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MOYCH02 Physics Challenges for ERL Light Sources linac, electron, emittance, brightness 16
 
  • L. Merminga
    Jefferson Lab, Newport News, Virginia
  We present an overview of the physics challenges encountered in the design and operation of Energy Recovering Linac (ERL) based light sources. These challenges include the generation and preservation of low emittance, high-average current beams, manipulating and preserving the transverse and longitudinal phase space, control of the multipass beam breakup instability, efficient extraction of higher order mode power and RF control and stability of the superconducting cavities. These key R&D issues drive the design and technology choices for proposed ERL light sources. Simulations and calculations of these processes will be presented and compared with experimental data obtained at the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in commissioning, and during a 1 GeV demonstration of energy recovery at CEBAF.  
Video of talk
Transparencies
 
MOYCH03 Superconducting RF Cavities for Synchrotron Light Sources damping, electron, storage-ring, insertion 21
 
  • P. Marchand
    SOLEIL, Gif-sur-Yvette
  Superconducting (sc) RF systems are already operational or planned in several third generation synchrotron light sources. In these machines, which require relatively low RF accelerating voltage and high beam loading, the advantage of using the sc technology essentially resides in the fact that one can achieve an efficient damping of the cavity Higher Order Modes (HOM) while still maintaining a high fundamental shunt impedance. The strong HOM damping practically is realised following two approaches : a) use of absorber material, located inside the cavity tube cut-off, through which the HOM propagate and then are damped (Cornell/KEK designs); b) two-cell cavity with coaxial HOM dampers located on the tube connecting the two cells (SOLEIL design). Third harmonic idle sc cavities (1.5 GHz) of the SOLEIL type are already operational in the Swiss Light Source and ELETTRA. The main RF system (500 MHz) of these machines consist of normal conducting cavities and the purpose of the third harmonic sc system is to lengthen the bunches in order to improve the beam lifetime and stability (additional Landau damping). Recently, several third generation synchrotron light sources have also planned to use sc cavities as main accelerating RF systems. The operational conditions of the existing systems as well as the status of the planned ones are reported here.  
Video of talk
Transparencies
 
MOPKF025 Planar and Planar Helical Superconductive Undulators for Storage Rings, State of the Art undulator, vacuum, polarization, storage-ring 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.  
 
MOPKF034 Status of the Development of Superconducting Undulators at the ESRF undulator, storage-ring, vacuum, 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.  
 
MOPKF047 Suppression of Stored Beam Oscillation Excited by Beam Injection injection, sextupole, storage-ring, optics 414
 
  • T. Ohshima, N. Kumagai, M. Masaki, S. Matsui, H. Ohkuma, K. Soutome, M. Takao, H. Tanaka
    JASRI/SPring-8, Hyogo
  Top-up operation is scheduled from May 2004 at SPring-8. For this operation it is important that frequent beam injections should not excite the oscillation of stored beams. However, injection bump orbit was not closed perfectly and residual beam oscillations lead to increase of effective beam sizes by twice and three times in the horizontal and vertical direction respectively. We are trying to reduce these excited oscillations to less than one third of the usual beam sizes. For the suppression of horizontal one, we applied a novel scheme to reduce the effect due to the nonlinearity of sextupole magnets by adjusting the strength ratio of the sextupoles. The field similarity of bump magnets was also improved by replacing them with newly designed ones, where the effect of eddy current at the end plates was reduced. These countermeasures suppressed the horizontal oscillation by about one order. For the suppression of vertical one, the excitation mechanism has being investigated in detail. Presently the tilt angle adjustment of bump magnets reduced the vertical oscillation by one third. For further reduction of these oscillations, corrections with pulse-magnets is under investigation.  
 
MOPKF052 Design of an In Archromatic Superconducting Wiggler at NSRRC wiggler, vacuum, 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.  
 
MOPKF053 Pulsed-wire Method of Field Measurement on Short Elliptically Polarized Undulator undulator, radiation, alignment, polarization 428
 
  • T.-C. Fan, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  With two sets of photo illuminator and detector, scientists already have applied pulsed-wire method to measure the magnetic field along two mutually perpendicular directions. Two-dimensional pulsed-wire method is useful for the test of elliptically polarlized undulator (EPU). We tried to use this method to observe the first integral and second integral fields of a short EPU in real time during the polarization tuning. We have taken care more details than the pulsed-wire measurement of planner undulators. The phase difference, the relative field strength along two direction as well as the precise centerline can be achieved.  
 
MOPKF055 A Study of CSR Induced Microbunching Using Numerical Simulations dipole, simulation, radiation, synchrotron-radiation 434
 
  • M.A. Bowler, H.L. Owen
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  Microbunching due to Coherent Synchrotron Radiation (CSR) has been predicted for high density bunches and has been 'observed' using numerical simulations by the code ELEGANT of M. Borland, which includes a 1D model of CSR. However, there is currently a debate as to whether this micro-bunching is a real physical effect or is a numerical artefact, possibly introduced by having to use macro-particles to model the electrons. In particular, the amplitude of the micro-bunching diminishes as the number of macroparticles increases, but the question remains open as to whether the amplitude converges to zero or a finite value. The micro-bunching produced by ELEGANT is being studied as a function of the numerical parameters of the code and also as a function of the range of bunch parameters and bending magnet strengths of relevance to the 180 degree bending arcs required for the proposed 4GLS at Daresbury Laboratory. Calculations with up to 2 million macroparticles have been carried out on a Linux workstation using gaussian bunches of FWHM of 2psec and charge of 1 nC, and show the existence of microbunching at the end of a 180 degree arc containing 5 TBA cells with magnet strengths of 0.5T. Further investigation of this problem is required.  
 
MOPKF068 Experimental Study of the Stability Margin with Beam Heating in a Short-Period Superconducting Undulator for the APS vacuum, undulator, photon, storage-ring 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.  
 
MOPKF076 An Overview of the Cryomodule for the Cornell ERL Injector linac, emittance, coupling, damping 491
 
  • H. Padamsee, B.M. Barstow, V. Medjidzade, V.D. Shemelin, K.W. Smolenski
    Cornell University, Ithaca, New York
  • I. Bazarov, C.K. Sinclair
    Cornell University, Department of Physics, Ithaca, New York
  • S.A. Belomestnykh, R. Geng, M. Liepe, M. Tigner, V. Veshcherevich
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  The first stage of the Cornell ERL project will be a 100 MeV, 100 mA (CW) prototype machine to study the energy recovery concept with high current, low emittance beams. In the injector, a bunched 100 mA, 500 keV beam of a DC gun will be compressed in a normal-conducting copper buncher and subsequently accelerated by five superconducting 2-cell cavities to an energy of 5.5 MeV. We will present an overview of the injector status to include the status of the cryomodule design along with the status of the 2-cell HOM-free cavity, the twin-input coupler and the ferrite HOM dampers in related papers.  
 
MOPKF077 Reducing the Synchrotron Radiation on RF Cavity Surfaces in an Energy-recovery Linac radiation, synchrotron-radiation, electron, linac 494
 
  • G. Hoffstaetter, M. Liepe, T. Tanabe
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  In Energy Recovery Linac (ERL) light sources, a high energy, high current beam has to be bend into a superconducting linac to be decelerated. The synchrotron radiation produced in the last bending magnet before the linac shines into the superconducting structures if not collimated appropriately. Due to the length of the linac, the radiation cannot be completely guided through the superconducting structure, as in existing SRF storage rings. For the example of an ERL extension to the existing CESR storage ring at Cornell we estimate the magnitude of this problem by quantifying the heat load that can be accepted on a superconducting surface and by analyzing how much radiation is deposited on the cavity surfaces for different collimation schemes.  
 
MOPLT027 Cold Beam Vacuum Interconnects for the LHC Insertion Regions vacuum, impedance, insertion, undulator 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.  
 
MOPLT031 LHC Abort Gap Filling by Proton Beam collimation, radiation, injection, proton 611
 
  • E.N. Shaposhnikova, S.D. Fartoukh, J.-B. Jeanneret
    CERN, Geneva
  Safe operation of the LHC beam dump relies on the possibility of firing the abort kicker at any moment during beam operation. One of the necessary conditions for this is that the number of particles in the abort gap should be below some critical level defined by quench limits. Various scenarios can lead to particles filling the abort gap. The relevant time scales associated with these scenarios are estimated for top energy where the synchrotron radiation losses are not negligible for uncaptured particle motion. Two cases are considered, both with RF on and RF off. The equilibrium distribution of lost particles in the abort gap defines the requirements for maximum tolerable relative loss rate and as a consequence the minimum acceptable longitudinal lifetime of the proton beam in collision.  
 
MOPLT033 Experimental Studies of Controlled Longitudinal Emittance Blow-up in the SPS as LHC Injector and LHC Test-Bed emittance, scattering, pick-up, beam-losses 617
 
  • J. Tuckmantel, T. Bohl, T.P.R. Linnecar, E.N. Shaposhnikova
    CERN, Geneva
  The longitudinal emittance of the LHC beam must be increased in a controlled way both in the SPS and the LHC itself. In the first case a small increase is sufficient to help prevent coupled bunch instabilities but in the second a factor three is required to also reduce intra-beam scattering effects. This has been achieved in the SPS by exciting the beam at the synchrotron frequency through the phase loop of the main RF system using bandwidth-limited noise, a method that is particularly suitable for the LHC which will have only one RF system. We describe the tests that have been done in the SPS both for low and high intensity beams, the hardware used and the influence of parameters such as time of excitation, bandwidth, frequency and amplitude on the resulting blow-up. After taking into account intensity effects it was possible to achieve a controlled emittance increase by a factor of about 2.5 without particle loss or the creation of visible tails in the distribution.  
 
MOPLT057 Proposal of a Strong RF Focusing Experiment at DAFNE lattice, focusing, luminosity, dipole 683
 
  • A. Gallo, D. Alesini, G. Benedetti, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, A. Clozza, G.O. Delle Monache, G. Di Pirro, A. Drago, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, M. Zobov
    INFN/LNF, Frascati (Roma)
  • E. Levichev, P.A. Piminov
    BINP SB RAS, Novosibirsk
  • C. Pagani
    INFN/LASA, Segrate (MI)
  The strong RF focusing is a recently proposed technique to obtain short bunches at the interaction point in the next generation colliders. A large momentum compaction factor together with a very high RF gradient across the bunch provide a modulation of the bunch length along the ring, which can be minimized at the Interaction Point (IP). No storage ring has been so far operated in such a regime, since it requires uncommonly high synchrotron tune values. In this paper we present the proposal of creating the experimental conditions to study the strong RF focusing in DAFNE. The proposed machine lattice providing the required high momentum compaction value, the upgrade of the RF system including the installation of a multi-cell superconducting cavity, the upgrade of the cryogenic plant and a list of the possible beam experiments are illustrated and discussed.  
 
MOPLT058 Status of CTF3 Stretcher-compressor and Transfer Line vacuum, dipole, 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.  
 
MOPLT066 Induction Accelerating Cavity for a Circular Ring Accelerator induction, acceleration, proton, linac 704
 
  • K. Torikai, Y.A. Arakida, T. Kono, K. Koseki, E. Nakamura, Y. Shimosaki, K. Takayama, T. Toyama, M. Wake
    KEK, Ibaraki
  • J. Kishiro
    JAERI/LINAC, Ibaraki-ken
  This paper reports details of an induction accelerating cavity employed for induction synchrotron POP experiments [*] using the KEK 12GeV PS. This cavity is the first induction cavity in the history of accelerator that is used in a circular ring. We focus our attention on crucial aspects distinguished from well-know properties of RF cavity. The single cavity is capable of generating an acceleration voltage of 2.5kV with a pulse width of 250ns, which is operated at a repetition　rate in the range of 667kHz - 882kHz. The cavity is driven by its own pulse modulator through a 25m long transmission cable of 125W, the end of which is connected with a matching resistance so as to minimize reflection in a wide range of frequency. Accelerating field characteristics are discussed and matching features of the cavity as a one-to-one transformer are presented. A longitudinal and transverse coupling impedance have been measured using a net-work analyzer.

* K.Takayama et al., 'POP Experiments of the Induction Synchrotron' in this conference

 
 
MOPLT070 FFAG as Phase Rotator for the PRISM Project simulation, kicker, lattice, injection 713
 
  • A. Sato, M. Aoki, Y. Arimoto, Y. Kuno, M. Yoshida
    Osaka University, Osaka
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • S. Machida, Y. Mori, C. Ohmori, T. Yokoi, K. Yoshimura
    KEK, Ibaraki
  • S. Ninomiya
    RCNP, Osaka
  A Fixed Field Alternating Gradient (FFAG) ring will be used as a phase rotator in the PRISM project. We report a design of the PRISM-FFAG in this paper. PRISM stands for "Phase Rotated Intense Slow Muon beam". It is a project to realize a super muon beam, which combines high-intensity, low-energy, narrow energy-spread and high purity. Its aimed intensity is about 1011-1012 muons per sec. The muon beam will be provided with a low kinetic energy of 20MeV to optimize for the stopped muon experiments. FFAG has some advantageous characteristics to achieve such superb beam. These are a large momentum (longitudinal) acceptance, a wide transverse acceptance with strong focusing, and synchrotron oscillation, which is needed to perform phase rotation. According to simulations, initial energy spread of 20MeV±40% is reduced down to ±6% after 5 turns of muons in the FFAG ring. In the FFAG ring almost all pions decay into muon, hence extracted beam has extremely low pion contamination. A program to construct the PRISM-FFAG ring has been started. It would be completed by the end of JFY 2005.  
 
MOPLT087 Research of Possibility to use Beam Polarization for Absolute Energy Calibration in High-precision Measurement of Tau Lepton Mass at VEPP-4M resonance, polarization, betatron, energy-calibration 737
 
  • A.V. Bogomyagkov, V. Kiselev, E.V. Kremyanskaya, E. Levichev, S.A. Nikitin, I.B. Nikolaev, E.A. Simonov, A.N. Skrinsky
    BINP SB RAS, Novosibirsk
  Experiments of 2002-2003 years on measurement of duration of beam polarization existence in VEPP-4M electron-positron storage ring after injection of polarized beams from VEPP-3 booster at energies in the vicinity of tau-lepton production threshold (1777 MeV) are described. Polarized beams in such conditions are planned to use in the experiment at VEPP-4M with KEDR detector on high precision measurement of tau-lepton mass wiyh the help of resonant depolarization technique for absolute calibration of particle energy. It was shown that despite of closeness of the strong depolarizing integer spin resonance (1763 MeV) the polarization lifetime though is limited, but still is sufficient for realization of energy calibration procedure with a high accuracy (10-6).  
 
MOPLT097 Co-sourcing Development of Accelerator Controls controls, vacuum, 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 vacuum, emittance, 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

 
 
MOPLT109 Longitudinal Schottky Spectra of Bunched Beams antiproton, storage-ring, proton, diagnostics 791
 
  • V. Balbekov, S. Nagaitsev
    Fermilab, Batavia, Illinois
  In this paper we derive an expression for longitudinal Schottky spectrum of a bunched beam in a stationary bucket. The expression is then used to calculate longitudinal emittance of the antiproton beam in the Fermilab Recycler ring. The Recycler beam is bunched longitudinally by a barrier-bucket rf waveform. Under certain bucket conditions, dependence of synchrotron frequency on particle energy becomes non-monotonic. It complicates the Schottky spectrum derivation and interpretation; we address these difficulties in our paper.  
 
MOPLT128 Lattice Effects due to High Currents in PEP-II sextupole, luminosity, emittance, photon 836
 
  • F.-J. Decker, H. Smith, J.L. Turner
    SLAC, Menlo Park, California
  The very high beam currents in the PEP-II B-Factory have caused many expected and unexpected effects: Synchrotron light fans move the beam pipe and cause dispersion, higher order modes cause excessive heating, e-clouds around the positron beam blow up its beam size. Here we describe an effect were the measured dispersion of the beam in the Low Energy Ring (LER) is different at high and at low beam currents. The dispersion was iteratively lowered by making anti-symmetric orbit bumps in many sextupole duplets, checking each time with a dispersion measurement where a dispersive kick is generated. This can be done parasitically during collisions. It was a surprise when checking the low current characterization data that there is a change. Subsequent high and low current measurements confirmed the effect. It is located far away from any synchrotron radiation in the middle of a straight (PR12), away from sextupoles and skew quadrupoles and creates a dispersion wave of about 70 mm at high current while at low current it is negligible.  
 
MOPLT137 Beam Delivery Layout for the Next Linear Collider luminosity, emittance, radiation, linac 860
 
  • A. Seryi, Y. Nosochkov, M. Woodley
    SLAC, Menlo Park, California
  We present the latest design and layout of the NLC Beam Delivery System (BDS) for the first and second interaction region (IR). This includes the beam switchyard, skew correction and emittance diagnostics section, collimation system integrated with the final focus, the primary and post linac tune-up beam dumps, and arcs of the second interaction region beamline. The layout and optics are optimized to deliver the design luminosity in the entire energy range from 90GeV to 1.3TeV CM, with the first IR BDS also having the capabilities for multi-TeV extension.  
 
MOPLT167 RHIC Operation with Longitudinally Polarized Protons polarization, resonance, proton, injection 920
 
  • H. Huang, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, A.U. Luccio, W.W. MacKay, C. Montag, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, S. Tepikian, D. Trbojevic, J. Van Zeijts, A.Y. Zelinsky, S.Y. Zhang
    BNL, Upton, Long Island, New York
  Longitudinally polarized proton beams have been accelerated, stored and collided at 100GeV in the Relativistic Heavy Ion Collider (RHIC) to study spin effects in the hadronic reactions. The essential equipment includes four Siberian snakes, eight spin rotators and a fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider.  
 
MOPLT174 Electron Acceleration for e-RHIC with the Non-scaling FFAG acceleration, electron, emittance, collider 932
 
  • D. Trbojevic, M. Blaskiewicz, E.D. Courant, J. Kewisch, T. Roser, A. Ruggiero, N. Tsoupas
    BNL, Upton, Long Island, New York
  A non-scaling FFAG lattice design to accelerate electrons from 3.2 to 10 GeV is described. This is one of the possible solutions for the future electron-ion collider (eRHIC) at Relativistic Heavy Ion Collier (RHIC) at Brookhaven National Laboratory (BNL). This e-RHIC proposal requires acceleration of the low emittance electrons up to energy of 10 GeV. To reduce a high cost of the full energy super-conducting linear accelerator an alternative approach with the FFAG is considered. The report describes the 1277 meters circumference non-scaling FFAG ring. The Courant-Snyder functions, orbit offsets, momentum compaction, and path length dependences on momentum during acceleration are presented.  
 
TUXCH02 FAIR - An International Accelerator Facility for Research with Ions and Antiprotons ion, antiproton, heavy-ion, plasma 50
 
  • W.F. Henning
    GSI, Darmstadt
  This presentation describes the conceptual design for the accelerator facility and the physics research program, and discusses the status and the new challenges in accelerator physics and technology.  
Video of talk
Transparencies
 
TUYBCH01 Design Criteria and Technology Challenges for the Undulators of the Future undulator, radiation, electron, vacuum 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
 
TUPKF001 Upgrade and Commissioning of the LNLS RF System storage-ring, klystron, damping, feedback 950
 
  • R.H.A. Farias, N.P. Abreu, L.C. Jahnel, L. Liu, C. Pardine, P.F. Tavares
    LNLS, Campinas
  In this paper we present a report on the commissioning of the new RF system of the electron storage ring of the brazilian synchrotron radiation facility (LNLS).  
 
TUPKF005 Inductive Output Tube Based 300 kW RF Amplifiers for the Diamond Light Source power-supply, klystron, factory, target 962
 
  • J. Alex, M. Brudsche, M. Frei, M. Müller, A. Spichiger
    Thales Broadcast & Multimedia AG, Turgi
  • M. Jensen
    Diamond, Oxfordshire
  All currently operating synchrotron light sources use klystron amplifiers to generate the RF power for the accelerator cavities. In TV broadcasting systems on the other hand, Inductive Output Tubes (IOT)are replacing the classical klystron based systems in all new high power UHF transmitters. The Diamond Light Source will be the first synchrotron to be operated using IOTs. For each accelerating cavity a total of four IOTs will be combined with a waveguide combiner to achieve the RF power requirement of 300 kW at 500 MHz. All IOTs will be supplied from a common crowbarless high voltage power supply. Three such systems will be installed starting in October 2004. This paper gives an overview of the design of the amplifiers, including the first test results from the factory commissioning.  
 
TUPKF013 Studies on Maximum RF Voltages in Ferrite-tuned Accelerating Cavities proton, ion, antiproton, acceleration 985
 
  • K. Kaspar, H.G. Koenig, T. Winnefeld
    GSI, Darmstadt
  The GSI SIS100 project requires very high accelerating voltages. With ferrite-tuned synchrotron cavities the gap voltage is often strongly limited by the Q-loss effect appearing at medium dc bias fields. At low bias fields, considerably higher voltages can be reached, however. The maximum usable amplitudes over the bias region have been studied. At zero bias, the ferrites could be driven to more than a factor 3 above the Q-loss limit. Except overheating, no other problems appeared. With increasing bias, the maximum amplitudes decrease continuously to the Q-loss level. In this fall-off region there is still a tuning factor up to 2.5 available, with rf flux densities by at least a factor 2 above the Q-loss level. Measurements on small samples of the ferrite material used in the GSI cavities could be verified very well in a full-size cavity, for the most part. The tests were mainly limited by the available anode voltage and the fear of damaging the cavity. It seems possible, to generalize the main results for other ferrite materials, also. Based on the results, a possible scenario for the SIS100 rf system is given. Additionally, the results lead to an alternative cavity design for higher voltages, which is described as well.  
 
TUPKF021 First Year of Operation of SUPER-3HC at ELETTRA damping, storage-ring, vacuum, electron 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.  
 
TUPKF031 Non-resonant Accelerating System at the KEK-PS Booster booster, impedance, power-supply, beam-losses 1027
 
  • S. Ninomiya, M. Muto, M. Toda
    KEK, Ibaraki
  The non-resonant accelerating system for the KEK-PS booster accelerator has been constructed. The system has been operating since October 2003 without trouble. The accelerating gap in the system is loaded with magnetic cores of high permeability. The cores produce high resistive impedance at the gap. The power dissipated in the cores amounts to 50kW at 16kV accelerating voltage. It is removed by forced-air cooling system. At the last operation of the accelerator, with the help of new COD-correction system, the average beam intensity of the booster increased to 2.6E+12ppp, which is 30% higher than before.  
 
TUPKF033 Cryogenic Performance of the Prototype Cryomodule for ADS Superconducting LINAC linac, alignment, proton, radiation 1033
 
  • N. Ohuchi, E. Kako, S. Noguchi, T. Shishido, K. Tsuchiya
    KEK, Ibaraki
  • N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno
    JAERI/LINAC, Ibaraki-ken
  • T. Fukano
    Nippon Sanso Corporation, Tokyo
  • H. Hara, M. Matsuoka, K. Sennyu
    MHI, Kobe
  A prottype cryomodule containing two 9-cell superconducting cavities of b=0.725 and f=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). Cryogenic performances of the cryomodule and 2K He-system will be reported.  
 
TUPKF034 Low Output-Impedance RF System for 2nd Harmonic Cavity in the ISIS Synchrotron feedback, cathode, impedance, beam-loading 1036
 
  • T. Oki, S. Fukumoto, Y. Irie, M. Muto, S. Takano, I. Yamane
    KEK, Ibaraki
  • R.G. Bendall, I.S.K. Gardner, M.G. Glover, J. Hirst, D. Jenkins, A. Morris, S. Stoneham, J.W.G. Thomason, T. Western
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  • J.C. Dooling, D. Horan, R. Kustom, M.E. Middendorf, G. Pile
    ANL, Argonne, Illinois
  In the ISIS facility based at Rutherford Appleton Laboratory (RAL) in the UK, second target station project was funded, which requires to increase the current intensity by 1.5-times (300 micro-A). Four 2nd harmonic RF cavities will be installed in the ISIS synchrotron in order to increase the trapping efficiency, and to mitigate the space charge detuning. A very low output-impedance RF system for the 2nd harmonic cavity has been developed by the collaboration between RAL, Argonne National Laboratory (US) and KEK (Japan). The system comprises the 240 kW triode as a final amplifier with plate-to-grid feedback path. The measured output-impedance was less than 30 ohms over the frequency range of 2.7 - 6.2 MHz, which agreed well with calculations. High power test was also performed under frequency swept mode at 50 Hz repetition. The operation was almost stable, and more than 12 kVpp was obtained as maximum. The voltage gain of the final amplifier was 25 - 30, which decreased gradually with frequency due to decreasing input-impedance of triode. The beam test is planned at ISIS in near future.  
 
TUPKF035 RF System for Compact Medical Proton Synchrotron proton, acceleration, impedance, radiation 1039
 
  • Z. Fang, K. Egawa, K. Endo, S. Yamanaka
    KEK, Ibaraki
  • Y. Cho, T. Fusato, T. Hirashima
    DKK, Kanagawa
  The rf system has been developed for the compact medical proton synchrotron. The rf system will be operated in pulse mode with the fundamental rf frequency sweeping from 1.6 to 15 MHz during the acceleration time of 5 ms. The required rf cavity voltage is a function of acceleration time too, with the voltage of fundamental varying from 13 to 6 kV. Besides, high order harmonics are also considered to apply to the rf system, and the cavity peak voltage varying from 20 to 9 kV during the acceleration time is expected. The performance of the rf system is being studied and will be presented.  
 
TUPKF037 Multi-harmonic RF Acceleration System for a Medical Proton Synchrotron acceleration, feedback, proton, impedance 1045
 
  • K. Saito, M. Katane, K. Kobayashi, K. Masui, K. Moriyama, H. Nishiuchi, H. Sakurabata, H. Satomi
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  We have developed an RF accelerating system for medical proton synchrotron. The RF cavity is a tuning-free wideband type, loaded with FINEMET cores, which is driven by a solid-state RF power amplifier with operation frequency range between 1MHz and 10MHz. Multi-harmonic RF acceleration scheme has been realized with the RF control system, to reduce beam loss by space-charge effect in low energy region. The original techniques for high-speed digital signal processing and high-precision RF signal processing have been applied, in order to fulfill feedback control of the frequency, phase and amplitude of the second and third harmonic RF signals as well as the fundamental one.  
 
TUPKF038 Reduced Length Designs of 500 MHz Damped Cavity Using SiC Microwave Absorber storage-ring, undulator, impedance, factory 1048
 
  • T. Koseki
    RIKEN/RARF/BPEL, Saitama
  • M. Izawa, S. Sakanaka, T. Takahashi, K. Umemori
    KEK, Ibaraki
  We present a new 500 MHz HOM (Higher-Order Modes) damped cavity for high brilliance synchrotron radiation sources. The design is based on the damped cavity, which is operated at the Photon Factory storage ring in KEK. The PF cavity has a large hole beam duct (140 mm in diameter), a part of which is made of a silicon carbide (SiC) microwave absorber. The new cavity, proposed in this paper, has parallel-plate radial transmission lines on the beam duct instead of the SiC beam duct. The outer end of the radial line is terminated by SiC absorbers. The HOMs, extracted from the center part of the cavity through the beam duct, propagate in the radial line and are dissipated in the absorber. The accelerating mode is not affected by the radial line damper since the frequency is sufficiently below the cutoff of the 140-mm beam duct. In this paper, optimized design of the radial line damper and damping properties for HOMs are described in detail.  
 
TUPKF053 New Waveguide-type HOM Damper for the ALS Storage Ring RF Cavities storage-ring, damping, vacuum, radiation 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.  
 
TUPKF072 Production and Performance of the CEBAF Upgrade Cryomodule Intermediate Prototypes linac, damping, vacuum, controls 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.  
 
TUPLT002 The Small-gap Undulator Impedance Study impedance, vacuum, undulator, resonance 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.  
 
TUPLT015 The Bunch Compressor System for SIS18 at GSI ion, heavy-ion, vacuum, 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.  
 
TUPLT035 Online Calculation of the Beam Trajectory in the HERA Interaction Regions quadrupole, alignment, proton, interaction-region 1222
 
  • F. Brinker
    DESY, Hamburg
  During the HERA luminosity upgrade the new super conducting mini beta quadrupoles have been placed inside the experiments for final focussing and separation of the lepton and proton beams. The synchrotron radiation of up to 12 kW produced in these magnets passes through the detector and is absorbed behind the experiments. In order to avoid background events from synchrotron radiation it is a mandatory to adjust precisely the beam trajectory before and inside the detector. A procedure has been developed to calculate the trajectory in the interaction regions. With a beam-based alignment the offsets of the beam with respect to the quadrupoles is measured. From this measurement the offsets of the quadrupoles and of the beam position monitors are fitted. With the knowledge of these offsets the trajectory of the beam is calculated with high precision. The display of the trajectory is online available as an operational tool for beam steering and background optimization.  
 
TUPLT047 First Results of Pulsed Superconducting Half-wave Resonators linac, vacuum, 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.  
 
TUPLT073 Observation of Coupling Resonance in HIMAC Synchrotron coupling, resonance, electron, ion 1321
 
  • T. Uesugi, T. Fujisawa, K. Noda, S. Shibuya, D. Tann, H. Uchiyama
    NIRS, Chiba-shi
  • Y. Hashimoto
    KEK, Ibaraki
  • I.N. Meshkov, E. Syresin
    JINR, Dubna, Moscow Region
  Coupling resonance was observed at operating points near to Qx-Qy=1. Two-dimensional profile of a beam at its equilibrium was measured, and it was found that the beam was inclined in transverse when the operating point is near to the resonance condition. We will present the detail of the measurement and the results.  
 
TUPLT074 Dark Current Reduction System for SPring-8 Linac linac, single-bunch, storage-ring, gun 1324
 
  • T. Kobayashi, T. Asaka, H. Hanaki, M. Shoji, S. Suzuki, K. Tamura
    JASRI/SPring-8, Hyogo
  The SPring-8 linac accelerates dark currents generated by its injector part up to 1 GeV. These dark currents are injected with main beam into the SPring-8 storage ring and then spoil the purity of the stored beam. The dark currents are mainly composed of a grid emission current from a thermionic gun and field emission currents from rf accelerating structures. A beam deflector for kicking only the grid emission by a pulsed electric field was developed and installed in the SPring-8 linac. We observed that the beam deflector greatly reduced the grid emission current accelerated up to 1 GeV. The measured purity of the stored single-bunched beam was about 5x10-6 when the deflector operated, which was almost 1/100 of the purity without filtering by the deflector. However, the deflector, which is installed before the prebucher, cannot reduced the field emission currents from the buncher cavities and the first acccelerating structure. These dark currents take considerable proportion of the total dark currents observed at the end of the linac. We are trying to spin off the field emission currents by weak magnetic fields across the accelerating structure generated by several coils.  
 
TUPLT075 Improvements of SPring-8 Linac towards Top-up Operation linac, injection, vacuum, 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.  
 
TUPLT076 Optimization of Sextupole Strengths in a Storage Ring for Top-up Operation sextupole, injection, optics, storage-ring 1330
 
  • H. Tanaka, T. Ohshima, K. Soutome, M. Takao, H. Takebe
    JASRI/SPring-8, Hyogo
  In top-up operation of a light source, electron or positron beams are frequently injected to keep the stored current constant. Closing an injection bump orbit is thus critically important not to disturb precise experiments. However, there are sextupole magnets inside the injection bump in the SPring-8 storage ring and the bump never closes all over the bump amplitude due to the sextupole nonlinearity. To solve the problem, we proposed a scheme based on minimum condition for the injection bump leakage. The scheme only restricts the sextupole strengths within the bump. Introduction of other sextupole families outside the bump can enlarge the dynamic aperture (DA) of the ring with keeping the minimum leakage. To find the best solution, we optimized the sextupole strengths changing the number of sextupole family as a parameter. The simulation shows that addition of two sextupole families sufficiently enlarges DA. Cabling of the sextupole magnets was partly changed in the summer 2003 and the effects of the strength optimization on the bump leakage, injection efficiency and beam lifetime has been investigated experimentally. We present the obtained results compared with the simulations.  
 
TUPLT078 Study of Impedances and Instabilities in J-PARC kicker, impedance, vacuum, resonance 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, vacuum, 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.  
 
TUPLT081 Lattice Design of Large Acceptance FFAGs for the PRISM Project optics, emittance, focusing, lattice 1345
 
  • A. Sato
    Osaka University, Osaka
  • S. Machida
    KEK, Ibaraki
  In order to realize a super muon beam that combines high-intensity, low-energy, narrow energy-spread and high purity, the PRISM project has been proposed. In this project, a FFAG ring is used as a phase rotator. In this paper, a method of designing the PRISM-FFAG lattice will be described. The PRISM-FFAG has to have both of large transverse acceptance and large momentum acceptance to achieve high intensity. Furthermore, long straight sections to install RF cavities are required to obtain a high surviving ratio of the muon. Therefore, the PRISM-FFAG requires its magnets to have large aperture and small opening angle. In such magnets, not only nonlinear effects but also magnetic fringing field are important to study the beam dynamics of FFAGs. Although using realistic 3D magnetic field maps made with programs such as TOSCA is the best solution to study the FFAG dynamics, it takes long time to make such field maps. On a design process of the PRISM-FFAG, quasi-realistic 3D magnetic field maps, which are calculated applying spline interpolation to POISSON 2D field, were used to study the beam dynamics. A program based on GEANT3.21 was used for particle tracking.  
 
TUPLT085 J-PARC Construction and its Linac Commissioning linac, proton, quadrupole, site 1351
 
  • Y. Yamazaki
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The J-PARC(Japan Proton Accelerator Research Complex) accelerator is under construction in JAERI Tokai site. The beam commissioning will be started there by the end of 2006. Prior to this, the front end of the linac was beam-commissioned in 2003 at KEK. The negative hydrogen beam with a peak current of 30 mA was accelerated up to 20 MeV by the first tank of three DTL's following the 3-MeV RFQ linac. The 324-MHz DTL contains the electro quadrupole magnets with water-cooling channels specially fabricated by means of electroforming and wire-cutting technologies. The construction status of the J-PARC accelerator is also presented.  
 
TUPLT102 Field Study of the 4T Superconducting Magnet for Rapid Cycling Heavy Ion Synchrotrons dipole, ion, heavy-ion, simulation 1390
 
  • V.A. Mikhaylov, P.G. Akishin, A.V. Butenko, A.D. Kovalenko
    JINR, Dubna, Moscow Region
  The problem of the magnetic field optimization of a 4T dipole magnet with circular aperture of 100-110 mm for rapid cycling synchrotron is considered. A single layer low inductance coil made of hollow superconducting high current cable operating at 30 kA is used. The magnetic field ramp rate up to 4 T/s should be achievable. Mathematical method to minimize sextupole and higher order non-linearities to the tolerable values by variation of angular coil turn position is developed. The results of numerical simulation for 2D part magnetic field are presented. The further possibilities to improve the field quality for similar lattice magnets and their application for heavy ion synchrotrons and boosters are discussed.  
 
TUPLT137 Comparative Simulation Studies of Electron Cloud Build-up for ISIS and Future Upgrades simulation, proton, electron, injection 1446
 
  • G. Bellodi
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Electron cloud effects currently limit the performance of several proton accelerators operating with high beam current. Although ISIS, the 160 kW 70-800 MeV proton synchrotron at the Rutherford Appleton Laboratory (UK), has never appeared to be affected by the problem in its 15 years of operations, e-p instabilities could potentially be a cause of concern for future machine upgrades to higher beam powers. In this paper we review the present status of simulations for ISIS and compare it to preliminary results for two upgrade options: a 0.5MW 180-800 MeV scheme and a 1MW 0.8-3 GeV scheme with an additional synchrotron using ISIS as a booster (see C. Prior et al., ISIS megawatt upgrade plans, in Proceedings of the 2003 Particle Accelerator Conference PAC 2003, Portland, Or, USA).  
 
TUPLT140 Redesign of the ISIS Main Magnet Power Supply Storage Choke power-supply, coupling, insertion, proton 1455
 
  • A.J. Kimber, J.W. Gray, A. Morris
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, provides intense pulsed neutron and muon beams for condensed matter studies. As part of the facilities upgrade and refurbishment program, the 1MJ storage choke which forms part of the main magnet power supply system, will be replaced with a number of smaller units. The present storage choke, which consists of a split secondary winding transformer, is incorporated into a series-parallel resonant circuit known as the 'white circuit'. This circuit ensures that each magnet receives identical currents, but is not subjected to excessive voltages. Although the storage choke is essentially a transformer, its secondary magnetising inductance is relatively low and a precisely defined value. This paper discusses the design and development of ten smaller units which will eventually replace the present equipment, and the testing of a one fifth scale model, which will be used to prove the technology.  
 
TUPLT143 Studies of Beam Loss Control on the ISIS Synchrotron proton, simulation, beam-losses, collimation 1464
 
  • C.M. Warsop
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. The ISIS 800 MeV Proton Synchrotron presently provides up to 2.5·1013 protons per pulse at 50 Hz, corresponding to a mean power of 160 kW. A dual harmonic RF system upgrade is expected to increase the intensity and power by about 50%. The tighter constraints expected for higher intensity running are motivating a detailed study of beam loss distributions and the main factors affecting their control. Main aims are maximising the localisation of activation in the collector straight, and minimising risk of damage to machine components. The combination of experimental work, developments of the loss measurement systems, and simulation studies are summarised. Key factors considered include: the effects of primary collector geometry and material; the nature of the beam loss; and methods for experimentally determining spatial loss distributions.  
 
TUPLT144 Upgrade of the ISIS Main Magnet Power Supply power-supply, feedback, proton, controls 1467
 
  • S. West, J.W. Gray, A. Morris
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  ISIS, situated at the Rutherford Appleton Laboratory (RAL) is the world?s most powerful pulsed neutron source. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of magnets connected in series and configured as a ?White Circuit?. The magnets are connected in series with capacitor banks so that they form a resonant circuit with a fundamental frequency of 50 Hz. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. The AC is currently provided by a 1MVA Motor-Alternator set and it is now proposed to replace this by a solid state UPS (Uninterruptible Power Supply) system. Tests on a smaller 80kVA unit have shown that it is possible to control the magnet current with a modified UPS system in such a way that both the frequency, phase and output voltage are under the direct influence of the control system. This paper discusses the issues surrounding the upgrading of AC supply to the main magnets with a view to improving the system reliability, improving magnet current stability and reducing the risk of mains failure.  
 
TUPLT146 Techniques to Extract Physical Modes in Model-independent Analysis of Rings betatron, coupling, storage-ring, simulation 1473
 
  • C.-X. Wang
    ANL, Argonne, Illinois
  SVD mode analysis is a basic techinique in Model-Independent Analysis of beam dynamics. It decomposes the spatial-temporal variation of a beam centroid into a small set of orthogonal modes based on statistical analysis. Although such modes have been proven to be rather informative, each orthogonal mode may not correspond to an individual physical source but a mix of several in order to be orthogonal. Such mixing makes it difficult to quantitatively understand the SVD modes and thus limits their usefulness. Here we report a new techinique to untangle the mixed modes in storage ring analysis based on the fact that most of the physical modes in a ring have identifiable characteristics in frequency domain.  
 
WEOACH01 High Field Gradient Cavity for J-PARC 3 GeV RCS impedance, beam-loading, acceleration, injection 123
 
  • C. Ohmori, S. Anami, E. Ezura, K. Hara, Y. Hashimoto, A. Takagi, M. Toda, M. Yoshii
    KEK, Ibaraki
  • M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  A new type of rf cavity will be used for J-PARC project. To minimize the beam loading effects, the quality factor of the core stack is increased by a cut core configuration. High power test of the rf system has been performed. Temperature rise around the cut surface of the cores were observed. It is minimized by improving the cooling efficiency.  
Video of talk
Transparencies
 
WEOACH02 Gas Condensates onto a LHC Type Cryogenic Vacuum System Subjected to Electron Cloud vacuum, electron, proton, 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
 
WEYCH01 Fast Pulsed SC Magnets dipole, ion, antiproton, storage-ring 132
 
  • G. Moritz
    GSI, Darmstadt
  The demand for high beam intensities leads to the requirement of fast pulsed magnets for synchrotrons. An example is the proposed 'International Facility for Beams of Ions and Antiprotons' at GSI, which will consist of two synchrotrons in one tunnel and several storage rings. The high field ramp rate and repetition frequency introduce many magnet design problems and constraints in the operation of the accelerator. Persistent currents in the superconductor and eddy currents in wire, cable, iron and vacuum chamber reduce the field quality and generate cryogenic losses. Due to the large number of magnet cycles during the lifetime of such a magnet, special attention has to be paid to magnet material fatigue problems. The large charging voltages put some constraints on the use of cold diodes for quench protection. R&D has started at GSI, in collaboration with many institutions, to comply with the constraints mentioned above. Model dipoles were built and tested. The results of the R&D are reported. The advantages of the use of low field, fast pulsed superconducting, compared to resistive, magnets will be discussed  
Video of talk
Transparencies
 
WEOCCH01 A New 180 MeV H- Linac for Upgrades of ISIS linac, quadrupole, emittance, injection 153
 
  • F. Gerigk
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Several options have been studied to raise the beam power of the ISIS spallation neutron source to a level of 1 MW with the possibility of going to 4-5 MW in the longer term. All scenarios can operate in 2 modes, where the beam power is either delivered to a spallation target or, alternatively, to a target suitable to produce muons via pion decay for a neutrino factory. A more recent upgrade option takes an intermediate step and uses a 180 MeV H- linac, which is also foreseen for the 4-5 MW upgrade, as a replacement for the current 70 MeV injector. First estimates indicate that, due to the lower space charge forces, the ring would be able to carry twice as many particles, thus doubling the final beam power to 0.5 MW. This paper presents a first design for the 180 MeV linac, using a triple frequency jump from 234.8 to 704.4 MHz. The design profits from the development of 704.4 MHz cavities and RF equipment within the framework of the European HIPPI collaboration. The low frequency for the front-end was chosen to ease the DTL design as well as the development of a low energy beam chopper, which will be necessary to reduce beam losses at injection into the synchrotron.  
Video of talk
Transparencies
 
WEILH04 Industrial Involvement in the Construction of Synchrotron Light Sources storage-ring, booster, vacuum, 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
 
WEPKF002 Magnets for the CANDLE Booster Synchrotron, Design and Prototyping dipole, booster, simulation, vacuum 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.  
 
WEPKF017 The 5 T Superconducting Undulator for the LHC Synchrotron Radiation Profile Monitor undulator, radiation, synchrotron-radiation, proton 1630
 
  • R. Maccaferri, M. Facchini, R. Jung, D. Tommasini, W.  Venturini Delsolaro
    CERN, Geneva
  A Synchrotron Radiation Profile Monitor will be used in the LHC to measure the beam profiles from the injection energy of 450 GeV to the nominal energy of 7 TeV. The radiation will be provided by a sequence of two separate magnets: a two-periods 5 T superconducting undulator and the beam separation dipole D3. After a short description of the profile monitor layout, the paper reviews the electromagnetic and mechanical design of the undulator, and reports on the fabrication and cold test results of a first half period prototype.Finally, for the LHC operation with lead ion beams,a proposal for a monitor sensitivity upgrade by using a 12 T. superconducting undulator is presented and discussed.  
 
WEPKF025 Experience with the Hydrostatic Levelling System of the SLS storage-ring, alignment, monitoring, synchrotron-radiation 1651
 
  • F.Q. Wei, L. Rivkin, A. Wrulich
    PSI, Villigen
  The Hydrostatic Levelling System (HLS) of the SLS was installed and commissioned in year 2000. It is a measurement system for monitoring the vertical positions of the SLS storage ring girders. It is integrated in the concept of dynamic alignment. The HLS was modified and re-calibrated in 2002. Since January 2003 the system has collected approximately 2 million measurements. The analysis of the data shows that displacement of the SLS storage ring foundation and the girder support was in the range of 0.15 mm in year 2003. The long term HLS stability was significantly improved. The short term precision of the HLS is in the micrometer range. The experience gained on the HLS is presented.  
 
WEPKF027 R&D Vacuum Issues of the Future GSI Accelerator Facilities ion, vacuum, target, dipole 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 vacuum, dipole, 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.  
 
WEPKF032 A General Method for 2d Magnet Pole Design quadrupole, dipole, storage-ring, cyclotron 1672
 
  • Z. Martí, J. Campmany, M. Traveria
    LLS, Bellaterra (Cerdanyola del Vallès)
  Accurate conventional combined magnets working in saturation are currently required to fulfil the increasing demands on low emittance accelerators with long straight sections required by the newest Synchrotron Light Sources. This fact yields stringent requirements on pole profile design, manufacture and characterization. The aim of this poster is to present a general method for designing two-dimensional pole profiles. To this end, we have set up a procedure with which to select an optimum pole profile in 2D without the constraint of relying on a set of initial assumptions, not only a particular set of initial parameters but even a particular pole profile model. Moreover, we have developed a group of codes that can be compiled and run on MS-DOS or UNIX which use POISSON or OPERA-2d codes. This procedure also includes the evaluation of the sensitivity of the final pole profile to geometrical and current intensity errors for tolerance estimation, a big requirement in this context. In order to test the feasibility of this method, we have applied it to the case of the 1.2 T combined magnet of the new synchrotron to be built nearby Barcelona.  
 
WEPKF039 The Vacuum System of Super SOR vacuum, 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 proton, vacuum, 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.  
 
WEPKF054 Auto-filling Cryogenic System for Superconducting Wiggler wiggler, radiation, synchrotron-radiation, superconducting-RF 1726
 
  • F.-Y. Lin, C.-H. Chang, H.-H. Chen, T.-C. Fan, M.-H. Huang, C.-S. Hwang
    NSRRC, Hsinchu
  A 3.2 Tesla superconducting wiggler with period length of 6.0 cm (SW6) was installed in January of 2004 at the National Synchrotron Radiation Research Center (NSRRC). A cryogenic plant for superconducting rf cavity will also provide liquid helium and liquid nitrogen for SW6 by using an independent automatic filling system. To facilitate a stable and precise auto-filling process, a PID controller, the kernel of the auto-filling system, will control the valves of liquid helium and liquid nitrogen, respectively. The authors shall present the control algorithm of different operation modes, namely the pre-cooling mode and normal auto-filling mode. The boil off rate of liquid helium and liquid nitrogen will be discussed.  
 
WEPKF055 Design and Implementation of a Switching Mode Bipolar Power Stage of the Correction Power Supply power-supply, feedback, synchrotron-radiation, radiation 1729
 
  • C.-Y. Liu, C.H. Kuo, K.-B. Liu
    NSRRC, Hsinchu
  In order to enhance efficiency of the correction power supply, the switching mode bipolar power stage was to implement and to substitute for the original power stage of the correction power supply. To ensure higher efficiency, the programming dc bus voltage of the power stage of the correction power supply must be working in accordance with the output current state and load. A new power conversion stage was constructed and employs power MOSFET operating at higher switching frequency then old 60 Hz energy conversion mode system. This will not only improve the efficiency but also decrease the weight of the correction power supply. The new switching mode power stage supply a bipolar power dc bus power and automatic turning working voltage by the feedback balance circuit. Results and working performance will be presented in this paper.  
 
WEPKF056 Reducing Output Current Ripple of Power Supply with Component Replacement power-supply, instrumentation, feedback, background 1732
 
  • K.-B. Liu, C.-S. Fann
    NSRRC, Hsinchu
  Correction magnets of synchrotron storage ring are served with linear power supplies (correction power supply) with 100 ppm output current ripple in National Synchrotron Radiation Research Center. Reducing output current ripple of correction power supply might reduce perturbation of beam position of storage ring. Replace correction power supplies with lower output current ripple ones is straightforward but costs lots of money. Without adding any other circuit and electronic component, some components of correction power supply are replaced by ones with more precious and lower output fluctuation; so that the same circuitry structure of correction power supply is kept without increasing its complexity and could reach 25 ppm output current ripple.  
 
WEPKF057 Design and Study of a Superferric Model Dipole and Quadrupole Magnets for the GSI Fast-pulsed Synchrotron SIS100. dipole, quadrupole, insertion, ion 1735
 
  • A.D. Kovalenko, N.N. Agapov, V. Bartenev, A. Donyagin, I. Eliseeva, H.G. Khodzhibagiyan, G.L. Kuznetsov, A. Smirnov, M.A. Voevodin
    JINR, Dubna, Moscow Region
  • E. Fischer, G. Moritz
    GSI, Darmstadt
  New experimental results from the investigation of a model superferric Nuclotron-type dipole and quadrupole magnets are presented. The magnets operate at pulse repetition rate f = 1Hz, providing peak magnetic field B = 2 T and the field gradient G = 34 T/m in the dipoles and quadrupoles respectively. The superconducting coil is made from a hollow multi-filamentary NbTi cable cooled with two phase helium flow. Different possibilities were investigated to reduce AC power losses in the case of a cold iron yoke (T=4.5K). The achieved results are discussed. The value of 9W/m has been obtained for dipole magnet with the yoke at T=50K. The first 50 K yoke quadrupole was designed and tested. Other problems, connected with the magnetic field quality, mechanical and cryogenic stability of the magnets under SIS100 operating conditions are also discussed.  
 
WEPKF083 SPEAR3 INTERMEDIATE DC MAGNET POWER SUPPLIES power-supply, quadrupole, synchrotron-radiation, radiation 1798
 
  • A.C. de Lira, P. Bellomo
    SLAC, Menlo Park, California
  The Stanford Synchrotron Radiation Laboratory (SSRL) has successfully commissioned SPEAR3, its newly upgraded 3-GeV synchrotron light source. First stored beam occurred December 15, 2003 and 100mA operation was reached on January 20, 2004. This paper describes the specification, design, and performance of the SPEAR3 intermediate DC magnet power supplies (IPS) that consist of tightly-regulated (better than 10 ppm) current sources ranging from 60 A to 500 A and output powers ranging from a few kW to 22.5kW. A total of 69 IPS are in successful operation. The SPEAR 3 upgrade performance and reliability requirements mandated new power supplies for both the SPEAR3 storage ring, and for the booster-to-SPEAR3 transport line. IPS are widely used at SPEAR3 to power single quadrupoles, dipoles, families of quadrupoles and sextupoles, and also on the Titanium sublimation pumps. IPS' topology allows them to be series operated for those magnet strings requiring higher voltages. A compact 19" standard rack-mounted design is common to all the units. These are off-line, switch-mode, operating at 16 kHz to reduce space and provide for fast output response and high efficiency.  
 
WEPKF084 SPEAR3 LARGE DC MAGNET POWER SUPPLIES power-supply, feedback, quadrupole, sextupole 1801
 
  • A.C. de Lira, P. Bellomo
    SLAC, Menlo Park, California
  The Stanford Synchrotron Radiation Laboratory (SSRL) has successfully commissioned SPEAR3, its newly upgraded 3-GeV synchrotron light source. First stored beam occurred December 15, 2003 and 100mA operation was reached on January 20, 2004. This paper describes the specification, design, and performance of the SPEAR3 DC magnet large power supplies (LGPS) that consist of tightly-regulated (better than 10 ppm) current sources ranging from 100 A to 225 A and output powers ranging from 70kW to 135kW. A total of 6 LGPS are in successful operation and are used to power strings of quadrupoles, and sextupoles. The LGPS are isolated by a delta/delta-wye 60Hz step-down transformer that provide power to 2 series connected chopper stages operating phase-shifted at a 16 kHz switching frequency to provide for fast output response and high efficiency. Also described are outside procurement aspects, installation, in-house testing, and operation of the power supplies.  
 
WEPLT001 Nonlinear Beam Dynamics Study with MATLAB simulation, lattice, storage-ring, quadrupole 1813
 
  • Y.L. Martirosyan, M. Ivanyan, D.K. Kalantaryan
    CANDLE, Yerevan
  In this paper, we present description of MATLAB based computer code, which allows tracking of single particles by numerical integration of Hamilton's equations. For storage rings the damping time is of the order of few ms (102 '104 turns) and therefore the short-term stability time is determinant. For this reason symplecticity condition of the tracking method for the electron machines is not as important as in hadron machines. Applying recently introduced modern tools for post process analyzing, such as interpolated FFT, early indicators for long term stability, the determination of the onset of chaotic behavior using the maximal Lyapunov exponent, and etc, one can carry out simulations to evaluate the dynamic aperture, amplitude dependent tunes, phase space distortions, nonlinear resonances etc. The proposed code is applied for beam nonlinear dynamics study in CANDLE storage ring.  
 
WEPLT029 Intensity Dependent Emittance Transfer Studies at the CERN Proton Synchrotron emittance, simulation, resonance, injection 1894
 
  • E. Métral, C. Carli, M. Giovannozzi, M. Martini, R.R. Steerenberg
    CERN, Geneva
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  • J. Qiang
    LBNL, Berkeley, California
  • R.D. Ryne
    LBNL/CBP, Berkeley, California
  An intensive study has been undertaken since the year 2002 to understand better the various high-intensity bottlenecks of the CERN Proton Synchrotron machine. One of these limitations comes from the so-called Montague resonance. High-intensity proton synchrotrons, having larger horizontal than vertical emittance, may suffer from this fourth-order coupling resonance driven by space charge only. In particular, such resonance may lead to emittance sharing and, possibly, beam loss due to vertical acceptance limitation. Experimental observations made in the 2002 and 2003 runs on the Montague resonance are presented in this paper and compared with 3D particle-in-cell simulation results and theoretical predictions.  
 
WEPLT041 RF Amplitude Modulation to Suppress Longitudinal Coupled Bunch Instabilities in the SPS damping, proton, impedance, pick-up 1924
 
  • E. Vogel, T. Bohl, U. Wehrle
    CERN, Geneva
  In the SPS, even after a considerable impedance reduction including the removal of all RF cavities used for lepton acceleration in the past, longitudinal coupled bunch instabilities develop with an LHC beam of about one fifth of the nominal bunch intensity. The nominal LHC beam is stabilised using both, the 800 MHz Landau damping cavities, in bunch shortening mode, and pre-emptive emittance blow-up. An alternative method to increase the synchrotron frequency spread and thus stabilise the beam is amplitude modulation of the accelerating RF voltage. This method might be especially suitable in accelerators without a higher harmonic RF system, as will be the case in LHC. The main results of recent studies using this method in the SPS and considerations about its use in LHC are presented.  
 
WEPLT051 Sub-Picosecond Electron Bunches in the BESSY Storage Ring electron, radiation, optics, storage-ring 1954
 
  • G. Wustefeld, J. Feikes, K. Holldack, P. Kuske
    BESSY GmbH, Berlin
  BESSY is a low emittance, 1.7 Gev electron storage ring. A dedicated, low alpha optics is applied to produce short electron bunches for coherent synchrotron radiation (CSR) in the THz range[*]. By a further detuning of the optics, stable pulses as short as 0.7 ps rms length were produced. The sub-ps pulse shape is analysed by an auto-correlation method of the emitted CSR. The CSR-bursting instability is measured and compared with theory to estimate the current for stable, sub-ps pulses. Present limits of the low alpha optics are discussed.

* M. Abo-Bakr et al., Phys. Rev. Lett. 88, 254801 (2002).

 
 
WEPLT053 Dynamical Effects of the Montague Resonance emittance, simulation, resonance, space-charge 1960
 
  • I. Hofmann, G. Franchetti
    GSI, Darmstadt
  • J. Qiang, R.D. Ryne
    LBNL/CBP, Berkeley, California
  In high-intensity accelerators emittance coupling, known as Montague resonance, may be an issue if the tune split is small. For static tunes within the stop-band of this fourth order space charge driven coupling the final emittances may become equal (equipartition). Using 2D computer simulation we show, however, that slow crossing of the resonance leads to merely an exchange of emittances. In 3D this is similar, if the crossing occurs over a time-scale shorter or comparable with a synchrotron period. For much slower crossing we find, instead, that the exchange may be suppressed by synchrotron motion. We explain this effect in terms of the mixing caused by the synchrotron motion.  
 
WEPLT059 Beam Loss Modeling for the SIS100 space-charge, beam-losses, resonance, lattice 1978
 
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  In long term storage dynamic aperture is typically regarded as the quantity which has to be maintained sufficiently large in order to prevent beam loss. In the SIS100 of the GSI future project, a beam size occupying a large fraction of the beam pipe is foreseen. This circumstance requires a careful description of the lattice magnetic imperfections. The dynamic aperture is estimated in relation with an optimization of the SIS100 working point. For a space-charge-free bunched beam, estimates of beam loss are computed and compared with dynamic aperture. The impact of space charge will be discussed, and preliminary results on its effect on dynamic aperture and beam loss are presented.  
 
WEPLT063 Investigation of Cavity Induced Longitudinal Coupled Bunch Mode Instability Behaviour and Mechanisms damping, storage-ring, simulation, radiation 1990
 
  • R.G. Heine, P. Hartmann, H. Huck, G. Schmidt, T. Weis
    DELTA, Dortmund
  The narrowband impedances of RF-resonators in a circular accelerator can drive coupled bunch mode - CBI - instabilities which might spoil the overall beam quality. Often, as in synchrotron radiation light sources e.g. the instability does not lead to beam loss but to a severe degradation of the source brilliance. Investigations of longitudinal CBIs have been performed at the DELTA storage ring with a single DORIS-type cavity for future comparision with the behaviour of a HOM-damped cavity to be tested at DELTA. This resonator is presently developed and built within an EU-collaboration. The beam was deliberately driven into instability using the beam current as well as the cavity temperature as individual parameters. The instability characterisations at low (542 MeV) and high (1,5 GeV) energy exhibit a complex behaviour. The strength of the instability measured by the bunch excursions in the case of longitudinal CBIs, but also the spreading of the instability across neighbouring modes depends on parameters such as beam energy, resonant impedance but also on counteracting mechanisms like synchrotron radiation and Landau damping. The paper will cover the experimental results together with estimations of the influence and mechanism of Landau damping.  
 
WEPLT065 Hybrid Dry Coolers in Cooling Systems of High Energy Physics Accelerators simulation, site, linac 1996
 
  • J.-P. Jensen, B. Conrad, U. Schuetz, F.-R. Ullrich, A. Wanning
    DESY, Hamburg
  Wet water cooling towers in high energy physics accelerators are state of the art. The advantages are robustness, effectiveness and cost-effectiveness. The return water temperature is lower than the air temperature due to cooling via evaporation. The disadvantages are the high water consumption, which becomes more costly in the future, and the soiling of the heat exchangers. If the water source is taken from wells then the drawdown of the ground water level has to be taken into account. DESY plans to use hybrid dry coolers for the two future projects: The XFEL linac and the PETRA 3 synchrotron light source. A hybrid dry cooler is a combination of a dry air cooler during cold and moderate seasons and additional wet cooling during the hot summer season. The cooling surface is wetted by adding water to increase the cooling capability by a factor of 250 %. The hybrid dry cooler saves a lot of water. The water consumption can be reduced by 70% compared to a wet cooling system. This contribution presents the auxiliary water consumption, the requirement of this water and an estimate of the temperature control behaviour of the hybrid dry cooling system.  
 
WEPLT068 Momentum Compaction Factor and Nonlinear Dispersion at the ANKA Storage Ring storage-ring, optics, electron, synchrotron-radiation 2005
 
  • A.-S. Müller, A. Ben Kalefa, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  The ANKA electron storage ring operates in the energy range from 0.5 to 2.5 GeV. In order to improve machine performance a precise modelling of linear and nonlinear optics is mandatory. Apart from higher order chromaticity also momentum compaction factor and dispersion have to be controlled. In this framework, the higher order momentum compaction factor has been determined exploiting the extraordinary precision of the resonant spin depolarisation method. Furthermore the nonlinear horizontal dispersion was measured as a function of the momentum deviation for different chromaticities. This paper discusses the experimental results and compares the findings to different simulations.  
 
WEPLT069 Investigation of Scraper Induced Wake Fields at ANKA impedance, closed-orbit, single-bunch, storage-ring 2008
 
  • A.-S. Müller, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  • F. Zimmermann
    CERN, Geneva
  The ANKA synchrotron light source operates in the energy range from 0.5 to 2.5 GeV. Typical requirements for light sources include small beam sizes, large lifetimes and high currents to provide the highest possible photon flux. The understanding of impedance and instability related issues is very important in order to improve the machine performance, in particular when small aperture insertion devices are installed that require protection by a scraper. In the framework of an impedance survey the transverse and longitudinal wake fields induced by a vertical scraper have been measured and analysed. This paper reports the beam observations and compares them with the expectation.  
 
WEPLT070 Studies of Current Dependent Effects at ANKA impedance, storage-ring, betatron, closed-orbit 2011
 
  • A.-S. Müller, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  • F. Zimmermann
    CERN, Geneva
  The ANKA electron storage ring is operated at energies between 0.5 and 2.5 GeV. A major requirement for a synchrotron light source, such as ANKA, is to achieve a high beam current. A multitude of mostly impedance related effects depend on either bunch or total beam current. This paper gives an overview over the various beam studies performed at ANKA in this context, specifically the observation of current dependent detuning, the dermination of the bunch length change with current from a measurement of the ratio between coherent and incoherent synchrotron tune and an assessment of the effective longitudinal loss factor from the current dependent horizontal closed orbit distortion.  
 
WEPLT080 Study of Resistive-wall Effects on SOLEIL impedance, single-bunch, vacuum, focusing 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.  
 
WEPLT092 Equilibrium Longitudinal Distribution for Localized Regularized Inductive Wake damping, radiation, radio-frequency, vacuum 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).

 
 
WEPLT098 Experience with Long Term Operation with Demineralized Water Systems at DAFNE wiggler, ion, vacuum, 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.  
 
WEPLT108 Diffusion caused by Beam-beam Interactions with Couplings simulation, coupling, luminosity, radiation 2104
 
  • K. Ohmi, S. Kamada, K. Oide, M. Tawada
    KEK, Ibaraki
  A system of colliding two beams is strong nonlinear in multi-dimension. In such a system, a symplectic diffusion called Arnold diffusion occurs, with the result that the beams are enlarged and the luminosity is degraded in circular colliders. We discuss the diffusion seen in beam-beam inetraction at a circular accelerator, especially finite crossing angle and/or x-y coupling errors enhance the diffusion.  
 
WEPLT110 Specific Beam Dynamics in Super-bunch Acceleration induction, emittance, acceleration, simulation 2110
 
  • Y. Shimosaki, E. Nakamura, K. Takayama, T. Toyama
    KEK, Ibaraki
  • K. Horioka, M. Nakajima
    TIT, Yokohama
  • K. Koseki
    GUAS/AS, Ibaraki
  • K. Torikai
    Kyushu University, Fukuoka
  • M. Watanabe
    RIKEN, Saitama
  Proof-of-principle experiments on the induction synchrotron concept using the KEK 12-GeV PS makes progress, in which RF bunches and a super-bunch will be accelerated with a long step voltage generated in the induction accelerating gaps. In order to give a guide for super-bunch acceleration, the beam stabilities against a droop and a fluctuation of the accelerating voltage have been examined by using a simulation. The droop voltage gives an additional focusing or defocusing force in the longitudinal direction, which leads the mismatching beyond the transition energy. Furthermore, the extremely slow fluctuation of the accelerating voltage causes a lowest-order resonance near the transition. These induce a serious emittance blow-up in the longitudinal, so that the compensating manners will be presented. Moreover, the other issues such as head-tail instability and intra beam scattering will be discussed.  
 
WEPLT117 Design of a Third Harmonic Superconducting RF System at PLS emittance, storage-ring, vacuum, 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.  
 
WEPLT119 Beam Instabilitiy Studies of BEPC and BEPCII impedance, electron, synchrotron-radiation, radiation 2131
 
  • J.Q. Wang, Z.Y. Guo, Y.D. Liu, Q. Qin, Z. Zhao, D.M. Zhou
    IHEP Beijing, Beijing
  BEPC has been well operated for more then 10 years, and it will be upgraded to a double ring electron positron collider using the existing tunnel, namely BEPCII. This paper describes the recent studies on beam instabilities in BEPC for the improvement of its performance as well as for BEPCII. The instabilities caused by impedance and two-stream effect are investigated. The experimental and simulation results are reported.  
 
WEPLT137 Higher Order Modes in the New 100 and 500 MHz Cavities at MAX-lab damping, synchrotron-radiation, coupling, impedance 2158
 
  • H. Tarawneh, Å. Andersson, M. Bergqvist, M. Brandin, M. Eriksson, L. Malmgren
    MAX-lab, Lund
  The MAX-II electron storage ring operates exclusively in multi-bunch mode with all buckets filled. Damping of the longitudinal higher order mode (HOM) instabilities has successfully been provided by passive third harmonic 1.5 GHz cavities. With a new RF employing three 100 MHz capacity loaded cavities and a fifth harmonic Landau cavity installed, a study of the HOM impedances, and related threshold instability currents, is necessary. Measurements and calculations so far, are being presented.  
 
WEPLT138 Laser Cooling of Electron Bunches in Compton Storage Rings laser, emittance, electron, damping 2161
 
  • E.V. Bulyak
    NSC/KIPT, Kharkov
  Self-consistent dynamics of a bunch circulating in the Compton storage ring has been studied analytically. Disturbances from both the synchrotron and Compton radiations were taken into account. The emittances in laser-dominated rings (where the synchrotron energy losses are much smaller then the Compton ones) were evaluated. The resultant emittances (synchrotrons plus Comptons) were compared with the synchrotrons. As were shown, the longitudinal degree of freedom is heated up due to Compton scattering. Almost the same conclusion is valid for the vertical uncoupled betatron emittance. Since it is impossible in principle to get zero dispersion in the banding magnets, the radial emittance almost always cooling down by laser. Therefore in practical cases of coupled transverse oscillations with the horizontal emittance determining the vertical one, the laser will cool down the transverse degrees of freedom.  
 
WEPLT144 New Characteristics of a Single-bunch Instability Observed in the APS Storage Ring betatron, single-bunch, storage-ring, lattice 2173
 
  • C.-X. Wang
    ANL, Argonne, Illinois
  • K. Harkay
    ANL/APS, Argonne, Illinois
  In the Advanced Photon Source storage ring, a transverse single-bunch instability has long been observed that appears unique to this ring. Many of its features have been previously reported. New results have recently been obtained using beam centroid history measurements and analysis. These preliminary results provide more detailed information regarding the characteristics of this instability and could provide insight into the physics mechanism.  
 
WEPLT154 UAL Implementation of String Space Charge Formalism space-charge, emittance, lattice, quadrupole 2200
 
  • R.M. Talman
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • N. Malitsky
    BNL, Upton, Long Island, New York
  By reformulating the force between point charges as the force on a point charge due to a co-moving line charge (or "string",) space charge calculations can be reformulated as intrabeam scattering, with no intermediate, particle-in-cell step required.[*] This approach is expected to be especially useful for calculating emittance dilution of ultrashort bunches in magnetic fields, where coherent radiative effects are important. This paper describes the partial implementation of this approach within UAL (Unified Accelerator Libraries.) The interparticle force is calculated and applied to the dynamics of a bunch represented by just two superparticles in an idealized lattice, with emphasis on the head-tail effect. Gridding of the interparticle force, as needed for realistic multiparticle simulation, is also described.

* R. Talman, "String Formulation of Space Charge Forces in a Deflected Bunch". Submitted to PRSTAB, January, 2004

 
 
WEPLT159 Linear Vlasov Analysis for Stability of a Bunched Beam damping, storage-ring, synchrotron-radiation, coupling 2215
 
  • R.L. Warnock, G.V. Stupakov
    SLAC, Menlo Park, California
  • J.A. Ellison
    UNM, Albuquerque, New Mexico
  • M. Venturini
    LBNL, Berkeley, California
  We study the linearized Vlasov equation for a bunched beam subject to an arbitrary wake function. Following Oide and Yokoya, the equation is reduced to an integral equation expressed in angle-action coordinates of the distorted potential well. Numerical solution of the equation as a formal eigenvalue problem leads to difficulties, because of singular eigenmodes from the incoherent spectrum. We rephrase the equation so that it becomes non-singular in the sense of operator theory, and has only regular solutions for coherent modes. We report on a code that finds thresholds of instability by detecting zeros of the determinant of the system as they enter the upper-half frequency plane, upon increase of current. Results are compared with a time-domain integration of the nonlinear Vlasov equation, and with experiment, for a realistic wake function for the SLC damping rings.  
 
THOBCH01 The Beijing Electron-positron Collider and its Second Phase Construction luminosity, synchrotron-radiation, vacuum, 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
 
THOBCH03 Barrier RF Systems in Synchrotrons antiproton, emittance, hadron, proton 236
 
  • C.M. Bhat
    Fermilab, Batavia, Illinois
  Recently, the barrier bucket techniques have been used in many interesting applications in proton synchrotrons around the world. Specially designed broad-band rf cavities are used to generate barrier buckets. At Fermilab we have barrier RF systems in four different rings and have used them for various beam gymnastics. Particularly, in the case of Fermilab Recycler Ring, all rf manipulations required during beam cooling, beam stacking and unstacking are carried out using barrier buckets. Also, we have explored new methods for increasing the beam intensities in the Main Injector. Here, I review various uses of barrier rf system in particle accelerators and possible new applications.  
Video of talk
Transparencies
 
THOBLH01 Recent Improvement of Slow-extraction at HIMAC Synchrotron extraction, simulation, feedback, heavy-ion 267
 
  • T. Furukawa, T. Furukawa, T.H. Uesugi
    Chiba University, Graduate School of Science and Technology, Chiba
  • T. Fujimoto, M. Kanazawa, K. Noda, S. Shibuya, E. Takada, S. Yamada
    NIRS, Chiba-shi
  • T. Naruse
    Seikei University, Graduate School of Engineering, Tokyo
  At HIMAC synchrotron, two kinds of slow-extraction method have been developed and utilized: third-order resonant slow-extraction and that with RF-knockout, not only for ion therapy but also for physics and biological experiments. Thus, the improvements of the extracted beam quality have also been carried out in both methods. One of the improvements is the global spill control. The global spill is improved owing to analytical approach in both methods. Cooperating with the feedback system, the flat spill is easily obtained without gain control of the feedback during the extraction. On the other hand, the effect of longitudinal motion for the bunched beam was studied to suppress the frequency component of the synchrotron oscillation in the spill ripple. Further, the transport of the extracted beam is readjusted for controlling the beam size. In this paper, recent improvement of slow-extraction at HIMAC is presented.  
Video of talk
Transparencies
 
THOBLH03 BESSY II Operated as a Primary Source Standard electron, photon, storage-ring, radiation 273
 
  • R. Klein, R. Thornagel, G. Ulm
    PTB, Berlin
  The Physikalisch-Technische Bundesanstalt (PTB) is the German National Metrology Institute and responsible for the realization and dissemination of the legal units in Germany. For the realization of the radiometric units in the VUV and X-ray spectral range PTB has been using calculable synchrotron radiation of bending magnets from the BESSY I and BESSY II electron storage rings for more than 20 years. The spectral photon flux of synchrotron radiation can be precisely calculated by Schwinger's theory. Therefore, all the storage ring parameters entering the Schwinger equation have to be measured with low uncertainty which requires a stable and reproducible operation of the storage ring. At BESSY II, PTB has installed all equipment necessary to measure the electron energy, the electron beam current, the effective vertical source size and the magnet induction at the radiation source point as well as all geometrical quantities with low uncertainty. The measurement accuracy for these quantities enables PTB to calculate the spectral photon flux from the visible up to the soft X-ray range with relative uncertainties below 0.4 %. We report on the measurement of the storage ring parameters with low uncertainty.  
Video of talk
Transparencies
 
THPKF001 Status of 3 GeV CANDLE Synchrotron Light Facility Project brightness, photon, scattering, emittance 2254
 
  • V.M. Tsakanov, M. Aghasyan, G. Amatuni, V.S. Avagyan, A. Grigoryan, B. Grigoryan, M. Ivanyan, V. Jalalyan, D.K. Kalantaryan, V.G. Khachatryan, E.M. Laziev, Y.L. Martirosyan, R.H. Mikaelyan, S. Minasyan, K.N. Sanosyan, S. Tatikian, S. Tunyan, A. Vardanyan
    CANDLE, Yerevan
  CANDLE- Center for the Advancement of Natural Discoveries using Light Emission – is a 3 GeV third generation synchrotron light facility project in Republic of Armenia. The presentation includes the main considerations that underlie the Conceptual Design Report of the project and the progress made after the last EPAC conference. An overview of machine and beam physics study, the prototype and laboratory development is given.  
 
THPKF004 The Australian Synchrotron Project - Update storage-ring, injection, site, insertion 2260
 
  • A. Jackson
    ASP, Melbourne
  The Australian Synchrotron - a 3rd generation synchrotron light facility based on a 3-GeV electron storage ring - is under construction at a site adjacent to Monash University in the Metropolitan District of Melbourne. Site preparation started in September 2003 and project completion is scheduled for March 2007. In this paper we present an overview of the facility and discuss progress to date in meeting this very agressive schedule.  
 
THPKF005 The Australian Synchrotron Project Storage Ring and Injection System Overview storage-ring, lattice, injection, dipole 2263
 
  • G. LeBlanc, M.J. Boland, Y.E. Tan
    ASP, Melbourne
  This paper describes the Australian Synchrotron storage ring. The storage ring is a 3 GeV machine with 14 cells and a circumference of 216 m. The unit cell is based on a Double Bend Achromat (DBA) structure. The design of the magnet lattice and the results of simulations pertaining to the storage ring performance are presented.  
 
THPKF006 Lifetime Studies in the LNLS Electron Storage Ring storage-ring, scattering, coupling, single-bunch 2266
 
  • N.P. Abreu, P.F. Tavares
    LNLS, Campinas
  In this paper we present a set of measurements performed at the 1.37 GeV electron storage ring of the Brazilian Synchrotron Light Source. We measured the beam lifetime as a function of: current per bunch, gap voltage and position of horizontal and vertical scrapers. Those measurements helped us to determine the contribution of various particle loss mechanisms (Touschek, elastic and inelastic scattering and quantum fluctuations) to the lifetime of the beam. Comparison with theory is also presented as well as an interpretation of each effect.  
 
THPKF016 The Metrology Light Source of the Physikalisch-Technische Bundesanstalt in Berlin-Adlershof electron, radiation, storage-ring, photon 2293
 
  • R. Klein, G. Ulm
    PTB, Berlin
  • M. Abo-Bakr, P. Budz, K. Bürkmann, D. Krämer, J. Rahn, G. Wustefeld
    BESSY GmbH, Berlin
  PTB, the German National Metrology Institute, has gained approval for the construction of a low-energy electron storage ring in the close vicinity of BESSY II, where PTB operates a laboratory for X-ray radiometry. The new storage ring, named 'Metrology Light Source MLS' will be dedicated to metrology and technology development in the UV and EUV spectral range and so will fill the gap that is present since the shut down of BESSY I. The MLS is designed in close cooperation with BESSY and is located adjacent to the BESSY II facility. Construction will start 2004 and user operation is scheduled to begin in 2008. The MLS has a circumference of 48 m, injection will be from a 100 MeV microtron. The electrons energy is ramped to an eligible value in the range from 200 MeV to 600 MeV. The MLS will be equipped with all the instrumentation necessary to measure the storage ring parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty, enabling PTB to operate the MLS as a primary source standard. Moreover, provision is taken to operated the MLS in a low alpha mode for the production of coherent synchrotron radiation in the far IR and THz region.  
 
THPKF017 Status of the Synchrotron Light Source DELTA injection, feedback, vacuum, 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.  
 
THPKF018 Study for a Frequent Injection Mode at Delta with Beam Shutters Open injection, radiation, storage-ring, feedback 2299
 
  • G. Schmidt, M. Benna, U. Berges, J. Friedl, A. Gasper, M. Grewe, P. Hartmann, R.G. Heine, H. Huck, D. Schirmer, S. Strecker, T. Weis, K. Wille, N. Zebralla
    DELTA, Dortmund
  The Dortmunder Electron Accelerator (DELTA) is a 1.5 GeV synchrotron light source. DELTA is now operated for 3000 h per year including 2000 h beam time for synchrotron radiation use. The maximum beam current is limited by rf power. To increase the average beam current a frequent injection scheme with beam shutters open is discussed for Delta. The peak current is not enlarged but the number of injections is increased to establish a quasi constant beam current. The quasi constant beam current has in addition the advantage of a constant synchrotron radiation heat-load on vacuum chambers and experiments. First tests at Delta have shown the gain in stability of the closed orbit during frequent injection. This article shows the possibility to install a frequent injection mode with beam shutters open during injection at DELTA. The results of measurements and simulations are presented.  
 
THPKF020 Improvements of the Orbit Stability at DORIS III feedback, photon, radiation, synchrotron-radiation 2305
 
  • F. Brinker, O. Kaul
    DESY, Hamburg
  Running since 1974, the storage ring DORIS experienced a major modification in 1991 to run as a dedicated synchrotron radiation source since 1993. Since then the increasing requirements of the users on beam stability lead to a series of technical and operational measures to improve the beam conditions. The beam pipe has been mechanically isolated from the magnets, the cooling has been improved and this year a new orbit feedback came to operation which uses positron beam position monitors as well as photon monitors in the beam lines to stabilise the different photon beams. The different measures taken are presented.  
 
THPKF021 Beam Current Limitations in the Synchrotron Light Source PETRA III impedance, vacuum, 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.  
 
THPKF022 Energy Calibration of the ANKA Storage Ring storage-ring, resonance, energy-calibration, synchrotron-radiation 2311
 
  • A.-S. Müller, I. Birkel, E. Huttel, M. Pont, F. Pérez, R. Rossmanith
    FZK-ISS-ANKA, Karlsruhe
  The ANKA electron storage ring operates in the energy range from 0.5 to 2.5 GeV. An energy calibration using the method of resonant spin depolarisation yields the exact beam energy of ANKA. In addition this method allows to determine other parameters such as nonlinear momentum compaction factor and incoherent synchrotron tune with extraordinary precision. This paper discusses experimental set-up and energy measurements. The reproducibility of the ANKA beam energy is addressed as well as energy drifts caused by thermal expansion of the floor.  
 
THPKF025 Commissioning Report of the CLS Booster Synchrotron booster, injection, beam-losses, lattice 2320
 
  • G. Georgsson
    Danfysik A/S, Jyllinge
  • L. Dallin
    CLS, Saskatoon, Saskatchewan
  • S.P. Møller
    ISA, Aarhus
  • L. Præstegaard
    Århus Sygehus, Århus
  A full energy booster is produced and taken into operation for the Canadian Light Source. The Booster accelerates the beam from the injection energy of 200 MeV to a maximum of 2.9GeV. The results of the commissioning and the characterized beam parameters are reported  
 
THPKF028 Upgrade of the Cryomodule Prototype before its Implementation in SOLEIL damping, dipole, storage-ring, impedance 2329
 
  • P. Bosland
    CEA/DSM, Gif-sur-Yvette
  • P. Bredy, S. Chel, G. Devanz
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • R. Losito
    CERN, Geneva
  • P. Marchand, K. Tavakoli, C. Thomas-Madec
    SOLEIL, Gif-sur-Yvette
  In the Storage Ring (SR) of the Synchrotron SOLEIL light source, two cryomodules 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. A cryomodule prototype, housing two 352 MHz superconducting single-cell cavities with strong damping of the Higher Order Modes has been built and successfully tested in the ESRF storage ring. Even though the achieved performance (3 MV and 380 kW) does meet the SOLEIL requirement for the 1st year of operation, the cryomodule prototype will be upgraded before its installation in the SR early 2005. Modifications will be made on the internal cryogenic system, and also on the power and dipolar HOM couplers. That requires a complete disassembling and reassembling of the cryomodule, which is being carried out at CERN in the framework of collaboration between SOLEIL, CEA and CERN. Additional 3D RF calculations have been performed on the full SOLEIL RF structure in order to get a more detailed description of the dipolar modes damping and of the dipolar HOM couplers tuning. A second cryomodule, similar to the modified prototype, will be built and installed in the SR about one year later.  
 
THPKF031 High Power (35 KW and 190 KW) 352 MHZ Solid State Amplifiers for Synchrotron SOLEIL vacuum, power-supply, booster, insertion 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.  
 
THPKF032 Cleaning of Parastic Bunches in the ESRF Booster Synchrotron for Time Structure Modes of Operation booster, injection, acceleration, betatron 2341
 
  • E. Plouviez, N. Michel
    ESRF, Grenoble
  The ESRF injector booster accelerates electron bunches from 200 MeV to 6 GeV and inject them in a storage ring. It can accelerate a small number (1 to 5) of high charge bunches for the so called "time structure" filling mode operation of the SR. In this case we must avoid storing parasitic low charge bunches in the unused RF bucket of the SR. Until now this was achieved by a resonant knockout of these parasitic bunches on the beam stored in the SR. We have developed and implemented a system allowing the removal of these parasitic electrons during the acceleration in the booster, so that no extra cleaning is needed on the beam stored in the SR. This paper describes our setup and its key components, the tuning of the operating parameters of the system and presents the results achieved.  
 
THPKF035 Design of the Super-SOR Light Source injection, storage-ring, linac, optics 2350
 
  • N. Nakamura
    ISSP/SRL, Chiba
  The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which is to be operated for nation-wide and world-wide users. The University of Tokyo has proposed to construct the facility in Kashiwa new campus and we have designed the light source intensively for more than two years. The light source consists of an electron storage ring, booster synchrotron and pre-injector linac. The 1.8-GeV storage ring has a circumference of about 280 m and 14 DBA cells with two 17-m and twelve 6.2-m long straight sections, which are used for twelve insertion devices and RF and injection systems. The booster synchrotron is compact, one third of the ring in circumference, and can achieve a low emittance of about 50 nmrad at 1.8 GeV. The 200-MeV linac is made up of S-band accelerating structures powered by two 50-MW klystrons and a SLED cavity and capable of changing the beam current widely in both single- and multi-bunch operation modes. These accelerators are designed so as to fully meet requirements for top-up injection. We describe the design of the Super-SOR accelerators here.

on behalf of the Super-SOR accelerator design group

 
 
THPKF037 Quasi-isochronus Operation at NewSUBARU betatron, emittance, radiation, electron 2356
 
  • Y. Shoji, S.H. Hisao, T. Matsubara
    LASTI, Ako-gun, Hyogo
  Quasi-isochronus operation is one of the operation modes of NewSUBARU, a 1.5 GeV VUV storage ring. NewSUBARU has six invert bending magnets to control the momentum compaction factor. The aim of this research is to explore the extreme reduction of electron bunch length by reducing the linear momentum compaction factor. We experimentally reduced the momentum compaction factor from 0.0014 down to less than 10-5, keeping the beam in the ring. The second-order momentum compaction factor was adjusted to almost zero, while keeping the third-order momentum compaction factor positive. The ring was operated at 1.0 GeV. Using a streak camera, the shortest bunch length we observed was 4 ps FWHM. With such a low momentum compaction factor, we expect an energy spreading by betatron oscillation even at the extremely low beam current.  
 
THPKF038 Radiation Damage of Magnet Coils due to Synchrotron Radiation radiation, acceleration, synchrotron-radiation, storage-ring 2359
 
  • K. Tsumaki, S. Matsui, M. Oishi, T. Yorita
    JASRI/SPring-8, Hyogo
  • T. Shibata, T. Tateishi
    KOBELCO, Hyogo
  Radiation damage of the equipment in the SPring-8 storage ring tunnel has become a serious problem. In the storage ring, the unnecessary radiation from bending magnets is shielded by absorbers. The equipment around the absorbers was damaged by the scattered radiation from the absorbers. Last year, cooling water leaked from the rubber hose of magnets. It was due to the deterioration of rubber hose caused by synchrotron radiation. We measured the radiation distribution around the storage ring and found that the most high intensity spot was on the magnet coil near the absorbers. If the coils are damaged and the magnets do not work correctly, we need to shut down the storage ring to exchange the magnet coils. To avoid such a situation, we needed to clarify the relation between the radiation damage of the coils and the dose of radiation. We did an acceleration test of the radiation damage of magnet coils. The magnet coils were exposed to the radiation from the bending magnet directly. We observed the degree of damage with changing the doses of radiation. In this paper, we describe about these acceleration tests and test results.  
 
THPKF041 SSRF: A 3.5GeV Synchrotron Light Source for China storage-ring, injection, booster, undulator 2368
 
  • Z. Zhao, H. Xu
    SINR, Jiading, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy light source that will be built at Zhang-Jiang Hi-Tech Park in Shanghai. The SSRF consists of a 432 m circumference storage ring with an operating energy of 3.5GeV and a minimum emittace of 2.95 nm-rad, a full energy bosster, a 100MeV electron Linac and dozens of beamlines and experimental stations. The design of the SSRF accelerator complex evolves timely along the technological progress such as top-up injection, mini-gap undulator, superconducting RF system and etc. This paper reports the design progress and status of the SSRF project.  
 
THPKF045 Accelerator Physics Issues at NSRRC insertion, insertion-device, coupling, injection 2377
 
  • C.-C. Kuo, H.-P. Chang, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  Over the past decade, NSRRC has served the synchrotron light users with its 1.5 GeV third-generation storage ring. To provide stable hard x-ray for the x-ray community, two strong-field superconduting wigglers have been installed and three more will be put in such a low energy ring. A superconduting rf cavity is to replace the conventional ones and the beam current will be double too. Top-up injection study is underway. This paper presents the accelerator physics issues at NSRRC such as single particle dynamics and collective effects.  
 
THPKF051 The Status-2004 of the KURCHATOV Center of SR electron, vacuum, 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.  
 
THPKF060 Singapore Synchrotron Light Source– Helios 2 and Beyond electron, plasma, linac, radiation 2400
 
  • H.O. Moser, B.D.F. Casse, E.P. Chew, M. Cholewa, C. Diao, S.X.D. Ding, M. Hua, J.R. Kong, Z. Li, S.bin. Mahmood, M.L. Ng, B.T. Saw, S.V.S. Vidyaraj, O. Wilhelmi, J.H.W. Wong, P. Yang, X.J. Yu
    SSLS, Singapore
  SSLS is operating a superconducting 700 MeV electron storage ring to produce synchrotron radiation over a useful spectral range from 10 keV to the far infrared for micro/nanofabrication, phase contrast imaging, surface and nano science with soft X-rays, and hard X-ray diffraction and absorption spectroscopy. An Infrared spectro/microscopy beamline is under construction. Latest results from all beamlines will be presented. SSLS is also working on a conceptual study of a Linac Undulator Light Installation (LIULI) that includes a superconducting miniundulator. Pursuing earlier work* a prototype built by ACCEL is being tested at SSLS and will later serve for FEL studies in cooperation with SSRF at Shanghai.

* A. Geisler, A. Hobl, D. Krischel, H.O. Moser, R. Rossmanith, M. Schillo, First Field Measurements and Performance Tests of a Superconductive Undulator for Light Sources with a Period Length of 14 mm, ASC Conference, Houston, TX, August 2002

 
 
THPKF073 CIRCE, the Coherent InfraRed CEnter at the ALS radiation, storage-ring, laser, synchrotron-radiation 2436
 
  • J.M. Byrd, S. De Santis, J.-Y. Jung, M.C. Martin, W.R. McKinney, D.V. Munson, H. Nishimura, D. Robin, F. Sannibale, R.D. Schlueter, M. Venturini, W. Wan, M.S. Zolotorev
    LBNL, Berkeley, California
  CIRCE (Coherent InfraRed Center) is a new electron storage ring to be built at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL). The ring design is optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. CIRCE operation includes three possible modes: ultra stable CSR, femtosecond laser slicing CSR and broadband SASE. CSR will allow CIRCE to produce an extremely high flux in the terahertz frequency region. The many orders of magnitude increase in the intensity is the basis of our project and enables new kinds of science. The characteristics of CIRCE and of the different modes of operation are described in this paper.  
 
THPKF084 Emerging Concepts, Technologies and Opportunities for Mezzo-scale Terahertz and Infrared Facilities electron, radiation, linac, laser 2454
 
  • S. Chattopadhyay, S.T. Corneliussen, G.P. Williams
    Jefferson Lab, Newport News, Virginia
  Recent advances in particle beam, laser and radiofrequency technologies, combined with innovative concepts and techniques such as energy recovery, coherent synchrotron radiation-induced bunching, laser-particle beam scattering, ultrashort pulse slicing, cw high current and brightness phtoinjectors, ultrafast laser switching and compact engineered end products have opened up new opportunities and vistas in terahertz/infrared radiation sources not available before. Such sources would complement the high energy short wavelength x-ray sources in that they will allow us to probe collective processes and their ?function? in complex systems and materials, in a fashion complementary to probing structure via x-rays. We will outline and give examples of both the scientific reach of such radiation sources as well as examples of a few conceived facilities and techniques worldwide spanning a diversity of spectral, coherence, brightness and application ranges in the long wavelength. Such facilities fall in the category of mezzo-scale facilities, bracketed by table top lasers on one hand and large scale synchrotron radiation sources on the other and offer very unique and directed advances in a few key areas in life, materials, imaging, instrumentation and communication sciences.  
 
THPKF088 NSLS II: A Future Source for the NSLS impedance, brightness, storage-ring, insertion 2457
 
  • J.B. Murphy, J. Bengtsson, L. Berman, R. Biscardi, A. Blednykh, G.L. Carr, W.R. Casey, S.B. Dierker, E. Haas, R. Heese, S. Hulbert, E. Johnson, C.C. Kao, S.L. Kramer, S. Krinsky, I.P. Pinayev, R. Pindak, S. Pjerov, B. Podobedov, G. Rakowsky, J. Rose, T.V. Shaftan, B. Sheehy, D.P. Siddons, J. Skaritka, N. Towne, J.-M. Wang, X.J. Wang, L.-H. Yu
    BNL/NSLS, Upton, Long Island, New York
  The National Synchrotron Light Source at BNL was the first dedicated light source facility and has now operated for more than 20 years. During this time, the user community has grown to more than 2400 users annually. To insure that this vibrant user community has access to the highest quality photon beams, the NSLS is pursuing the design of a new ultrahigh brightness (~ 1E21) electron storage ring, tailored to the 0.3-20 keV photon energy range. We present our preliminary design and review the critical accelerator physics design issues.  
 
THPLT004 Toroidal Cavity Loaded with an Electron Beam radiation, electromagnetic-fields, synchrotron-radiation, acceleration 2463
 
  • E.D. Gazazyan, T. Harutyunyan, D.K. Kalantaryan
    YSU, Yerevan
  • V. Kocharyan
    DESY, Hamburg
  Three problems have been considered in this paper: the development of Maxwell's equations strict solution method to define the electromagnetic own values and own functions of the toroidal cavity; the radiation of the charged bunch rotating along the average radius, and, at last, the consideration of the case of a toroid filled with dielectric medium. The peculiarities of this radiation have been investigated as well. We suppose to consider the case when toroid is filled with plasma like a disperse medium.  
 
THPLT025 Using Visible Synchrotron Radiation at the SLS Diagnostics Beamline radiation, storage-ring, synchrotron-radiation, diagnostics 2526
 
  • V. Schlott, M. Dach, Ch. David, B. Kalantari, M. Pedrozzi, A. Streun
    PSI, Villigen
  A diagnostics beamline has been set-up at the BX05 bending magnet of the SLS storage ring. It is equipped with a standard bending magnet front end, including two photon beam position monitors (PBPM) for determination of photon beam angle and position as well as a pinhole array monitor for online monitoring of beam size. The visual part of the dipole radiation is transported to an optical lab, where the temporal profile of the storage ring bunches can be measured with a minimal time resolution of 2 ps using a dual sweep, synchrocan streak camera. Simultaneously, beam size and coupling can be measured at 1.8 keV radiation energy with a zome plate monitor overcoming diffraction limitations. This paper describes the beamline design and summarizes the first experimental results.  
 
THPLT032 Computer Controlled Beam Diagnostics for the HICAT Facility diagnostics, linac, pick-up, ion 2547
 
  • M. Schwickert, A. Peters
    GSI, Darmstadt
  A set of 93 diagnostic devices for beam diagnostics in the heavy ion cancer therapy facility (HICAT) at the university hospital in Heidelberg is currently under development at GSI. For the HICAT facility that is presently under construction, all beam diagnostic devices are fully computer controlled and allow an automated detection of all relevant beam parameters. The HICAT rasterscan method with active variation of intensity, energy and beam size requires the exact knowledge of the time resolved and spatial structure of the ion beam. An overview of the integrated devices is presented and the intensity measurement of both, the DC and AC beam in the different parts of the accelerator facility are reviewed. Additionally, the timing and control of the diagnostic devices are described.  
 
THPLT038 The Synchrotron Radiation Interferometer using Visble Light at DELTA radiation, synchrotron-radiation, electron, storage-ring 2565
 
  • U. Berges, K. Wille
    DELTA, Dortmund
  Synchrotron radiation sources such as DELTA, the Dortmund electron accelerator, rely on a monitoring system to measure the beam size and emittance with sufficient resolution. The resolution limits of the different types of optical synchrotron light monitors at DELTA have been investigated. The minimum measurable beam size with the standard synchrotron light monitor using visible light at DELTA is appr. 80 μm. Due to this limitation an interferometer was built up and tested using the same beamline in the visible range. A minimum measurable beam size of appr. 8 μm could be obtained, which gives an increased resolution of one order of magnitude with the new system.  
 
THPLT039 SVD Based Orbit Correction Incorporating Corrector Limitations at DELTA dipole, storage-ring, beam-losses, multipole 2568
 
  • M. Grewe, P. Hartmann, G. Schmidt, K. Wille
    DELTA, Dortmund
  Singular Value Decompostion (SVD) of the orbit response matrix has become an invaluable tool for orbit correction at storage rings worldwide. SVD based orbit correction has now been realised at DELTA, a 1.5 GeV electron storage ring. However, due to special orbit demands at DELTA and possibly by magnetic imperfections within the storage ring, we frequently have to face corrector limitations during the process of orbit correction. This work focuses on presenting an analytic algorithm on how to treat these limitations when seeking for an optimal SVD based orbit correction. In contrast to previously published methods, this approach is fairly easy to implement and does not afford an numerical solver. Concepts and results will be presented.  
 
THPLT043 Development of a New Orbit Measurement System storage-ring, damping, controls, vacuum 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.  
 
THPLT045 A more Accurate Approach to Calculating Proton Bunch Evolution under Influence of Intra-beam Scattering in a Storage Ring. scattering, proton, storage-ring, background 2583
 
  • I.V. Agapov, F.J. Willeke
    DESY, Hamburg
  Some perturbations of discrete nature are known to influence the performance of a proton storage ring, contributing to parasitic background, decay of beam currents and bunch tail buildup. Such are, for example, intra-beam scattering and residual gas scattering .These processes are to a big extent described by existing analytical theory. The latter, employing a large amount of averaging, usually neglects effects arising from system nonlinearity. So, the motion of tail particles in the presence of a sufficiently nonlinear RF voltage under influence of intra-beam scattering strongly deviates from the average across the bunch and the analytical approach seems inadequate for it. To overcome this situation we have developed more accurate numerical methods for calculations of bunch evolution under influence of a rather broad class of jump-like perturbations. Here we present the computational algorithms and their application to assessment of coasting beam and proton background in HERA-p.  
 
THPLT046 The Synchrotron Radiation Beamline at TTF2 radiation, synchrotron-radiation, electron, polarization 2586
 
  • O. Grimm, S. Casalbuoni, L. Fröhlich, O. Peters, J. Rossbach
    DESY, Hamburg
  The VUV-FEL at DESY, Hamburg, will require novel techniques to characterize the longitudinal charge distribution of the electron bunches that drive the free-electron laser. Conventional methods are inadequate at the short bunch lengths that will be obtained. One technique under study uses coherent far-infrared radiation to reconstruct the bunch shape through Fourier analysis of the spectrum. In a first step, a beam line to guide both far-infrared (50-1000 um) and optical synchrotron radiation from one of the bunch compressor magnets of the linear accelerator to a diagnostic station outside of the controlled area is currently under construction. It will also allow a comparison between streak camera and far-infrared measurements for features on length scales above some 100 um (the streak camera resolution). Later, infrared techniques extending to shorter wavelengths, i.e. to shorter bunch lengths, will also be used further downstream the accelerator, employing synchrotron, transition and undulator radiation. The beam line design, measurement principle and first measurements will be presented.  
 
THPLT063 Proposal of Carbon-beam Facility for Cancer Therapy in Japan linac, rfq, ion, extraction 2634
 
  • K. Noda, T. Fujisawa, T. Furukawa, Y. Iwata, T. Kanai, M. Kanazawa, N. Kanematsu, A. Kitagawa, Y. Kobayashi, M. Komori, S. Minohara, T. Murakami, M. Muramatsu, S. Sato, Y. Sato, S. Shibuya, E. Takada, O. Takahashi, M. Torikoshi, E. Urakabe, S. Yamada, K. Yoshida
    NIRS, Chiba-shi
  Since 1994, the clinical trial at HIMAC has been successfully being progressed and more than 1,700 patients have treated with carbon ions. Owing to the good result of HIMAC, several medical groups in Japan have strongly required the carbon therapy facility. Based on the development of accelerator and the irradiation technologies for 10 years, therefore, we started to design a carbon therapy facility in Japan. The accelerator complex for the facility consists of two ECR ion sources with permanent magnets, an injector linac cascade (RFQ+IH) with the energy of 4 MeV/n, a synchrotron ring with the maximum energy of 400 MeV/n and beam delivery system for three treatment rooms. The R&D for the new facility has been already approved and will be started from April 2004. We will describe the conceptual design of the new facility.  
 
THPLT065 Study of Multiturn Injection at HIMAC Synchrotron injection, simulation, optics, emittance 2640
 
  • T.H. Uesugi, T. Furukawa, T. Naruse, K. Noda
    NIRS, Chiba-shi
  • T. Fujimoto, S. Shibuya
    AEC, Chiba
  In the multiturn injection method at the HIMAC synchrotron, a collapsing speed of the bump orbit was decreased from 200 to 350 microseconds in order to obtain higher intensity beam. The injection line was readjusted to satisfy the optimum condition of multiturn injection method. Furthermore, COD correction and bump-orbit optimization were carried out. On the other hand, in order to prevent the resonance by tune shift and to keep the beam intensity constant, tune survey was carried out. While vertical tune is adjusted, we propose that the method to reduce beam loss after injection by expanding vertical beam size by means of the RF-knockout. This paper describes the improvement of injection at HIMAC synchrotron.  
 
THPLT072 Magnet and RF Systems of Small Pulse Synchrotron for Radiotherapy dipole, quadrupole, proton, sextupole 2661
 
  • K. Endo, K. Egawa, Z. Fang, S. Yamanaka
    KEK, Ibaraki
  To cure the malignant tumor it is desirable to equalize the treatment level to everybody anywhere he lives in. Proton and/or carbon-ion therapy are now considered as a powerful remedy as the radiation dose can be easily concentrated to the target volume by utilizing the Bragg?s peak. If a small medical accelerator is developed at a reasonable cost, it has a big potential to promote the advanced medical treatment with the accelerator in every place. This pulse synchrotron aims to reduce the size of the accelerator by generating the high magnetic field in a short time which leads to a compact ring of high field magnets. Acceleration time is only 5 msec by using the discharge current of a capacitor bank as large as 200 kA at peak, almost equivalent to half sinusoidal 50 Hz. Part of the discharge current is branched to excite the quadrupole magnets to assure the tracking between the dipole and quadrupole fields. Pulsed power technique is also adopted to drive the RF power tubes. Both magnet and RF systems have been developed and being extensively studied. Technological sides of both systems will be treated in details as well as the computational beam behaviors in this pulse synchrotron.  
 
THPLT073 Numerical Methods for the Orbit Control at the KEK 12 GeV PS beam-losses, injection, closed-orbit, vacuum 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.  
 
THPLT091 The Synchrotron Radiation Monitor Upgradation in NSRRC radiation, booster, synchrotron-radiation, optics 2709
 
  • C.H. Kuo, J. Chen, K.-T. Hsu, S.Y. Hsu, Y.-T. Yang
    NSRRC, Hsinchu
  Synchrotron radiation monitor in the storage has been operated for a long time. This system is upgrading to booster operation now. The basic system includes optics, digital image acquisition, image analysis, compressed image transportation and visualization tools at workstation. The linearity and dynamic of new is discussed for some beam physics study. This system is also supported to the booster by new camera and addition operation. The hardware configuration and software structure will be summarized in this report.  
 
THPLT100 Development of a Permanent Magnet Residual Gas Profile Monitor With Fast Readout electron, ion, injection, photon 2724
 
  • D.A. Liakin, S.V. Barabin, V. Skachkov
    ITEP, Moscow
  • P. Forck, T. Giacomini
    GSI, Darmstadt
  • A. Vetrov
    MSU, Moscow
  The beam profile measurement at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. From the other hand, high spatial resolutions are very desirable for cold beams. We are developing a residual gas monitor to cover the wide range of beam currents and transversal distributions of particles. It supplies the needed high-resolution and high-speed tools for beam profiling. The new residual gas monitor, will operate on secondary electrons whose trajectories are localized within 0.1 mm filaments. The required magnetic field of 100 mT will be excited by a permanent magnet. In the fast turn-by-turn mode the beam profile will be read out with a resolution of 1 mm by a 100-channel photodiode-amplifier-digitizer. The high resolution mode of 0.1 mm is provided by a CCD camera with upstream MCP-phosphor screen assembly. In this paper the first results of the photodiode-digitizer device testing, the compact mechanical design features and simulation results of the permanent magnet device are presented.  
 
THPLT107 VEPP-4M Optical Beam Profile Monitor with a One-turn Temporal Resolution collider, pick-up, diagnostics, betatron 2733
 
  • O.I. Meshkov, V.F. Gurko, A.D. Khilchenko, V. Kiselev, N.Y. Muchnoi, N.A. Selivanov, V.V. Smaluk, A.N. Zhuravlev, P.V. Zubarev
    BINP SB RAS, Novosibirsk
  The transverse beam profile monitor based on Hamamatsu multi-anode photomultiplier with 16 anode strips is used at the VEPP-4M collider. The monitor is applied to study turn-to-turn dynamics of the transverse beam profile during 131 000 turns. The device provides a permanent measurement of synchrotron and betatron frequencies as well.  
 
THPLT127 Beam Diagnostics Systems for the Diamond Synchrotron Light Source electron, linac, booster, storage-ring 2765
 
  • G. Rehm, A.F.D. Morgan, C. Thomas
    Diamond, Oxfordshire
  We present an overview of the diagnostics systems that will be implemented at the Diamond synchrotron light source. The aim of this paper is to give a complete picture of the systems to measure the quality of the electron beam from the injector through to the storage ring. We will show how we intend to measure the dimensions, the position and the time structure of the electron bunches. In addition, the instrumentation to measure the charge, the current and the emittance of the electron beam will be described. Finally, systems to provide accurate measurement of electron losses and the injection efficiency will be detailed.  
 
THPLT137 Commissioning of the Head-tail Monitoring Application for the Tevatron kicker, proton, acceleration, monitoring 2780
 
  • V.H. Ranjbar, V. Lebedev, E. Lorman, A. Xiao
    Fermilab, Batavia, Illinois
  A head-tail beam monitoring application has recently been developed for use in the Tevatron. With this application beam dynamics problems including head-tail instabilities can be monitored. In addition it can be use to perform chromaticity measurements using the head-tail technique developed at CERN. This application speeds up chromaticity measurements in the Tevatron especially during the acceleration ramp and low beta squeeze, which previously required three separate ramps using uncoalesced protons  
 
THPLT142 A Laser-Based Longitudinal Density Monitor for the Large Hadron Collider laser, photon, monitoring, radiation 2789
 
  • S. De Santis, J.F. Beche, J.M. Byrd, P. Datte, M. Placidi, V. Riot, R.W. Schoenlein, W.C. Turner, M.S. Zolotorev
    LBNL, Berkeley, California
  We report on the development of an instrument for the measurement of the longitudinal beam profile in the Large Hadron Collider. The technique used, which has been successfully demonstrated at the Advanced Light Source, mixes the synchrotron radiation with the light from a mode-locked solid state laser oscillator in a non-linear crystal. The up-converted radiation is then detected with a photomultiplier and processed to extract, store and display the required information. A 40 MHz laser, phase-locked to the ring radiofrequency system, with a 50 ps pulse length, would be suitable for measuring the dynamics of the core of each of the LHC 2808 bunches in a time span much shorter then the synchrotron period. The same instrument could also monitor the evolution of the bunch tails, the presence of untrapped particles and their diffusion into nominally empty RF buckets ("ghost bunches") as required by the CERN specifications. We also specify the required characteristics of the diagnostic light port in the LHC where our instrument would be installed.

* Presently at Lawrence Livermore National Laboratory.

 
 
THPLT143 Development of an Abort Gap Monitor for the Large Hadron Collider photon, synchrotron-radiation, radiation, diagnostics 2792
 
  • S. De Santis, J.F. Beche, J.M. Byrd, M. Placidi, W.C. Turner, M.S. Zolotorev
    LBNL, Berkeley, California
  The Large Hadron Collider, presently under construction at CERN, requires a monitor of the parasitic charge in the 3.3 ?s long gap in the machine fill structure, referred to as the abort gap, which corresponds to the raise time of the abort kickers. Any circulating particle present in the abort gap at the time of the kickers firing is lost inside the ring, rather than in the beam dump, and can potentially damage a number of the LHC components. CERN specifications indicate a linear density of 6x106 protons over a 100 ns interval as the maximum charge safely allowed in the abort gap at 7 TeV. We present a study of an abort gap monitor, based on a photomultiplier with a gated microchannel plate, which would allow for detecting such low charge densities by monitoring the synchrotron radiation emitted in the superconducting undulator dedicated to the measurement of the longitudinal beam properties. We show results of beam test experiments at the Advanced Light Source using an Hamamatsu 5916U MCP-PMT which indicate that such an instrument has the required sensitivity to meet LHC specifications.  
 
THPLT155 Development and Testing of a Low Group-delay Woofer Channel for PEP-II feedback, damping, impedance, diagnostics 2822
 
  • J.D. Fox, L. Beckman, D. Teytelman, D. Van Winkle, A. Young
    SLAC, Menlo Park, California
  The PEP-II HER and LER require active longitudinal feedback to control coupled-bunch instabilities. The PEP-II RF systems use direct and comb loop feedback to reduce the cavity fundamental impedance, though the remaining low-mode impedance is providing the fastest growing unstable modes in both rings. Since commissioning the longitudinal feedback systems have used a dedicated "woofer" channel to apply the low-frequency correction kick via the RF system. The performance of this original controller is limited by the maximum gain that can be supported due to the processing delay (group delay), as well as the difficulty in configuring a common correction controller that acts via two correction paths. A dedicated low-mode signal processing system has been developed to allow higher damping rates. It is a digital processing channel, operating at a 10 MHz sampling rate, and implementing flexible 5 to 10 tap FIR control filters. The design of the channel and initial control filters is presented, as are initial machine experiments quantifying the damping and noise floor of this low group delay woofer system.  
 
THPLT159 Instability Thresholds and Generation of the Electron-cloud in the GLC/NLC and Tesla Damping Rings electron, damping, simulation, single-bunch 2831
 
  • M.T.F. Pivi, T.O. Raubenheimer
    SLAC/NLC, Menlo Park, California
  In the beam pipe of the Damping Ring (DR) of a linear collider, an electron cloud may be produced by ionization of residual gas and secondary emission. This electron cloud can reach equilibrium after the passage of only a few bunches. We present recent computer simulation results for the main features of the electron cloud generation in the GLC/NLC main DR and for the TESLA DR. Single and multi-bunch instability thresholds are also calculated for the NLC main DR. The results are obtained by the computer simulation codes HEAD-TAIL and POSINST, which were developed to study the electron cloud effect in particle accelerators.  
 
THPLT165 Synchrotron Light Interferometry at JEFFERSON Lab betatron, instrumentation, monitoring, alignment 2846
 
  • A. Freyberger, P. Chevtsov, T. Day, R. Hicks
    Jefferson Lab, Newport News, Virginia
  • J-C. Denard
    SOLEIL, Gif-sur-Yvette
  The hyper-nuclear physics program at JLAB requires an upper limit on the RMS momentum spread of dp/p<3e-5. The momentum spread is determined by measuring the beam width at a dispersive location (D~4m) in the transport line to the experimental halls. Ignoring the epsilon-beta contribution to the intrinsic beam size, this momentum spread corresponds to an upper bound on the beam width of σ_beam<120um. Typical techniques to measure and monitor the beam size are either invasive or do not have the resolution to measure such small beam sizes. Using interferometry of the synchrotron light produced in the dispersive bend, the resolution of the optical system can be made very small. The non-invasive nature of this measurement allows continuous monitoring of the momentum spread. Two synchrotron light interferometers have been built and installed at JLAB, one each in the Hall-A and Hall-C transport lines. The devices operate over a beam current range from 1uA to 100uA and have a spatial resolution of 10um. The structure of the interferometers, the experience gained during its installation, beam measurements and momentum spread stability are presented. The dependence of the measured momentum spread on beam current will be presented.  
 
FRYACH01 HICAT - The German Hospital-Based Light Ion Cancer Therapy Project ion, extraction, injection, beam-transport 290
 
  • H. Eickhoff, T. Haberer, B. Schlitt, U. Weinrich
    GSI, Darmstadt
  At the University Clinics at Heidelberg /Germany the realization of a cancer Therapy facility using light and medium ions (from protons up to oxygen) has started. This facility will be capable to treat about 1000 patients per year by means of the 'intensity controlled rasterscan technique', that has been already successfully applied to about 200 patients since 1998 at the GSI therapy pilot project. The presentation will give an overview of the facility layout and especially the accelerator- and beam transport systems, capable to provide 3 treatment places with light ions between 50 and 430 MeV/u. Two treatment places are located after horizontal beam lines and one after an isocentric gantry. A further horizontal beam line for research and development activities is foreseen. Besides the technical description and the status and schedule for the project realization organizational aspects of this project will be discussed with the project leadership at the University Clinics, the strong technical assistance of GSI and the role of industrial partners.  
Video of talk
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