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Paper Title Other Keywords Page
MOPKF005 Preliminary Results on a Low Emittance Gun Based on Field Emission emittance, undulator, alignment, damping 306
 
  • R. Ganter, A.E. Candel, M. Dehler, G.J. Gobrecht, C. Gough, S.C. Leemann, K.L. Li, M. Paraliev, M. Pedrozzi, J.-Y. Raguin, L. Rivkin, V. Schlott, L. Schulz, A. Streun, A. Wrulich
    PSI, Villigen
  The development of a new electron gun with the lowest possible emittance would help reducing the total length and cost of a free electron laser. Recent progresses in vacuum nanoelectronics make field emitter arrays (FEAs) an attractive technology to explore for high brightness sources. Indeed, several thousands of microscopic tips can be deposited on a 1 mm diameter area. Electrons are then extracted by a first grid layer close to tip apex and focused by a second grid layer one micrometer above the tip apex. The typical aperture diameter of this focusing layer is also in the range of one micrometer. The big challenge with FEA, is to achieve good emission homogeneity, we hope to achieve this with diverse conditioning techniques. However if we can achieve a low emittance with FEAs another challenge will be to preserve the emittance during the beam acceleration.  
 
MOPKF006 Enhancements of Top-up Operation at the Swiss Light Source emittance, linac, undulator, alignment 309
 
  • B. Kalantari, T. Korhonen, A. Lüdeke, C. Quitmann
    PSI, Villigen
  Since the first experience on 2001, Top-Up is the standard mode of operation at the Swiss Light Source (SLS) for users. In order to fulfill the ongoing demands of machine experts and experiments we have had to add more functionality to the Top-Up mode thus make it more flexible. Some time-resolved experiments require a constant charge in a single isolated bucket in the gap of the normal filling of a bunch train of 80% of the circumference of the storage ring. Therefore the Hybrid application was developed that keeps the beam current distribution constant in this mode. We developed a maintenance mode too, to allow to work continuously on the Linac and booster - for example to optimize injection/extraction - without disturbing the Top-up for user operation. Even beam destructive experiments at the Linac during Top-Up or Hybrid operation are supported, where the Linac can be used synchronously at the times between successive refilling of the storage ring. The flexible control and timing systems at the SLS made these applications feasible. We describe the controls, operation and applications of each of the above functionalities in this paper.  
 
MOPKF008 The BESSY Soft X-ray FEL User Facility emittance, undulator, alignment, damping 312
 
  • D. Krämer
    BESSY GmbH, Berlin
  A FEL User Facility for the VUV to soft X-ray spectral range is planned at the BESSY site based on a cascaded HGHG-FEL scheme. Simultaneous operation of 3 - later 5 - FELs fed by a superconducting 2.3 GeV CW linac generates most flexible pulse structures for experiments, while the seeding scheme utilizing Ti:Sa fs-lasers results in ultrashort reproducible circular polarized FEL pulses on a shot to shot basis at a pulse-duration < 20 fs. Peak brilliances in the 1·1031 ph/(s mm2 mrad2 0.1% bw)-regime are feasible. All necessary hardware for the FEL is within existing technology. Future upgrade options, e.g. a superconducting photoinjector, seeding with short wavelength HHG lasers of about 1 fs pulse duration have been considered. A status on the design aspects is given.  
 
MOPKF009 Photoinjector Studies for the BESSY Soft X-ray FEL gun, linac, undulator, alignment 315
 
  • F. Marhauser
    BESSY GmbH, Berlin
  A linac driven soft X-Ray FEL facility has been proposed at BESSY with the aim to produce high brilliance photon beams within the energy range of 20eV to 1keV. The driver linac is based on superconducting (sc) L-Band rf-technolgy to enable cw operation of the FEL. As the electron beam emittance directly influence the photon beam characteristics, transverse slice emittances of 1.5pimmmrad are envisaged as a target goal. This demands for a high brilliance laser driven photoinjector rf-gun as electron source. For the first years of operation it is intended to use well known normal conducting (nc) L-Band rf-gun technology thereby restricting the macropulse repetition rate to 1 kHz to cope with the thermal power dissipation. At a later stage the nc rf-gun shall be replaced by a sc rf-gun, which is favoured conceptually as it allows to generate outmost flexible bunch patterns according to the needs of the experiments by fully exploiting the capabilities of the sc linac. This paper details the design considerations for a high power nc rf-gun complemented by results of beam dynamic studies up to the exit of the booster linac using ASTRA. Perspectives for the use of a sc photoinjector gun cavity are addressed.  
 
MOPKF020 Proposal for a Sub-100 fs Electron Bunch Arrival-time Monitor for the VUV-FEL at DESY laser, wiggler, damping, gun 345
 
  • H. Schlarb, S. Düsterer, J. Feldhaus, J. Hauschildt, R. Ischebeck, K. Ludwig, B. Schmidt, P. Schmüser, S. Simrock, B. Steffen, F. Van den Berghe, A. Winter
    DESY, Hamburg
  • P.H. Bucksbaum, A. Cavalieri, D. Fritz, S. Lee, D. Reis
    Michigan University, Ann Arbor, Michigan
  For pump-probe experiments at the VUV-Free Electron Laser at DESY, an external optical laser system will be installed, capable of delivering ultra-short pulses of high intensity. The laser pulses with a center wavelength of 800 nm are synchronized with the VUV-FEL beam which covers the wavelength range between 6 nm and 80 nm. The expected pulse durations are typically 100 fs FWHM or below. For high-resolution pump-probe experiments a precise knowledge of the time difference between both pulses is mandatory. In this paper we describe the layout and the design of a high-precision electron bunch arrival time monitor based on an electro-optic technique. We present the numerical results of simulations that include: the laser propagation in a specifically designed demanding optical system, the laser transport through a 150 m long optical fibre, the electro-optically induced effect in different types of crystals and for different electron bunch shapes as well as the effects of wake fields on the co-propagating electric-fields and their impact on the observable signals.  
 
MOPKF021 Properties of Cathodes Used in the Photoinjector RF Gun at the DESY VUV-FEL laser, wiggler, damping, alignment 348
 
  • S. Schreiber
    DESY, Hamburg
  • J.H. Han
    DESY Zeuthen, Zeuthen
  • P. Michelato, L. Monaco, D. Sertore
    INFN/LASA, Segrate (MI)
  The new injector of the DESY VUV-FEL is being commissioned in spring 2004. Several cathodes have been tested in the photoinjector RF Gun. We report on quantum efficiency, dark current, and the overall appearance of the cathodes after their use.  
 
MOPKF022 Commissioning of the VUV-FEL Injector at TTF laser, wiggler, damping, alignment 351
 
  • S. Schreiber
    DESY, Hamburg
  The VUV-FEL at the TESLA Test Facility (TTF) at DESY is being upgraded to an FEL user facility serving high brilliance beams in the wavelength range from the VUV to soft X-rays. The photoinjector has been redesigned to meet the more demanding beam parameters in terms of transverse emittance, peak current, and energy spread. The first phase of the injector upgrade has been finished in spring 2004. We report on its commissioning, including first measurements of beam parameters.  
 
MOPKF025 Planar and Planar Helical Superconductive Undulators for Storage Rings, State of the Art laser, wiggler, damping, alignment 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.  
 
MOPKF027 Optimizing the PITZ Electron Source for the VUV-FEL wiggler, damping, alignment, linac 360
 
  • M. Krasilnikov, J. Bähr, U. Gensch, H.-J. Grabosch, J.H. Han, D. Lipka, V. Miltchev, A. Oppelt, B. Petrosyan, D. Pose, L. Staykov, F. Stephan
    DESY Zeuthen, Zeuthen
  • K. Abrahamyan
    YerPhI, Yerevan
  • W. Ackermann, R. Cee, W.F.O. Müller, S. Setzer, T. Weiland
    TEMF, Darmstadt
  • G. Asova, G. Dimitrov, I. Tsakov
    INRNE, Sofia
  • I. Bohnet, J.-P. Carneiro, K. Floettmann, S. Riemann, S. Schreiber
    DESY, Hamburg
  • M.V. Hartrott, E. Jaeschke, D. Krämer, R. Richter
    BESSY GmbH, Berlin
  • P. Michelato, L. Monaco, C. Pagani, D. Sertore
    INFN/LASA, Segrate (MI)
  • J. Rossbach
    Uni HH, Hamburg
  • W. Sandner, I. Will
    MBI, Berlin
  The goal of the Photo Injector Test Facility at DESY Zeuthen (PITZ) is to test and optimize electron sources for Free Electron Lasers and future linear colliders. At the end of 2003 the first stage of PITZ (PITZ1) has been successfully completed, resulting in the installation of the PITZ RF gun at the Vacuum Ultra Violet - Free Electron Laser (VUV-FEL) at DESY Hamburg. The main results achieved during the PITZ1 extensive measurement program are discussed in this paper. A minimum normalized beam emittance of about 1.5 pi mm mrad for 1 nC electron bunch charge has been reached by optimizing numerous photo injector parameters, e.g. longitudinal and transverse profiles of the photocathode laser, RF phase, main and bucking solenoid current. The second stage of PITZ (PITZ2), being a large extension of the facility and its research program, has started now. Recent progress on the PITZ2 developments will be reported as well.  
 
MOPKF035 Stabilization of the Pulsed Regimes on Storage Ring Free Electron Laser: The Cases of Super-ACO and Elettra injection, booster, wiggler, damping 381
 
  • C. Bruni, D. Garzella, G. Lambert, G.L. Orlandi
    LURE, Orsay
  • E. Allaria, R. Meucci
    INOA, Firenze
  • S. Bielawski
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex
  • M.-E. Couprie
    CEA/DSM, Gif-sur-Yvette
  • M. Danailov, G. De Ninno, B. Diviacco, M. Trovò
    ELETTRA, Basovizza, Trieste
  • D. Fanelli
    KTH/NADA, Stockholm
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma)
  In a Storage Ring Free Electron Laser (SRFEL) a relativistic electron beam interacts with the magnetostatic periodic field of an undulator, thus emitting synchrotron radiation. The light is stored in an optical cavity and amplified during successive turns of the particles in the ring. The laser intensity may appear as a "continuous wave (cw)" or show a stable pulsed behaviour depending on the value of the temporal detuning, i.e. the difference between the electron beam revolution period and the round trip of the photons in the cavity. It was recently shown, that the loss of stability in a SRFEL occurs through an Hopf bifurcation [*]. This observation opens up the perspective of introducing a derivative self-controlled feedback to suppress locally the bifurcation and enlarge the region of stable signal. A feedback of this type has been implemented on Super-ACO and shown to produce a significant and reproducible extension of the stable "cw" region. We review here these results and discuss new experiments performed on the Super-ACO and ELETTRA SRFELs.

* G. De Ninno and D. Fanelli, Phys. Rev. Lett. in press; M.E. Couprie et al. Nucl. Instrum.and Meth. A., in press

 
 
MOPKF040 Effect of Electron-beam Feedbacks on the ELETTRA Storage-ring Free-electron Laser injection, laser, booster, linac 393
 
  • M. Trovò, D. Bulfone, M. Danailov, G. De Ninno, B. Diviacco, V. Forchi', M. Lonza
    ELETTRA, Basovizza, Trieste
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma)
  As is well known, the stability of a storage-ring free-electron laser is strongly related to that of the electron beam. With respect to second-generation devices, such as Super ACO and UVSOR, the free-electron laser at ELETTRA is characterized by a noticeably higher gain and, consequently, shows to be much more sensitive to electron-beam instabilities. In order to counteract the impact of such instabilities, both a longitudinal multibunch and a local orbit feedbacks have been implemented for free-electron laser operation. Aim of this paper is to report on the beneficial effect of these feedback systems on the laser performance.  
 
MOPKF041 SPARC Photoinjector Working Point Optimization, Tolerances and Sensitivity to Errors injection, laser, booster, emittance 396
 
  • M. Ferrario, M.E. Biagini, M. Boscolo, V. Fusco, S. Guiducci, M.  Migliorati, C. Sanelli, F. Tazzioli, C. Vaccarezza
    INFN/LNF, Frascati (Roma)
  • L. Giannessi, L. Mezi, M. Quattromini, C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma)
  • J. Rosenzweig
    UCLA, Los Angeles, California
  • L. Serafini
    INFN-Milano, Milano
  A new optimization of the SPARC photoinjector, aiming to reduce the FEL saturation length, is presented in this paper. Start to end simulations show that with 1.1 nC charge in a 10 ps long bunch we can deliver at the undulator entrance a beam having 100 A in 50% of the slices (each slice being 300 mm long) with a slice emittance ?1 mm, thus reducing the FEL-SASE saturation length to 12 m at 500 nm wavelength. In addition the stability of the nominal working point and its sensitivity to various type of random errors, under realistic conditions of the SPARC photoinjector operation, are discussed. A systematic scan of the main parameters around the operating point, performed with PARMELA code interfaced to MATLAB, shows that the probability to get a projected emittance exceeding 1 mm is only 10 % and the slice emittance remains below 1 mm in all cases.  
 
MOPKF042 Status of the SPARC Project injection, booster, linac, vacuum 399
 
  • M. Ferrario, D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, D. Filippetto, V. Fusco, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario
    INFN/LNF, Frascati (Roma)
  • F. Alessandria, A. Bacci, M. Mauri
    INFN/LASA, Segrate (MI)
  • I. Boscolo, F. Brogli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, M. Romé, L. Serafini
    INFN-Milano, Milano
  • L. Catani, E.C. Chiadroni, A. Cianchi, S. Tazzari
    Università di Roma II Tor Vergata, Roma
  • F. Ciocci, G. Dattoli, A. Doria, F. Flora, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, L. Mezi, P.L. Ottaviani, L. Picardi, M. Quattromini, A. Renieri, C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma)
  • D. Dowell, P. Emma, C. Limborg-Deprey, D. Palmer
    SLAC, Menlo Park, California
  • D. Levi, M. Mattioli, G. Medici
    Università di Roma I La Sapienza, Roma
  • M.  Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma
  • P. Musumeci, J. Rosenzweig
    UCLA, Los Angeles, California
  • M. Nisoli, S. Stagira, S. de Silvestri
    Politecnico/Milano, Milano
  The aim of the SPARC project is to promote an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments at 500 nm and higher harmonics generation. It has been proposed by a collaboration among ENEA-INFN-CNR-Universita‘ di Roma Tor Vergata-INFM-ST and funded by the Italian Government with a 3 year time schedule. The machine will be installed at LNF, inside an existing underground bunker. It is comprised of an rf gun driven by a Ti:Sa laser to produce 10-ps flat top pulses on the photocathode, injecting into three SLAC accelerating sections. We foresee conducting investigations on the emittance correction and on the rf compression techniques up to kA level. The SPARC photoinjector can be used also to investigate beam physics issues like surface-roughness-induced wake fields, bunch-length measurements in the sub-ps range, emittance degradation in magnetic compressors due to CSR. We present in this paper the status of the design activities of the injector and of the undulator. The first test on diagnostic prototypes and the first experimental achievements of the flat top laser pulse production are also discussed.  
 
MOPKF074 Harmonic Cascade FEL Designs for LUX wiggler, cathode, laser, insertion 488
 
  • G. Penn, J.N. Corlett, W. Fawley, M. Reinsch, W. Wan, J.S. Wurtele, A. Zholents
    LBNL, Berkeley, California
  LUX is a proposed facility for ultrafast X-ray science, based on an electron beam accelerated to GeV energies in a recirculating linac. Included in the design are short duration (200 fs or shorter FWHM) light sources using multiple stages of higher harmonic generation, seeded by a 190–250 nm laser of similar duration. This laser modulates the energy of a group of electrons within the electron bunch; this section of the electron bunch then produces radiation at a higher harmonic after entering a second, differently tuned undulator. Repeated stages in a cascade yield increasing photon energies up to 1 keV. Most of the undulators in the cascade operate in the low-gain FEL regime. Harmonic cascades have been designed for each pass of the recirculating linac up to a final electron beam energy of 3.1 GeV. For a given cascade, the photon energy can be selected over a wide range by varying the seed laser frequency and the field strength in the undulators. We present simulation results using the codes GENESIS and GINGER, as well as the results of analytical models which predict FEL performance. We discuss lattice considerations pertinent for harmonic cascade FELs, as well as sensitivity studies and requirements on the electron beam.  
 
MOPKF076 An Overview of the Cryomodule for the Cornell ERL Injector wiggler, cathode, laser, insertion 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 wiggler, linac, radiation, cathode 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.  
 
MOPKF078 ERL Upgrade of an Existing X-ray Facility: CHESS at CESR wiggler, cathode, linac, laser 497
 
  • G. Hoffstaetter, M. Liepe, R.M. Talman, M. Tigner
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • I. Bazarov, H. Bilderback, M. Billing, S. Gruner, D. Sagan, C.K. Sinclair
    Cornell University, Department of Physics, Ithaca, New York
  CORNELL has proposed an Energy-Recovery Linac (ERL) based synchrotron-light facility which can provide improved x-ray radiation due to the high beam quality that can be available from a linac. To additionally utilize beam currents that are competitive with ring-based light sources, the linac has to operate with the novel technique of energy recovery, the feasibility of which CORNELL plans to demonstrate in a downscaled prototype ERL. Here we present an ERL upgrade of the existing 2nd generation light source CHESS at CESR. This proposed upgrade suggests how existing storage rings can be extended to ERL light sources with much improved beam qualities.  
 
MOPKF080 Controlling Emittance Growth in an FEL Beam Conditioner linac, wiggler, cathode, gun 503
 
  • P. Emma, G.V. Stupakov
    SLAC, Menlo Park, California
  It has been proposed [*] to 'condition' an electron beam prior to the undulator of a Free-Electron Laser (FEL) by increasing each particle's energy in proportion to the square of its transverse betatron amplitude. This conditioning enhances FEL gain by reducing the axial velocity spread within the electron bunch. Previosly [**] we presented a system that allows conditioning of the beam on a relatively short distance, however, it suffers from projected beam emittance growth to the extent that makes it impractical for application for X-ray FELs. In this paper we extend analysis proposed by A. Wolski for general requirements to the conditioner which does not have such emittance growth. We also present a possible implementation of a beam conditioner consisting of multiple solenoid cells in combination with quadrupole magnets. Simulations show that in such a system the emittance growth can be suppressed to acceptable level, albeit in a longer system.

* A. Sessler et al., Phys. Rev. Lett., 68, 309 (1992).** P. Emma and G. Stupakov. PRSTAB, 6, 030701 (2003).

 
 
MOPKF081 Peak Current Optimization for LCLS Bunch Compressor 2 linac, wiggler, cathode, gun 506
 
  • A.C. Kabel, P. Emma
    SLAC, Menlo Park, California
  The performance of an FEL will be a function of both the driving bunch's current and its slice emittance. We have studied a set of parameters for the bunch compression section of the LCLS, simulating the effects of Coherent Synchrotron Radiation (CSR) on the slice emittance of the bunch core as a function of peak current. We use the code TraFiC4 for a three-dimensional, self-consistent simulation on parallel computers. While higher currents will increase FEL performance, its detrimental effects, due to CSR, on slice emittance will counteract this beneficial effect. From our simulations, we determine a near-optimum current, balancing these effects.  
 
MOPKF082 A Multi-bunch, Three-dimensional, Strong-strong Beam-beam Simulation Code for Parallel Computers linac, wiggler, cathode, gun 509
 
  • A.C. Kabel, Y. Cai
    SLAC, Menlo Park, California
  We have developed a parallel simulation code allowing the self-consistent, three-dimensional simulation of the strong-strong beam-beam effect, using a particle-on-mesh technique and fast elliptic solvers. It is able to operate with sufficiently high logitudinal resolution to treat phase-averaging and hourglass effects in the interaction point (IP) correctly. This code has been generalized to handle the collisions of an arbitrary set of bunches at arbitrary positions in the ring (parasitic crossings), using appropriately reduced longitudinal resolution of collisions not in the design IP. We provide benchmarking results and parameter studies based on PEP-II.  
 
MOPKF083 Inverse Free Electron Laser Heater for the LCLS laser, wiggler, gun, undulator 512
 
  • R. Carr, L.D. Bentson, P. Bolton, D. Dowell, P. Emma, A. Gilevich, Z. Huang, J.J. Welch, J. Wu
    SLAC, Menlo Park, California
  The LCLS Free Electron Laser employs an RF photocathode gun that yields a 1 nC charge bunch a few picoseconds long, which must be further compressed to yield the high current required for SASE gain. The very cold electron beam from the RF photocathode gun is quite sensitive to microbunching instabilities such as coherent synchrotron radiation (CSR) in the compressor chicanes and longitudinal space charge (LSC) in the linac. These effects can be Landau damped by adding energy spread to the electron bunch prior to compression. We propose to do this by interacting an infrared laser beam with the electron bunch in an undulator added to the LCLS gun-to-linac injector. The undulator is placed in a 4-bend chicane to allow the IR laser beam to propagate co-linearly with the e-beam while it oscillates in the undulator. The IR laser beam is derived from the photocathode gun laser. Simulations presented elsewhere in these proceedings show that the laser interaction damps the microbunching instabilities to a very great extent. This paper is a description of the implementation of the laser heater  
 
MOPLT099 NSC KIPT Accelerator on Nuclear and high Energy Physics plasma, wiggler, vacuum, wakefield 761
 
  • I.S. Guk, A. Dovbnya, S.G. Kononenko, A.S. Tarasenko
    NSC/KIPT, Kharkov
  • J.I.M. Botman, M.J. Van der Wiel
    TUE, Eindhoven
  One of the main reasons for the outflow of experts in nuclear physics and adjacent areas of science from Ukraine is the absence of modern accelerating facilities, for conducting research in the present fields of interest worldwide in this area of knowledge. A qualitatively new level of research can be achieved by the construction of a new generation accelerator applying the latest developments in the field of electron beam acceleration, in particular on the basis of superconducting accelerating structures of the TESLA type. Such structures may be used for continuous, polarized electron beams, which is crucial e.g. for thin(?) experiments checking modern theoretical models of interactions of nuclear substance, and for beams with high current and extremely short pulses for research in free electron laser and neutron physics. Such a facility will create an opportunity for carrying out research representing the interest of scientists from other countries, which will promote the integration of Ukrainian science into European and worldwide research.  
 
MOPLT101 Performances of the Beam Generated by Metal-Dielectric Cathodes in RF Electron Guns wiggler, gun, wakefield, beamloading 767
 
  • I.V. Khodak, I.V. Khodak, V.A. Kushnir
    NSC/KIPT, Kharkov
  The paper describes results of the experimental research of the metal-dielectric cathode operation in RF electron gun. Application of these cathodes permits RF guns to generate intense beams with nanosecond current pulse duration. Electron beam is extracted from plasma sheath developed during the surface vacuum flashover dielectric. Simulated and experimental parameters of the beam obtained at the single-cavity RF gun output are summarized in the paper. The beam formation and its interaction with microwave field of high strength are analyzed qualitatively. Results are compared with experimental results obtained before in the 1.5-cavity RF electron gun. First experimental results on electron beam generation by the RF gun with a ferroelectric cathode are discussed in the paper.  
 
MOPLT102 To the Problem of Wake-field Excitation for Advanced Accelerator Concept wiggler, gun, wakefield, beamloading 770
 
  • I.N. Onishchenko, V. Kiselev, A. Linnik, N. Onishchenko, G. Sotnikov
    NSC/KIPT, Kharkov
  • V. Ushkov
    RRC Kurchatov Institute, Moscow
  The advanced accelerator concept to use the wake-fields exited in dielectric by a sequence of electron bunches for high-gradient particle acceleration has been proposed and investigated in [*-***]. Two essential merits are being exploited. First of them [**] is the excitation by a regular sequence of electron bunches that allows superposing coherently the wake-fields excited by each bunch. The second one [***] concludes to multi-mode operation that leads to peaking of the resulting HF-field that is represented by a sequence of spikes of alternative signs with essentially higher amplitude comparatively to only principle mode excitation. The recent works performed in NSC/KIPT on theoretical studies, simulation, and experimental investigations of the wake-fields excitation by a train of 2 MeV electron bunches in a dielectric waveguide are presented. Transition and Cerenkov radiation excited by short bunches in a limited dielectric medium was theoretically investigated. The measurements of wake-fields output power and the electron energy spectrum were experimentally performed.

* W.Gai, P.Schoessow, B.Cole et al. Phys. Rev. Lett. 61, 2756 (1988) ** I.N.Onishchenko, V.A.Kiselev, G.V.Sotnikov et al. Proc. 1995 Particle Accelerator Conf., p. 782-3*** T.B.Zhang, J.L.Hirshfield, T.C.Marshall et al Proc. 1997 Particle Accelerator Conf., V.42, No.3, p.1341

 
 
MOPLT103 Radiation Resistant Magnetic Sensors for Accelerators wiggler, gun, radiation, wakefield 773
 
  • I. Bolshakova, R. Holyaka
    LPNU, Lviv
  • S. Kulikov
    JINR, Dubna, Moscow Region
  • M. Kumada
    NIRS, Chiba-shi
  • C. Leroy
    CERN, Geneva
  The technology of obtaining the radiation resistant magnetic sensors, which characteristics remain stable under the irradiation with high dose of fast neutrons was designed. Radiation resistant sensors are developed on the base of InSb. While irradiation with neutron flux of 1010 n*cm-2*c-1 with energies 0.1…13 MeV, with the thermal neutrons part in the general flux of 20% and intermediate fluxes of 25%, the main sensors’ characteristics, that is their sensitivity to the magnetic field, change no more than for 0.05% up to the fluence of 1*1015 n*cm-2 and no more than for 1% up to the fluence of 3*1016 n*cm-2. Radiation resistant sensors are used for development of magnetic field monitoring system with measuring channels accuracy of 0,01%, which have a function of temperature measurement with the accuracy of 0.1 С at the place of sensor location, moreover, it has self diagnostics and self correction functions. This system passed the long-term testing of continuous 3 months operation at the Neutron Physics Laboratory, JINR, Dubna at the IBR-2 neutron reactor.  
 
MOPLT104 Quantitative Optimisation Studies of the Muon Front-End for a Neutrino Factory wiggler, gun, radiation, wakefield 776
 
  • S.J. Brooks
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  In a Neutrino Factory, short proton pulses hit a target, producing pions at widely varying angles and energies. Efficient pion capture is required to maximise the yield of decayed muons, which proceed via acceleration stages into a muon storage ring to produce neutrinos. This paper presents optimisation of a solenoidal decay channel designed for high-emittance pions, based on schemes from CERN and RAL. A non-linear tracking code has been written to run under an optimisation algorithm where every beamline element can be varied, which is then deployed as a distributed computing project. Some subsequent stages of muon beamline are also simulated, including RF and non-RF phase-rotation techniques and in one option, initial muon acceleration to 400MeV. The objective is to find optimal transmissions for each front-end concept.  
 
MOPLT105 Implementation of MICE at RAL wiggler, gun, radiation, wakefield 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

 
 
MOPLT106 MICE: the Muon Ionisation Cooling Experiment wiggler, gun, radiation, wakefield 782
 
  • M. Ellis
    Imperial College of Science and Technology, Department of Physics, London
  The provision of intense stored muon beams would allow the properties of neutrinos to be measured precisely and provide a route to multi-TeV lepton-anti-lepton collisions. The short muon-lifetime makes it impossible to employ traditional cooling techniques while maintaining the muon-beam intensity. Ionisation cooling, a process in which the muon beam is passed through a series of liquid hydrogen absorbers followed by accelerating RF-cavities, is the proposed cooling technique. The international Muon Ionisation Cooling Experiment (MICE) collaboration proposes to perform an engineering demonstration of ionisation cooling. The MICE cooling channel, the instrumentation and the implementation at the Rutherford Appleton Laboratory is described together with the predicted performance of the channel and the measurements that will be made.  
 
MOPLT107 Nanosecond-timescale Intra-bunch-train Feedback for the Linear Collider: Results of the FONT2 Run feedback, wiggler, gun, radiation 785
 
  • P. Burrows, T. Hartin, S.M. Hussain, S. Molloy, G.R. White
    Queen Mary University of London, London
  • C. Adolphsen, J.C. Frisch, L. Hendrickson, R.K. Jobe, T. Markiewicz, D.J. McCormick, J. Nelson, M.C. Ross, S. Smith, T.J. Smith
    SLAC, Menlo Park, California
  • R. Barlow, M. Dufau, A. Kalinin
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Myatt, C. Perry
    OXFORDphysics, Oxford, Oxon
  We report on experimental results from the December 2003/January 2004 data run of the Feedback On Nanosecond Timescales (FONT) experiment at the Next Linear Collider Test Accelerator at SLAC. We built a second-generation prototype intra-train beam-based feedback system incorporating beam position monitors, fast analogue signal processors, a feedback circuit, fast-risetime amplifiers and stripline kickers. We applied a novel real-time charge-normalisation scheme to account for beam current variations along the train. We used the system to correct the position of the 170 nanosecond-long bunchtrain at NLCTA, in both 'feed forward' and 'feedback' modes. We achieved a latency of 53 nanoseconds, representing a significant improvement on FONT1 (2002), and providing a demonstration of intra-train feedback for the Linear Collider.  
 
MOPLT111 On using NEA Cathodes in an RF Gun wiggler, radiation, luminosity, acceleration 797
 
  • M. Huening
    Fermilab, Batavia, Illinois
  RF guns have been proven to deliver high brightness beams and therefore appear attractive as electron source for a linear collider. Only so far no polarized beams have been produced. To create a polarized electron beam GaAs NEA cathodes are used. Operating rf guns with a NEA cathode poses concerns in three areas, oxidation by residual gas, ion bombardment, and electron bombardment. In this paper we report about an attempt to reduce the vacuum pressure inside the gun by cooling it to cryogenic temperatures. Furthermore the energy deposition by ions and electrons will be quantified.  
 
MOPLT117 An Electron Front End for the Fermilab Multi-species 8 GeV SCRF Linac acceleration, wiggler, radiation, linac 809
 
  • P. Piot, G.W. Foster
    Fermilab, Batavia, Illinois
  Fermilab is considering 8 GeV superconducting linac whose primary mission is to serve as an intense H- injector for the main injector. This accelerator is also planned to be used for accelerating various other species (e.g. electrons and muons). In the present paper we investigate the possibility of such a linac to accelerate a high brightness electron beam to ~7 GeV. We propose a design for the electron front end, based on a photoinjector, and consider the electron beam dynamics along the linac. Start-to-end simulations of the full accelerator for electrons are presented. Finally the potential applications of the such an electron beam are discussed.  
 
MOPLT118 Muon Test Area at Fermilab acceleration, wiggler, radiation, luminosity 812
 
  • M. Popovic
    Fermilab, Batavia, Illinois
  A construction of a new experimental area designed to develop, test and verify muon ionization cooling using the 400- MeV Fermilab Linac proton beam was finished in fall of 2003. This area will be used initially for cryogenic tests of liquid-hydrogen absorbers for the MUCOOL R&D program and, later, for high-power beam tests of these absorbers and other prototype muon-cooling apparatus. The experimental scenarios being developed for muon facilities involve collection, capture, and cooling of large-emittance, high-intensity muon beams–~1013 muons at a repetition rate of 15Hz, so that conclusive tests of the apparatus require full Linac beam, or 1.6 x 1013 p at 15 Hz. The area has 12MW 805MHz, 5MW 201MHz RF, 4K Helium, 500W refrigeration and 400MeV H-/proton beam.  
 
MOPLT119 Fabrication of X-band Accelerating Structures at FERMILAB acceleration, vacuum, wiggler, radiation 815
 
  • T.T. Arkan, C. Boffo, E. Borissov, H. Carter, D. Finley, I. Gonin, T. Khabibouline, S.C. Mishra, G. Romanov, N. Solyak
    Fermilab, Batavia, Illinois
  The RF Technology Development group at Fermilab is working together with the NLC and GLC groups at SLAC and KEK on developing technology for room temperature X-band accelerating structures for a future linear collider. We built seven 60cm long, high phase advance, detuned structures (HDS or FXB series). These structures have 150 degrees phase advance per cell, and are intended for high gradient tests. The structures were brazed in a vacuum furnace with a partial pressure of argon, rather than in a hydrogen atmosphere. We have also begun to build 60cm long, damped and detuned structures (HDDS or FXC / FXD series). So far, we have built 3 FXC structures. Our goal is to build 4 FXC and 2 FXD structures for the 8-pack test at SLAC by the end of March 2004, as part of the GLC/NLC effort to demonstrate the readiness of room temperature RF technology for a linear collider. This poster describes the RF structure factory infrastructure (clean rooms, vacuum furnaces, vacuum equipment, RF equipment etc.), and the fabrication techniques utilized (the machining of copper cells / couplers, quality control, etching, vacuum brazing, cleanliness requirements etc.) for the production of FXB and FXC structures.  
 
MOPLT120 Proposals for Improvements of the Correction of Sextupole Dynamic Effects in the Tevatron Dipole Magnets acceleration, vacuum, wiggler, radiation 818
 
  • P. Bauer, G. Ambrosio, J. Annala, J. DiMarco, R. Hanft, M. Lamm, M. Martens, P. Schlabach, D. Still, M. Tartaglia, J. Tompkins, G. Velev
    Fermilab, Batavia, Illinois
  It is well known that the sextupole (b2) components in the superconducting dipole magnets decay during the injection plateau and snap back rapidly at the start of the ramp to flat top current. These so-called dynamic effects were originally discovered in the Tevatron. They are compensated for by the chromaticity correctors distributed around the ring. Imperfect control of the chromaticity during the snapback can contribute to beam loss and emittance growth. A thorough investigation of the chromaticity correction in the Tevatron was launched in the context of Run II, including beam chromaticity measurements and extensive magnetic measurements on a series of spare Tevatron dipole magnets. The study has yielded new information about the effect of the powering history on the dynamic b2. A companion paper at this conference describes in detail the results of these magnetic measurements [reference to George Velev's paper]. Study findings have given directive to new proposals for improvement of the b2 snapback correction in the Tevatron, including a revised functional form for the snapback algorithm and the elimination of the beam-less pre-cycle. This paper reports the results of beam studies performed recently to test these improved procedures.  
 
MOPLT121 Water Flow Vibration Effect on the NLC RF Structure-girder System acceleration, vacuum, wiggler, radiation 821
 
  • C. Boffo, T.T. Arkan, E. Borissov, H. Carter
    Fermilab, Batavia, Illinois
  • F. Le Pimpec, A. Seryi
    SLAC, Menlo Park, California
  In order to meet the vibration budget for the Next Linear Collider main Linac components, the vibration sources in the NLC girder are being studied. The activity is focused on the vibration induced by the cooling water flow for the 60 cm long accelerating copper structures. Understanding the vibration in the structures will enable us to push forward the design of the interface between the structures and the quadrupoles. This paper reports on the ongoing work and presents results from experimental data as well as finite element simulations.  
 
MOPLT122 Dynamical Aperture Study for the NLC Main Damping Rings acceleration, vacuum, radiation, luminosity 824
 
  • M. Venturini, S. Marks, A. Wolski
    LBNL, Berkeley, California
  A sufficiently large acceptance is critical for the NLC Main Damping Rings (MDR) as the high power carried by the beams demands very high injection efficiency. Both chromatic sextupoles and wiggler insertions, needed for damping, are substantial sources of nonlinearities limiting the dynamical aperture. We report on our latest studies on single particle dynamics for the MDR current lattice with and without inclusion of lattice errors and with attention paid to working point optimization. The possibility to use octupole magnets for compensation is also explored.  
 
MOPLT123 A Reduced Emittance Lattice for the NLC Positron Pre-damping Ring acceleration, vacuum, damping, emittance 827
 
  • I. Reichel, A. Wolski
    LBNL, Berkeley, California
  The Pre-Damping Ring of the Next Linear Collider has to accept a large positron beam from the positron production target, and reduce the emittance and energy spread to low enough values for injection into the Main Damping Ring. A previous version of the lattice yielded an emittance of the extracted beam which was about 20% too large. In order to get the emittance down to the required value the quadrupole magnets in the dispersive regions in the ring were moved horizontally; this modifies the damping partition numbers. In addition, the model of the wigglers has been modified to reflect more closely the magnetic field map. The new lattice design meets damping and emittance requirements. The lattice and dynamic aperture studies are presented.  
 
MOPLT124 Control System of the Small Isochronous ring damping, acceleration, vacuum, lattice 830
 
  • J.A. Rodriguez, F. Marti
    NSCL, East Lansing, Michigan
  • E. Pozdeyev
    Jefferson Lab, Newport News, Virginia
  The purpose of this paper is to describe the control system of the Small Isochronous Ring (SIR) developed and built at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). SIR is a small-scale experiment that simulates the dynamics of intense beams in large accelerators. A 20 to 30 keV hydrogen or deuterium ion bunch is injected in the ring, extracted after a variable number of turns and its longitudinal profile is studied. Information about the electronics used and software written to control different injection line, ring and extraction line elements is included. Some of these elements are magnets, electrostatic quadrupoles, electric and magnetic correctors, scanning wires, emittance measurement system, chopper and a fast Faraday cup.  
 
MOPLT127 Diagnosing the PEP-II Injection System damping, acceleration, vacuum, injection 833
 
  • F.-J. Decker, M.H. Donald, R.H. Iverson, A. Kulikov, G.C. Pappas, M. Weaver
    SLAC, Menlo Park, California
  The injection of beam into the PEP-II B-Factory, especially into the High Energy Ring (HER) has some challenges. A high background level in the BaBar Detector has so far inhibited us from trickling charge into the HER similar to the Low Energy Ring (LER). Analyzing the injection system has revealed many issues which could be improved. The injection bump between two kickers was not closed, mainly because the phase advance wasn't exactly 180 degrees and the two kicker strengths were not balanced. Additionally we found reflections which kick the stored beam after the main kick and cause the average luminosity to drop about 3% for a 10 Hz injection rate. The strength of the overall kick is nearly twice as high than the design, indicating a much bigger effective septum thickness. Compared with single beam the background is worse when the HER beam is colliding with the LER beam. This hints that the beam-beam force and the observed vertical blow-up in the HER pushes the beam and especially the injected beam further out to the edge of the dynamic aperture or beyond.  
 
MOPLT128 Lattice Effects due to High Currents in PEP-II damping, acceleration, vacuum, injection 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.  
 
MOPLT129 Identifying Lattice, Orbit, and BPM Errors in PEP-II damping, acceleration, vacuum, injection 839
 
  • F.-J. Decker
    SLAC, Menlo Park, California
  The PEP-II B-Factory is delivering peak luminosities of up to 7.4·1033 1/cm2 1/s. This is very impressive especially considering our poor understanding of the lattice, absolute orbit and beam position monitor system (BPM). A few simple MATLAB programs were written to get lattice information, like betatron functions in a coupled machine (four all together) and the two dispersions, from the current machine and compare it the design. Big orbit deviations in the Low Energy Ring (LER) could be explained not by bad BPMs (only 3), but by many strong correctors (one corrector to fix four BPMs on average). Additionally these programs helped to uncover a sign error in the third order correction of the BPM system. Further analysis of the current information of the BPMs (sum of all buttons) indicates that there might be still more problematic BPMs.  
 
MOPLT148 Progress of the eRHIC Electron Ring Design acceleration, quadrupole, beamloading, undulator 887
 
  • F. Wang, M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • D.P. Barber
    DESY, Hamburg
  • C. Montag, S. Peggs, V. Ptitsyn
    BNL, Upton, Long Island, New York
  • A.V. Otboev, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  • J. Shi
    KU, Lawrence, Kansas
  Over the past year, a baseline design of the electron ring for the eRHIC hadron-lepton collider has been developed.This site-specific design is based on the understanding of the existing RHIC machine performance and its possible upgrades.The design includes a full energy polarized electron beam injector to ensure operational reliability and to provide high integrated luminosity.The electron ring energy range is 5 to 10 GeV.The electron beam emittance, the electron beam path length and the interaction region optics have to be adjusted over a wide range to match the hadron beam of various species and variable energies.We describe the expected machine perfomance, the interaction region and the lattice design. We also discuss the possible approaches leading to the 1033 cm-2s-1 luminosity for the collisions between 10 GeV polarized electron beam and 250 GeV polarized proton beam.  
 
MOPLT170 eRHIC, Future Electron-ion Collider at BNL gun, ion, vacuum, quadrupole 923
 
  • V. Ptitsyn, L. Ahrens, M. Bai, J. Beebe-Wang, I. Ben-Zvi, M. Blaskiewicz, J.M. Brennan, R. Calaga, X. Chang, E.D. Courant, A. Deshpande, A.V. Fedotov, W. Fischer, H. Hahn, J. Kewisch, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, B. Parker, S. Peggs, T. Roser, A. Ruggiero, B. Surrow, S. Tepikian, D. Trbojevic, V. Yakimenko, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • D.P. Barber
    DESY, Hamburg
  • M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, F. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • A.V. Otboev, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  The paper reviews the progress made lately in the design of eRHIC, proposed future electron-ion collider on the basis of the existing RHIC machine. The eRHIC aims to provide collisions of electrons and positrons on ions and protons in center mass energy range of 25-70 GeV. The goal luminosities are in 1032-1033 1/(s*cm2) values for e-p and in 1030-1031 1/(s*cm2) values for e-Au collisions. An essential design requirement is to provide longitudinally polarized beams of electrons and protons (and, possibly lighter ions) at the collision point. The eRHIC ZDR has been recently developed which considers various aspects of the accelerator design. An electron accelerator, which delivers about 0.5A polarized electron beam current in the electron energy range of 5 to 10 GeV, should be constructed at the BNL near existing ion rings of the RHIC collider and should intersect an ion ring at least in one of the available ion ring interaction regions. In order to reach the luminosity goals some upgrades in ion rings also would be required. Ways to reach lower beam emmittances (electron cooling) and higher beam intensities have to be realized.  
 
MOPLT171 A Pratical Demonstration of the CRFQ Storage Ring gun, vacuum, beamloading, undulator 926
 
  • A. Ruggiero
    BNL, Upton, Long Island, New York
  • L. Campajola, V.G. Vaccaro
    Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli
  • D. Davino
    Universita' degli Studi del Sannio, Benevento
  • M.R. Masullo
    INFN-Napoli, Napoli
  The Circular Radiofrequency Quadrupole (CRFQ) is a new concept of a storage and accelerator ring for intense beams of light and heavy ions, protons and electrons. It is basically a Linear Radio-Frequency Quadrupole completely bent on a circle. The advantages are expected to be equivalent to those of a Linear RFQ, namely higher beam intensity and smaller beam dimensions. Moreover, it is a more compact device when compared to conventional accelerators. A collaboration was created between Brookhaven National Laboratory, the University of Naples, the University of Sannio, and the INFN-Section of Naples (Italy) for the purpose of developing a proof of principle (PoP) of the CRFQ. During the initial stage the main goal is the demonstration of the curvature effect of the quadrupolar RFQ field. At that purpose, the project is actually conceived of three phases: (i) develop an adequate 30 keV proton source, (ii) design, manufacture and test a linear RFQ section, and (iii) design, manufacture and test a curved RFQ section, both operating at 200 MHz. The linear section acts as a matching with the ion source at one end, and the curved section at the other. The paper discusses mechanical and RF considerations during the design and experiment. The final goal of the collaboration is eventually to build enough curved sections to complete the storage ring where to demonstrate storage of 30 keV protons over long periods of time.  
 
MOPLT172 Quest for a New Working Point in RHIC gun, vacuum, beamloading, undulator 929
 
  • R. Tomas, M. Bai, W. Fischer, V. Ptitsyn, T. Roser, T. Satogata
    BNL, Upton, Long Island, New York
  The beam-beam interaction is a limiting factor in RHIC's performance, particularly in proton operation. Changing the working point is a strategy to minimize the beam-beam effect and improve the performance of the machine. Experiments at injection energy and simulations have been performed for a set of working points in order to determine what are the best candidates.  
 
MOPLT176 Mechanism of Electron Multipacting with a Long Bunch Proton Beam gun, vacuum, focusing, beamloading 938
 
  • L. Wang, M. Blaskiewicz, J. Wei
    BNL, Upton, Long Island, New York
  • R.J. Macek
    LANL/LANSCE, Los Alamos, New Mexico
  The mechanism of electron multipacting in long bunched proton machine has been quantitatively described by the electron energy gain and electron motion. Some important parameters related to electron multipacting are investigated in detail. It is proved that multipacting is sensitive to beam intensity, longitudinal beam profile shape and transverse beam size. Agreement is achieved among our analysis, simulation and experiment.  
 
MOPLT177 Stochastic Cooling Power Requirements gun, vacuum, focusing, beamloading 941
 
  • J. Wei, M. Blaskiewicz, J.M. Brennan
    BNL, Upton, Long Island, New York
  A practical obstacle for stochastic cooling in high-energy colliders is the large amount of power needed for the cooling system. This paper discusses the cooling power needed for the longitudinal cooling process. Based on the coasting-beam Fokker-Planck equation, we analytically derived the optimum cooling rate and cooling power for a beam of uniform distribution and a cooling system of linear gain function. The results indicate that the usual back-of-envelope formula over-estimated the cooling power by a factor of the mixing factor $M$. On the other hand, the scaling laws derived from the coasting-beam Fokker-Planck approach agree with those derived from the bunched-beam Fokker-Planck approach if the peak beam intensity is used as the effective coasting-beam intensity. A longitudinal stochastic cooling system of 4 – 8 GHz bandwidth in RHIC can effectively counteract intrabeam scattering, preventing the beam from escaping the RF bucket becoming debunched around the ring.  
 
TUPLT011 The LHC Lead Ion Injector Chain ion, target, plasma, laser 1153
 
  • K. Schindl, A. Beuret, A. Blas, J. Borburgh, H. Burkhardt, C. Carli, M. Chanel, T. Fowler, M. Gourber-Pace, S. Hancock, C.E. Hill, M. Hourican, J.M. Jowett, K. Kahle, D. Kuchler, A.M. Lombardi, E. Mahner, D. Manglunki, M. Martini, S. Maury, F. Pedersen, U. Raich, C. Rossi, J.-P. Royer, R. Scrivens, L. Sermeus, E.N. Shaposhnikova, G. Tranquille, M. Vretenar, T. Zickler
    CERN, Geneva
  A sizeable part of the LHC physics programme foresees heavy ion (lead-lead) collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines. Each LHC ring will be filled in ~10 minutes with ~600 bunches, each of 7 107 Pb ions. Central to the scheme is the Low Energy Ion Ring (LEIR), which transforms long pulses from Linac3 to high-brilliance bunches by means of 6D multi-turn injection and accumulation via electron cooling. Major limitations along the chain, including space charge, intra-beam scattering, vacuum issues, and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR includes new magnets and power converters, high-current electron cooling, broad-band RF cavities, upgraded beam diagnostics, and UHV vacuum equipment relying on beam scrubbing to achieve a few 10-12 mbar. Major hardware changes in Linac3 (Electron Cyclotron Resonance source, repetition rate, energy ramping cavity), PS (new injection hardware, elaborate RF gymnastics, stripping insertion), and SPS (100 MHz system) are described. An early beam scenario, using fewer bunches but the same bunch intensity to deliver a lower luminosity, reduces the work required for LHC ion operation in spring 2008.  
 
TUPLT012 Adjusting the IP Beta-functions in RHIC. ion, target, plasma, laser 1156
 
  • W. Wittmer, F. Zimmermann
    CERN, Geneva
  • F.C. Pilat, V. Ptitsyn, J. Van Zeijts
    BNL, Upton, Long Island, New York
  The beta- functions at the IP can be adjusted without perturbation of other optics functions via several approaches. In this paper we describe a scheme based on a vector knob, which assigns fixed values to the different tuning quadrupoles and scales them by a common multiplier. The values for the knob vector were calculated for a lattice without any errors using MADX. Previous studies for the LHC have shown that this approach can meet the design goals. A specific feature of the RHIC lattice is the nested power supply system. To cope with the resulting problems a detailed response matrix analysis has been carried out and different sets of knobs were calculated and compared. The knobs are tested at RHIC during the 2004 run and preliminary results maybe discussed. Simultaneously a new approach to measure the beam sizes of both colliding beams at the IP, based on the tune ability provided by the knobs, was developed and tested.  
 
TUPLT013 Calculating LHC Tuning Knobs using Various Methods ion, target, plasma, laser 1159
 
  • W. Wittmer, D. Schulte, F. Zimmermann
    CERN, Geneva
  By measuring and adjusting the beta-functions at the IP the luminosity is being optimized. In LEP this was done with the two closest doublet magnets. This approach is not applicable for the LHC due to the asymmetric lattice and common beam pipe through the triplet magnets. To control and change the beta-functions quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called tuning knobs for the IP beta-functions. We compare the performance of such knobs calculated by different methods: (1) matching in MAD, (2) inversion of the re-sponse matrix and singular value decomposition inversion and conditioning and (3) conditioning the response matrix by multidimensional minimization using Hessian method.  
 
TUPLT014 Comparative Design Studies of a Super Buncher for the 72 MeV Injection Line of the PSI Main Cyclotron ion, target, plasma, laser 1162
 
  • J.-Y. Raguin, A. Adelmann, M. Bopp, H. Fitze, M. Pedrozzi, P. Schmelzbach, P. Sigg
    PSI, Villigen
  The envisaged current upgrade from 2 to 3 mA of the PSI 590-MeV main cyclotron requires an increase of the global accelerating voltage of the 50-MHz cavities which leads to a nearly unacceptable RF requirement for the 150-MHz flattop cavity. In order to preserve the longitudinal acceptance and transmission of the machine while relaxing the high demands on the flattop system, it is conceivable to install a buncher in the 72-MeV injection line. To this end, normal-conducting 150-MHz half-wave resonators and 500-MHz two-gap drift-tube cavities have been designed and optimised for minimum input power and peak surface fields. The dependence of the RF properties (Q0, shunt impedances and peak fields) with beam apertures and gap voltages compatible with beam-dynamics requirements are presented.  
 
TUPLT015 The Bunch Compressor System for SIS18 at GSI target, plasma, laser, booster 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.  
 
TUPLT016 Improved Performance of the Heavy Ion Storage Ring ESR target, plasma, laser, booster 1168
 
  • M. Steck, K. Beckert, P. Beller, B. Franczak, B.  Franzke, F. Nolden
    GSI, Darmstadt
  The heavy ion storage ring ESR at GSI allows experiments with stable and radioactive heavy ions over a large range of energies. The energy range available for operation with completely stripped ions has recently been extended to energies as low as 3 MeV/u. Even for bare uranium such low energies can be provided by deceleration of the ions which are stripped to high charge states in a foil at energies of 300-400 MeV/u. After injection the beam is cooled and decelerated in an inverse synchrotron mode interspersed with electron cooling at an intermediate energy. At the lowest energy of 3 MeV/u some hundreds of thousands ions could be electron cooled after deceleration. At energies of 10-20 MeV/u physics experiments with stored and slowly extracted beam have been performed with some million decelerated cooled ions. The cooling of radioactive ions by a combination of stochastic pre-cooling and final electron cooling has been demonstrated. The hot fragment beam, which was injected at an energy of 400 MeV/u, was cooled in about 6 s to a quality useful for precision experiments.  
 
TUPLT017 Achievements of the High Current Beam Performance of the GSI Unilac target, plasma, laser, booster 1171
 
  • W. Barth, L. Dahl, J. Glatz, L. Groening, S.G. Richter, S. Yaramishev
    GSI, Darmstadt
  The present GSI-accelerator complex is foreseen to serve for the future synchrotron SIS100 as an injector for up to 1012 U28+ particles/sec. The High Current Injector of the Unilac was successfully commissioned five years ago. An increase of more than two orders of magnitude in particle number for the heaviest elements in the SIS had to be gained. Since that time many different ion species were accelerated in routine operation. In 2001 a physics experiment used 2×109 Uranium ions per spill. In order to meet this request the MEVVA ion source provided for the first time in routine operation a high intense Uranium beam. The main purpose for the machine development program during the last two years was the enhancement of the intensity for Uranium beams. Different hardware measures and a huge investigation program in all Unilac-sections resulted in an increase of the uranium intensity by a factor of 7. The paper will focus on the measurements of beam quality, as beam emittance and bunch structure for Megawatt-Uranium beams. Additionally the proposed medium- and long-term hardware measures will be described, which should gain in the required uranium intensity to fill the SIS up to the space charge limit.  
 
TUPLT023 A New Ion Beam Beam Facility for Slow Highly Charged Ions ion, beamloading, antiproton, betatron 1189
 
  • G. Zschornack, S. Landgraf
    TU Dresden, Dresden
  • S. Facsko, D. Kost, W. Möller, H. Tyrroff
    FZR, Dresden
  • F. Grossmann, U. Kentsch, V.P. Ovsyannikov, M. Schmidt, F. Ullmann
    Leybold Vacuum Dresden, Dresden
  A new ion beam facility for slow highly charged ions is presented. It will provide slow highly charged ions from an Electron Cyclotron Resonance (ECR) ion source as well as very highly charged ions at lower ion currents from an Electron Beam Ion Trap (EBIT). As ECR ion source a SUPERNANOGAN source* is applied. The Dresden EBIT**, a room-temperature EBIT, is used to produce comparatively low currents of very highly charged ions. This very compact and long-term stable device is producing highly charged ions at ultimate low costs. The Dresden EBIT working with electron energies up to 15 keV at electron currents up to 50 mA is able to produce bare nuclei up to nickel as Fe26+ or Ni28+, helium-like ions for medium Z such as Ge30+ or Kr34+ and neon-like ions for elements of the high-Z region such as Xe44+ or Ir67+. The ion currents extracted from the Dresden EBIT are typically in the range of some nA per pulse. With the new ion beam facility outstanding possibilities for a wide range of investigations are opened up in areas such as surface analysis, materials science and nanotechnology as well as for basic research in different fields as for instance in atomic and solid state physics.

*The Pantechnik Catalogue, August 2001 Edition, Caen 2001, France **V.P.Ovsyannikov, G.Zschornack; Review of Scientific Instruments, 70 (1999) 2646

 
 
TUPLT024 A Comparison of High Current Ion Beam Matching from an Ion Source to a RFQ by Electrostatic and by Magnetic Lenses ion, beamloading, antiproton, betatron 1192
 
  • R. Becker, R.A. Jameson, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Hata, N. Hayashizaki, H. Kashiwagi, K. Yamamoto
    RLNR, Tokyo
  • T. Hattori, M. Okamura, A. Sakumi
    RIKEN, Saitama
  In order to improve the ?direct? injection scheme of the Riken Nd-YAK-laser driven ion source into a RFQ rf-accelerator, several basic methods have been investigated and compared, in order to transform the initially divergent ion beam into a convergent one, needed for matching the high current (100 mA C6+) ion beam at an energy of 100 keV to a RFQ. From the point of power supplies and break down characteristics, the simplest solution is a decelerating electrostatic lens, with the decelerating electrode operated on ion source potential. Due to the strong divergence of the ions beam after acceleration, this lens will be filled to an aperture, which causes strong aberrations. Therefore, we also investigated to use an accelerating potential on the lens electrode. This reduces significantly the filling of the lens and the emittance growth is only a factor of 3, as compared to the decelerating lens with a factor of 30! Finally we have been looking also into a magnetic matching system, which can match the ion beam to the RFQ with virtually no emittance growth.  
 
TUPLT025 Matching of a C6+ Ion Beam from a Laser Ion Source to a RFQ ion, beamloading, antiproton, betatron 1195
 
  • R. Becker, R.A. Jameson, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Hattori
    RIKEN, Saitama
  • N. Hayashizaki, H. Kashiwagi
    RLNR, Tokyo
  • M. Okamura
    RIKEN/RARF/CC, Saitama
  • K. Yamamoto
    RIKEN/RARF/BPEL, Saitama
  A laser ion source, driven by a Nd-YAG laser can provide more than 100 mA of C6+ ions for a duration of about 1 μs, which is well matching the task of single-turn injection into synchrotrons for hadron tumor therapy with light ions. The ?direct? injection scheme has been improved by providing a design, which reduces the surface field strength to less than 30 kV/cm on all critical parts on relative negative potential. The new design keeps the advantage of divergent ion emission and acceleration, which seems to be the only way to keep the surface fields in limits, but includes a decelerating electrostatic lens on birth potential of the ions to refocus the emerging ion beam to the RFQ entrance. The whole design is very compact and allows for electrostatic steering between the ion source and the RFQ.  
 
TUPLT026 High Current Ion Beams at Frankfurt University beamloading, antiproton, betatron, cathode 1198
 
  • M. Droba, O. Meusel, U. Ratzinger, K. Volk
    IAP, Frankfurt-am-Main
  A new building for the physics faculty at the Goethe-University in Frankfurt is under construction including an experimental hall. The Institute of Applied Physics IAP has started development of a high current ion beam facility consisting of a high voltage terminal(150 kV,I_beam < 300 mA,H-,p,Bi+), a 10 MV linear rf accelerator and a high current storage ring for 150 keV beams. The 150 kV terminal equipment is already ordered while the subsequent units are in the design stage. The storage ring will use a stellarator-like magnetic configuration to allow for a high degree of space charge compensation by electrons. The facility will allow high current beam investigations as well as experiments in fields of plasma, nuclear and atomic physics.  
 
TUPLT027 Status of the HITRAP Decelerator Linac at GSI linac, beamloading, antiproton, betatron 1201
 
  • C.A. Kitegi, A. Bechtold, U. Ratzinger, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Beier, L. Dahl, C. Kozhuharov, W. Quint, M. Steck
    GSI, Darmstadt
  • S. Minaev
    ITEP, Moscow
  Within the European Network HITRAP (heavy Ion trap) trapped and cooled higly charged ions up to U92+ will become avilable for a variety of attractive experiments in atomic physics. Heavy ions are produced, accelerated and stripped in the GSI accelerator complex and are stored in the ESR down to 4 MeV/u. To be captured in HITRAP, ions have to be decelerated to energies below 6 keV/u. The decelerator proposed to achieve these energies is a combination of an IH Drift tube cavity operating in the H11(0) mode and a RFQ. The operating frequency is 108.408MHz . The A/q range of the linac is up to 3. A very efficient deceleration by up to 11 MV along the 2.7 m long IH cavity with a rf power of 200kw is achieved by applying the KONUS beam dynamics. The deceleration from 500 A.keV down 6A.keV is provided by a 1.8 m long 4-rod RFQ.The beam dynamics as well as the cavity design of that linac will be described.The decelerator linac will be installed in the reinjection beam line and is being developed in collaboration between GSI and the Frankfurt University .  
 
TUPLT028 Development of Finger Drift Tube Linacs linac, focusing, beamloading, antiproton 1204
 
  • K.-U. Kuehnel, A. Schempp
    IAP, Frankfurt-am-Main
  • C.P. Welsch
    MPI-K, Heidelberg
  At higher particle energies the efficiency of RFQs decreases and DTL structures in combination with magnetic quadrupoles are used. One approach at IAP is the combination of RFQ and DTL. To compensate the defocusing effects of a DTL structure, the accelerating gaps of a spiral loaded cavity were equiped with small focusing fingers. These fingers arranged in a quadrupole symmetry provide an additional focusing field component. The beam dynamics of such a cavity has been studied with PARMTEQ. Simulations of the rf properties have been done using microwave studio. A prototype of a spiral loaded cavity with finger drift tubes has been built and low power measurement were made. Results of the calculations as well as low level and bead pertubation measurements are presented in this contribution.  
 
TUPLT029 Status of the Superconducting D+-CH-DTL Design for IFMIF linac, focusing, beamloading, antiproton 1207
 
  • A.C. Sauer, H. Deitinghoff, H. Klein, H. Liebermann, O. Meusel, H. Podlech, U. Ratzinger, R. Tiede
    IAP, Frankfurt-am-Main
  Within the IFMIF project (International Fusion Materials Irradiation Facility) a high current D+-linac operated in cw mode has to be developed. The acceleration of a 125 mA D+-beam from 0.1 MeV up to 40 MeV must be performed at an extremely low loss rate (0.1-0.2 microA/m). One optional layout of the acceleration facility consists of a high current ion source, low energy beam transport (LEBT), Radio-Frequency-Quadrupol (RFQ) followed by a superconducting H-type DTL. The matching of the beam between subsequent linac sections has to be carefully optimized to avoid an activation of the structures. Actual beam dynamics simulations for such a linac design including parameter errors of components are reported. Consequences for the LEBT- and RFQ-section are discussed.  
 
TUPLT030 Numerical Simulations for the Frankfurt Funneling Experiment linac, ion, focusing, beamloading 1210
 
  • J. Thibus, A. Schempp
    IAP, Frankfurt-am-Main
  High beam currents are necessary for heavy ion driven fusion (HIF) or XADS. To achieve these high beam currents several ion beams are combined at low energies to one beam using the funneling technique. In each stage a r.f. funneling deflector bunches two accelerated beam lines to a common beam axis. The Frankfurt Funneling Experiment is a scaled model of the first stage of a HIF driver consisting of a Two-Beam RFQ accelerator and a funneling deflector. Our two different deflectors have to be enhanced to reduce particle losses during the funneling process. This is done with our new developed 3D simulation software DEFGEN and DEFTRA. DEFGEN generates the structure matrix and the potential distribution matrix with a Laplace 3D-solver. DEFTRA simulates ion beam bunches through the r.f. deflector. The results of the simulations of the two existing deflectors and proposals of new deflector structures will be presented.  
 
TUPLT032 The Frankfurt Funneling Experiment linac, focusing, beamloading, antiproton 1213
 
  • H. Zimmermann, U. Bartz, N. Mueller, A. Schempp, J. Thibus
    IAP, Frankfurt-am-Main
  The Frankfurt Funneling Experiment is a scaled model of the first funneling stage of a HIF driver to gather experiences in the funneling technique. It is a procedure to multiply beam currents at low energies in several stages. In each stage two beam lines are combined to a common beam line. The funneling technique is required for new proposed high current accelerator facilities like HIDIF. The main goal is to prevent emittance growth during the funneling process. Our experiment consists of two ion sources, a Two-Beam RFQ accelerator, two different funneling deflectors and a beam diagnostic equipment system. We have demonstrated the principle of funneling with both deflector types. But the measurements have shown a bad matching of the RFQ to the funneling deflector. Now with our new RFQ electrode design we achieve a special three dimensional matching to the deflector. The new results of our measurements and simulations will be presented.  
 
TUPLT033 RF Design of the MAFF IH-RFQ Power Resonator focusing, beamloading, antiproton, betatron 1216
 
  • M. Pasini, D. Habs, O. Kester
    LMU, München
  • T. Sieber
    CERN, Geneva
  The low energy part of the LINAC of the MAFF facility will be an IH-RFQ cavity with 101.28 MHz resonance frequency. The RF design of the cavity has been completed, including design calculations and model measurements. The RFQ is designed to deliver ions of A/q = 6.5 up to 300 keV/u to be injected into the following LINAC. The structure chosen was an IH type of resonator since it was demontrated to have a better shunt impedance. The required voltage between the electrodes is 70kV and the operation mode is pulsed with a duty cycle of 10%. The structure will be made out from bulk copper in order to improve the shunt impedance and hence to allow not direct cooling on the electrodes. The optimizazion of the several parameters of the structure, and the technique for tuning the voltage distribution are presented in this paper. Measurements with a short model will be shown as well.  
 
TUPLT034 Beam Dynamics Studies for the Low Energy Section at MAFF focusing, beamloading, antiproton, betatron 1219
 
  • M. Pasini, D. Habs, O. Kester
    LMU, München
  • A. Bechtold, A. Schempp
    IAP, Frankfurt-am-Main
  For the LINAC of the Munich accelerator for fission fragments (MAFF) a new scheme for the low energy section has been proposed in order to fulfill new experimental requirements, such as time spacing between bunches and low longitudinal emittance. The proposed solution consists in a combination of an external multi-harmonic buncher with a "traditional" RFQ with a shaper and an adiabatic bunching section included where the employment of the external buncher is upon request from the experiment. The matching section downstream the RFQ has been re-designed in order to allow room for the installation of a beam cleaning section and to a proper injection into the following DTL. Details about the optics and beam dynamics studies of the low energy section are presented in this paper.  
 
TUPLT035 Online Calculation of the Beam Trajectory in the HERA Interaction Regions focusing, beamloading, antiproton, betatron 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.  
 
TUPLT036 Optimization of Low Emittance Lattices for PETRA III lattice, focusing, beamloading, antiproton 1225
 
  • W. Decking, K. Balewski
    DESY, Hamburg
  The reconstruction of the existing 2.3 km long storage ring PETRA II into a 3rd generation synchrotron light source (PETRA III) calls for an horizontal emittance of 1 nm rad. In addition the on- and off-momentum dynamic acceptance should be large to ensure sufficient injection efficiency and beam lifetime. We present three different types of lattices for the arcs of PETRA: a so-called TME lattice and a FODO lattice which both are newly designed to reach the specified emittance and the present FODO lattice with damping wigglers. The different lattice types have been compared through tracking calculations, including wiggler nonlinearities. Only the relaxed FODO lattice with damping wigglers meets the acceptance goals.  
 
TUPLT037 Dispersion Correction in HERA lattice, focusing, beamloading, antiproton 1228
 
  • J. Keil, W. Decking
    DESY, Hamburg
  The electron-proton collider HERA at the DESY laboratory in Hamburg has been in operation since 1991. After the luminosity upgrade of HERA in 2001 the control of the horizontal and vertical dispersion function of the positron beam became more important than before. Deviations from the design dispersion in the horizontal plane can change the emittance of the electron beam significantly thus leading to a reduction of the luminosity. For optimizing the polarization of the electron beam the reduction of vertical orbit and dispersion deviations is important. In this paper the combined dispersion and orbit correction in HERA is described and first results are reported.  
 
TUPLT038 Closed Orbit Correction and Orbit Stabilisation Scheme for the 6 GEV Synchrotron Light Source PETRA III lattice, focusing, beamloading, antiproton 1231
 
  • G.K. Sahoo, K. Balewski, W. Decking, Y.L. Li
    DESY, Hamburg
  PETRA III is a 6 GeV synchrotron light source being reconstructed out of the existing storage ring PETRA II. It will have a horizontal beam emittance of 1nm.rad and a 1% emittance ratio. Since the vertical beam sizes are ~5?10 micron in the low gap undulators sections the beam position stability requirement in the vertical plane is between 0.5 and 1 micron whereas the stability requirement in the horizontal plane is more relaxed. In this paper determination of golden orbit in the presence of magnetic field errors and magnet misalignments and correction of vertical spurious dispersion is discussed. A scheme of slow and fast orbit correction using the SVD algorithm has been developed. The distribution of monitors and the location of slow and fast correctors are reported. Estimations of the parameters of the fast orbit feedback have been derived from present measurements on PETRA II.  
 
TUPLT039 An Electrostatic Quadrupole Doublet with an Integrated Steerer lattice, beamloading, antiproton, damping 1234
 
  • C.P. Welsch, M. Grieser, J. Ullrich
    MPI-K, Heidelberg
  • C. Glaessner
    IAP, Frankfurt-am-Main
  Electrostatic storage rings have proven to be a valuable tool for atomic and molecular physics Due to the mass independence of the fields in the bending and focusing elements, different kinds of ions with the same charge/energy ratio from light protons to very heavy biomolecules, can be stored with the same field setup. The transverse dimensions of the circulating beam are controlled by electrostatic quadrupole doublets or triplets. It is essential that the fields in these lenses can be adjusted independently one from another to allow an exact control of the stored ions. In this paper, first an overview of the principle of electrostatic lenses is given. After a short discussion of fringe field effects, the results of field calculations are presented and the final layout of an electrostatic quadrupole doublet with an integrated steerer as it will be used in future electrostatic storage rings in Frankfurt and Heidelberg is discussed.  
 
TUPLT082 Generation of a Femtosecond Electron Beam for Nanoscience and Nanotechnology septum, sextupole, gun, booster 1348
 
  • J. Yang, T. Kozawa, S. Tagawa, Y. Yoshida
    ISIR, Osaka
  A new S-band femtosecond electron linear accelerator was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. The femtosecond electron accelerator was constructed with a laser driven photocathode RF gun, a linear accelerator (linac) and a magnetic pulse compressor. The RF gun was driven by a mode-locked Nd:YLF picosecond laser. The electron beam produced by the RF gun was accelerated in the linac with energy modulattion by adjusted the RF phase. The magnetic pulse compression, which was constructed with two 45o-bending magnets and four quadrupole magnets, is a technique to longitudinally focus a charged beam by rotating the phase space distribution in a magnetic field. The picosecond electron pulse, which was generated in the RF gun and accelerated in the linac with energy modulation, was compressed into femtosecond by adjusted the quadrupole magnetic fields. The femtosecond electron pulse is expected for the studies of ultrafast reactions in nano-space.  
 
TUPLT085 J-PARC Construction and its Linac Commissioning septum, sextupole, gun, booster 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.  
 
TUPLT086 A 40MeV Electron Source with a Photocathode for X-ray Generation through Laser-compton Scattering septum, sextupole, gun, booster 1354
 
  • F. Sakai, N. Nakajyo, Y. Okada, T. Yanagida, M. Yorozu
    SHI, Tokyo
  .3 keV femtosecond X-ray generation through laser-Compton scattering with 14MeV electron source and a TW Ti:sapphire laser was achieved. In order to increase the X-ray energy up to 15 keV for some applications, e.g. protein crystallography, we modified the system to increase electron energy. Electron beams emitted from a S-band RF photocathode are accelerated up to 40MeV with two 1.5m standing-wave linacs. The beams are bended at 90 degree using an achromatic bending system, then focused with a triplet quadrupole-magnet to be interacted with laser pulses. The characteristics of electron beams, emittance, energy and energy dispersion, will be described.  
 
TUPLT087 Deflection Element for S-LSR septum, sextupole, gun, booster 1357
 
  • M. Ikegami, H. Fadil, A. Noda, T. Shirai, M. Tanabe, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • T. Fujimoto, K. Noda, H. Ogawa, S. Shibuya, T. Takeuchi
    NIRS, Chiba-shi
  • M. Grieser
    MPI-K, Heidelberg
  • H. Okamoto
    HU/AdSM, Higashi-Hiroshima
  Main lattice of the ion storage and cooler ring, S-LSR is composed of 6 dipole and 12 quadrupole magnets. The maximum magnetic field, the radius of curvature and gap height are 0.95 T, 1050 mm and 70 mm, respectively. The field measurement of the dipole magnets has been completed with use of Hall-probe position controlled by driving mechanism composed of stepping motors and ball-screws. In order to cancel out the momentum dispersion, the radial electric field is superposed with the magnetic field. The radial electric field is applied by the electrodes installed into the vacuum vessel set inside the rather limited gap of the dipole magnet. Good field quality is to be realized with use of intermediate electrodes. In the present paper, the results of the magnetic field measurements are presented together with the design of the superposed electric field.  
 
TUPLT104 Particle Dynamics in the Low Energy Positron Toroidal Accumulator: First Experiments and Results ion, gun, booster, optics 1396
 
  • G.V. Troubnikov, V. Antropov, E. Boltushkin, V. Bykovsky, A.I. Ivanov, S. Ivashkevich, A. Kobets, I.I. Korotaev, V. Lohmatov, I.N. Meshkov, D. Monahov, V. Pavlov, R. Pivin, I.A. Seleznev, A.O. Sidorin, A. Smirnov, E. Syresin, S. Yakovenko
    JINR, Dubna, Moscow Region
  The project of Low Energy Particle Toroidal Accumulator (LEPTA) is dedicated to construction of a positron storage ring with electron cooling of positrons circulating in the ring. Such a peculiarity of the LEPTA enables it automatically to be a generator of positronium (Ps) atoms, which appear in recombination of positrons with cooling electrons inside the cooling section of the ring. The project has a few goals: to study electron and positron dynamics in the ring (particle motion in the horizontal and vertical planes are coupled contrary to of classic cycle accelerators), to set up first experiments with Ps in flight; Magnetic measurements of main LEPTA elements are performed. Several elements : kicker, injection system of electron beam, helical quadrupole, septum magnet are tested and expected design parameters were achieved for those elements. The investigations of electron beam dynamics are started. First results of experiments with circulating electron beam are presented and discussed in this article. Several beam diagnostic methods for studying of strong coupled motion of charged particles are proposed and tested.  
 
TUPLT105 Measurement of Activation Induced by an Argon Beam in a Copper Target at the SIS18 ion, gun, booster, optics 1399
 
  • A. Fertman, A. Golubev, M. Prokuronov, B.Y. Sharkov
    ITEP, Moscow
  • G. Fehrenbacher, R.W. Hasse, I. Hofmann, E. Mustafin, D. Schardt, K. Weyrich
    GSI, Darmstadt
  Results of the measurement of activation induced by Argon beam with energies of E=100,200,800 MeV/u in the copper target are presented. The densities of various radioactive isotopes are derived from the measurements. Long-time prediction of radioactivity and accumulated doses in the accelerator equipment is calculated.  
 
TUPLT106 New Developments of a Laser Ion Source for Ion Synchrotrons gun, booster, optics, proton 1402
 
  • S. Kondrashev, A. Balabaev, K. Konukov, B.Y. Sharkov, A. Shumshurov
    ITEP, Moscow
  • O. Camut, J. Chamings, H. Kugler, R. Scrivens
    CERN, Geneva
  • A. Charushin, K. Makarov, Y. Satov, Y. Smakovskii
    SRC RF TRINITI, Moscow region
  Laser Ion Sources (LIS) are well suited to filling synchrotron rings with highly charged ions of almost any element in a single turn injection mode. We report the first measurements of the LIS output parameters for Pb27+ ions generated by the new 100 J/1 Hz Master Oscillator - Power Amplifier CO2-laser system. A new LIS has been designed, built and tested at CERN, as an ion source for ITEP-TWAC accelerator/accumulator facility, and as a possible future source for an upgrade of the Large Hadron Collider (LHC) injector chain. The use of the LIS based on 100 J/1 Hz CO2-laser together with the new ion LINAC, as injector for ITEP-TWAC project is discussed.  
 
TUPLT111 RF Focusing of Low-Charge-to-Mass-Ratio Heavy-Ions in a Superconducting Linac focusing, linac, gun, booster 1405
 
  • E.S. Masunov, D.A. Efimov
    MEPhI, Moscow
  • P.N. Ostroumov
    ANL/Phys, Argonne, Illinois
  A post-accelerator of radioactive ions (RIB linac) must produce high-quality beams over the full mass range, including uranium, with high transmission and efficiency (P.N. Ostroumov and et al., Proc. of the PAC2001, p. 4080.). The initial section of the RIB linac is a low-charge-to-mass-ratio superconducting RF linac which will accelerate any ion with q/A>=1/66 to ~900 keV/u or higher. This section of the linac consists of many interdigital cavities operating at –20 degree synchronous phase and focusing can be provided by SC solenoids following each cavity. For the charge-to-mass ratio q/A=1/66 a proper focusing can be reached with the help of strong SC solenoid lenses with magnetic fields up to 15 T. These state-of-the-art solenoids are expensive. A possible lower cost alternative focusing method based on the combination of low-field SC solenoids and RF focusing is proposed and discussed in this paper.  
 
TUPLT112 Radiation Damage to the Elements of the Nuclotron-type Dipole of SIS100 focusing, linac, gun, booster 1408
 
  • E. Mustafin, G. Moritz, G. Walter
    GSI, Darmstadt
  • L. Latysheva, N. Sobolevskiy
    RAS/INR, Moscow
  Radiation damage to various elements of the Nuclotron-type dipole of SIS100 sensitive to irradiation was calculated. Among the elements of consideration were the superconducting cables, insulating materials, ceramic insertions and high-current by-pass diodes. The Monte-Carlo particle transport code SHIELD was used to simulate propagation of the lost ions and protons together with the products of nuclear interactions in the material of the elements. The results for the proton projectiles were cross-checked using the particle transport code MARS, and a good agreement between the codes were found. It was found that the lifetime of the organic materials under irradiation are much more restrictive limit for the tolerable level of beam particle losses than the danger of the quench events.  
 
TUPLT113 Technicalities for a Novel Medium Energy Ion Accelerator focusing, linac, gun, ion 1411
 
  • V. Gorev
    RRC Kurchatov Institute, Moscow
  Transmutation of radioactive waste,high-intensity pulsed sources of fast neutrons,problem of inertially-confined fusion and a lot of different problems of science and technology put increased demands on the linear high power medium energy proton and heavy ion accelerators.But these accelerators are presently massive,huge and very expansive,which restrict now and in a near future their wide use and motivates the study of altenetive methods to achieve the design current,power and economic characteristics.This report decribes the present reseach on attaining high power medium energy ion beams,using novel idea for accelerator design.Theoretical proposal and preliminary conceptual design for the accelerator,based on a principle of free flying ion emitter("ballistic anode"),were discussed first a few years ago.The principle involves a high potencial difference generated only for a short time in the special vacuum chamber,but not steady-state conditions.Now,we would like to discuss next problems:1.technicalities of the ballistic anode design,both for proton and heavy ion beams generation.2 pulse power multiplication.3.high current sources for charge pumping of the ballistic anode.4 experimental modelling.  
 
TUPLT120 Commissioning of Electron Cooler EC-300 focusing, linac, gun, ion 1419
 
  • V.B. Reva, E.A. Bekhtenev, V.N. Bocharov, A.V. Bubley, Y. Evtushenko, A.D. Goncharov, A.V. Ivanov, V.I. Kokoulin, V.V. Kolmogorov, M.N. Kondaurov, S.G. Konstantinov, V.R. Kozak, G.S. Krainov, Ya.G. Kruchkov, E.A. Kuper, A.S. Medvedko, L.A. Mironenko, V.M. Panasyuk, V.V. Parkhomchuk, K.K. Schreiner, B.A. Skarbo, A.N. Skrinsky, B.M. Smirnov, M.A. Vedenev, R. Voskoboinikov, M.N. Zakhvatkin, N.P. Zapiatkin
    BINP SB RAS, Novosibirsk
  • J. Li, W. Lu, L.J. Mao, Z.X. Wang, X.B. Yan, X.D. Yang, J.H. Zhang, W. Zhang, H.W. Zhao
    IMP, Lanzhou
  The article deals with the commissioning of electron cooler EC-300. It was designed and manufactured for CSR experiment (IMP, Lanzhou, China) by BINP, Russia. The energy of electron beam is up to 300 keV, the electron current is up to 3 A, the magnetic field in the cooling section is up to 1.5 kG. The major innovation of the cooler is the variable profile of electron beam, the electrostatic bends of the electron beam and the system of the magnetic field correction. During commissioning the linearity of the magnetic field 10-6 was obtained, the recuperation efficiency was observed up 10-6 , the pressure of residual gas in the vacuum chamber was 5? 10-11 torr during operation with the electron beam. The CSRe cooler for IMP is a new step at cooling technique and the first results achieved during commissioning are very interesting for accelerator physics.  
 
TUPLT121 Compact Tandem Accelerator Based Neutron Source for the Medicine focusing, linac, gun, booster 1422
 
  • V.V. Shirokov, A.A. Babkin, P.V. Bykov, G.S. Kraynov, G. Silvestrov, Y. Tokarev
    BINP SB RAS, Novosibirsk
  • M.V. Bokhovko, O.E. Kononov, V.N. Kononov
    IPPE, Kaluga Region
  Status of original heavy hydrogen ion electrostatic accelerator-tandem is described. Potential electrodes with vacuum insulation organize tract for accelerating ion beam before and after gas stripper, located inside the high voltage electrode. There are no accelerating tubes in the tandem proposed. 20 kHz, 10 kW, 500 kV compact sectioned rectifier is a high voltage source. Both the geometry of neutron source and results of the rectifier testing are presented. Estimation of yield and space-energy distribution of neutron, as a result of nuclear reactions produced by heavy hydrogen ion in beryllium or carbon targets are given. Result of Monte-Carlo simulation of neutron and photon transferring for these sources of neutron is the distribution of the absorbed dose incide phantom. Result of the simulation are compared with result of the experiment. The possibility of use of this neutron source for the neutron or neutron capture therapy is discussed too.  
 
TUPLT124 DESIREE - A Double Electrostatic Storage Ring focusing, linac, gun, booster 1425
 
  • K.-G. Rensfelt, G. Andler, L. Bagge, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, P. Löfgren, A. Paal, A. Simonsson, Ö. Skeppstedt
    MSL, Stockholm
  • H. Cederquist, M. Larsson, H. Schmidt, K. Schmidt
    Stockholm University, Department of Physics, Stockholm
  The advantages of storage rings with only electrostatic elements were first demonstrated by ELISA in Aarhus and later in other places. At MSL and Fysikum at Stockholm University the ideas have been developed further in the Double Electrostatic Storage Ion Ring ExpEriment, DESIREE. Beams of negative and positive ions will be merged in a common straight section of the rings so that low energy collisions can be studied. Furthermore the rings will be cooled to 10 - 20 K in order to relax internal excitations in circulating molecules. A design report can be found at www.msl.se. The project is now (January 2004) almost fully financed and the final design work has recently been started. The paper will shortly review the physics programme and describe the status of the design work.  
 
TUPLT134 Lattice of NSC KIPT Compact Intense X-ray Generator NESTOR linac, booster, bunching, optics 1440
 
  • A.Y. Zelinsky, P. Gladkikh, I.M. Karnaukhov, V. Markov, A. Mytsykov, A.A. Shcherbakov
    NSC/KIPT, Kharkov
  The new generation of the intense X-rays sources based on low energy electron storage ring and Compton scattering of laser beam allows to produce X-rays with intensity up to 1014 phot/s. One of the main traits of a storage ring lattice for such generator type is using of magnetic elements with combined focusing functions such as bending magnets with quadrupole and sextupole field components. In combination with very low bending radius and dense magnetic elements setting along ring circumference it leads to increasing of 3D magnetic field effects on electron beam dynamics and can decrease generated radiation intensity drastically. For the reasons of very low electron beam size at the interaction point and strong focusing in a compact storage ring the questions of determination of accuracy of bending magnet is very important too. The paper is devoted to the description of lattice of NSC KIPT Compact X-ray generator NESTOR. The results of investigations of the effects of 3D magnetic field and harmonic compound due to manufacture errors of bending magnets, bending magnet and lenses edges on electron beam dynamics are presented.  
 
TUPLT136 Proton Beam Line for the ISIS Second Target Station target, linac, booster, bunching 1443
 
  • D.J. Adams
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense pulsed source of Muons and Neutrons used for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz. As part of the facility upgrade, which includes increasing the source intensity to 3.7x1013 protons per pulse using a dual harmonic RF system, it is planned to share the source with a second, 10 Hz, target station. A beam line supplying this target will extract from the existing target station beam line. Measurements and models characterising the optical functions around the extraction point of the existing line are discussed. The optical design, diagnostics and beam correction systems for second target station beam line are presented.  
 
TUPLT151 Status of the Fermilab Electron Cooling Project target, bunching, injection, beamloading 1485
 
  • J.R. Leibfritz, D.R. Broemmelsiek, A.V. Burov, K. Carlson, B. Kramper, T. Kroc, M. McGee, S. Nagaitsev, L. Nobrega, G. Saewert, C.W. Schmidt, A.V. Shemyakin, M. Sutherland, V. Tupikov, A. Warner
    Fermilab, Batavia, Illinois
  • G. Kazakevich
    BINP SB RAS, Novosibirsk
  • S. Seletsky
    Rochester University, Rochester, New York
  Fermilab has constructed and commissioned a full-scale prototype of a multi-MV electron cooling system to be installed in the 8.9 GeV/c Fermilab Recycler ring. This prototype was used to test all of the electron beam properties needed for cooling. However, because the prototype is not located within proximity of the Recycler ring, the actual electron cooling of antiprotons can not be demonstrated until it is relocated. The Fermilab electron cooling R&D project is scheduled to be completed in May, 2004 at which time it will be disassembled and relocated to a newly constructed facility where it will be installed in the Recycler. This paper describes the experimental results obtained with the prototype cooler system, gives an overview of the new electron cooling facility, and discusses the overall status of the project.  
 
TUPLT153 Orbit Response Matrix Analysis Applied at PEP-II target, lattice, bunching, injection 1488
 
  • C. Steier, A. Wolski
    LBNL/AFR, Berkeley, California
  • S. Ecklund, J.A. Safranek, P. Tenenbaum, A. Terebilo, J.L. Turner, G. Yocky
    SLAC, Menlo Park, California
  Beam-based techniques to study lattice properties have proven to be a very powerful tool to optimize the performance of storage rings. The analysis of orbit response matrices has been used very successfully to measure and correct the gradient and skew gradient distribution in many accelerators. The first applications were mostly in synchrotron light sources, but the technique is also used increasingly at colliders. It allows determination of an accurately calibrated model of the coupled machine lattice, which then can be used to calculate the corrections necessary to improve coupling, dynamic aperture and ultimately luminosity. At PEP-II, the Matlab version of LOCO has been used to analyze coupled response matrices for both the LER and the HER. The large number of elements in PEP-II and the very complicated interaction region present unique challenges to the data analysis. The orbit response matrix analysis will be presented in detail, as well as results of lattice corrections based on the calibrated machine model.  
 
TUPLT154 Aperture Studies for the Fermilab AP2 Anti-proton Line bunching, injection, beamloading, antiproton 1491
 
  • I. Reichel, M. Placidi, M.S. Zisman
    LBNL, Berkeley, California
  • K. Gollwitzer, S. Werkema
    Fermilab, Batavia, Illinois
  The AP2 beamline transports anti-protons from the production target to the Debuncher ring. In the past the observed aperture has been smaller than that estimated from linear, on-energy optics. We have investigated possible reasons for the aperture limitation and have identified possible sources, including residual vertical dispersion from alignment errors and chromatic effects due to very large chromatic lattice functions. Some experiments have already been performed to study these effects. We present results of the experimental and theoretical studies and possible remedies.  
 
TUPLT156 Progress in Ideal High-intensity Unbunched Beams in Alternating Gradient Focusing Systems focusing, bunching, injection, beamloading 1494
 
  • R. Bhatt, C. Chen, J. Zhou
    MIT/PSFC, Cambridge, Massachusetts
  A persistent challenge in high-intensity accelerator design is the optimization of matching conditions between a beam injector and a focusing system in order to minimize non-laminar flows, envelope oscillations, emittance growth, and halo production. It has been shown [*] that the fluid motion of a thin space-charge dominated beam propagating through a linear magnetic focusing channel consisting of any combination of uniform or periodic solenoidal fields and alternating gradient quadrupole fields can be solved by a general class of corkscrewing elliptic beam equilibria. The present work extends this discussion to asymmetric PPM focusing and derives conditions under which a uniform density elliptical beam can be matched to such a focusing channel by considering the fluid equilibrium in the paraxial limit. Methods of constructing such a beam are also discussed, with particular attention devoted to analytic electrode design for Pierce-type gun diodes of elliptical cross-section. Several applications are discussed, including heavy-ion fusion and a high-efficiency ribbon beam microwave amplifier for accelerator applications.

* C. Chen, R. Pakter, R. Davidson, "Ideal Matching of Heavy Ion Beams," Nucl. Inst. And Methods, A 464 (2001) p. 518-523

 
 
TUPLT163 Achieving Beam Quality Requirements for Parity Experiments at Jefferson Lab focusing, bunching, betatron, injection 1509
 
  • Y.-C. Chao, H. Areti, F.J. Benesch, B. Bevins, S.A. Bogacz, S. Chattopadhyay, J.M. Grames, J. Hansknecht, A. Hutton, R. Kazimi, L. Merminga, M. Poelker, Y. Roblin, M. Tiefenback
    Jefferson Lab, Newport News, Virginia
  • D. Armstrong
    The College of William and Mary, Williamsburg
  • D. Beck, K. Nakahara
    University of Illinois, Urbana
  • K. Paschke
    University of Massachusetts, Amherst
  • M. Pitt
    Virginia Polytechnic Institute and State University, Blacksburg
  Measurement of asymmetry between alternating opposite electron polarization in electron-nucleon scattering experiments can answer important questions about nucleon structures. Such experiments impose stringent condition on the electron beam quality, and thus the accelerator used for beam creation and delivery. Of particular concern to such ?parity? experiments is the level of correlation between beam characteristics (orbit, intensity) and electron polarization that can obscure the real asymmetry. This can be introduced at the beam forming stage, created due to scraping, or not damped to desired level due to defective transport. Suppression of such correlation thus demands tight control of the beam line from cathode to target, and requires multi-disciplined approach with collaboration among nuclear physicists and accelerator physicists/engineers. The approach adopted at Jefferson Lab includes reduction of correlation source, improving low energy beam handling, and monitoring and correcting global transport. This paper will discuss methods adopted to meet the performance criteria imposed by parity experiments, and ongoing research aimed at going beyond current performance.  
 
TUPLT183 Magnetized Beam Transport in Electron Coolers with Opposing Solenoid Fields focusing, bunching, beamloading, antiproton 1556
 
  • J. Kewisch, C. Montag
    BNL, Upton, Long Island, New York
  To improve cooling capability of electron coolers magnetized beams in strong solenoid fields are used. Too avoid betatron coupling in the ion coupling compensation is required. For the RHIC electron cooler we propose a scheme consisting of two identical solenoids with opposing fields, connected by a quadrupole matching section that preserves the electron beam magnetization. Since the fringe fields of the individual magnets overlap, the matching section can not be designed with standard optics codes. We developed an optimization code based on particle tracking instead. Input for the program are the simulated/measured field maps of the magnets. We demonstrate that the transverse temperature of the electron beam does not increase.  
 
TUPLT184 Operational Measurement of Coupling by Skew Quadrupole Modulation focusing, coupling, bunching, beamloading 1559
 
  • Y. Luo, P. Cameron, R. Lee, A. Marusic, F.C. Pilat, T. Roser, D. Trbojevic, J. Wei
    BNL, Upton, Long Island, New York
  The measurements of betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been recently developed and tested at RHIC. By modulating the current of different skew quadrupole families with different frequencies and measuring the resulting eigentunes response with a high resolution phase lock loop (PLL) system, it is possible to determine the projections of the residual coupling coefficients. We report the results of extensive beam studies carried on at RHIC injection, store energy and on the ramp. The capability of measuring coupling on the ramp opens the possibility of continuous coupling corrections during acceleration.  
 
TUPLT185 Principle of Skew Quadrupole Modulation to Measure Betatron Coupling focusing, bunching, beamloading, antiproton 1562
 
  • Y. Luo, F.C. Pilat, T. Roser, D. Trbojevic, J. Wei
    BNL, Upton, Long Island, New York
  The idea of modulating Skew Qudrupoles to measure the ring betatron coupling was put forth by T. Roser. In this paper, analytical solutions for this technique is given. Simulation are also carried out based on RHIC. And other relevent issues concerning this technique's application are also discussed. All of them show this idea of modulating skew qudrupoles to measure the betatron coupling are applicable.  
 
TUPLT186 Managing System Parameters for SNS Magnets and Power Supplies focusing, bunching, beamloading, antiproton 1565
 
  • W.J. McGahern, S. Badea, F.M. Hemmer, H.-C. Hseuh, J.W. Jackson, A.K. Jain, F.X. Karl, R.F. Lambiase, Y.Y. Lee, C.J. Liaw, H. Ludewig, G.J. Mahler, W. Meng, C. Pai, C. Pearson, J. Rank, D. Raparia, J. Sandberg, S. Tepikian, N. Tsoupas, J. Tuozzolo, P. Wanderer, J. Wei, W.-T. Weng
    BNL, Upton, Long Island, New York
  • R. Cutler, J.J. Error, J. Galambos, M.P. Hechler, S. Henderson, P.S. Hokik, T. Hunter, G.R. Murdoch, K. Rust, J.P. Schubert
    ORNL/SNS, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort of six U.S. Department of Energy partner laboratories. With over 312 magnets and 251 power supplies that comprise the beam transport lines and the accumulator ring, it is a challenge to maintain a closed loop on the variable parameters that are integral to these two major systems. This paper addresses the input variables, responsibilities and design parameters used to define the SNS magnet and power supply systems.  
 
TUPLT187 SNS Extraction Kicker Power Supply Control focusing, bunching, beamloading, antiproton 1568
 
  • J.-L. Mi, L. Hoff, R.F. Lambiase, Y.Y. Lee, J. Sandberg, Y. Tan, N. Tsoupas, R. Zapasek, W. Zhang
    BNL, Upton, Long Island, New York
  There are fourteen PFN power supplies, which will be installed in the SNS Extraction Kicker System. This paper will introduce these fourteen-power supplies arrangement and control schematic. These control instruments and boards are installed into four standard racks. Some of the control boards functions will be list in this paper. Control racks and some control boards pictures will be shown in this paper.  
 
TUPLT188 SNS Extraction Kicker Power Supply Manufacture Status focusing, kicker, bunching, extraction 1571
 
  • J.-L. Mi, H. Hahn, R.F. Lambiase, Y.Y. Lee, C. Pai, J. Sandberg, Y. Tan, N. Tsoupas, D.S. Warburton, R. Zapasek, W. Zhang
    BNL, Upton, Long Island, New York
  There are fourteen PFN power supplies, which will be installed in the SNS Extraction Kicker System. The Pulse Forming Network (PFN) power supplies for the SNS Extraction kicker were designed by Brookhaven. The basic configuration of the PFN is a lumped element Blumlein pulse forming network (BPFN). The PFN and power supply are fabricated by an industrial company. The first article of. PFN and power supply has been manufactured and tested with a dummy load at the company and onsite with the prototype magnet. The PFN has been tested beyond its specification and has met all requirements including rise time, pulse flatness, amplitude and pulse repetition rate. Additional heat runs are scheduled. The transverse coupling impedance of the kicker system with attached PFN has been measured. This paper will report on the SNS Extraction Kicker Power Supply engineering status, and will include output waveforms, impedance measurements, and production projections.  
 
TUPLT189 Dipole and Quaqdrupole Sorting for the SNS Ring focusing, kicker, bunching, extraction 1574
 
  • D. Raparia, A.V. Fedotov, Y.Y. Lee, J. Wei
    BNL, Upton, Long Island, New York
  The Spallation Neutron Source (SNS) accumulator ring is a high intensity ring and must have low uncontrolled losses for hands on maintenance. To achieve these low losses one needs very tight tolerance. These tight tolerances have been achieved through shimming the magnets and sorting. Dipoles are solid core magnets and had very good field quality but magnet to magnet variation were sorted out according to ITF, since all the dipole are powered with one power supply. Typically, sorting is done to minimize linear effects in beam dynamics. Here, sorting of quadrupoles was done according to a scheme which allows to reduce unwanted strength of nonlinear resonances. As a result, the strength of sextupole resonances for our base line tune-box was strongly reduced which was confirmed by a subsequent beam dynamics simulation.  
 
TUPLT190 Acceleration of Polarized Beams using Multiple Strong Partial Siberian Snakes focusing, kicker, bunching, beamloading 1577
 
  • T. Roser, L. Ahrens, M. Bai, E.D. Courant, J. Glenn, R.C. Gupta, H. Huang, A.U. Luccio, W.W. MacKay, N. Tsoupas, E. Willen
    BNL, Upton, Long Island, New York
  • M. Okamura, J. Takano
    RIKEN, Saitama
  Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20 - 30 % partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.  
 
TUPLT191 Transverse Optics Improvements for RHIC Run 4 focusing, kicker, bunching, beamloading 1580
 
  • J. Van Zeijts
    BNL, Upton, Long Island, New York
  The magnetic settings in RHIC are driven by an online model, and the quality of the resulting lattice functions depend on the correctness of the settings, including knowledge of the magnet transfer-functions. Here we first present the different inputs into the online model, including dipole sextupole compenents, used to set tunes and chromaticities along the ramp. Next, based on an analysis of measured tunes and chromaticities along the fy03 polarized proton ramp, we present predictions for quadrupole transfer-function changes. The changes are implemented for the fy04 Au ramp, and we show the improved model agreement for tunes, and chromaticities along the ramp, and measured transverse phase-advance at store. We also describe model improvements for derived observables like the quality of transverse bump closure and observed luminosity ratios between individual interaction points.  
 
TUPLT192 Transition Crossing for the BNL Super Neutrino Beam focusing, kicker, bunching, beamloading 1583
 
  • J. Wei, N. Tsoupas
    BNL, Upton, Long Island, New York
  The super neutrino beam facility proposed at the Brookhaven National Laboratory requires proton beams to cross the transition energy in the AGS to reach 1 MW beam power at top energy. High intensity beams are accelerated at a fast repetition rate. Upon transition crossing, such high intensity bunches of large momentum spreads suffer from strong nonlinear chromatic effects and self-field effects. Using theoretical and experimental methods, we determine the impact of these effects and the effectiveness of transition-jump compensation schemes, and determine the optimum crossing scenario for the super neutrino beam facility.  
 
WEXCH01 Experience with LHC Magnets from Prototyping to Large-scale Industrial Production and Integration focusing, kicker, bunching, beamloading 118
 
  • L. Rossi
    CERN, Geneva
  The construction of the LHC superconducting magnets is approaching one third of its completion. At the end of 2003, main dipoles cold masses for more than one octant were delivered; meanwhile the winding for the second octant was almost completed. The other big magnets, like the main quadrupoles and the insertion quadrupoles, have entered into series production as well. Providing more than 20 km of superconducting magnets, with the quality required for an accelerator like LHC, is an unprecedented challenge in term of complexity that has required several steps from the construction of 1 meter-long magnets in the laboratory to today production of more than one 15 meter-long magnet per day in Industry. The work and its organization is made even more complex by the fact that CERN supplies most of the critical components and part of the main tooling to the magnet manufacturers, both for cost reduction and for quality issues. In this paper the critical aspects of the construction and the time plan will be reviewed and the actual achievements in term of quality and construction time will be compared with the expectations.  
Video of talk
Transparencies
 
WEOACH01 High Field Gradient Cavity for J-PARC 3 GeV RCS focusing, kicker, bunching, beamloading 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
 
WEODCH02 Interaction of Stored Ions with Electron Target in Low Energy Electrostatic Ring radiation, focusing, ion, kicker 162
 
  • E. Syresin
    JINR, Dubna, Moscow Region
  • K. Noda
    NIRS, Chiba-shi
  • T. Tanabe
    KEK, Ibaraki
  The KEK electrostatic ring is used for investigations of molecular, bimolecular and DNA ions. The electron target installed in this ring has same construction as usual electron cooler. The interaction of stored ions with the electrons increases the ion lifetime at electron cooling caused by a suppression of the ion scattering on the residual gas atoms. The proton lifetime of 2 s was increased in the experiments by factor 2 at the electron cooling with the electron beam current of 0.2 mA, the proton energy of 20 keV and the residual gas pressure of 0.04 nTorr. However the electron-ion interaction can decrease the ion lifetime caused by an excitation of the transverse instability produced by an intensive electron beam. So in the KEK electrostatic ring the proton lifetime is reduced to 1.7 s at detuning of electron acceleration voltage from nominal cooler value on 0.4 V. The simulation of electron cooling and transverse instability of the light and DNA ions are discussed in this report.  
Video of talk
Transparencies
 
WEXLH01 Non-destructive Beam Measurements radiation, focusing, ion, kicker 165
 
  • M. Bai
    BNL, Upton, Long Island, New York
  In high energy accelerators especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with Schottky detector, phase advance measurement as well as non-linear resonance measurements with the ac dipoles in the Brookhaven RHIC.  
Video of talk
Transparencies
 
WEOALH01 Particle-in-cell Beam Dynamics Simulations radiation, focusing, ion, kicker 170
 
  • T. Lau, E. Gjonaj, T. Weiland
    TEMF, Darmstadt
  We describe the application of the Conformal Finite Integration Technique (CFIT) in the time-domain to beam dynamics simulations with the Particle-In-Cell (PIC) method. The conformal method results in a more accurate field solution for complicated geometries than the traditional FIT approach. For long-time simulations we investigate several methods for the suppression of the spurious noise, typically emerging in PIC simulations. The results are compared with the analytical solution for a bunch in a semi-infinite waveguide for each of the presented methods. As a realistic example simulations for the RF-Gun installed at Photo Injector Test Facility in DESY Zeuthen (PITZ) will be presented.  
Video of talk
Transparencies
 
WEOALH02 Multiturn Extraction Based on Trapping in Stable Islands at CERN PS: Recent Measurement Advances radiation, focusing, ion, kicker 173
 
  • M. Giovannozzi, R. Cappi, S.G. Gilardoni, M. Martini, E. Métral, A. Sakumi, R.R. Steerenberg
    CERN, Geneva
  • A.-S. Müller
    FZK-ISS-ANKA, Karlsruhe
  Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. During the year 2002 run, preliminary measurements at the CERN Proton Synchrotron with a low-intensity, single-bunch, proton beam, confirmed the possibility of generating various beamlets starting from a single Gaussian beam. The experimental campaign continued also in the year 2003 run to assess a number of key issues, such as feasibility of trapping with high-intensity beam, capture efficiency, and multi-turn extraction proper. The experimental results are presented and discussed in detail in this paper.  
Video of talk
Transparencies
 
WEOALH03 Installation Strategy for the LHC Main Dipoles radiation, focusing, ion, kicker 176
 
  • S.D. Fartoukh
    CERN, Geneva
  All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. In view of present state of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a robust installation algorithm for the LHC main dipoles. Among the different possible strategies, the proposed one has been optimised in terms of simplicity and flexibility in order not to slow down and complicate the installation process. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or field quality issues.  
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WEYLH01 Emittance Control for Very Short Bunches focusing, ion, kicker, bunching 179
 
  • K.L.F. Bane
    SLAC, Menlo Park, California
  Many recent accelerator projects call for the production of high energy bunches of electrons or positrons that are simultaneously short, intense, and have small emittances. Two examples of such projects are linear colliders, such as the GLC/NLC, and Self-Amplified Spontaneous Emission (SASE) FEL's, such as the Linac Coherent Light Source (LCLS). A major challenge in such projects is keeping in check forces that increase short bunch emittances in accelerator components, such as: wakefields of accelerator structures, collimators, and surface roughness, and coherent synchrotron radiation (CSR). We describe such forces and their control.  
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WEYLH02 Single Particle Linear and Non-linear Dynamics focusing, ion, kicker, bunching 184
 
  • Y. Cai
    SLAC, Menlo Park, California
  I will give a comprehensive review of existing particle tracking tools to assess long-term particle stability for small and large accelerators in the presence of realistic magnetic imperfections and machine misalignments. The emphasis will be given to the tracking and analysis tools based upon the differential algebra, Lie operator, and "polymorphism". Using these tools, a uniform linear and non-linear analysis will be outlined as an application to the normal form. Finally I will compare simulation results with observations in existing circular accelerators. "Model independent analysis" will be treated as an example for measuring machine optics.  
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WEPKF080 Secondary Electron Yield Measurements from Thin Surface Coatings for NLC Electron Cloud Reduction focusing, bunching, site, quadrupole 1789
 
  • F. Le Pimpec, F. King, R.E. Kirby, M.T.F. Pivi
    SLAC, Menlo Park, California
  In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the beam bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions include reducing residual gas ionization by the beam, minimizing photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.  
 
WEPKF081 Prototype Development Progress toward a 500kV Solid State Marx Modulator focusing, bunching, site, quadrupole 1792
 
  • G. Leyh
    SLAC, Menlo Park, California
  Recent advances in high voltage IGBT capabilities have made possible a range of novel solid-state modulator concepts that were unthinkable a decade ago. At present, there are two prototype solid-state modulator designs under evaluation at SLAC – A conventional pulse-transformer design using an 80kV solid-state switch in place of a thyratron, and an 'induction modulator', which uses a stack of magnetic cores to couple many paralleled primary windings to a common secondary winding. Both of these prototype modulators are currently driving actual klystron loads at SLAC. Another promising solid-state modulator concept still in the early stages of development is the Marx configuration – where an array of stacked modules generates high-voltage output pulses directly from a low DC input supply voltage. This scheme eliminates the large and costly magnetic cores inherent in the other two designs, resulting in a considerably simpler and cheaper mechanical solution. The main disadvantage to this approach is that the individual Marx sections must float at high voltages, complicating the distribution of power and timing signals. Several research groups have produced limited scale Marx prototypes in recent years. The largest prototype built to date [DTI] generates an output pulse of approximately 50kV, with plans to eventually move to higher voltage levels. This paper examines in closer detail the practical advantages and pitfalls of a solid-state Marx configuration, and explores a design approach with emphasis on performance, wall-plug efficiency, cost of manufacture, availability and ease of service. The paper presents electrical diagrams, mechanical CAD layout and preliminary prototype test data.  
 
WEPKF082 Radiation Damage Studies with Hadrons on Materials and Electronics focusing, bunching, site, quadrupole 1795
 
  • J.E. Spencer, J. Allan, S. Anderson, R. Wolf
    SLAC, Menlo Park, California
  • M. Boussoufi
    UCD/MNRC, McClellan, California
  • D.E. Pellet
    UCD, Davis
  • J.T. Volk
    Fermilab, Batavia, Illinois
  Many materials and electronic devices need to be tested for the radiation environment expected at the proposed linear colliders (LC) where the accelerator and detectors will be subjected to large fluences of hadrons, electrons and gammas during the life of the facility. Examples are NdFeB permanent magnets which are being considered for the damping rings and final focus, electronic and electro-optical devices which will be utilized in the detector readout and accelerator control systems and CCDs required for the vertex detector. The effects of gammas on a broad range of materials was presented at NSREC2002 and our understanding of the current situation concerning rare earth permanent magnets at PAC2003 where a program was proposed using neutrons from the McClellan Nuclear Reactor Center (MNRC) that has a number of areas for irradiating samples with neutron fluxes up to 4.5·1013 n/cm2s. A specialized area allows irradiation with 1 MeV-equivalent neutrons with fluxes of 4.2·1010 n/cm2s while suppressing thermal neutrons and gammas by large factors. We give our latest results and their interpretation using this facility.  
 
WEPKF083 SPEAR3 INTERMEDIATE DC MAGNET POWER SUPPLIES focusing, bunching, site, quadrupole 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 focusing, bunching, site, quadrupole 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.  
 
WEPKF085 Secondary Electron Emission Measurements for TiN Coating on Stainless Steel of SNS Accumulator Ring Vacuum Chamber focusing, bunching, site, quadrupole 1804
 
  • P. He, H.-C. Hseuh, R. Todd
    BNL, Upton, Long Island, New York
  • B. Henrist, N. Hilleret
    CERN, Geneva
  • S. Kato, M. Nishiwaki
    KEK, Ibaraki
  • R.E. Kirby, F. Le Pimpec, M.T.F. Pivi
    SLAC, Menlo Park, California
  BNL is responsible for the design and construction of the US Spallation Neutron Source (SNS) accumulator ring. Titanium Nitride(TiN) coating on the stainless steel vacuum chamber of the SNS accumulator ring is needed to reduce undesirable resonant multiplication of electrons. The Secondary Electron Yield(SEY) of TiN coated chamber material has been measured after coated samples were exposed to air and after electron and ion conditioning. We are reporting about the TiN coating system setup at BNL and SEY measurements results performed at CERN, SLAC and KEK. We also present updated electron-cloud simulation results for the SNS accumulator assuming different SEY values.  
 
WEPKF086 A Model for Determining Dipole, Quadrupole and Combined Function Magnet Costs focusing, bunching, site, quadrupole 1807
 
  • R. Palmer, J.S. Berg
    BNL, Upton, Long Island, New York
  One of the most important considerations in designing large accelerators is cost. Magnet costs are a significant component of that. This paper describes a model for estimating magnet costs. The reasoning behind the cost model is explained, and the parameters of the model are chosen so as to correctly give the costs for existing magnets.  
 
WEPKF087 SNS Extraction Fast Kicker Pulsed Power System focusing, bunching, site, quadrupole 1810
 
  • W. Zhang, H. Hahn, J.-L. Mi, C. Pai, J. Sandberg, Y. Tan, N. Tsoupas, J. Tuozzolo, D.S. Warburton, J. Wei
    BNL, Upton, Long Island, New York
  • R. Cutler, K. Rust
    ORNL/SNS, Oak Ridge, Tennessee
  The Spallation Neutron Source (SNS) is a next generation high intensity beam facility. Its Accumulator Ring Extraction Fast Kicker System is a very high peak power, high average power, high precision pulse-waveform, ultra-low beam impedance, and high repetition rated pulsed power system. It has been successfully design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage modulators and fourteen extraction magnet sections located inside of the SNS accumulator ring. The overall system output will reach multiple GW peak power with 60 Pulse-per-second repetition rates. The techniques of reducing impedance, improving rise time, and minimizing ripples will be discussed. The lifetime considerations, issues of the system design, development and construction are presented in this paper.  
 
WEPLT044 Electron-cloud Build-up Simulations and Experiments at CERN radiation, focusing, resonance, bunching 1930
 
  • F. Zimmermann, G. Arduini, V. Baglin, T. Bohl, B.J. Jenninger, J.M. Jimenez, J.-M. Laurent, F. Ruggiero, D. Schulte
    CERN, Geneva
  We compare the predications of electron-cloud build-up simulations with measurements at the CERN SPS. Specifically, we compare the electron flux at the wall, electron-energy spectra, heat loads, and the spatial distribution of the electrons for two different bunch spacings, with variable magnetic fields, and for several chamber temperatures and associated surface conditions. The simulations employ a modified, improved version of the ECLOUD code. The main changes are briefly described. We finally present updated simulation results for the heat load in the cold LHC arcs.  
 
WEPLT045 Experiments on LHC Long-range Beam-beam Compensation in the CERN SPS radiation, focusing, resonance, bunching 1933
 
  • F. Zimmermann, J.-P. Koutchouk, J. Wenninger
    CERN, Geneva
  Long-range beam-beam collisions may limit the dynamic aperture and the beam lifetime in storage-ring colliders. Their effect can be compensated by a current-carrying wire mounted parallel to the beam. A compensation scheme based on this principle has been proposed for the Large Hadron Collider (LHC). To demonstrate its viability, a prototype wire was installed at the CERN SPS in 2002. First successful machine experiments explored the dependence of beam loss, beam size, and beam lifetime on the beam-wire distance and on the wire excitation. They appear to confirm the predicted effect of the long-range collisions on the beam dynamics. In 2004, two further wires will become available, by which we can explicitly demonstrate the compensation, study pertinent tolerances, and also compare the respective merits of different beam-beam crossing schemes for several interaction points.  
 
WEPLT055 Observation of Ultracold Heavy Ion Beams with Micrometer Size by Scraping focusing, ion, bunching, impedance 1963
 
  • M. Steck, K. Beckert, P. Beller, B.  Franzke, F. Nolden
    GSI, Darmstadt
  The existence of an ordered beam state for low intensity, electron cooled heavy ion beams has been evidenced by a sudden reduction of the momentum spread. The detection of a similar effect in the transverse degree of freedom by non-destructive diagnostics is ruled out by the limited resolution of beam profile detectors. A method to probe the horizontal beam size of an electron cooled beam in a dispersive section has been developed. It is based on beam scraping and allows a resolution on the order of micrometers. This good transverse resolution for the cooled ion beam is achieved by precise changes of the ion energy which is varied by changes of the electron beam energy. The lower resolution limit due to power supply ripple is estimated to be below 1 micrometer. This method evidenced that the reduction of the momentum spread by one order of magnitude coincides with a reduction of the transverse beam emittance by 2-3 orders of magnitude, at least. A horizontal beam radius of a few micrometer could be demonstrated for electron cooled heavy ion beams with less than 1000 particles. This gives new evidence for the formation of an ordered beam arranged as a linear string of ions.  
 
WEPLT063 Investigation of Cavity Induced Longitudinal Coupled Bunch Mode Instability Behaviour and Mechanisms focusing, antiproton, bunching, coupling 1987
 
  • 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.  
 
WEPLT064 2-nd Order Sextupole Effects on the Dynamic Aperture in HERA-e focusing, antiproton, bunching, coupling 1990
 
  • M. Vogt
    DESY, Hamburg
  During the first year after the luminosity upgrade HERA-e was operated in a mode for which the accessible area in transverse tune space was determined by resonances driven by sextupoles in 2-nd order. It turned out that with typical total incoherent beam beam tune shifts (.05,.08) for 2 IPs this space was too small for stable operation. We have used 2-nd order canonical perturbation theory to analyze the impact of the increased sextupole strengths in the upgraded lattice on the relevant resonance strengths and the detuning. Moreover, we have studied whether it is possible to compensate the resonances with localized octupole schemes (6 or 9 independent magnets) to 1-st and 2-nd order, computed the resulting detuning and compared the results with 6D tracking.  
 
WEPLT065 Hybrid Dry Coolers in Cooling Systems of High Energy Physics Accelerators focusing, antiproton, bunching, coupling 1993
 
  • 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.  
 
WEPLT067 Space Charge Problem in Low Energy Super-conducting Accelerator antiproton, damping, bunching, coupling 1999
 
  • N.E. Vasyukhin, R. Maier, Y. Senichev
    FZJ/IKP, Jülich
  At present the super-conducting option of linear accelerators is considered for low energy, and new type of RF cavities is considered for this purpose. However, together with electrodynamics problems we should solve the transverse stability problem, since in structures with external focusing elements the focusing period is longer, and in higher accelerating field the defocusing factor increases as well. In this paper we consider the transverse stability problem, taking into account the non-linear space charge problem. The fundamental mechanism of hallo creation in super-conducting linear accelerators is investigated to minimize the particle losses. The theoretical results are supported by numerical simulation.  
 
WEPLT100 Planar Electron Sources and the Electron Trap ELTRAP antiproton, damping, plasma, vacuum 2080
 
  • M. Cavenago
    INFN/LNL, Legnaro, Padova
  • G. Bettega, F. Cavaliere, A. Illiberi, R. Pozzoli, M. Romé, L. Serafini
    INFN-Milano, Milano
  Filamentation and other space charge effects (both transverse and longitudinal) of intense electron beams, found for example in rf photoinjectors (beam energy 1 MeV, current 100 A), are easily studied in small voltage traps and drift channels (0.01-10 kV), keeping the same perveance order. A suitable Malmberg-Penning trap, named ELTRAP, installed and operated at the University of Milan, is briefly described; trap length ranges from 10 cm to 1 m; an uniform magnetic field confines electron radially. Several experimental regimes were investigated with the internal CW planar electron source: plasma, beam-plasma, beam, depending on the injection/extraction method chosen. Evolution of electron vortices and virtual cathode formation is documented; analogy with meteorologic and astrophysical plasma is discussed. Upgrading with an external laser pulsed electron source is in course. Larger planar sources are also under construction. (Main classification 4: Beam Dynamics and Electro-magnetic Fields; D03 High Intensity, Incoherent Instabilities, Space Charge, Halos, Cooling; Other classification 8: Low and Intermediate Energy Accelerators and Sources; T12 Beam Injection/Extraction and Transport; T02 Lepton sources)  
 
WEPLT101 On-line Mechanical Instabilities Measurements and Tuner Development in SC Low-beta Resonators antiproton, plasma, vacuum, booster 2083
 
  • A. Facco, E. Bissiato, S. Canella, D. Carlucci, M. Lollo, F. Scarpa, D. Zenere
    INFN/LNL, Legnaro, Padova
  The use of high-Q and small rf bandwidth superconducting quarter wave resonators made of bulk niobium put severe requirements to the helium bath pressure stability to avoid cavity detuning. This is not always possible, and cavity detuning caused by slow pressure changes must be precisely followed by the cavity tuner. The LNL philosophy is based on mechanical damping of cavity vibrations and mechanical tuning in feedback for slow frequency compensation. The old-fashioned tuners installed in the ALPI linac had significant performance limitations. To replace them, we have designed, constructed and tested a new tuner which integrates the LNL system and control with the TRIUMF, backlash-free tuner leverage design. The new tuner is designed to compensate pressure changes up to 100 mbar/minute with a precision of 0.5 Hz, and it will be installed in the ALPI resonators. An upgraded prototype for future applications includes a piezoelectric actuator for fast tuning. Tuner characteristics and first test results will be presented. This system is extendable to other low-beta cavity types like superconducting rfqs.  
 
WEPLT105 Beam-Beam Effects Measured Using Gated Monitors at KEKB radiation, antiproton, plasma, vacuum 2092
 
  • T. Ieiri, Y. Funakoshi, T. Kawamoto, M. Masuzawa, M. Tawada, M. Tobiyama, S.S. Win
    KEK, Ibaraki
  KEKB is a multi-bunch, high-current, electron/positron collider for B meson physics. The two beams collide at one interaction point (IP) with a finite horizontal crossing angle and with a bunch-space of 6 to 8 ns. The luminosity of KEKB is the best in the world. The collision is performed by carefully adjusting a horizontal orbit bump of the electron beam at IP, which results in a horizontal offset to obtain the best luminosity. In order to investigate the asymmetric beam-beam effects, beam parameters of collision and non-collision bunches were compared using beam monitors capable of selecting a specific bunch in a bunch train. The beam-beam kick and the beam-beam tune-shift were obtained by the gated beam-position monitor and by the gated tune monitor. It was found that the horizontal offset was negligibly small in the case of a wide bunch-space of 48 ns. This result suggests that the horizontal offset is related to wake fields including electron-cloud effects.  
 
WEPLT126 Beam Dynamics Simulation in High Energy Electron Cooler radiation, sextupole, antiproton, resonance 2143
 
  • A.V. Ivanov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva
    BINP SB RAS, Novosibirsk
  The article deals with electron beam dynamics in projected high energy electron cooler. Classical electrostatic scheme with several MeV electron energy is considered. The increase of transversal energy of electrons in an accelerating section, in bends and at the matching point of magnetic fields is calculated. In order to calculate beam behavior in bends with electrostatic compensation of centripetal drift new ELEC3D electro- and magnitostatic 3D code is developed. BEAM code is used for simulation of dynamics in an accelerating section. The methods of keeping low transversal energy are estimated.  
 
WEPLT128 Charge Particle Source for Industrial and Research Accelerators Operating at the Poor Vacuum Conditions radiation, sextupole, antiproton, resonance 2146
 
  • E.O. Popov, A.A. Pashkevich, S.O. Popov, A.V. Vitugov
    IOFFE, St. Petersburg
  We investigated the original method of fabrication of the great number of emitting tips by pulling liquid metal through the holes in track membrane under influence of electric field. The track membranes are produced by cyclotron of Physicotechnical Institute. This method enables to fabricate up to 1·108 emitting tips per square cm. Special test facility to investigate emitter parameters operating at different values of background residual gas pressure was designed and developed. The liquid metal multiple tip field emitters possess some unique characteristics which are attractive in accelerators for material irradiation: unlimited life expectancy, large current densities (about 100 mA per sq. cm), practically unlimited surface, stable emission in poor vacuum.  
 
WEPLT133 On Beam Dynamics Optimization radiation, sextupole, antiproton, resonance 2149
 
  • D.A. Ovsyannikov, S.V. Merkuryev
    St. Petersburg State University, St. Petersburg
  Mathematical optimization methods are widely used in designing and construction of charged particle accelerators. In this paper new approach to beam dynamics optimization is considered. Suggested approach to the problem is based on the analytical representation for variation of examined functionals via solutions of special partial differentional equations. The problem of optimization is considered as a problem of mutual optimization chosen synchronous particle motion and charged particles beam at whole. This approach was applied to the beam dynamics optimization for RFQ structures.  
 
WEPLT156 Suppression of Microbunching Instability in the Linac Coherent Light Source sextupole, optics, proton, resonance 2203
 
  • Z. Huang, P. Emma, C. Limborg-Deprey, G.V. Stupakov, J.J. Welch, J. Wu
    SLAC, Menlo Park, California
  • M. Borland
    ANL/APS, Argonne, Illinois
  A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation and linac wakefields is studied for the linac coherent light source (LCLS) accelerator system. Since the uncorrelated (local) energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify shot noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude without degrading the free-electron laser performance to provide strong Landau damping against the instability. We study different damping options in the LCLS and discuss an effective laser heater to minimize the impacts of the instability on the quality of the electron beam.  
 
WEPLT157 Single-bunch Electron Cloud Effects in the GLC/NLC, US-cold and TESLA Low Emittance Transport Lines sextupole, optics, proton, resonance 2206
 
  • M.T.F. Pivi, D. Bates, A. Chang, D. Chen, T.O. Raubenheimer
    SLAC, Menlo Park, California
  In the beam pipe of the Beam Delivery System (BDS) and Bunch Compressor system (BCS) of a linear collider, ionization of residual gasses and secondary emission may lead to amplification of an initial electron signal during the bunch train passage and ultimately give rise to an electron-cloud. A positron beam passing through the linear collider beam delivery may experience unwanted additional focusing due to interaction with the electron cloud. This typically leads to an increase in the beam size at the interaction point (IP) when the cloud density is high. Interaction with the electron cloud in the bunch compressor could also potentially cause an instability. This paper examines the severity of the electron cloud effects in the BCS and BDS of both the GLC/NLC and US-Cold linear collider design through the use of specially developed simulation codes. An estimate of the critical cloud density is given for the BDS and BCS of both designs.  
 
WEPLT158 Direct Measurement of the Resistive Wakefield in Tapered Collimators sextupole, optics, proton, wakefield 2209
 
  • P. Tenenbaum
    SLAC, Menlo Park, California
  • D. Onoprienko
    Brunel University, Middlesex
  The transverse wakefield component arising from surface resistivity is expected to play a major role in the beam dynamics of future linear colliders. We report on a series of experiments in which the resistive wakefield was measured in a series of tapered collimators, using the Collimator Wakefield beam test facility at SLAC. In order to separate the contributions of geometric and resistive wakefields, two sets of collimators with identical geometries but different resistivities were measured. The results are in agreement with the theoretical prediction for the high-resistivity (titanium) collimators, but in the case of low-resistivity (copper) collimators the resistive deflections appear to be substantially larger than predicted.  
 
WEPLT159 Linear Vlasov Analysis for Stability of a Bunched Beam sextupole, optics, proton, wakefield 2212
 
  • 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.  
 
WEPLT167 A Cure for Multipass Beam Breakup in Recirculating Linacs sextupole, optics, proton, wakefield 2215
 
  • B.C. Yunn
    Jefferson Lab, Newport News, Virginia
  We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.  
 
WEPLT168 ORBIT Benchmark of Space-charge-induced Emittance Growth in the CERN PS sextupole, optics, proton, wakefield 2218
 
  • S.M. Cousineau, J.A. Holmes
    ORNL/SNS, Oak Ridge, Tennessee
  • E. Métral
    CERN, Geneva
  Particle tracking codes provide an invaluable tool in the design and operation of high intensity machines. An important task in the development of these codes is the validation of the space charge models through benchmark with experimental data. Presented here are benchmarks of the ORBIT particle tracking code with recent measurements of space-charge-induced transverse emittance growth in the CERN PS machine. Benchmarks of two experimental data sets are performed: Integer resonance crossing, and Montague resonance crossing.  
 
WEPLT169 Benchmark and Threshold Analysis of Longitudinal Microwave Instability in the PSR sextupole, optics, wakefield, collider 2221
 
  • S.M. Cousineau, J.A. Holmes
    ORNL/SNS, Oak Ridge, Tennessee
  • C. Beltran, R.J. Macek
    LANL/LANSCE, Los Alamos, New Mexico
  A set of inductive inserts used to provide passive longitudinal space charge compensation in the Los Alamos Proton Storage Ring cause a strong microwave instability in the beam when the inductors are at room temperature. We use the ORBIT code to perform benchmarks of the microwave instability dynamics, including the mode spectrum and the instability growth time. Additionally, we analyze the experimental instability intensity threshold and compare it with the simulated threshold. For all parameters benchmarked, results of simulations are in good agreement with the experimental data.  
 
WEPLT170 Injection Schemes for Self Consistent Space Charge Distributions sextupole, optics, wakefield, collider 2224
 
  • V.V. Danilov, S.M. Cousineau, S. Henderson, J.A. Holmes, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
  This paper is based on recently found sets of self-consistent 2D and 3D time-dependent space charge distributions. A subset of these distributions can be injection-painted into an accumulator ring, such as Spallation Neutron Source Ring, to produce periodic space charge conditions. The periodic condition guarantees zero space-charge-induced halo growth and beam loss during injection. Practical aspects of such schemes are discussed, and simulations of a few specific cases are presented.  
 
WEPLT171 Rotating Electromagnetic Field Trap for High Temperature Plasma and Charge Confinement sextupole, optics, wakefield, collider 2227
 
  • V.V. Danilov
    ORNL/SNS, Oak Ridge, Tennessee
  This paper demonstrates that there exists a special combination of oscillating electromagnetic fields capable of trapping ultra high charge densities. Trapped particles undergo stable motion when their frequencies of oscillation are much higher than that of the ocillating field. Contrary to conventional electromagnetic traps, the motion in this dynamic trap is stable for arbitrarily high electromagnetic field amplitudes. This, in turn, leads to the possibility of using enormous electric and magnetic fields from RF or laser sources to confine dense ultrahigh temperature plasmas and particle beams.  
 
WEPLT172 Design & Handling of High Activity Collimators &Ring Components on the SNS sextupole, optics, wakefield, collider 2230
 
  • G.R. Murdoch, D. Crisp, S. Henderson, M. Holding, K. Potter, T. Roseberry
    ORNL/SNS, Oak Ridge, Tennessee
  Design & Handling of High Activity Collimators on the SNS*G Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.  
 
WEPLT174 Higher Order Hard Edge End Field Effects sextupole, optics, wakefield, collider 2233
 
  • J.S. Berg
    BNL, Upton, Long Island, New York
  In most cases, nonlinearities from magnets must be properly included in tracking and analysis to properly compute quantities of interest, in particular chromatic properties and dynamic aperture. One source of nonlinearities in magnets that is often important and cannot be avoided is the nonlinearity arising at the end of a magnet due to the longitudinal variation of the field at the end of the magnet. Part of this effect is independent of the shape of the end. It is lowest order in the body field of the magnet, and is the result of taking a limit as the length over which the field at the end varies approaches zero. This is referred to as a hard edge" end field. This effect has been computed previously to lowest order in the transverse variables. This paper describes a method to compute this effect to arbitrary order in the transverse variables, under certain constraints. The results of using this hard edge model are compared with performing the computation with finite-length end fields, as well as to the lowest-order hard-edge end field model.  
 
WEPLT177 Analysis of Electron Cloud at RHIC sextupole, optics, wakefield, collider 2236
 
  • U. Iriso, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, H.-C. Hseuh, R. Lee, S. Peggs, L. Smart, D. Trbojevic, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • G. Rumolo
    GSI, Darmstadt
  Pressure rises with high intense beams are becoming the main luminosity limitation at RHIC. Observations during the latest runs show beam induced electron multipacting as one of the causes for these pressure rises. Experimental studies are carried out at RHIC using devoted instrumentation to understand the mechanism leading to electron clouds. Possible cures using NEG coated beam pipes and solenoids are experimentally tested. In the following, we report the experimental electron cloud data and analyzed the results using computer simulation codes.  
 
WEPLT181 Measurement of Multipole Strengths from RHIC BPM Data sextupole, optics, wakefield, collider 2239
 
  • R. Tomas, M. Bai, W. Fischer
    BNL, Upton, Long Island, New York
  • F. Franchi, G. Rumolo
    GSI, Darmstadt
  Recently resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of BPM data. Based on these measurements a new analysis has been derived to extract multipole strengths.In this paper we present experimental measurements of sextupolar and skew quadrupolar strengths carried out at RHIC. Also discussed is the possibility of a non-destructive measurement using an AC dipole.  
 
WEPLT182 Non-linear Modeling of the RHIC Interaction Regions sextupole, optics, wakefield, collider 2242
 
  • R. Tomas, W. Fischer, A.K. Jain, Y. Luo, F.C. Pilat
    BNL, Upton, Long Island, New York
  For RHIC's collision lattices the dominant sources of transverse non-linearities are located in the interaction regions. The field quality is available for most of the magnets in the interaction regions from the magnetic measurements, or from extrapolations of these measurements. We discuss the implementation of these measurements on the MADX models of the Blue and the Yellow rings and their impact on beam stability.  
 
WEPLT184 Preliminary Estimation of the Electron Cloud in RHIC sextupole, optics, wakefield, collider 2248
 
  • L. Wang, P. He, J. Wei
    BNL, Upton, Long Island, New York
  Electron cloud due to beam induce multipacting is suspected to be one of the source of pressure rises in RHIC. This paper estimates the possible electron cloud in RHIC. Various parameters related electron multipacting has been investigated.  
 
THYCH01 Issues and Challenges for Short Pulse Radiation Production injection, wakefield, collider, beamloading 225
 
  • P. Emma
    SLAC/ARDA, Menlo Park, California
  A new generation of light sources are being planned at many locations, pushing the frontiers of brightness, wavelength, and peak power well beyond existing 3rd generation sources. In addition to these large scale improvements there is great interest in extremely short duration pulses into the femtosecond and sub-femtosecond regime. Collective electron bunch instabilities at these scales are severe, especially in consideration of the high-brightness electron bunch requirements. Several new schemes propose very short radiation pulses generated with moderate electron bunch lengths. Such schemes include radiation pulse compression, differential bunch spoiling, staged high-gain harmonic generation, and selective pulse seeding schemes. We will describe a few of these ideas and address some of the electron bunch length limitations, highlighting recent measurements at the Sub-Picosecond Pulse Source (SPPS) at SLAC where <100-fs electron and x-ray pulses are now available.  
Video of talk
Transparencies
 
THZCH02 Electron Cooling: Remembering and Reflecting synchrotron, injection, radiation, wakefield 244
 
  • I.N. Meshkov
    JINR, Dubna, Moscow Region
  The report contains a brief review of developments in electron cooling methods. The influence of electron cooling concepts on progress in particle beam physics is considered, particularly: development of alternative and complementary cooling methods - stochastic, laser, muon cooling; physics of cooled and intense particle beams; ordering effects in cooled ion beams and the idea of crystalline beams; intrabeam scattering in cooled beams, etc. Creation of new accelerator technology, based on electron cooling and its application to different fields of experimental physics, particle, nuclear and atomic physics, is described. Modern trends and new concepts of electron cooling applications are discussed.  
Video of talk
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THZCH03 JACoW, a Collaboration Serving the Accelerator Community synchrotron, injection, radiation, wakefield 249
 
  • J. Poole, C. Petit-Jean-Genaz
    CERN, Geneva
  The Joint Accelerator Conferences Website started from an idea to publish the conference proceedings on the WWW and has grown to an international collaboration which does much more than just publish the proceedings and is currently supported by seven conference series. Through attendance at Steering Committee meetings and Team Meetings and through active participation in the work of the editorial teams of sister conferences, people with the responsibility for the production of the electronic versions of conference proceedings come together to learn from the experience of colleagues, and to develop common approaches to problems. The activities of the collaboration cover all aspects of electronic publication and have recently extended into conference scientific programme management. This paper reviews the history of the collaboration, describes some of the highlights in the activities during the life of the collaboration and presents the current status and future plans.  
Video of talk
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THOALH01 Bunch Length Measurements at the SLS Linac using Electro-optical Techniques laser, synchrotron, injection, wakefield 253
 
  • A. Winter, M. Tonutti
    RWTH, Aachen
  • S. Casalbuoni, P. Schmüser, S. Simrock, B. Steffen
    DESY, Hamburg
  • T. Korhonen, T. Schilcher, V. Schlott, H. Sigg, D. Suetterlin
    PSI, Villigen
  The temporal profile of the electron bunches in the SLS Linac will be determined by means of electro-optical techniques. A mode locked Ti:Sa Laser with 15 fs pulse width is used for coincidence measurements between the laser pulse and the coherent transition radiation (CTR) generated by short electron bunches. Synchronization accuracy of 100 fs rms between the 3 GHz Linac RF and the 81 MHz repetition rate of the laser was achieved, which is important for the optimum time resolution of the applied electro-optical sampling technique. Likewise, a mode locked Nd:YAG laser with 400 ps long pulses will be used for electro-optical autocorrelation measurements between the CTR and the laser pulses. This alternative technique promises single shot capability and requires much relaxed synchronization stability between laser and electron beam.  
Video of talk
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THYLH01 Beam Diagnostics at the VUV-FEL Facility injection, radiation, undulator, wakefield 262
 
  • J. Feldhaus, D. Noelle
    DESY, Hamburg
  The free electron laser (FEL) at the TESLA Test facility at DESY will be the first FEL user facility for VUV and soft X-ray radiation down to 6 nm wavelength, the commissioning starts in summer 2004. Commissioning as well as stable FEL operation require a combination of different diagnostic tools for measuring both electron and photon beam parameters, including the full phase space distribution of the bunch charge, exact timing with sub-picosecond resolution, electron and photon beam overlap along the undulator, radiation beam position in the user area 50-70 m behind the undulator, intensity and spectral distribution of the radiation pulses and others. Much effort has been put in the development of instrumentation for measuring the longitudinal bunch charge distribution, for controlling the electron beam orbit along the undulator, and for online monitoring the radiation intensity, position and spectral distribution. This contribution gives an overview of the complete electron and photon beam diagnostics of the FEL facility and focuses particularly on the instrumentation which is crucial or specific for the FEL operation.  
Video of talk
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THOBLH01 Recent Improvement of Slow-extraction at HIMAC Synchrotron extraction, injection, radiation, undulator 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
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THPKF034 Design of a Photoneutron Source based on a 5 MeV Electron Linac target, booster, beamloading, damping 2344
 
  • L. Auditore, R.C. Barnà, D. De Pasquale, A. Trifirò, M. Trimarchi
    INFN & Messina University, S. Agata, Messina
  • A. Italiano
    INFN - Gruppo Messina, S. Agata, Messina
  A photoneutron source, based on a 5 MeV electron linac was designed by means of the MCNP simulation code. Although higher electron energies are required to produce acceptable neutron fluxes, the availability of a 5 MeV electron linac developed at the Dipartimento di Fisica (Università di Messina) has suggested this project, in sight of a future development and testing of the studied neutron source. Be and BeD2 targets were considered, whose neutron production was studied optimizing two sequential steps: the bremsstrahlung production in a suitable e-gamma converter and the (gamma,n) production in an properly designed photoneutron target-reflector-moderator system. As a result of a comparative study of different materials performances, a 0.88 mm-thick W layer was chosen as e-gamma converter. A natural graphite reflector was designed, surrounding the target, enhancing the neutron flux of two order of magnitude. The final neutron flux, at 50 cm from the photoneutron target, thermalized by a 12.2 cm-thick PE layer, was estimated to be 8.48E+07 n/cm2/sec/mA with Be target and 1.23E+08 n/cm2/sec/mA with BeD2 target.  
 
THPKF040 Development of a Femtosecond Pulse Radiolysis for Reaction Analysis in Nano-space target, cathode, laser, booster 2362
 
  • Y. Yoshida, T. Kozawa, S. Tagawa, J. Yang
    ISIR, Osaka
  A new femtosecond pulseradiolysis system was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. In the pulseradiolysis system, a femtosecond electron beam produced by a photocathode RF gun is used as an irradiation source, while a mode-locked Ti:Sapphire femtosecond laser was used as a probe light source. A time jitter between the electron pulse and the femtosecond laser was compensated by a jitter compensation technique used a femtosecond streak camera. An oblique incidence of the probe light is considered in the system to reduce the degradation of velocity difference between the electron and the laser light in samples. A time resolution of <100 fs is expected in the pulse radiolysis system for the analysis of utrafast physical and chemical reactions in nano-space.  
 
THPKF050 Electron Accelerator for Energy up to 5.0 MeV and Beam Power up to 50 KW with X-ray Converter target, cathode, laser, injection 2380
 
  • V. Auslender, A.A. Bryazgin, B.L. Faktorovich, E.N. Kokin, I. Makarov, S.A. Maximov, V.E. Nekhaev, A.D. Panfilov, V.M. Radchenko, M.A. Tiunov, V.O. Tkachenko, A.F.A. Tuvik, L.A. Voronin
    BINP SB RAS, Novosibirsk
  In recent time the new powerful industrial electron accelerators appear on market. It caused the increased interest to radiation technologies using high energy X-rays due to their high penetration ability. One of the promising directions is the creation of the irradiation installations for treatment of wide variety of food products. The report describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The ILU-10 accelerator generates the vertical electron beam. The beam line turns the beam through an angle of 90 degrees and transports the beam to the vertically posed X-ray converter to generate the horizontal beam of X-rays. In the work presented results of measurements of the dose distribution profiles on the surface of treated products.  
 
THPKF075 LUX - A Recirculating Linac-based Facility for Ultrafast X-ray Science radiation, linac, coupling, simulation 2436
 
  • J.N. Corlett, W.A. Barletta, S. De Santis, L.R. Doolittle, W. Fawley, P.A. Heimann, S.R. Leone, D. Li, S.M. Lidia, G. Penn, A. Ratti, M. Reinsch, R.W. Schoenlein, J.W.  Staples, G.D. Stover, S.P. Virostek, W. Wan, R. Wells, R.B. Wilcox, A. Wolski, J.S. Wurtele, A. Zholents
    LBNL, Berkeley, California
  We present design concepts for LUX - a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux VUV-x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1 - 10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and to propagate electron beams carrying nm-scale density modulation in the final stages of cascaded harmonic generation. Synchronization of tens of femtoseconds is achieved by use of an optical master oscillator distributing timing signals over actively stabilized fiber, and generation of rf signals from the optical master oscillator. We describe technical developments in key areas including injection from a high repetition rate rf photocathode gun, lattice design, UV and soft x-ray production by high-gain harmonic generation, a kicker design for rapid transfer of the electron beam between radiator beamlines, lasers systems concepts, and synchronization between experimental pump lasers and the x-ray pulse.  
 
THPKF076 Plan to Upgrade the Advanced Light Source to Top-off Injection Operation radiation, linac, simulation, insertion 2439
 
  • D. Robin, B. J. Bailey, K.M. Baptiste, W. Barry, E. Byrne, J.-Y. Jung, S. Kwiatkowski, R.S. Mueller, H. Nishimura, S. Prestemon, S.L. Rossi, F. Sannibale, D. Schlueter, D. Shuman, C. Steier, G.D. Stover, T. Warwick
    LBNL, Berkeley, California
  • R.J. Donahue
    LBNL/ALS, Berkeley, California
  The brightness and thermal stability of the Advanced Light Source (ALS) is lifetime limited. Brightness improvements such as narrower gap insertion devices, smaller emittance coupling, and higher currents all result in short lifetimes. In addition current changes over a fill impact the thermal stability of both the storage ring and beamlines. In order to mitigate these limitations there is a plan to upgrade the injector of the ALS to full energy injection and to operate in a quasi-continuous filling (Top-Off) injection operation. With Top-Off, the ALS will increase its time-averaged current by two, reduce the vertical emmittance, and operate with smaller gap insertion devices. In this paper we describe our upgrade plan.  
 
THPKF078 Coherent Infrared Radiation from the ALS Generated via Femtosecond Laser Modulation of the Electron Beam linac, laser, simulation, insertion 2445
 
  • A. Zholents, J.M. Byrd, Z. Hao, M.C. Martin, D. Robin, F. Sannibale, R.W. Schoenlein, M. Venturini, M.S. Zolotorev
    LBNL, Berkeley, California
  Interaction of an electron beam with a femtosecond laser pulse co-propagating through a wiggler at the ALS produces significant modulation of the electron energies within a short ~100 fs slice of the electron bunch. Subsequent propagation of the energy-modulated bunch around the storage ring results in an appearance of a local temporal modulation of the electron density (micro-bunching) due to the dispersion of electron trajectories. The temporal width of this perturbation evolves as the electron bunch propagates around the ring. The shortest modulation, ~50 microns, appears in the ALS sector immediately following the wiggler magnet, and stretches to ~ 500 microns following propagation over 2/3 of a storage ring orbit. The modulated electron bunch emits single-cycle pulses of temporally and spatially coherent infrared light which are automatically synchronized to the laser pulses. The intensity and spectra of the infrared light were measured in two locations in the ring indicated above and were found to be in good agreement with analytical calculations. Ultra-short pulses of coherent infrared radiation are presently used for a fine tuning the laser ? electron beam interaction for generating femtosecond x-ray pulses.  
 
THPKF082 The Completion of SPEAR 3 linac, laser, simulation, insertion 2448
 
  • R.O. Hettel, R. Akre, S. Allison, P. Bellomo, R.F. Boyce, L. Cadapan, R. Cassel, B. Choi, W.J. Corbett, D. Dell'Orco, T. Elioff, I. Evans, R. Fuller, S. Hill, D. Keeley, N. Kurita, J. Langton, G. Leyh, C. Limborg-Deprey, D. Macnair, D.J. Martin, P.A. McIntosh, E. Medvedko, C.-K. Ng, I. Nzeadibe, J. Olsen, M. Ortega, G.C. Pappas, S. Park, T. Rabedeau, H. Rarback, A. Ringwall, P. Rodriguez, J.A. Safranek, H.D. Schwarz, B. Scott, J.J. Sebek, S. Smith, T. Straumann, J. Tanabe, A. Terebilo, T.A. Trautwein, C. Wermelskirchen, M. Widmeyer, R. Yotam, K. Zuo
    SLAC/SSRL, Menlo Park, California
  On December 15, 2003, 8 1/2 months after the last electrons circulated in the old SPEAR2 storage ring and 5 days after the beginning of commissioning, the first electrons were accumulated in the completely new SPEAR3 ring. The rapid installation and commissioning is a testimony to the SPEAR3 project staff and collaborators who have built an excellent machine and equipped it with powerful and accessible machine modeling and control programs. The final year of component fabrication, system implementation and testing, the 7-month installation period leading up to the beginning of commissioning, and lessons learned are described.  
 
THPKF084 Emerging Concepts, Technologies and Opportunities for Mezzo-scale Terahertz and Infrared Facilities radiation, linac, laser, simulation 2451
 
  • 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.  
 
THPLT018 Electron Beam Dynamics Simulations for the Low Emittance Gun feedback, antiproton, gun, target 2502
 
  • M. Dehler, S.C. Leemann
    PSI, Villigen
  • A.E. Candel
    ETH, Zürich
  We report on theoretical simulation performed for the development of a high brightness, field emitter based electron gun suitable for an Angstrom wavelength free electron laser\cite{LEG}. First simulations have been done with available codes in 2 1/2D and 3D for basic gun configurations showing the global and local (due to the granularity of the emitter array) effects on the emittance dilution.Design and construction started on a test setup consisting of a 100 keV electron gun with solenoidal focusing and a diagnostics module. In addition to solenoid focussing, anode shaping will be investigated in order to compensate for non-linear fields leading to space charge blow-up. For advanced simulations of field emitter based guns allowing to resolve individual emitters and to capture the influence of mechanical imperfections, a massive parallel code for 3D particle-in-cell simulations is in development. The electromagnetic field solver is fully functional and the particle tracker has been completed in its basic structures.  
 
THPLT019 Commissioning Results of the Multi Bunch Feedback System at SLS antiproton, gun, target, lattice 2505
 
  • M. Dehler, R. Kramert, P. Pollet, T. Schilcher
    PSI, Villigen
  • D. Bulfone, M. Lonza
    ELETTRA, Basovizza, Trieste
  Within the frame of the project for a multi bunch feedback system for the Swiss Light Source (SLS), a new family of 500 MS/s analog to digital and digital to analog conversion boards with an 8 bit resolution has been developed, containing on board MUX and DEMUX circuitry to reduce data rates to approximately 20 MS/s using up to ten Front Panel Data Port (FPDP) ports. Using six quad processor DSP boards, full bandwidth bunch by bunch feedbacks in the transverse and longitudinal planes are set up to provide bunch by bunch correction kicks with a 2 nsec resolution. We report on the hardware setup and properties as well as feedback performance in the SLS storage ring.  
 
THPLT020 The DSP-based Betatron Tune Feedback of the Ramped 1.5 GeV Electron Storage Ring BoDo antiproton, feedback, gun, target 2508
 
  • B. Keil
    PSI, Villigen
  • K. Wille
    DELTA, Dortmund
  The ramped storage ring BoDo is the full energy injector of the 1.5 GeV synchrotron light source DELTA. All ramped booster magnet power supplies, RF power and beam diagnostics of BoDo are handled by a distributed VME-based DSP (digital signal processor) multiprocessing system developed at DELTA. The VME DSP boards of this system are interconnected by DeltaNet, a novel reflective memory ring network. DeltaNet transmits the measurement data from each DSP board to all other boards in real-time via fibre optic links. The generic hardware and software architecture of the system allows the implementation of different kinds of global real-time feedbacks with correction rates in the range from some 100 Hz to some 10 kHz. This paper presents architecture and performance of a real-time betatron tune feedback that was implemented with the DSP system. The betatron tune is measured and corrected in both planes at a rate of typically 700 Hz for arbitrary beam optics and energy ramps of BoDo. In combination with the global Bodo orbit feedback, the tune feedback increases the performance of Bodo both as an injector and as a testbed for machine studies and newly developed accelerator components.  
 
THPLT021 A DSP-Based Fast Orbit Feedback System for the Synchrotron Light Source DELTA antiproton, feedback, gun, target 2511
 
  • B. Keil
    PSI, Villigen
  • K. Wille
    DELTA, Dortmund
  A DSP-based Fast Orbit Feedback (FOFB) system has been designed for the synchrotron light facility DELTA. DELTA consists of a 60 MeV linac, the ramped storage ring BoDo as full-energy injector and the 1.5 GeV storage ring Delta. BoDo and Delta have the same dipole, quadrupole and corrector magnet design, the same beam pipe design and the same BPM RF frontends, therefore BoDo was used as a testbed for the newly developed FOFB hardware and software. Using the fast corrector magnet power supplies of BoDo, the FOFB could damp orbit perturbations up to 90 Hz. The envisaged future use of the FOFB for the Delta storage ring will require either the partial or full replacement of the present slow (1 Hz bandwidth) Delta corrector power supplies, or additional fast power supplies with dedicated FOFB corrector magnets. A first test of the FOFB in Delta for local orbit stabilization at one beamline is in preparation. This paper presents the results of a successful test of the FOFB at BoDo, where it achieves a correction rate of 4 kHz for a global SVD-based feedback in both planes. The FOFB is based on the "DeltaDSP" VMEbus DSP boards that are also used for the BoDo betatron tune feedback.  
 
THPLT035 Development of a 3D-Gun-Code based on a Charge Conserving Algorithm antiproton, ion, positron, simulation 2553
 
  • E. Gjonaj, J. Mudiganti, T. Weiland
    TEMF, Darmstadt
  Recent efforts in the development of electron sources are aiming at high intensity electron beams, beyond the limitations posed by space-charge effects in conventional guns. Field emitter arrays, multi-beam and sheet-beam guns are a few examples of emerging technology, which require an accurate characterization of the limiting current in complicated 3D-geometry. The newly developed gun code at the Technische Universität Darmstadt, implements a novel approach to the numerical simulation of space-charge-limited electron emission, which is based on the local conservation of charge for arbitrary cathode surfaces. It is shown that, imposing exact charge conservation using the CAD-data of the geometry eliminates the spurious oscillations in the charge density, which typically arise when the piecewise-planar diode approximation is applied in the simulation. The accuracy of this approach is demonstrated in the validation study of a spherical diode and in the large-scale simulation of a Traveling Wave Tube amplifier.  
 
THPLT036 New Discretization Scheme for Wake Field Computation in Cylindrically Symmetric Structures antiproton, ion, positron, simulation 2556
 
  • R. Hampel, T. Weiland, I. Zagorodnov
    TEMF, Darmstadt
  Collective effects due to wake fields are a limiting factor in almost every new front line accelerator. Since the early 80's computer codes such as TBCI and MAFIA have been developed for computing wake fields in realistic accelerator structures. With the advent of linear collider studies and small wavelength FEL projects these codes had to face a severe limitation. For the very short bunches in these new accelerators combined with the need for an analysis of very long sections the discrete dispersion became a serious drawback. This effect of having only discrete field values rather than continous ones can be overcome by special algorithms such as semi-implicit integrators as used e.g. in the wake field code ECHO. In this paper we present a new explicit approach which combines the advantage of explicit algorithms (fast) with the absence of dispersion in beam direction.  
 
THPLT037 Investigation of Numerical Noise in PIC-Codes antiproton, ion, positron, simulation 2559
 
  • S. Schnepp, S. Setzer, T. Weiland
    TEMF, Darmstadt
  For a detailed analysis of the dynamics of space charge dominated beams a combination of Particle-in-Cell methods with efficient FDTD schemes is widely used. Besides the calculation of the forces acting on the particles the interaction of the beam itself with the surrounding geometries is taken into account. A drawback of this method is its sensitivity to numerical noise in the spectral range nearby the grid cutoff frequency. In this paper we will present results of detailed studies of the impact of the bunch shape on the level of the numerical noise. Furthermore an a priori scheme for efficient noise suppression is derived which does not affect the FDTD update algorithm.  
 
THPLT081 Present Status of Photo-cathode RF Gun System and its Applications at Waseda University antiproton, booster, laser, cyclotron 2682
 
  • R. Kuroda, Y. Hama, K. Hidume, H. Hirama, M. Kawaguchi, N. Kudo, T. Kuribayasi, S. Minamiguchi, R. Moriyama, T. Saito, K. Sakaue, D. Ueyama, M. Washio
    RISE, Tokyo
  • H. Hayano, J. Urakawa
    KEK, Ibaraki
  • S. Kashiwagi
    ISIR, Osaka
  • X.J. Wang
    BNL/NSLS, Upton, Long Island, New York
  High quality electron beam generation using photo-cathode rf gun system and its application have been developed at Waseda University. This system can generate about 4 MeV low emittance electron beam. This is applied for soft X-ray generation using laser Compton scattering and pulse radiolysis experiments based on the pump-probe technique. In case of the soft X-ray generation, Compton scattering experiments between about 4.2 MeV electron beam and Nd:YLF laser light (1047nm) is performed at 20 degrees interaction angle, so that about 300 eV soft X-ray is generated. In case of the pulse radiolysis experiments, the electron beam is used for the pump beam. The probe light is generated as white light by concentrating Nd:YLF laser light (1047nm) on the water cell. The measurement with about 30 ps (FWHM) time resolution of this system is demonstrated for the absorption of hydrated electrons. In this conference, we will present the experimental results, status of this system and future applications.  
 
THPLT082 Beam Diagnostics for a Photocathode Rf-gun System antiproton, emittance, booster, cyclotron 2685
 
  • K. Sakaue, N. Kudo, R. Kuroda, M. Washio
    RISE, Tokyo
  • H. Hayano, J. Urakawa
    KEK, Ibaraki
  • S. Kashiwagi
    ISIR, Osaka
  Beam diagnostic systems for high quality electron beam emitted from photo-cathode rf gun have been developed. Beam characteristics such as bunch length and emittance measurements were performed at Waseda University. The bunch length was measured using an rms bunch length monitor based on beam spectrum analysis. The monitor is very useful as the non-destructive and conventional tool even for the relatively low energy electron beam around 5MeV. The measurement results of the rms bunch lengths using this monitor are in good agreement with the simulation results of PARMELA. However, it is not applicable for the measurement of longitudinal profile of the electron bunch, so that we have started the manufacturing of a deflection cavity, so-called RF-Kicker, to measure the longitudinal profiles of the bunch. The emittance has been measured by using a slit scan technique. By using double slit scan technique, emittance of 9mmmrad has been obtained. Though the value is not satisfactory small, we believe that much smaller emittance can be obtained by optimizing a laser profile. The measurement results and progress of rf gun at Waseda University will be presented at the conference.  
 
THPLT086 High Temporal Resolution, Single-shot Electron Bunch-length Measurements feedback, antiproton, emittance, booster 2697
 
  • G. Berden, B. Redlich, A.F.G. Van der Meer
    FOM Rijnhuizen, Nieuwegein
  • W.A. Gillespie, A. MacLeod
    UAD, Dundee
  • S.P. Jamison
    Strathclyde University, Glasgow
  A new technique, combining the electro-optic detection of the Coulomb field of an electron bunch and the single-shot cross-correlation of optical pulses, is used to provide single-shot measurements of the shape and length of sub-picosecond electron bunches. As in our previous technique [I. Wilke et al., Phys. Rev. Lett. 88, 124801 (2002)], the electric field of the electron beam is encoded electro-optically on an optical pulse. Our earlier measurements, which involved encoding the time profile of the electron bunch on the spectrum of the optical pulse, showed electric field profiles with a FWHM of the order of 1.7 ps. The new method offers a much better time resolution since it avoids the significant measurement artifacts that can arise in our previous (spectral encoding technique due to the coupling between the temporal envelope and spectral content of the optical pulse. The cross-correlation technique has been applied to the measurement of electron bunches in FELIX, showing single bunches of around 500fs FWHM. The resolution is limited primarily by the electro-optic crystal thickness and the relatively low energy of the electrons (50 MeV).  
 
THPLT089 MATLAB Based TPSA Toolbox for the Particle Mapping Through Three-dimensional Magnetic Fields feedback, antiproton, emittance, booster 2700
 
  • H.-P. Chang, H.-J. Tsai
    NSRRC, Hsinchu
  Based on the object-oriented programming of MATLAB, a truncated power series algebra (TPSA) toolbox has been developed. The TPSA toolbox as a differential algebra has been applied to realize the algorithm of particle mapping through three-dimensional magnetic field configurations. The capability of symbolic calculation by using this MATLAB-based TPSA toolbox can be used for the theoretical simulation and modeling in accelerator physics. Associated with the use of MATLAB in the control of machines, one can derive the real machine with a virtual machine model built in MATLAB. In this paper, the method of symplectic mapping of three-dimensional magnetic fields is introduced and the structure of TPSA toolbox is presented. Applications of TPSA toolbox in the symplectic mapping of three-dimensional magnetic fields are demonstrated as well.  
 
THPLT090 The Operating of Digital Beam Position Monitor in NSRRC feedback, antiproton, emittance, booster 2703
 
  • C.H. Kuo, J. Chen, K.-T. Hsu, K.H. Hu, D. Lee
    NSRRC, Hsinchu
  The digital beam position monitors are configured to operation system in the NSRRC now. This integration includes of multi-channel access, channel calibration, gain control, and parameter control to meet various operation condition, perform functionality and performance evaluation. The programmability nature of DBPM system is essential for multi-mode high precision beam position measurement. The system will support high performance beam position, turn-by-turn beam position, tune and other diagnostic measurements. Control system interface was implemented to support the operation of DBPM system. T various aspects will be discussed and presented in this report.  
 
THPLT091 The Synchrotron Radiation Monitor Upgradation in NSRRC feedback, antiproton, emittance, cyclotron 2706
 
  • 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.  
 
THPLT127 Beam Diagnostics Systems for the Diamond Synchrotron Light Source plasma, gun, antiproton, polarization 2762
 
  • 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.  
 
THPLT130 Synchronization of the Fermilab Booster and Main Injector for Multiple Batch Injection plasma, gun, proton, polarization 2768
 
  • R.M. Zwaska, S.E. Kopp
    The University of Texas at Austin, Austin, Texas
  • W. Pellico, R.C. Webber
    Fermilab, Batavia, Illinois
  To date, the 120 GeV Fermilab Main Injector accelerator has accelerated a single batch of protons from the 8 GeV rapid-cycling Booster synchrotron for production of antiprotons for Run II. In the future, the Main Injector must accelerate 6 or more Booster batches simultaneously; the first will be extracted to the antiproton source, while the remaining are extracted for the NuMI/MINOS neutrino experiment. Performing this multi-batch operation while avoiding unacceptable radioactivation of the beamlines requires a previously unnecessary synchronization between the accelerators. We describe a mechanism and present results of advancing or retarding the longitudinal progress of the Booster beam by active feedback radial manipulation of the beam during the acceleration period.  
 
THPLT133 Simulation of RF Control of a Superconducting Linac for Relativistic Particles plasma, gun, proton, polarization 2771
 
  • M. Huening, P. Bauer, G.W. Foster
    Fermilab, Batavia, Illinois
  We present a code to simulate the rf field and field control in a superconducting linac for relativistic heavy particles. In such a linac the field stability is strongly influenced by the longitudinal beam dynamics. So the code has to simulate both the field and the beam dynamics with the resulting varying beam loading. Other effects included in the simulation are Microphonics and Lorentz force. The code can simulate both single cavity and vector sum control.  
 
THPLT135 Experience with the 1.7 GHz Schottky Pick-ups in the Tevatron plasma, gun, proton, polarization 2774
 
  • A. Jansson, P. Lebrun, R. Pasquinelli
    Fermilab, Batavia, Illinois
  During a 2003 shutdown, new high-frequency Schottky pick-ups were installed in the Tevatron. These devices operate at 1.7 GHz (harmonic ~36000 of the revolution frequency) and can in principle be used to measure tunes, chromaticities, momentum spread and transverse emittances of individual bunches. Only the transverse signal is used, as the longitudinal is dominated by coherent signal. The default mode of operation during a store is to sequentially acquire and analyze frequency data from different sets of bunches in the machine. This function is performed by an open access client written in Java/C++, running in the background. The resulting fit parameters are datalogged and can also be plotted in "real time" during the store. With an alternative setup, data from select bunches can be acquired continuously during the entire ramp (and squeeze), for analysis off-line. This paper describes the evolution, current status and performance of the acquisition and analysis software, and presents measurements with comparison to predictions and other measurement techniques. One example of such a measurement is the variation of beam-beam tune shift as a function of intensity and bunch position within a train.  
 
THPLT137 Commissioning of the Head-tail Monitoring Application for the Tevatron plasma, gun, proton, polarization 2777
 
  • 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  
 
THPLT159 Instability Thresholds and Generation of the Electron-cloud in the GLC/NLC and Tesla Damping Rings plasma, gun, proton, polarization 2828
 
  • 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.