique should widen the recipe to design a magnet with such a complex magnetic field.  
 
WEPKF050 Measurement of Fast High Voltage Pulse and High Noisy DC Siganla for Modulator at the PLS Linac linac, klystron, electron, monitoring 1717
 
  • S.-C. Kim, Y.J. Han, S.H. Kim, S.-H. Nam, S.S. Park
    PAL, Pohang
  The 2.5-GeV electron linac at Pohang accelerator laboratory (PAL) has been operated continuously as a full energy injector for the Pohang Light Source (PLS) since Dec. 1994. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. At pulse operated modulator system, important pulse and DC signals are beam voltage, beam current, EOLC current HVDC voltage and HVDC current. Pulse signals are fast high voltage pulse 30 Hz, 5ms. These signals are adequate level down from modulator but including high level switching noisy. To amplitude measure of these signals for every trigger signal, we developed special module sampling hold, A/D, calculating and D/A. The output signals of these modules are 0 ~ 10 V DC signal and not include any noise signal. These output signals are connected interlock interface module of the modulator controller. Therefore computer system (PC) of the modulator controller is free to noise of these signals and can precise monitor pulse & noise DC signal. In these paper, we are described itself characteristics pulse and high noisy DC signals of the modulator, signal conditioning technique after noise elimination and operation status of the modulator controller.  
 
WEPKF051 Operational Analysis of PLS 2-GeV Electron Linac Klystron-modulator System klystron, linac, electron, impedance 1720
 
  • S.S. Park, Y.J. Han, S.H. Kim, S.-C. Kim, S.-H. Nam
    PAL, Pohang
  The klystron-modulator(K&M) system of the Pohang Light Source(PLS) had been supplying high power microwaves for the acceleration of 2 GeV electron beams. There are 11 sets of K&M systems to accelerate electron beams to 2 GeV nominal beam energy without operating one klystron-modulator. One module of the K&M system consists of an 80 MW S-band (2856 MHZ) klystron tube and the matching 200 MW modulator. The total accumulated high-voltage run-time of the oldest unit among the 12 K&M systems has reached nearly 68,000 hours as of Dec. 2003 and the summation of all the units' high voltage run-time is approximately 820,000 hours. The overall system availability is well over 95%. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. To improve self-diagnostic, operation, monitoring, and remote communication, we developed a new modulator controller based on an industrial PC platform in 2002. In this paper, we are able to review overall system performance of the high-power K&M system and the operational characteristics of the klystrons and thyratrons, and overall system's availability analysis from Jan. to Dec. 2003.  
 
WEPKF069 52 kV Power Supply for Energy Recovery Linac Prototype RF klystron, power-supply, cathode, linac 1762
 
  • J.E. Theed, M. Dykes, A. Gallagher, S.A. Griffiths, S.H. Hands, A.J. Moss, J.F. Orrett, C.J. White
    CCLRC/DL, Daresbury, Warrington, Cheshire
  Daresbury Laboratory is constructing a Radio-Frequency (RF) Test Facility to be capable of testing RF cavities for accelerator applications. Electrical power for the RF equipment will be provided from an existing -52 kV 6-pulse rectifier and transformer system capable of delivering 16A DC continuous current. A crowbar circuit will be provided to divert the large amount of stored energy in the smoothing capacitor bank in the event that a spark should occur between the cathode and the body or modulating anode. Traditionally, the crowbar has been provided by using an ignitron, but modern solid state devices have sufficient performance to meet the requirements. This paper discusses the numerous design options that were considered for the circuit parameters.  
 
WEPKF070 Design Issues for the Superconducting Magnet that goes around the Liquid Hydrogen Absorber for the Muon Ionization Cooling Experiment (MICE) focusing, magnet-design, superconducting-magnet, radiation 1765
 
  • M.A. Green, G. Barr, J. Cobb, W. Lau, R.S. Senanayake, H. Witte, S.Q. Yang
    OXFORDphysics, Oxford, Oxon
  • E. Baynham, T.W. Bradshaw, P. Drumm, Y. Ivanyushenkov, J. Rochford
    CCLRC/RAL, Chilton, Didcot, Oxon
  This report describes the design issues that are associated with a superconducting focusing solenoid that goes around a liquid hydrogen absorber for the Muon Ionization Cooling Experiment (MICE) proposed for the Rutherford Appleton Laboratory. The solenoid consists of two superconducting coils that may operated at the same polarity or at opposite polarities. As a result, the coils and their support structure must be designed to carry a 300 ton inter-coil force that is forcing the coils apart along their axis. The basic design parameters for the focusing magnet are discussed. The magnet and its cryostat are designed so that the absorber can be assembled and tested before installation into the pre-tested focusing solenoid. A safety requirements for MICE dictate that the insulating vacuum for the superconducting magnet be separated from the insulating vacuum for the absorber and that both vacuum be separated from the experiment vacuum and the vacuum within adjacent RF cavities. The safety issues associated with the arrangement of the various vacuums in the MICE focusing modules are presented. The effect of magnet operation and magnet quench on the liquid hydrogen absorber is also discussed.  
 
WEPKF072 Clearing Electrodes for Vacuum Monitoring at the Fermilab Recycler ion, electron, antiproton, monitoring 1771
 
  • D.R. Broemmelsiek, S. Nagaitsev
    Fermilab, Batavia, Illinois
  The Fermilab Recycler is a fixed 3.3-km 8-GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel. Each split-plate beam position monitor in the Recycler is also used to generated an ion clearing field for ions trapped by the antiproton beam. Approximately 100 locations have been instrumented with pico-amp meters to measure the electron current, generated by the beam-ionized residual gas in the vacuum chamber. This electron current is found to be proportional to the beam current and to the residual gas pressure in the Recycler and may be used to monitor the Recycler vacuum.  
 
WEPKF080 Secondary Electron Yield Measurements from Thin Surface Coatings for NLC Electron Cloud Reduction electron, damping, luminosity, positron 1789
 
  • F. Le Pimpec, F. King, R.E. Kirby, M.T.F. Pivi
    SLAC, Menlo Park, California
  In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the beam bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions include reducing residual gas ionization by the beam, minimizing photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.  
 
WEPKF085 Secondary Electron Emission Measurements for TiN Coating on Stainless Steel of SNS Accumulator Ring Vacuum Chamber electron, ion, simulation, cathode 1804
 
  • P. He, H.-C. Hseuh, R. Todd
    BNL, Upton, Long Island, New York
  • B. Henrist, N. Hilleret
    CERN, Geneva
  • S. Kato, M. Nishiwaki
    KEK, Ibaraki
  • R.E. Kirby, F. Le Pimpec, M.T.F. Pivi
    SLAC, Menlo Park, California
  BNL is responsible for the design and construction of the US Spallation Neutron Source (SNS) accumulator ring. Titanium Nitride(TiN) coating on the stainless steel vacuum chamber of the SNS accumulator ring is needed to reduce undesirable resonant multiplication of electrons. The Secondary Electron Yield(SEY) of TiN coated chamber material has been measured after coated samples were exposed to air and after electron and ion conditioning. We are reporting about the TiN coating system setup at BNL and SEY measurements results performed at CERN, SLAC and KEK. We also present updated electron-cloud simulation results for the SNS accumulator assuming different SEY values.  
 
WEPKF087 SNS Extraction Fast Kicker Pulsed Power System kicker, extraction, impedance, pulsed-power 1810
 
  • W. Zhang, H. Hahn, J.-L. Mi, C. Pai, J. Sandberg, Y. Tan, N. Tsoupas, J. Tuozzolo, D.S. Warburton, J. Wei
    BNL, Upton, Long Island, New York
  • R. Cutler, K. Rust
    ORNL/SNS, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS) is a next generation high intensity beam facility. Its Accumulator Ring Extraction Fast Kicker System is a very high peak power, high average power, high precision pulse-waveform, ultra-low beam impedance, and high repetition rated pulsed power system. It has been successfully design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage modulators and fourteen extraction magnet sections located inside of the SNS accumulator ring. The overall system output will reach multiple GW peak power with 60 Pulse-per-second repetition rates. The techniques of reducing impedance, improving rise time, and minimizing ripples will be discussed. The lifetime considerations, issues of the system design, development and construction are presented in this paper.  
 
WEPLT010 Design and Fabrication of Superfluid Helium Heat Exchanger Tubes for the LHC Superconducting Magnets electron, quadrupole, dipole, site 1837
 
  • F.F. Bertinelli, G. Favre, L.M.A. Ferreira, S.J. Mathot, L. Rossi, F. Savary
    CERN, Geneva
  • E. Boter
    CELLS, Bellaterra (Cerdanyola del Vallès)
  The dipole and quadrupole cold masses of the LHC machine require about 1700 heat exchanger tubes (HET). In operation the HET carries a two-phase flow of superfluid helium at sub-atmospheric pressure. The HET consists of an oxygen-free, seamless copper tube equipped with stainless steel ends. After an evaluation of different design alternatives, a design based on the technologies of vacuum brazing and electron beam welding has been adopted. Presence of these multiple technologies at CERN and synergies with the cleaning, handling and transport of other 15-metre components for LHC, motivated CERN to undertake this series fabrication on site. The raw copper tubes are procured in Industry, presenting challenging issues of geometric precision. Organisation of the HET fabrication includes cryomeasurements to validate cleaning procedures, characterization of welding procedures, buckling design by FEA and experimental verification, quality control during series production. The series fabrication of these long, multi-technological components is continuing successfully, respecting the project?s tight budgetary and planning constraints.  
 
WEPLT016 Logistics of LHC Cryodipoles: from Simulation to Storage Management simulation, insertion, background, quadrupole 1855
 
  • K. Foraz, B. Nicquevert, D. Tommasini
    CERN, Geneva
  The particles traveling in the Large Hadron Collider are guided by superconducting magnets. The main magnets (cryodipoles) are 16 m long, 30 tons objects placed with accuracies of few tenths of mm and therefore imposing challenging requirements for handling and transportation. Numerous contracts are constraining the production and installation of these cryodipoles. These contracts have been rated according to the baseline schedule, based on a "just in time" scheme. However the complexity of the construction and the time required to fully test the cryodipoles before installation in the LHC required to decouple as much as possible each contract from the others' evolutions and imposed temporary storage between different assembly and test steps. Therefore a tool simulating the logistics was created in order to determine the number of cryodipoles to store at the various stages of their production. In this paper the organization of cryodipole flow and the main challenges of logistics are analyzed on the basis of the planning of each main step before installation. Finally the solutions implemented for storage, handling and transportation are presented and discussed.  
 
WEPLT020 Installation of A Particle Accelerator: from Theory to Practice. The LHC Example site, collider, feedback, survey 1867
 
  • C. Hauviller, S. Weisz
    CERN, Geneva
  Installing and commissioning the thousands of equipments constituting a Particle Accelerator is a lengthy and complex process. A large number of multidisciplinary teams are involved over a long period lasting usually many years. Diverse boundary constrains must be taken into account: space, a long and narrow tunnel with few accesses, time, with milestones set many years in advance, and obviously budget. A strict organisation associated with the management tools and the right people is the only way to arrive to a success. The keywords are: Knowledge: A unique and up-to-date database of all the elements and their location, Integration: Study the physical position of the elements, suppress the interferences and define the installation methodology, Prevision: Schedule all the activities and update on-line, In-situ management and supervision: Teams dedicated to follow-up, corrective actions and orphan jobs, Safety. After presenting the planned overall organization, the paper will present practical achievements with the example of the LHC machine installation.  
 
WEPLT023 Transverse Resistive Wall Impedance and Wake Function with Inductive Bypass impedance, dipole, simulation, betatron 1876
 
  • A. Koschik, F. Caspers, E. Métral, L. Vos
    CERN, Geneva
  • B. Zotter
    Honorary CERN Staff Member, Grand-Saconnex
  We analyze the resistive wall impedance with an "inductive bypass" due to alternate current paths in the outer vacuum chamber proper. Also the corresponding wake function has been obtained which is useful for the simulation of beam stability in the time domain. Results are presented for the LHC.  
 
WEPLT024 Scheduling the Installation of the LHC Injection Lines injection, radiation, dipole, quadrupole 1879
 
  • L. Lari, H. Gaillard, V. Mertens
    CERN, Geneva
  The installation of the two LHC injection lines has to fit within tight milestones of the LHC project and of CERN?s accelerator activity in general. For instance, the transfer line from the SPS to LHC point 8 (to fill the anti-clockwise LHC ring) should be tested with beam before the end of 2004 since the SPS will not run in 2005. It will first serve during the LHC sector test in 2006. Time constraints are also very strong on the installation of the transfer line from the SPS to LHC point 2 (for the clockwise LHC ring): its tunnel is the sole access for the LHC cryo-magnets and a large part of the beam line can only be installed once practically all LHC cryo-magnets are in place. Of course, the line must be operational when the LHC starts. This paper presents the various constraints and how they are taken into account for the logistics and installation planning of the LHC injection lines.  
 
WEPLT025 LHC Reference Database : Towards a Mechanical, Optical and Electrical Layout Database collider, instrumentation, radio-frequency, injection 1882
 
  • P. Le Roux, S. Chemli, A. Jimeno Yepes, B. Maire, H. Prin, A. Vergara-Fernández, M. Zerlauth
    CERN, Geneva
  The LHC project has entered a phase of integration and installation of thousands of diverse components. The Hardware Commissioning work has also started. Collecting and distributing reliable and coherent information on the equipments and their layout becomes a crucial requirement in the lifecycle of the project. Existing database tools had to evolve to a more generic model to cover not only optical layout, but also the mechanical and the electrical aspects. This paper explains the requirements, the implementation and the benefits of this new database model.  
 
WEPLT027 Connection Cryostats for LHC Dispersion Suppressors alignment, dipole, shielding, radiation 1888
 
  • S. Marque, T. Colombet, M. Genet, B. Skoczen
    CERN, Geneva
  The lattice of the Large Hadron Collider (LHC) being built at CERN is based on 8 standard arcs of 2.8 km length. Each arc is bounded on either side by Dispersion Suppressors connected to the arc by connection cryostats providing 15m long drift spaces. As for a dipole magnet, the connection cryostat provides a continuity of beam and insulation vacuum, electrical powering, cryogenic circuits, thermal and radiation shielding. In total 16 modules will be constructed. The stringent functional specification has led to various analyses. Among them, a light mechanical structure has been developed to obtain a stiffness comparable to a dipole magnet, for alignment purpose. Thermal studies, included λ front propagation, have been performed to ensure a cooling time down to 1.9K within the time budget. A special cooling scheme around the beam tubes has been chosen to cope with heat loads produced during operation. We will report on the general design of the module and on the manufacturing process adopted to guarantee the tight alignment of the beam tubes once the module installed in the machine. Special emphasis will be given on thermo-mechanical analysis, λ front propagation and on beam-tubes cooling scheme.  
 
WEPLT037 A J2EE Solution for Technical Infrastructure Monitoring at CERN monitoring, controls, laser, collider 1912
 
  • J. Stowisek, R.M. Martini, P. Sollander
    CERN, Geneva
  The Technical Infrastructure Monitoring project (TIM) will design and implement the future control system for CERN's technical infrastructure. The control system will be built using standard components including industrial PLCs, Java Enterprise Edition (J2EE) including Enterprise Java Beans and the Java Message Service and relational databases. This paper describes how these standard technologies are used to build a flexible, scalable, robust and reliable control system.  
 
WEPLT040 Layout Drawings of the LHC Collider collider, cryogenics, site, survey 1921
 
  • A. Vergara-Fernández, S. Chemli, B. Maire, Y. Muttoni
    CERN, Geneva
  • A. Kournossenko, R. Zalyalov
    IHEP Protvino, Protvino, Moscow Region
  The team in charge of the LHC integration largely uses 3D scenes combining functional positions of equipments and the 3D CAD model issued from the Cern Drawing Directory (CDD) repository. This is made possible through the Digital Mock-Up tool developed at CERN. Giving dimensions in 3D context is a challenge with the current 3D CAD tools used at CERN. Requirements from users groups have made clear a need for automatic production of 2D layout drawings. This paper presents the retained solution to create on-request dimensioned drawings, to publish them, while maintaining coherence and consistency with the 3D integration scenes. Reliability of the information, on-line availability of the latest layout changes on dimensions and positions of equipments, and the maintenance of the facility will also be described.  
 
WEPLT044 Electron-cloud Build-up Simulations and Experiments at CERN electron, simulation, injection, quadrupole 1933
 
  • F. Zimmermann, G. Arduini, V. Baglin, T. Bohl, B.J. Jenninger, J.M. Jimenez, J.-M. Laurent, F. Ruggiero, D. Schulte
    CERN, Geneva
  We compare the predications of electron-cloud build-up simulations with measurements at the CERN SPS. Specifically, we compare the electron flux at the wall, electron-energy spectra, heat loads, and the spatial distribution of the electrons for two different bunch spacings, with variable magnetic fields, and for several chamber temperatures and associated surface conditions. The simulations employ a modified, improved version of the ECLOUD code. The main changes are briefly described. We finally present updated simulation results for the heat load in the cold LHC arcs.  
 
WEPLT076 SPIRAL 2 RFQ Design rfq, ion, emittance, electron 2026
 
  • R. Ferdinand, G. Congretel, A. Curtoni, O.D. Delferriere, A. France, D.L. Leboeuf, J. Thinel, J.-C. Toussaint
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M. Di Giacomo
    GANIL, Caen
  The SPIRAL2 RFQ is designed to accelerate at 88MHz two kinds of charge-over-mass ratio, Q/A, particles. The proposed injector can accelerate a 5 mA deuteron beam (Q/A=1/2) or a 1 mA particles beam with q/A=1/3 up to 0.75 MeV/A. It is a CW machine which has to show stable operation, provide the request availability, have the minimum losses in order to minimize the activation constraints and show the best quality/cost ratio. It will be a 4-vane RFQ type, with a mechanical assembly, the global assumption being to build an RFQ without any brazing step. Extensive modelisation was made to ensure a good vane position under RF. A 1-m long hot model prototype is under construction in order to validate the manufacturing concept.  
 
WEPLT080 Study of Resistive-wall Effects on SOLEIL impedance, single-bunch, focusing, synchrotron 2038
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  The presence of low-gap chambers for insertion devices, along with a relatively small vertical gap of 25 mm chosen for the standard vacuum chambers, implies a significant influence of the resistive-wall on the beam in the future SOLEIL storage ring. A systematic approach was taken to quantify the net contribution by taking into account all local variations of the non-circular chamber cross-sections as well as beta functions. Low multibunch instability thresholds were found in both transverse planes, indicating the necessity of cures, by means of transverse feedback and/or chromaticity shifts. An effort was made to evaluate the effect of metallic coating, particularly that of NEG, which was adopted in all straight sections. The dependence on both resistivity and thickness of NEG was followed. It is found that, the NEG coating nearly doubles the reactive part of the impedance in the frequency range seen by the beam. Implication on the reduction of the transverse mode-coupling instability threshold is discussed. Incoherent tune shifts arising from the non-circular chamber cross-section were also evaluated, including a non-negligible NEG contribution in the short-range wakes.  
 
WEPLT081 Numerical Evaluation of Geometric Impedance for SOLEIL impedance, dipole, collective-effects, coupling 2041
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  Good knowledge and minimisation of the coupling impedance is of great importance for the future storage ring SOLEIL, envisaged to operate in both high current multibunch and high bunch intensity modes. Three-dimensional computations of the geometric impedance of various vacuum chamber components have been made with the code GdfidL, which allows parallel processing with a cluster of computers, rendering the computation with a small mesh size and a long integrated distance feasible. Many treated objects were found to exhibit large asymmetry in the two transverse planes, as well as resonant behaviour at high frequencies, both of which being non-straightforward to follow with the conventional analytical methods and 2-dimensional calculations. In particular, strongly trapped modes found for the flange impedance resulted in an unacceptably low vertical multibunch instability threshold, which urged a modification of the original cavity-like structure. The dependence of the dipole chamber impedance on the vertical slot size was followed to determine the optimal slot opening. Characteristics of the total broadband impedance obtained, along with relative contributions are also presented.  
 
WEPLT083 Coherent and Incoherent Tune Shifts Deduced from Impedance Modelling in the ESRF-Ring impedance, single-bunch, storage-ring, coupling 2047
 
  • T.F. Günzel
    ESRF, Grenoble
  In single bunch the detuning of the transverse modes m=0,1 and -1 are calculated on the base of an impedance model contructed from element-wise wakefield calculation and the resistive wall impedance of the ESRF-ring. As the vacuum chambers of the ESRF storage ring have notably flat cross sections incoherent wake fields have an impact on the tune shifts as well as coherent wake fields. Compared to tune shift measurements in single bunch the calculated transverse mode detuning can explain half of the tune shift in the vertical plane and almost completely the tune shift in horizontal plane.  
 
WEPLT085 Vertcal Effective Impedance Mapping of the ESRF Storage Ring impedance, closed-orbit, insertion, insertion-device 2053
 
  • T. Perron, L. Farvacque, E. Plouviez
    ESRF, Grenoble
  Transverse impedance increase due to installation of low gap vacuum chambers is a general effect observed in synchrotron light sources. ESRF has been sensitive to this increase of impedance, as its single bunch threshold has dramatically decreased. This paper presents a method based on closed orbit distortion measurements, witch allows to measure locally the vertical effective impedance. Results of measurements performed on low gap vacuum chambers and in-vacuum ondulators are presented. As an extension to this experiment, a new global method is discussed. This method, also based on closed orbit measurement allows measuring simultaneously all areas of high impedance in the machine  
 
WEPLT092 Equilibrium Longitudinal Distribution for Localized Regularized Inductive Wake synchrotron, damping, radiation, radio-frequency 2065
 
  • S. Petracca, T. Demma
    U. Sannio, Benevento
  • K. Hirata
    GUAS, Kanagawa
  In a recent paper [*] we have shown that a localized wake assumption and the Gaussian approximation for the longitudinal beam distribution function can be used to understand the nature of the stationary solutions for the inductive wake, by comparison between the resulting map and the Haissinski equation, which rules the (less realistic) case of a uniformly distributed wake. In particular we showed the non-existence of solutions of Haissinski's equation when the inductive wake strength exceeds a certain threshold [**] to correspond to the onset of chaos in the map evolving the moments of the beam distribution from turn to turn. In this paper we use the same formalism to confirm that as noted in [**] for Haissinski's equation, a steady state solution for the longitudinal phase space distribution function always exists if a physically regularized inductive wake, which satisfies an obvious causality condition, is used.

* S. Petracca and Th. Demma, Proc. of the 2003 PAC, IEEE Press, New York, 2003, ISBN 0-7803-7739-9, p.2996.** Y. Shobuda and K. Hirata, Part. Accel. vol. 62, 165 (1999).

 
 
WEPLT093 Electromagnetic Fields of an Off-axis Bunch in a Circular Pipe with Finite Conductivity and Thickness - I multipole, injection, single-bunch, electromagnetic-fields 2068
 
  • S. Petracca, L. Cappetta, T. Demma
    U. Sannio, Benevento
  The electromagnetic field produced by a bunched beam in a circular pipe is usually computed under the assumption that the field penetration(skin depth) is far less than the wall thickness. Chao [*] gave a formula which exploits the wall thickness, but his result is restricted to the monopole term. Piwinski [**] treated the case of a metal coated ceramic wall, when the coating thickness is much smaller than the skin-depth, but his analysis is also limited to the monopole term.In this paper we solve the problem in full generality, by providing an exact (Green's functions) solution for the field of an off-axis point particle running at constant velocity in a circular pipe with finite wall conductivity and thickness.

* A.W. Chao, Phys. of Collective Beam Instab. in High En. Accel., Wiley,1993** S. Piwinski, DESY 1972/72

 
 
WEPLT095 Modified Polarizabilities and Wall Impedance for Shielded Perforated Beam Pipes with General Shape impedance, coupling, dipole, shielding 2074
 
  • S. Petracca, T. Demma
    U. Sannio, Benevento
  We extend previous results [*] concerning the modified polarizability of (electrically small) holes/slots in the wall of a circular beam liner surrounded by a coaxial circular tube to the most general liner and cold bore geometries. We obtain an equivalent wall impedance to describe the electromagnetic boundary conditions at perforated walls for this most general case, and use a general perturbational approach [**] for computing the pertinent longitudinal and transverse coupling impedances.

* R.L. Gluckstern, CERN SL 92-06 (AP), 1992, CERN SL 92-31 (AP), 1992; R.L. Gluckstern, B. Zotter, CERN SL 96-56 (AP), 1996.** S. Petracca, Part. Acc., {\bf 50}, 211, 1995; id., Phys. Rev. E, 60 (3),1999.

 
 
WEPLT098 Experience with Long Term Operation with Demineralized Water Systems at DAFNE wiggler, ion, synchrotron, booster 2080
 
  • L. Pellegrino
    INFN/LNF, Frascati (Roma)
  During eight years operation of the Dafne water cooling system we coped with several critical situations and managed successfully specific upgrades to the demineralized water system. Here we revise critically the collected data and the experience gained in the field of copper corrosion and related water treatment.  
 
WEPLT101 On-line Mechanical Instabilities Measurements and Tuner Development in SC Low-beta Resonators linac, feedback, injection, resonance 2086
 
  • A. Facco, E. Bissiato, S. Canella, D. Carlucci, M. Lollo, F. Scarpa, D. Zenere
    INFN/LNL, Legnaro, Padova
  The use of high-Q and small rf bandwidth superconducting quarter wave resonators made of bulk niobium put severe requirements to the helium bath pressure stability to avoid cavity detuning. This is not always possible, and cavity detuning caused by slow pressure changes must be precisely followed by the cavity tuner. The LNL philosophy is based on mechanical damping of cavity vibrations and mechanical tuning in feedback for slow frequency compensation. The old-fashioned tuners installed in the ALPI linac had significant performance limitations. To replace them, we have designed, constructed and tested a new tuner which integrates the LNL system and control with the TRIUMF, backlash-free tuner leverage design. The new tuner is designed to compensate pressure changes up to 100 mbar/minute with a precision of 0.5 Hz, and it will be installed in the ALPI resonators. An upgraded prototype for future applications includes a piezoelectric actuator for fast tuning. Tuner characteristics and first test results will be presented. This system is extendable to other low-beta cavity types like superconducting rfqs.  
 
WEPLT109 Simulation of Ep Instability for a Coasting Proton Beam in Circular Accelerators electron, proton, simulation, ion 2107
 
  • K. Ohmi, T. Toyama
    KEK, Ibaraki
  • G. Rumolo
    GSI, Darmstadt
  ep instability is discussed for a coasting beam operation of J-PARC 50 GeV Main Ring. Our previous study (PAC2003) was focussed only ionization electron. We now take into account electrons created at the chamber wall due to proton loss and secondary emission with higher yield than ionization.  
 
WEPLT117 Design of a Third Harmonic Superconducting RF System at PLS emittance, storage-ring, synchrotron, radiation 2125
 
  • E.-S. Kim, M.-H. Chun, H.-G. Kim, K.-R. Kim, I.-S. Park, Y.-U. Sohn, J.S. Yang
    PAL, Pohang
  • J.-K. Ahn, J.-S. Cho
    Pusan National University, Pusan
  A superconducting third harmonic rf system has been designed in the PLS to raise beam lifetime. Expected beam lifetimes verse beam emittance and operational beam current are presented. A multibunch multiparticle tracking simulation is performed to investigate energy spread, bunch-lengthening and beam instabilities due to the rf cavities. The parameters of the designed rf cavity, designed cryogenic system and estimation of heat load are also presented.  
 
WEPLT123 Engineering Design of High-current 81.36 MHz RFQ with Elliptic Coupling Windows rfq, alignment, coupling, ion 2143
 
  • D. Kashinskiy, A. Kolomiets, S. Minaev, V. Pershin, B.Y. Sharkov, T. Tretyakova
    ITEP, Moscow
  Four-vane RFQ structure with elliptic coupling windows has been originally developed at ITEP for injection into ITEP-TWAC synchrotron/storage ring complex, being lately adapted for RIA project too. As the electrodynamics simulations show, this structure combines the high efficiency with the operating mode stability against asymmetric detuning and electrode misalignment. A considerable reduction of structure diameter due to coupling windows becomes important for low frequency range which is necessary for the heavy ion acceleration. At the same time, the electrode configuration allows the efficient cooling and high duty factor operation. A mechanical design of 81 MHz, 1.6 MeV/u, 6 m long heavy ion RFQ section is discussed. The outer tank is made of two layers, steel and copper, joined by using the thermal diffusion technology. Each electrode is supplied with the alignment mechanism and connected to the tank by the flexible conducting insert. The whole setup is in manufacturing now.  
 
WEPLT126 Beam Dynamics Simulation in High Energy Electron Cooler electron, simulation, antiproton, target 2146
 
  • A.V. Ivanov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva
    BINP SB RAS, Novosibirsk
  The article deals with electron beam dynamics in projected high energy electron cooler. Classical electrostatic scheme with several MeV electron energy is considered. The increase of transversal energy of electrons in an accelerating section, in bends and at the matching point of magnetic fields is calculated. In order to calculate beam behavior in bends with electrostatic compensation of centripetal drift new ELEC3D electro- and magnitostatic 3D code is developed. BEAM code is used for simulation of dynamics in an accelerating section. The methods of keeping low transversal energy are estimated.  
 
WEPLT128 Charge Particle Source for Industrial and Research Accelerators Operating at the Poor Vacuum Conditions electron, cathode, ion, background 2149
 
  • E.O. Popov, A.A. Pashkevich, S.O. Popov, A.V. Vitugov
    IOFFE, St. Petersburg
  We investigated the original method of fabrication of the great number of emitting tips by pulling liquid metal through the holes in track membrane under influence of electric field. The track membranes are produced by cyclotron of Physicotechnical Institute. This method enables to fabricate up to 1·108 emitting tips per square cm. Special test facility to investigate emitter parameters operating at different values of background residual gas pressure was designed and developed. The liquid metal multiple tip field emitters possess some unique characteristics which are attractive in accelerators for material irradiation: unlimited life expectancy, large current densities (about 100 mA per sq. cm), practically unlimited surface, stable emission in poor vacuum.  
 
WEPLT146 Mismatch Oscillations in High-current Accelerators quadrupole, emittance, focusing, ion 2179
 
  • O.A. Anderson
    LBNL, Berkeley, California
  Strong space charge challenges the designers of modern accelerators such as those used in Heavy Ion Inertial Fusion. Simple, accurate design tools are useful for predicting beam behavior, such as phase advances and envelope oscillation periods, given the beam emittance and charge and the lattice parameters. Along with the KV beam model, the smooth approximation [*] is often used. It is simple but not very accurate in many cases. Although Struckmieir and Reiser [**] showed that the stable envelope oscillations of unbalanced beams could be obtained accurately, they used a hybrid approach where the phase advances σ0 and σ were already known precisely. When starting instead with basic quantities–quadrupole dimensions, field strength, beam line charge and emittance–the smooth approximation formulas give substantial errors (10% or more). We previously described an integration method [***] for matched beams that yields fairly simple third-order formulas for σ0, σ, beam radius and ripple. Here we extend the method to include small-amplitude mismatch oscillations. We derive a simple modification of the smooth approximation formulas and show that it improves the accuracy of the predicted envelope frequencies significantly–for example, by a factor of five when σ0 is 83 degrees.

* M. Reiser, Particle Accelerators 8, 167 (1978) ** J. Struckmeier and M. Reiser, Particle Accelerators 14, 227 (1984)*** O. A. Anderson, Particle Accelerators 52, 133 (1996)

 
 
WEPLT158 Direct Measurement of the Resistive Wakefield in Tapered Collimators linac, impedance, electron, damping 2212
 
  • P. Tenenbaum
    SLAC, Menlo Park, California
  • D. Onoprienko
    Brunel University, Middlesex
  The transverse wakefield component arising from surface resistivity is expected to play a major role in the beam dynamics of future linear colliders. We report on a series of experiments in which the resistive wakefield was measured in a series of tapered collimators, using the Collimator Wakefield beam test facility at SLAC. In order to separate the contributions of geometric and resistive wakefields, two sets of collimators with identical geometries but different resistivities were measured. The results are in agreement with the theoretical prediction for the high-resistivity (titanium) collimators, but in the case of low-resistivity (copper) collimators the resistive deflections appear to be substantially larger than predicted.  
 
WEPLT170 Injection Schemes for Self Consistent Space Charge Distributions injection, space-charge, closed-orbit, betatron 2227
 
  • V.V. Danilov, S.M. Cousineau, S. Henderson, J.A. Holmes, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
  This paper is based on recently found sets of self-consistent 2D and 3D time-dependent space charge distributions. A subset of these distributions can be injection-painted into an accumulator ring, such as Spallation Neutron Source Ring, to produce periodic space charge conditions. The periodic condition guarantees zero space-charge-induced halo growth and beam loss during injection. Practical aspects of such schemes are discussed, and simulations of a few specific cases are presented.  
 
WEPLT172 Design & Handling of High Activity Collimators &Ring Components on the SNS target, shielding, linac, extraction 2233
 
  • G.R. Murdoch, D. Crisp, S. Henderson, M. Holding, K. Potter, T. Roseberry
    ORNL/SNS, Oak Ridge, Tennessee
  Design & Handling of High Activity Collimators on the SNS*G Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.  
 
WEPLT184 Preliminary Estimation of the Electron Cloud in RHIC electron, proton, simulation, dipole 2251
 
  • L. Wang, P. He, J. Wei
    BNL, Upton, Long Island, New York
  Electron cloud due to beam induce multipacting is suspected to be one of the source of pressure rises in RHIC. This paper estimates the possible electron cloud in RHIC. Various parameters related electron multipacting has been investigated.  
 
THOBCH01 The Beijing Electron-positron Collider and its Second Phase Construction luminosity, synchrotron, synchrotron-radiation, injection 230
 
  • C. Zhang, J.Q. Wang
    IHEP Beijing, Beijing
  The Beijing Electron-Positron Collider (BEPC) was constructed for both high energy physics and synchrotron radiation researches. As an e+ e- collider operating in the tau-charm region and a first synchrotron radiation source in China, the machine has been well operated for 14 years since it was put into operation in 1989. As a collider, the peak luminosity of the BEPC has reached its design goal of 5*1030 cm-2s-1 at J/sai energy of 1.55 GeV and 1*1031 cm-2s-1 at 2 GeV respectively. The main parameters in the dedicated synchrotron radiation operation are: E=2.2~2.5 GeV, ex0=80 mm mrad at 2.2 GeV, Ib=140 mA and the beam lifetime of 20~30 hours. As the second phase project of the BEPC, the BEPCII , has been approved with total budget of 640 million RMB. The construction is started in the beginning of 2004 and is scheduled to complete by the end of 2007. The BEPCII is a double ring machine with its luminosity goal of 1*1033 cm-2s-1 at 1.89 GeV, two orders of magnitude higher than present BEPC. The BEPCII will operate in the beam energy of 1-2.1 GeV so that its physical potential in the whole t and charm range is preserved, while the collider will be optimized at 1.89 GeV. The upgrading of the collider should also provide an improved SR performance with higher beam energy and intensity. The beam currents will be increased to 250 mA at E=2.5 GeV for the dedicated synchrotron radiation operation of the BEPCII. Some key technologies, such as superconducting RF system, low impedance vacuum devices, superconducting micro-beta quadrupoles and etc., has been intensively studied in order to achieve the target of the BEPCII.  
Video of talk
Transparencies
 
THPKF017 Status of the Synchrotron Light Source DELTA injection, synchrotron, feedback, radiation 2296
 
  • D. Schirmer, U. Berges, J. Friedl, A. Gasper, M. Grewe, P. Hartmann, R.G. Heine, H. Huck, G. Schmidt, C. Sternemann, M. Tolan, T. Weis, C. Westphal, K. Wille
    DELTA, Dortmund
  Since 1999, the Dortmunder 1.5 GeV electron storage ring DELTA was continuously extended. The facility serves universities and industries as a source of synchrotron radiation on a regional level. The consolidation of the machine was finally completed in 2002. By now, DELTA, operated for 3000 hours per year, has reached a reliability comparable to other facilities in the world. Large improvements have been made in the installation of the beamlines. At present, two undulator beamlines and several dipole beamlines in the range of soft X-rays are in operation. The 5.3 T superconducting asymmetric wiggler (SAW) serves three beamlines in the hard X-ray regime with circular polarized light. Also the accelerator physics research program has been promoted. The vacuum system was revised during the last year to provide extra space for test sections and additional diagnostics. Substantial progress was achieved by SVD based orbit correction and LOCO based optics modelling as well as detailed CBM studies and a new method for fast tune measurements has been implemented. Future developments for machine improvements, such as DSP-based fast local orbit feedback and a frequent injection mode are in preparation.  
 
THPKF021 Beam Current Limitations in the Synchrotron Light Source PETRA III impedance, synchrotron, electron, radiation 2308
 
  • R. Wanzenberg, K. Balewski
    DESY, Hamburg
  At DESY it is planned to rebuild the PETRA ring into a synchrotron radiation facility, called PETRA III, in 2007. Different operation modes with single bunch intensities of up-to 5 mA are been considered to serve the needs of the user communities. A first estimate of the impedance budget of PETRA III is given based on analytical models and numerical wakefield calculations of several vacuum chamber elements. The impedance model includes higher order modes (HOMs) of the cavities to cover also multi bunch aspects. The beam current limitations due to multi and single bunch instabilities are discussed. The build up of an electron cloud is also investigated for the option of using a positron beam to generate the synchrotron radiation.  
 
THPKF023 Studies using Beam Loss Monitors at ANKA beam-losses, electron, storage-ring, injection 2314
 
  • F. Pérez, I. Birkel, K. Hertkorn, E. Huttel, A.-S. Müller, M. Pont
    FZK-ISS-ANKA, Karlsruhe
  ANKA is a synchrotron light source that operates in the energy range from 0.5 to 2.5 GeV. In order to investigate the electron beam losses, two kind of beam loss monitors have been installed: 24 Pin Diode from Bergoz distributed around the storage ring, and one Pb-glass calorimeter located in a high dispersion region. The Pin Diodes are used to obtain information about the distribution of the losses while the Pb-glass detector provides higher sensitivity. The Pin Diodes allow to locate and distinguish the regions of higher losses due to Touschek and Elastic scattering. Furthermore, regions of higher losses at injection have been identified. The Pb-glass detector has been used to determine the beam energy with the resonant spin depolarisation technique. A strong spin orbit resonance has been observed with both detectors.  
 
THPKF031 High Power (35 KW and 190 KW) 352 MHZ Solid State Amplifiers for Synchrotron SOLEIL power-supply, booster, insertion, synchrotron 2338
 
  • P. Marchand, R.L. Lopes, J. Polian, F. Ribeiro, T. Ruan
    SOLEIL, Gif-sur-Yvette
  In the SOLEIL Storage Ring (SR), two cryomodules, each containing a pair of superconducting cavities will provide the maximum power of 600 kW, required at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. Each of the four cavities will be powered with a 190 kW solid state amplifier consisting in a combination of 315 W elementary modules (about 750 modules per amplifier). The amplifier modules, based on a technology developed in house, with MOSFET transistor, integrated circulator and individual power supply, will be fabricated in the industry. In the booster, a 40 kW solid state amplifier (147 modules) will power a 5-cell copper cavity of the LEP type. The status and the test results of the different parts of the equipment are reported in this paper.  
 
THPKF050 Electron Accelerator for Energy up to 5.0 MeV and Beam Power up to 50 KW with X-ray Converter electron, extraction, cathode, coupling 2383
 
  • V. Auslender, A.A. Bryazgin, B.L. Faktorovich, E.N. Kokin, I. Makarov, S.A. Maximov, V.E. Nekhaev, A.D. Panfilov, V.M. Radchenko, M.A. Tiunov, V.O. Tkachenko, A.F.A. Tuvik, L.A. Voronin
    BINP SB RAS, Novosibirsk
  In recent time the new powerful industrial electron accelerators appear on market. It caused the increased interest to radiation technologies using high energy X-rays due to their high penetration ability. One of the promising directions is the creation of the irradiation installations for treatment of wide variety of food products. The report describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The ILU-10 accelerator generates the vertical electron beam. The beam line turns the beam through an angle of 90 degrees and transports the beam to the vertically posed X-ray converter to generate the horizontal beam of X-rays. In the work presented results of measurements of the dose distribution profiles on the surface of treated products.  
 
THPKF051 The Status-2004 of the KURCHATOV Center of SR electron, synchrotron, radiation, optics 2386
 
  • V. Korchuganov, V. Korchuganov, Y.V. Krylov, V.V. Kvardakov, D.G. Odintsov, V. Ushkov, A.G. Valentinov, Y.L. Yupinov, S.I. Zheludeva
    RRC Kurchatov Institute, Moscow
  • M.V. Kovalchuk
    RAS/A.V.Shubnikov, Moscow
  Kurchatov Synchrotron Radiation Source (KCSR) began the work as a first dedicated synchrotron radiation facility in Russia in 1999. The facility includes two storage rings: 450 MeV SIBERIA-1 and 2.5 GeV SIBERIA-2 and is intended for experiments in the range of SR from VUV up to hard X-ray. Large progress was achieved in increasing SIBERIA-2 stored current during last year. Now maximum current at injection energy is more than 220 mA and it equals to 140 mA at operation energy. The SR dose is rising fast and the life time is also grown because of the outgassing of vacuum chamber by SR. Consequently, after the only one electrons accumulation the work during 24 hours on experimental stations becomes possible with SR beams unbroken. Eight experimental stations with SR beam lines and hutches were mounted and are now in routine operation with SR from bending magnets in experimental hall of Siberia-2. We are installing next beam lines there. SIBERIA-1 also has experimental hall with three beam lines and three experimental stations being in operation. The report describes the current work and the plans on the storage rings. It informs about achieved consumer parameters of an electron beam and status of SR stations.  
 
THPKF072 Progress with the Diamond Light Source storage-ring, booster, injection, diagnostics 2433
 
  • R.P. Walker
    Diamond, Oxfordshire
  Construction of Diamond, the UK?s new 3 GeV, 3rd generation synchrotron light source, is well underway and progressing in-line with the original target of starting storage ring commissioning in January 2006 and being operational for users in January 2007. Having completed the foundations, the main building works are now proceeding at their maximum rate. Most of the major machine components are also under construction, aiming towards the key target date of starting machine installation in September 2004. As well as reporting on the overall status, detailed design developments and component choices will be summarised. The results of tests of various prototype components, including magnets, vacuum vessels and girders, will also be presented.  
 
THPKF082 The Completion of SPEAR 3 shielding, power-supply, injection, radiation 2451
 
  • R.O. Hettel, R. Akre, S. Allison, P. Bellomo, R.M. Boyce, L. Cadapan, R. Cassel, B. Choi, W.J. Corbett, D. Dell'Orco, T. Elioff, I. Evans, R. Fuller, S. Hill, D. Keeley, N. Kurita, J. Langton, G. Leyh, C. Limborg-Deprey, D. Macnair, D.J. Martin, P.A. McIntosh, E. Medvedko, C.-K. Ng, I. Nzeadibe, J. Olsen, M. Ortega, G.C. Pappas, S. Park, T. Rabedeau, H. Rarback, A. Ringwall, P. Rodriguez, J.A. Safranek, H.D. Schwarz, B. Scott, J.J. Sebek, S. Smith, T. Straumann, J. Tanabe, A. Terebilo, T.A. Trautwein, C. Wermelskirchen, M. Widmeyer, R. Yotam, K. Zuo
    SLAC/SSRL, Menlo Park, California
  On December 15, 2003, 8 1/2 months after the last electrons circulated in the old SPEAR2 storage ring and 5 days after the beginning of commissioning, the first electrons were accumulated in the completely new SPEAR3 ring. The rapid installation and commissioning is a testimony to the SPEAR3 project staff and collaborators who have built an excellent machine and equipped it with powerful and accessible machine modeling and control programs. The final year of component fabrication, system implementation and testing, the 7-month installation period leading up to the beginning of commissioning, and lessons learned are described.  
 
THPLT003 Vibrating Wire Scanner Parameters Optimization proton, ion, electron, pick-up 2460
 
  • S.G. Arutunian, K.G. Bakshetyan, N.M. Dobrovolski, M.R. Mailian, V.A. Oganessian, H.E. Soghoyan, I.E. Vasiniuk
    YerPhI, Yerevan
  • K. Wittenburg
    DESY, Hamburg
  The idea to use the metallic vibrating wire as a scanner of particles beams was experimentally confirmed [1, 2] and showed unprecedented sensibility and a huge dynamic rage of the output signal. In this work the response time of the system is estimated on the base of the dynamic model of heat transfer through the wire. A comparison of different materials of the wire is presented and the most suitable materials for different tasks are suggested. The dielectric materials are considered as possible materials of the wire, use of which allows to eliminate the electromagnetic induction from high current beams during the scanning of beam halo. The results of scanning of the iron ion beam of the mass spectrometer are presented. 1. Arutunian S.G., Avetisyan A.E., Dobrovolski N.M., Mailian M.R., Vasiniuk I.E, Wittenburg K., Reetz R., Problems of Installation of Vibrating Wire Scanners into Accelerator Vacuum Chamber. - Proc. 8-th Europ. Part. Accel. Conf. (3-7 June 2002, Paris, France), pp. 1837-1839. 2. Arutunian S.G., Dobrovolski N.M., Mailian M.R., Vasiniuk I.E., Vibrating wire scanner: first experimental results on the injector beam of Yerevan synchrotron.- Phys. Rev. Special Topics. - Accelerators and Beams, 2003, v. 6, 042801.  
 
THPLT010 Limiting High Frequency Longitudinal Impedance of an Inductive Pick-up by a Thin Metallic Layer impedance, simulation, pick-up, insertion 2481
 
  • M. Gasior
    CERN, Geneva
  An Inductive Pick-Up (IPU) was developed to measure the position and current of an electron beam of the CTF3 Drive Beam Linac. The pick-up construction is similar to a wall current monitor, but the pick-up inner wall is divided into 8 electrodes, each of which forms the primary winding of a toroidal transformer. The beam image current component flowing along each electrode is transformed to a secondary winding, connected to an output. The continuity of the vacuum chamber is taken care of by a ceramic insertion surrounded by the electrodes. The insertion is titanium coated on the inside and the end-to-end resistance of the layer is chosen in such a way that within the IPU bandwidth the image current flows over the electrodes. For higher frequencies the current is conducted by the coating to limit the longitudinal impedance of the device in the GHz range. This paper describes a simple electric network model, which was used to simulate the influence of the coating and to optimize its resistance. The model is built from sections of ideal transmission lines and resistors and is suitable for SPICE simulations. Results of measurements and simulations are compared.  
 
THPLT013 Simulation of Multi-bunch Multi-turn Instabilities in High Energy Proton Rings: Algorithms and Results simulation, impedance, proton, target 2490
 
  • A. Koschik
    CERN, Geneva
  A simulation code to study collective effects in multi-bunch proton machines has been developed and applied to the CERN SPS and LHC. The 3D simulation program allows the exploration of long-range effects due to resistive-wall and HOMs in circular, elliptic and rectangular vacuum chambers also for uneven filling schemes. The code has been benchmarked with measurements in the SPS. Results obtained for LHC, including beam stability and emittance growth, are presented and discussed.  
 
THPLT014 Coupler Structures for the LHC Beam-pipe Waveguide Mode Reflectometer coupling, higher-order-mode, simulation, dipole 2493
 
  • T. Kroyer
    TU Vienna, Vienna
  • F. Caspers
    CERN, Geneva
  The LHC reflectometer will be used to detect and localize obstacles and other kinds of discontinuities in the LHC beam screen. An important part of this device is the RF coupler element, which provides the interface between the circular beam screen and the measurement equipment. Two different scenarios of operation are considered. The first option consists in carrying out measurements during assembly by directly branching a coupler to the end of the beam screen. The other one is a permanent installation to be used in situ requiring a different kind of coupler to keep the aperture free. The goal is to achieve a reasonably well-matched spurious mode-free excitation over a 25% bandwidth for the TM01 and the T·1011 mode, respectively. The fulfillment of the required features is severely complicated by space and material restrictions arising mainly from vacuum and installation constraints.  
 
THPLT029 Parallel Particle in Cell Computations with GdfidL electromagnetic-fields, simulation, plasma, acceleration 2538
 
  • W. Bruns
    WBFB, Berlin
  The electromagnetic field solver GdfidL has been extended to compute with free moving charges. For computing in parallel, GdfidL partitions the computational volume in many small subvolumes. Each processor computes the electromagnetic field in its part of the whole volume. In addition to the normal field update equations, the movement of the particles must be computed from the Lorentz-force, and the convection current due to the moving charges must be computed and be used to change the electric field near the particle. For each particle, these computations are performed by the processor which is responsible for the volume where the particle is in. Details of the parallel implementation of the used algorithm, Particle in Cell, are given.  
 
THPLT043 Development of a New Orbit Measurement System storage-ring, damping, controls, synchrotron 2577
 
  • O. Kaul, F. Brinker, R. Neumann, R. Stadtmüller
    DESY, Hamburg
  Since DORIS III became a dedicated source for synchrotron radiation in 1993, the demands of the synchrotron-light-users concerning the beam position stability have permanently increased.In order to improve this stability, different measures have been adopted, all with success. The vacuum chambers have been renewed, since they were the source of quadrupole movement, which caused strong horizontal orbit distortion. In 2003 a new orbit position control was implemented, based on the ?Singular Value Decomposition? method. The position information comes from synchrotron light monitors, installed in the beam-lines, and from the orbit measurement system, which operates with a maximal measurement rate of 5Hz and a spatial resolution not less than 20μm. To satisfy the requirements for beam-position stability, the orbit measurement system has been further developed. The test stage is nearly finished and the new system will be installed soon. The orbit measurement rate will exceed 250Hz und the spatial resolution will be less than 2μm. In addition beam oscillations of up to 20Hz can be damped.  
 
THPLT047 Beam Position Monitor Development for the IThemba LABS Cyclotron Beamlines cyclotron, proton, diagnostics, alignment 2589
 
  • J. Dietrich, I. Mohos
    FZJ/IKP, Jülich
  • A.H. Botha, J.L. Conradie, J.L.G. Delsink, P.F. Rohwer
    IThemba Labs, Somerset West
  In cooperation of iThemba LABS (South Africa) and Forschungszentrum Juelich the specification of a sensitive tunable rf narrowband beam position monitor system for cyclotron beamlines has been elaborated. iThemba LABS developed and manufactured the four section stripline monitor chamber. The monitor electronics were developed in the Forschungszentrum Juelich-IKP. The electronics consisting of an RF signal processing module (BPM-RF) and a data acquisition and control module (BPM-DAQ) sequentially processes and measures the monitor signals and deliver via serial network calculated horizontal and vertical beam position data. First measurements with cyclotron beam has been performed in the iThemba LABS in November 2003. Changed beam position due to changing different cyclotron parameters could be studied with high accuracy. The resolution of the beam position measurement was better than 0.1 mm with beam currents down to 0.0005 mA.  
 
THPLT052 Measurement of Relative Gas Chamber Pressure in Narrow Straight Section Vacuum Vessels by Observing Gas Bremstrahlung radiation, electron, background, beam-losses 2601
 
  • G.A. Naylor, B. Joly, D. Robinson
    ESRF, Grenoble
  The measurement of gas pressure inside long, small cross section, vacuum vessels is difficult due to the distance between the centre of the vacuum vessel and vacuum gauges (leading to a low vacuum conductance). Following initial chamber installation, significant out-gassing is observed leading to a significant pressure bump within the chamber. A modified beam loss detector has been developed in order to monitor the gamma radiation produced by the collision of the 6GeV electrons in the storage ring with residual gas atoms. The narrow beam of gamma radiation is intercepted at various points by high Z materials in the beam line front-end allowing a radiation shower to be detected outside the vacuum vessel proportional to the gas pressure in the corresponding storage ring straight section. Various locations are considerred and results shown.  
 
THPLT073 Numerical Methods for the Orbit Control at the KEK 12 GeV PS beam-losses, injection, synchrotron, closed-orbit 2664
 
  • Y. Hitaka, H. Sato, M.J. Shirakata
    KEK, Ibaraki
  • M.K. Kono, Y.M. Yokomichi
    Miyazaki University, Miyazaki
  At the KEK 12GeV-PS main ring, when the least square method is applied to correct whole beam orbit all at once, it remains unacceptable beam loss and it is necessary to adjust the local positions of the beam orbit by hands with the beam loss monitors until the beam loss is suppressed under an acceptable level. However, the orbit does not realize the minimum-loss condition. In this paper, a new method is proposed. It focuses a fact that the beam loss distribution depends on the shape of the beam orbit and formulates this relationship to a functional approximation by using a nural network algorithm. Then, solving an optimization problem for generated network system, data of the beam shape which is more suitable for the beam loss of the accelerator can be obtained. The description of the system construction and experimental results are presented.  
 
THPLT102 Characteristics of Sealed-off Electron Gun with Wide Beam electron, gun, radiation, cathode 2727
 
  • V.M. Pirozhenko
    MRTI RAS, Moscow
  • A.N. Korolev, K.G. Simonov
    ISTOK, Moscow Region
  Compact sealed-off electron gun is a new promising type of devices. The gun generates wide beam of electrons with energy up to 200 keV and high peak power in 2-microsecond pulses. The beam is extracted to the atmosphere or a gas through the foil being uniformly distributed over the area of exposure. The gun contains the long ribbon cathode of oxide type, the electrodes for forming required distribution of the beam, the output window with 20-micron titanium foil, the high-voltage ceramic insulator, and the vacuum casing of rectangular shape. The gun is applied in the radiation technology system intended for the treatment of continuously moving tapes with 300 mm width. The gun design provides 10% uniformity of the radiation dose on the tape width.  
 
THPLT108 The Study of the Beam TAILS with the Optical Coronagraph simulation, scattering, storage-ring, collider 2736
 
  • O.I. Meshkov, M.G. Fedotov, E.V. Kremyanskaya, E. Levichev, N.Y. Muchnoi, Yu.A. Pakhotin, N.A. Selivanov, A.N. Zhuravlev
    BINP SB RAS, Novosibirsk
  Optical white-light Lyot coronograph is applied at the VEPP-4M collider to study the "tails" of the transverse beam profile. The device is used for investigation of the beam-beam effects.  
 
THPLT145 Automated High-power Conditioning of Medical Accelerators radiation, medical-accelerators, ion, shielding 2795
 
  • S.M. Hanna, S. Storms
    Siemens Medical Solutions USA, Inc., Oncology Care Systems Group, Concord
  Medical accelerators require arc-free operation. Due to high-field emission, arcing and outgasing can occur in high-power accelerators. Therefore, the accelerator?s inner surfaces have to be conditioned before its use at high gradient levels in Radiation Therapy machine. At Siemens, we have developed a techniqu·101 to automatically condition an accelerator waveguide structure by continually inspecting the accelerator running conditions (arcing and vacuum) and stepping up the pulse repetition frequency (PRF) and RF power until reaching maximum power rating. The program implemented also reads, displays, and archives the data it collects along the full process of conditioning.  
 
THPLT154 Design of an X-ray Imaging System for the Low-Energy Ring of PEP-II photon, positron, dipole, radiation 2819
 
  • A.S. Fisher, D. Arnett, H. De Staebler, S. Debarger, R.K. Jobe, D. Kharakh, D.J. McCormick, M. Petree, M.C. Ross, J. Seeman, B. Smith
    SLAC, Menlo Park, California
  • J. Albert, D. Hitlin
    CALTECH, Pasadena, California
  • J. Button-Shafer, J.A. Kadyk
    LBNL, Berkeley, California
  An x-ray beam-size monitor for positrons in the low-energy ring (LER) of the PEP-II B Factory at SLAC is being designed to accommodate the present 2-A, 3.1-GeV beam and anticipated currents of up to 4.7 A. The final photon stop of an arc will be rebuilt to pass dipole radiation through cooled apertures to optics 17 m from the source. Zone-plate imaging there can achieve a resolution of 6 microns, compared to 35 for a pinhole camera. Two multilayer x-ray mirrors precede the zone plate, limiting the bandwidth to 1%, in order to avoid chromatic blurring and protect the zone plate. Despite the narrow bandwidth, the zone plate?s larger diameter compared to a pinhole camera allows for a comparable photon flux. We will image all 1700 LER bunches and also measure them individually, searching for variations along the train due to electron-cloud and beam-beam effects, using a scanning detector conceptually derived from a wire scanner. A mask with three narrow slots at different orientations will scan the image to obtain three projections. In one passage, signals from a fast scintillator and photomultiplier will be rapidly digitized and sorted to profile each bunch.  
 
THPLT163 High-temperature Kicker Electrodes for High-beam-current Operation of PEP-II kicker, impedance, feedback, radiation 2843
 
  • U. Wienands, R. Akre, D.E. Anderson, S. Debarger, K. Fant, D. Kharakh, R.E. Kirby, A. Krasnykh, A. Kulikov, J. Langton
    SLAC, Menlo Park, California
  The strip line electrodes of the kickers used in the transverse bunch-by-bunch feedback systems see significant power deposition by beam and HOM-induced currents. This leads to elevated temperatures of the aluminum electrodes and will ultimately become a limit for the beam current in the Low Energy Ring. Heat is transported to the environment primarily by radiation from the blackened surface of the electrodes. In order to extend the beam-current range of these kickers, new electrodes have been fabricated from molybdenum which are able to run at significantly higher temperature, thus greatly increasing the efficiency of the radiative cooling of the electrodes. Blackening of the electrodes is achieved by oxidation in air at 1000°F using a recipe first applied in aviation research for supersonic aircraft. Emissivity was measured on coupons and a whole electrode to be about 0.6. In addition, the match at the terminations of the electrodes is improved following field calculations and measurements on a model of the kicker.