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MOOCH02 First Full Beam Loading Operation with the CTF3 Linac simulation, alignment, emittance, linac 39
 
  • R. Corsini, H.-H. Braun, G. Carron, O. Forstner, G. Geschonke, E. Jensen, L. Rinolfi, D. Schulte, F. Tecker, L. Thorndahl
    CERN, Geneva
  • M. Bernard, G. Bienvenu, T. Garvey, R. Roux
    LAL, Orsay
  • A. Ferrari
    Uppsala University, Uppsala
  • L. Groening
    GSI, Darmstadt
  • R.F. Koontz, R.H. Miller, R.D. Ruth, A.D. Yeremian
    SLAC, Menlo Park, California
  • T. Lefevre
    NU, Evanston
  The aim of the CLIC Study is to investigate the feasibility of a high luminosity, multi-TeV linear e+e- collider. CLIC is based on a two-beam method, in which a high current drive beam is decelerated to produce 30 GHz RF power needed for high-gradient acceleration of the main beam running parallel to it. To demonstrate the outstanding feasibility issues of the scheme a new CLIC Test Facility, CTF3, is being constructed at CERN by an international collaboration. In its final configuration CTF3 will consist of a 150 MeV drive beam linac followed by a 42 m long delay loop and an 84 m combiner ring. The installation will include a 30 GHz high power test stand, a representative CLIC module and a test decelerator. The first part of the linac was installed and commissioned with beam in 2003. The first issue addressed was the generation and acceleration of a high-current drive beam in the "full beam loading" condition where RF power is converted into beam power with an efficiency of more than 90%. The full beam loading operation was successfully demonstrated with the nominal beam current of 3.5 A. A variety of beam measurements have been performed, showing good agreement with expectations.  
Video of talk
Transparencies
 
MOOCH03 Status of a Linac RF Unit Demonstration for the NLC/GLC X-band Linear Collider simulation, alignment, emittance, damping 42
 
  • D.C. Schultz, C. Adolphsen, D.L. Burke, J. Chan, S. Doebert, V.A. Dolgashev, J.C. Frisch, R.K. Jobe, D.J. McCormick, C.D. Nantista, J. Nelson, M.C. Ross, T.J. Smith, S.G. Tantawi
    SLAC, Menlo Park, California
  • D.P. Atkinson
    LLNL, Livermore, California
  • Y.H. Chin, S. Kazakov, A. Lounine, T. Okugi, N. Toge
    KEK, Ibaraki
  Designs for a future TeV scale electron-positron X-band linear collider (NLC/GLC) require main linac units which produce and deliver 450 MW of rf power at 11.424 GHz to eight 60 cm accelerator structures. The design of this rf unit includes a SLED-II pulse compression system with a gain of approximately three at a compression ratio of four, followed by an overmoded transmission and distribution system. We have designed, constructed, and operated such a system as part of the 8-Pack project at SLAC. Four 50 MW X-band klystrons, running off a common 400 kV solid-state modulator, drive a dual-moded SLED-II pulse compression system. The compressed power is delivered to structures in the NLCTA beamline. Four 60 cm accelerator structures are currently installed and powered, with four additional structures and associated high power components available for installation late in 2004. We describe the layout of our system and the various high-power components which comprise it. We also present preliminary data on the processing and initial high-power operation of this system.  
Video of talk
Transparencies
 
MOPKF003 Design of 2 T Wiggler Vacuum Chamber for the LNLS Storage Ring alignment, emittance, damping, simulation 300
 
  • M.J. Ferreira, R.O. Ferraz, H.G. Filho, M.B. Silva
    LNLS, Campinas
  A 2 T wiggler with 2.8 m long and a gap of 22 mm will be installed at LNLS storage ring. The main requirements of the chamber design are short conditioning time and low mechanical deformation. Two different designs in stainless steel are proposed for the prototypes, an elliptical tube and a machined sheet. A pressure profile simulation with and without a NEG coating were made for evaluating the life-time influence and the time necessary for conditioning. A simulation with finite element of mechanical deformation for both case show equivalent results. The first prototype was made with the elliptical tube and a NEG coating deposition will be made at ESRF. The second prototype with machined parts is under construction and will be TIG welded. Descriptions of mounting structure for the prototype are show and the evaluation the dimension tolerance of the chambers.  
 
MOPKF004 Magnet Sorting Algorithm Applied to the LNLS EPU undulator, alignment, emittance, damping 303
 
  • X.R. Resende, R.M. Dias
    LNLS, Campinas
  The Brazilian Synchrotron Light Laboratory is about to begin the construction of the first Undulator for its 1.37 GeV electron storage ring. This device will be of the EPU type with a period of 50 milimeters and 22 milimeters minimum magnetic gap. In this work we report on the sorting algorithm applied in the construction of a 10-period undulator prototype.  
 
MOPLT001 Acceleration of Electrons by Spatially Modulated Laser Wave lepton, wiggler, undulator, cathode 527
 
  • R.A. Melikian, M.L. Petrosyan, V.S. Pogosyan
    YerPhI, Yerevan
  We study the acceleration of electrons in a system of linearly polarized laser wave, propagating at small angles to the direction of electron motion. The parameters of electron bunch and laser wave are chosen so, that during driving electrons in a band of a wave, the electric field of a wave has not changed the direction. The requirements of deriving of maximum rate of acceleration are found depending on parameters of electronic bunch and laser wave. It is shown, that the dependence of growth of electrons energy from number of light bands has nonlinear character. The influence of light diffraction on process of acceleration is considered. It is shown, that the discussed scheme of acceleration allows a possibility of deriving of high acceleration rate owing to existence of modern powerful lasers.  
 
MOPLT003 Upgrading the LNLS Control System from a Proprietary to a Commercial Communications Environment lepton, wiggler, undulator, cathode 530
 
  • J.G.R.S. Franco, R.M. Ernits, M. Fernandes, A.F.A. Gouveia, J.R. Piton, M.A. Raulik, F.D.S. Rodrigues
    LNLS, Campinas
  The LNLS Control System was built over a proprietary technology, due to governmental policy of information technology in the mid 80's. This made interfacing to commercial systems difficult, limited the technology transfer to the private sector, required a staff with specific knowledge and reduced the possibility of new implementations on the system. Nowadays, the cost to move all of our hardware to a commercial one is out of our budget. This paper describes a proposal, the viability study and first results to move only the communication interfaces to a commercial environment, keeping most of our hardware unchanged and opening the way to gradually move the system to widely accepted standards, when and if necessary. This solution allows a smooth implementation without long periods of machine shutdown and keeps the possibility to operate the machine concurrently between old and new communication interfaces.  
 
MOPLT004 Control of the LHC 400 MHz RF System (ACS) lepton, wiggler, undulator, cathode 533
 
  • L. Arnaudon, M.D. Disdier, P.M. Maesen, M.P. Prax
    CERN, Geneva
  The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring. Each ring has two cryomodules, each containing four cavities. Each cavity is powered by a 300 kW klystron. The klystrons are grouped in fours, the klystrons in each group sharing a common 58 kV power converter and HV equipment bunker. The ACS RF control system is based on modern industrial programmable controllers (PLCs). A new fast interlock and alarm system with inbuilt diagnostics has been developed. Extensive use of the FIPIO Fieldbus drastically decreases the cabling complexity and brings improved signal quality, increased reliability and easier maintenance. Features of the implementation, such as system layout, communication and the high level software interface are described. Operational facilities such as the automatic switch on procedure are described, as well as the necessary specialist tools and interfaces. A complete RF chain,including high voltage, cryomodule and klystron is presently being assembled in order to check, as far as possible, all aspects of RF system operation before LHC installation. The experience gained so far in this test chain with the new control system is presented  
 
MOPLT005 An Improved Collimation System for the LHC lepton, wiggler, undulator, cathode 536
 
  • R.W. Assmann, O. Aberle, A. Bertarelli, H.-H. Braun, M. Brugger, L. Bruno, O.S. Brüning, S. Calatroni, E. Chiaveri, B. Dehning, A. Ferrari, B. Goddard, E.B. Holzer, J.-B. Jeanneret, J.M. Jimenez, V. Kain, M. Lamont, M. Mayer, E. Métral, R. Perret, S. Redaelli, T. Risselada, G. Robert-Demolaize, S. Roesler, F. Ruggiero, R. Schmidt, D. Schulte, P. Sievers, V. Vlachoudis, L. Vos, G. Vossenberg, J. Wenninger
    CERN, Geneva
  • I.L. Ajguirei, I. Baishev, I.L. Kurochkin
    IHEP Protvino, Protvino, Moscow Region
  • D. Kaltchev
    TRIUMF, Vancouver
  • H. Tsutsui
    SHI, Tokyo
  The LHC design parameters extend the maximum stored beam energy 2-3 orders of magnitude beyond present experience. The handling of the high-intensity LHC beams in a super-conducting environment requires a high-robustness collimation system with unprecedented cleaning efficiency. For gap closures down to 2mm no beam instabilities may be induced from the collimator impedance. A difficult trade-off between collimator robustness, cleaning efficiency and collimator impedance is encountered. The conflicting LHC requirements are resolved with a phased approach, relying on low Z collimators for maximum robustness and hybrid metallic collimators for maximum performance. Efficiency is further enhanced with an additional cleaning close to the insertion triplets. The machine layouts have been adapted to the new requirements. The LHC collimation hardware is presently under design and has entered into the prototyping and early testing phase. Plans for collimator tests with beam are presented.  
 
MOPLT006 The New Layout of the LHC Cleaning Insertions lepton, wiggler, undulator, cathode 539
 
  • R.W. Assmann, O. Aberle, O.S. Brüning, S. Chemli, D. Gasser, J.-B. Jeanneret, J.M. Jimenez, V. Kain, E. Métral, G. Peon, S. Ramberger, C. Rathjen, T. Risselada, F. Ruggiero, L. Vos
    CERN, Geneva
  • D. Kaltchev
    TRIUMF, Vancouver
  The improved LHC collimation system required significant changes in the layout and design of the warm insertion IR7. Requirements for collimation, optics, impedance, vacuum, and additional infrastructure are described and the adopted layout is discussed. Various design principles have been explored during the re-design, ranging from a regular 90 degree lattice and special low impedance lattices to an option with additional warm quadrupole units that could have extended the usable space for collimator installations in the insertion. The various constraints for the optics and cleaning design in the LHC cleaning insertions are summarized. Magnet positions and collimators were moved significantly, such that a good cleaning efficiency was maintained while impedance was reduced by a factor of two. Metallic phase 2 collimators allow a better efficiency than originally achievable and additional scrapers were allocated. The required infrastructure was specified, including a powerful cooling system for the collimators.  
 
MOPLT007 Base Line Design for a Beta-beam Neutrino Facility lepton, wiggler, undulator, cathode 542
 
  • M. Benedikt, S. Hancock, M. Lindroos
    CERN, Geneva
  The term beta-beam has been coined for the production of pure beams of electron neutrinos or their antiparticles through the decay of radioactive ions circulating in a storage ring. The neutrino source itself consists of a high energy storage ring (gamma ~150), with long straight sections in line with the experiment(s). The radioactive ions (6He and 18Ne) will be produced in an ISOL type target system. Due to the short life times of around 1s at rest, the beam needs to be accelerated as quickly as possible. For this a staged system of accelerators is proposed. The chain starts with a linac followed by a rapid cycling synchrotron for acceleration up to ~300 MeV/u. For further acceleration the existing PS and SPS machines are used. Finally, after acceleration to SPS top energy, the ions are transferred to the decay ring where they are merged with the already circulating bunch through a longitudinal stacking procedure. The base line design of the beta beam facility will be presented and the major design problems encountered as well possible solutions will be discussed.  
 
MOPLT008 The Mechanical Design for the LHC Collimators lepton, wiggler, undulator, cathode 545
 
  • A. Bertarelli, O. Aberle, R.W. Assmann, E. Chiaveri, T. Kurtyka, M. Mayer, R. Perret, P. Sievers
    CERN, Geneva
  The design of the LHC collimators must comply with the very demanding specifications entailed by the highly energetic beam handled in the LHC: these requirements impose a temperature on the collimating jaws not exceeding 50°C in steady operations and an unparalleled overall geometrical stability of 25micro-m on a 1200 mm span. At the same time, the design phase must meet the challenging deadlines required by the general time schedule. To respond to these tough and sometimes conflicting constraints, the chosen design appeals to a mixture of traditional and innovative technologies, largely drawing from LEP collimator experience. The specifications impose a low-Z material for the collimator jaws, directing the design towards graphite or such novel materials as 3-d Carbon/Carbon composites. An accurate mechanical design has allowed to considerably reduce mechanical play and optimize geometrical stability. Finally, all mechanical studies were supported by in-depth thermo-mechanical analysis concerning temperature distribution, mechanical strength and cooling efficiency.  
 
MOPLT009 The Design of the New Fast Extraction Channel for LHC extraction, lepton, wiggler, undulator 548
 
  • J. Borburgh, B. Balhan, E.H.R. Gaxiola, B. Goddard, Y. Kadi, J.A. Uythoven
    CERN, Geneva
  The Large Hadron Collider (LHC) project requires the modification of the existing extraction channel in the long straight section 6 of the CERN Super Proton Synchrotron (SPS). The new extraction will be used to transfer protons at 450 Gev/c as well as ions via the 2.8 km long transfer line TI 2 to the clockwise ring of the LHC. As the resonant extraction to the present SPS west area will be stopped after 2004, the electrostatic septa will be replaced by new fast extraction kicker magnets. The girder for the existing DC septa will be modified to accommodate a new septum protection element. Other modifications concern the replacement of a machine quadrupole, a new scheme for the extraction bumpers, new instrumentation and interlocks. The requirements and the design of the new extraction channel will be described as well as the modifications which will mainly be carried out in the long SPS shutdown 2005.  
 
MOPLT010 Collimation of Heavy Ion Beams in LHC extraction, lepton, wiggler, collimation 551
 
  • H.-H. Braun, R.W. Assmann, A. Ferrari, J.-B. Jeanneret, J.M. Jowett
    CERN, Geneva
  • I.A. Pshenichnov
    RAS/INR, Moscow
  The LHC collimation system is designed to cope with requirements of proton beams having 100 times higher beam power than the nominal LHC heavy ion beam. In spite of this, specific problems occur for ion collimation, due to different particle-collimator interaction mechanism for ions and protons. Ions are subject to hadronic fragmentation and electromagnetic dissociation, resulting in a non-negligible flux of secondary particles of small angle divergence and Z/A ratios slightly different from the primary beam. These particles are difficult to intercept by the collimation system and can produce significant heat-load in the superconducting magnets when they hit the magnet vacuum chamber. A computer program has been developed to obtain quantitative estimates of the magnitude and location of the particle losses. Hadronic fragmentation and electromagnetic dissociation of ions in the collimators were considered within the frameworks of abrasion-ablation and RELDIS models, respectively. Trajectories of the secondary particles in the ring magnet lattice and the distribution of intercept points of these trajectories with the vacuum chamber are computed. Results are given for the present collimation system design and potential improvements are discussed.  
 
MOPLT012 Collimation in the Transfer Lines to the LHC extraction, lepton, wiggler, undulator 554
 
  • H. Burkhardt, B. Goddard, Y. Kadi, V. Kain, W.J.M. Weterings
    CERN, Geneva
  The intensities foreseen for injection into the LHC are over an order of magnitude above the expected damage levels. The TI 2 and TI 8 transfer lines between the SPS and LHC are each about 2.5 km long and comprise many magnet families. Despite planned power supply surveillance and interlocks, failure modes exist which could result in uncontrolled beam loss and serious transfer line or LHC equipment damage. We describe the collimation system in the transfer lines that has been designed to provide passive protection against damage at injection. Results of simulations to develop a conceptual design are presented. The optical and physical installation constraints are described, and the resulting element locations and expected system performance presented, in terms of the phase space coverage, local element temperature rises and the characteristics of the beam transmitted into the LHC.  
 
MOPLT013 Fatigue Testing of Materials by UV Pulsed Laser Irradiation extraction, lepton, wiggler, undulator 557
 
  • S. Calatroni, H. Neupert, M. Taborelli
    CERN, Geneva
  The energy dissipated by the RF currents in the cavities of high-power pulsed linacs induces cycles of the surface temperature. In the case of the CLIC main linac the expected amplitude of the thermal cycles is about hundred degrees, for a total number of pulses reaching 10e11. The differential thermal expansion due to the temperature gradient in the material creates a cyclic stress that can result in surface break-up by fatigue. The materials for cavity fabrication must therefore be selected in order to withstand such constraints whilst maintaining an acceptable surface state. The fatigue behaviour of Cu and CuZr alloy has been tested by inducing larger surface peak temperatures, thus reducing the number of cycles to failure, irradiating the surface with 50 ns pulses of UV light (308 nm) from an excimer laser. Surface break-up is observed after different number of laser shots as a function of the peak temperature. CuZr appears to withstand a much larger number of cycles than Cu, for equal peak temperature. The characterization of the surface states and possible means of extrapolating the measured behaviour to the expected number of pulses of CLIC are discussed in detail.  
 
MOPLT014 Testing of the LHC Magnets in Cryogenic Conditions: Current Experience and Near Future Outlook extraction, lepton, wiggler, undulator 560
 
  • V. Chohan, M. Buzio, G. De Rijk, J. Miles, P. Pugnat, V. Remondino, S. Sanfilippo, A.D. Siemko, N. Smirnov, B. Vullierme, L. Walckiers
    CERN, Geneva
  For the Large Hadron Collider under construction at CERN, a necessary and primordial condition prior to its installation is that all the main twin-aperture Dipole and Quadrupole magnets are tested in the 1.9K cryogenic conditions. These tests are not feasible at the manufacturers and hence, are carried out at CERN at a purpose built facility on the site. This presentation will give an overall view of the issues related to the operation of the tests facility. In particular, it will give the goals that need to be met to ensure the magnet integrity and performance and the context & constraints on the test programme. Results accumulated from the tested magnets and the ensuing tests stream-lining will be presented, together with some of the explanations and hard limits. Finally, some improvements planned for efficient operation will be given within the confines of the testing programme as was foreseen and the project goals and deadlines.  
 
MOPLT015 Reliability Issues of the LHC Beam Dumping System lepton, wiggler, undulator, cathode 563
 
  • R. Filippini, E. Carlier, B. Goddard, J.A. Uythoven
    CERN, Geneva
  The Beam Dumping System of the Large Hadron Collider, presently under construction at CERN, must function with utmost reliability to protect the personnel, minimize the risk of severe damage to the machine and avoid undue impact to the environment. The dumping action must be synchronized with the particle free gap and the field of the extraction and dilution elements must be well adjusted to the beam energy. The measures taken to arrive at a reliable and safe system will be described, like the adoption of fault tolerant design principles and other safety related features as comprehensive monitoring, diagnostics and protection facilities. These issues will be discussed in the general framework of the IEC standard recommendations for safety critical systems. Some examples related to the most critical functions will be included.  
 
MOPLT016 Upgrade and Tests of the SPS Fast Extraction Kicker System for LHC and CNGS extraction, lepton, wiggler, undulator 566
 
  • E.H.R. Gaxiola, A. Antoine, P. Burkel, E. Carlier, F. Castronuovo, L. Ducimetière, Y. Sillanoli, M. Timmins, J.A. Uythoven
    CERN, Geneva
  A fast extraction kicker system has been installed in the SPS and successfully used in extraction tests in 2003. It will serve to send beam to the anticlockwise LHC ring and the CNGS neutrino facility. The magnets and pulse generators have been recuperated from an earlier installation and upgraded to fit the present application. Hardware improvements include diode stacks as replacement of the previous dump thyratron switches, a cooling system of the magnets, sensors for its ferrite temperatures and magnetic field quality assessment. In preparation of the future use for 450 GeV/c transfer to LHC and double batch extraction at 400 GeV/c for CNGS the tests comprised extractions of single bunches, twelve bunches in a single extraction and single bunches in a double extraction. The simulated and measured kick characteristics of the upgraded system are presented, along with results from uniformity calculations of the magnetic field after the modifications to accommodate the cooling circuitry. Further improvements will be discussed which are intended to make the system comply with the specifications for CNGS.  
 
MOPLT017 Beam Commissioning of the SPS LSS4 Extraction and the TT40 Transfer Line lepton, wiggler, undulator, cathode 569
 
  • B. Goddard, P. Collier, M. Lamont, V. Mertens, K. Sigerud, J.A. Uythoven, J. Wenninger
    CERN, Geneva
  The new fast extraction system in LSS4 of the SPS and the transfer line TT40 were installed between 2000 and 2003, and commissioned with beam in late 2003. The extraction system and transfer line will serve both the anti-clockwise ring of the Large Hadron Collider (LHC), and the long baseline neutrino (CNGS) facility. The layout and functionality of the main elements are briefly explained, including the various hardware subsystems and the controls system. The safety procedures, test objectives and results of the system commissioning with beam are described, together with the test methodology. Conclusions are drawn concerning the performance of the system elements, agreement between predicted and expected activation levels and test efficiency and procedures. The test results are also briefly discussed in the context of future LHC beam commissioning activities.  
 
MOPLT018 Aperture and Delivery Precision of the LHC Injection System injection, lepton, wiggler, undulator 572
 
  • B. Goddard, M. Gyr, J.-B. Jeanneret, V. Kain, M. Lamont, V. Maire, V. Mertens, J. Wenninger
    CERN, Geneva
  The main LHC injection elements in interaction regions 2 and 8 comprise the injection septa (MSI), the injection kicker (MKI), together with three families of passive protection devices (TDI, TCDD and TCLI). The apertures of the injection septa for the injected and two circulating beams are detailed with a new enlarged vacuum chamber and final septum alignment. The circulating beam aperture of the TDI is detailed with a new TDI support design and modified vacuum tank alignment. A modified TCDD shape is also presented and the implications for the aperture and protection level discussed. The various errors in the SPS, the transfer lines and the injection system, which contribute to injection errors, are analysed, and the expected performance of the system is derived, in terms of the expected delivery precision of the injected beam.  
 
MOPLT019 Experience Gained in the SPS for the Future LHC Abort Gap Cleaning lepton, wiggler, undulator, cathode 575
 
  • W. Höfle
    CERN, Geneva
  Abort gap cleaning using a transverse damper (feedback) has been previously shown in the RHIC accelerator. We report on experimental results in the SPS, where the transverse damper was used to excite transverse oscillations on part of an LHC test beam, and by the induced losses, creating a practically particle free zone. It is proposed to use the same principle for abort gap cleaning in the LHC. For the LHC abort gap cleaning may be required at injection energy, during the ramp and at top energy. It is shown how the transverse excitation can be optimized taking into account the actual bandwidth of the damper systems and the possibility to fully modulate their input signal to match the beam batatron tune distribution. The cleaning efficiency and speed is estimated considering the porcesses involved, the cleaning (with damper) and the filling of the abort gap.  
 
MOPLT020 Limits to the Performance of the LHC with Ion Beams lepton, wiggler, undulator, cathode 578
 
  • J.M. Jowett, H.-H. Braun, M.I. Gresham, E. Mahner, A.N. Nicholson, E.N. Shaposhnikova
    CERN, Geneva
  • I.A. Pshenichnov
    RAS/INR, Moscow
  The performance of the LHC as a heavy-ion collider will be limited by a diverse range of phenomena that are often qualitatively different from those limiting the performance with protons. We summarise the latest understanding and results concerning the consequences of nuclear electromagnetic processes in lead ion collisions, the interactions of ions with the residual gas and the effects of lost ions on the beam environment and vacuum. Besides these limitations on beam intensity, lifetime and luminosity, performance will be governed by the evolution of the beam emittances under the influences of synchrotron radiation damping, intra-beam scattering, RF noise and multiple scattering on residual gas. These effects constrain beam parameters in the LHC ring throughout the operational cycle with lead ions.  
 
MOPLT021 Attenuation and Emittance Growth of 450 GeV and 7 TeV Proton Beams in Low-Z Absorber Elements lepton, wiggler, injection, undulator 581
 
  • V. Kain, B. Goddard, Y. Kadi, R. Schmidt
    CERN, Geneva
  The intensity of the LHC beams will be several orders of magnitude above the damage thresholds for equipment, at 7 TeV, but also already at injection energy of 450 GeV. Passive protection of the equipment against failures during beam transfer, injection and dumping of the beam with absorbers and collimators is foreseen to ensure safe operation. Since these protection devices must be robust in case of beam impact, low-Z materials such as graphite are favored. The reduction of the energy density of the primary beam by the absorber is determined by the attenuation of the beam due to nuclear collisions and the emittance growth of the surviving protons due to scattering processes. Absorbers with low density materials tend to be several meters long to ensure sufficient reduction of the transverse energy density of the impacting beam. The physics principles leading to attenuation and emittance growth for a hadron beam traversing matter are summarised, and FLUKA simulation results for 450 GeV and 7TeV proton beams on low-Z absorbers are compared with theoretical predictions. Design criteria for the LHC absorbers can be derived from these results. As an example, for the transfer line from SPS to LHC a short, low-Z absorber has been proposed to protect the LHC injection elements.  
 
MOPLT022 The Expected Performance of the LHC Injection Protection System lepton, wiggler, injection, undulator 584
 
  • V. Kain, O.S. Brüning, L. Ducimetière, B. Goddard, M. Lamont, V. Mertens
    CERN, Geneva
  The passive protection devices TDI, TCDD and TCLI are required to prevent damage to the LHC in case of serious injection failures, in particular of the MKI injection kicker. A detailed particle tracking, taking realistic mechanical, positioning, injection, closed orbit and local optical errors into account, has been used to determine the required settings of the absorber elements to guarantee protection against different MKI failure modes. The expected protection level of the combination of TDI with TCLI, with the new TCLI layout, is presented. Conclusions are drawn concerning the expected damage risk level.  
 
MOPLT073 Picosecond High Voltage Switching for Pulsed DC Acceleration background, laser, wiggler, vacuum 722
 
  • J. Hendriks, G.J.H. Brussaard
    TUE, Eindhoven
  Laser wakefield acceleration promises the production of high energy electrons from table-top accelerators. External injection of a (low energy) electron bunch into a laser wakefield requires acceleration gradients of the order GV/m. In principle DC acceleration can achieve GV/m acceleration gradients. If high voltage pulses of the order MV can be switched with picosecond precision, the performance of such an accelerator would be greatly enhanced and even multistage DC acceleration would become feasible. Presently risetime and jitter of high voltage pulses in high voltage laser triggered spark gaps are limited to the nanosecond regime by the initial stochastic breakdown process in the gap. A way to overcome this limitation is to create a line focus between the electrodes with an intensity above 1018 W/m2 using a high power femtosecond Ti:Sapphire laser. Because of the instantaneous ionization and high degree of ionization in the plasma channel, picosecond switching precision can be achieved and jitter is reduced significantly. A spark gap test setup with 3 mm interelectrode distance has been build and the first measurements have been done. Femtosecond diagnostics for characterization of the laser induced plasma and electro-optic diagnostics for the high voltage pulse have been developed.  
 
MOPLT075 Ideal Waterbag Electron Bunches from an RF Photogun background, laser, wiggler, vacuum 725
 
  • O.J. Luiten, M.J. Van der Wiel, S.B. van der Geer
    TUE, Eindhoven
  • F. Kiewiet
    FOM Rijnhuizen, Nieuwegein
  • M.J. de Loos
    PP, Soest
  With the implementation of fs mode-locked Ti:Sapphire lasers in high-gradient RF photoguns, a new charged particle acceleration regime has emerged, the so-called pancake regime. Pancake bunches have by definition a restframe length which is much smaller than the bunch radius. This geometry allows a relatively simple, but effective analytical description of the space-charge dominated, critical initial part of the acceleration trajectory. In high-gradient RF photoguns the pancake regime can be relevant up to several MeV. The general opinion is that extremely short bunches should be avoided during the initial stages of the acceleration process, because high space charge densities are always detrimental to the final beam quality. We show that this is not necessarily true: shorter bunches may even lead to better beams.  
 
MOPLT078 The Coupling Compensation and Measurement in the Interaction Region of BEPCII background, laser, wiggler, vacuum 728
 
  • C.H. Yu, G. Xu
    IHEP Beijing, Beijing
  The detector solenoid field in the BEPCII interaction region will be compensated by 6 anti-solenoids, which are located nearby the interaction point. The coupling compensation scheme and the method to tune the x-y coupling at the interaction point will be introduced in detail.  
 
MOPLT088 Experimental Plasma Wake-field Acceleration Project at the VEPP-5 Injection Complex plasma, background, laser, wiggler 740
 
  • A.V. Petrenko, A. Burdakov, A.M. Kudryavtsev, P.V. Logatchev, K.V. Lotov, A.N. Skrinsky
    BINP SB RAS, Novosibirsk
  The project of an experimental facility based on the VEPP-5 injection complex is described. Due to a good quality of electron or positron beams and special beam preparation system, the facility opens several possibilities for studies of the plasma wakefield acceleration: high peak beam currents, arbitrary beam profiles, long term beam-plasma interaction (up to the full driver depletion), and precise beam diagnostics. Various wakefield regimes can be experimentally demonstrated and studied: the efficient blow-out regime with a low energy spread and high acceleration rate (up to several GeV per meter); multibunch regime; long bunch instabilities; beam self-organization in plasma; plasma lens. If successfully realized, this experiment becomes a solid argument for feasibility of a high-energy collider based upon the plasma wakefield acceleration.  
 
MOPLT089 SOS-diode Based Pulser for the Injection System of the Collider VEPP-2000 plasma, background, laser, wiggler 743
 
  • F.V. Podgorny, B.I. Grishanov, A.S. Kasaev
    BINP SB RAS, Novosibirsk
  We describe high voltage pulsers for supplying of kickers of the collider VEPP-2000 injection system. The high voltage pulse is formed as a result of a sharp break of a high current, accumulated previously in storage elements, by means SOS-diode. Pulse forming lines or inductances could be used as the storage elements. The generators form the quasi-rectangular pulses on the 50-Ohm load. The generator scheme is described also.  
 
MOPLT090 High Pulse and Average Power Low-induction Load plasma, background, laser, wiggler 746
 
  • F.V. Podgorny, B.I. Grishanov
    BINP SB RAS, Novosibirsk
  A high pulse and average power low-induction load with a built-in divider is described in this report. The load has a nominal resistance of 25 Ohm and is designed to operate with a repetition rate of up to 50 Hz at a pulse duration (FWHM) of 100 ns, a rise/fall time of 50 ns and a pulse amplitude of up to 40 kV. In this mode the dissipated energy is equal to about 8 J per pulse and average power is up to 400 W. The load can be used as an absorbing load and as a block element in high-voltage engineering.  
 
MOPLT091 Accelerator Physics Issues of the VEPP-4M at Low Energy plasma, background, laser, wiggler 749
 
  • V.V. Smaluk
    BINP SB RAS, Novosibirsk
  The VEPP-4M electron-positron collider is being prepared for a new high-energy physics run in the 1.5 - 2.0 GeV energy range. During the first run (2001-2002), precision mass measurements of the J/psi and psi' mesons using the KEDR detector have been carried out with a record accuracy. To provide high performance, efforts for investigation and further development of the machine have been done. The most important results are described. A record absolute accuracy of energy measurement was achieved using the resonant depolarization method. A possibility to use this method for the absolute energy calibration in tau-lepton mass measurements is studied. For the first time, the Moeller polarimeter based on an internal polarized gas jet target has been developed and successfully used at the VEPP-3 booster storage ring. A system of energy measurement using Compton back-scattering has been put into operation. To increase the machine luminosity, operation with dipole wigglers is studied, and a project of turn-by-turn feedback system to suppress beam instabilities has been started. For beam diagnostics, a multi-anode photomultiplier tube and a white light coronograph were installed. The VEPP-4M operation experience with the longitudinal magnetic field within the KEDR detector is also described.  
 
MOPLT092 Single Mode RF Cavity for VEPP-2000 Storage Ring Based Collider plasma, background, laser, wiggler 752
 
  • V. Volkov, A. Bushuev, E. Kenjebulatov, I. Koop, A. Kosarev, Ya.G. Kruchkov, S.A. Krutikhin, I. Kuptcov, I. Makarov, N. Mityanina, V. Petrov, E. Rotov, I. Sedlyarov, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  Accelerating cavity 172 MHz with strong damped higher-order modes (HOM) for VEPP-2000 electron-positron collider have been made in Novosibirsk. Resonance frequences and Q values of cavity HOMs are measured and analysed. Most of HOMs have Q values less than 300. We compare these results with computer calculations of HOM.  
 
MOPLT096 Machine Induced Background in the High Luminosity Experimental Insertion of the LHC Project plasma, laser, wiggler, vacuum 755
 
  • V. Talanov, I. Azhgirey, I. Baishev
    IHEP Protvino, Protvino, Moscow Region
  • K.M. Potter
    CERN, Geneva
  The methodical approach, developed for the solution of the radiation problems in the LHC project, is used for the estimation of the machine induced background in the high luminosity experimental insertion IR1. The results of the cascade simulations are presented for the cases of the proton losses in the cold and warm parts of the collider. The formation of the machine induced background in the interaction region is discussed.  
 
MOPLT097 Co-sourcing Development of Accelerator Controls plasma, laser, wiggler, vacuum 758
 
  • K. Zagar, R. Sabjan, I. Verstovsek
    JSI, Ljubljana
  • M. Plesko
    Cosylab, Ljubljana
  Frequently, accelerator facilities make use of products and services offered by the industry. This paper's focus is on such outsourcing of control system hardware and software. Firstly, an attempt is made to explain the facility's motivation for seeking outside help, which is typically due to lack of resources, technology or knowledge. Then, the risks of outsourcing are enumerated. To mitigate them, the industrial partner should have not only the adequate technical expertise, but also a reliable, yet agile management and quality assurance process that meets the facility's expectations, schedule, budget constraints, maintenance and support needs. Finally, Cosylab's business model is presented, designed to provide lasting open-source solutions that help not only a single facility, but the entire community.  
 
MOPLT108 TESLA Linac-IP Simulations wiggler, gun, radiation, luminosity 788
 
  • G.R. White
    Queen Mary University of London, London
  • D. Schulte
    CERN, Geneva
  • N.J. Walker
    DESY, Hamburg
  We have formulated integrated simulations of the transport of the electron and positron bunches in the Linear Collider from the linac entrance through the beam delivery system and the interaction region, taking wakefield effects into account. We have set up the simulations to run on the 64-cpu prototpye Grid cluster at QMUL and generated results for various sets of input parameters for the TESLA and NLC machines. For TESLA we have evaluated the distortion of the phase-space of the bunches at the interaction point due to wakefields. We have calculated the luminosity degradation and the production of photons and e+e- pairs. We have simulated the performance of the intra-train beam feedback systems based on bunch position, angle and luminosity measures, and have evauated the luminosity recovery potential of these systems for TESLA and NLC.  
 
MOPLT109 Longitudinal Schottky Spectra of Bunched Beams wiggler, gun, radiation, luminosity 791
 
  • V. Balbekov, S. Nagaitsev
    Fermilab, Batavia, Illinois
  In this paper we derive an expression for longitudinal Schottky spectrum of a bunched beam in a stationary bucket. The expression is then used to calculate longitudinal emittance of the antiproton beam in the Fermilab Recycler ring. The Recycler beam is bunched longitudinally by a barrier-bucket rf waveform. Under certain bucket conditions, dependence of synchrotron frequency on particle energy becomes non-monotonic. It complicates the Schottky spectrum derivation and interpretation; we address these difficulties in our paper.  
 
MOPLT110 Stochastic Cooling in Barrier Buckets at the Fermilab Recycler wiggler, gun, radiation, luminosity 794
 
  • D.R. Broemmelsiek, M. Hu, S. Nagaitsev
    Fermilab, Batavia, Illinois
  The Fermilab Recycler is a fixed 8-GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. The role of stochastic cooling in the Recycler is to pre-cool the transverse phase-space of injected antiprotons for efficient electron cooling. This requires a gated stochastic cooling system working on beam confined in a barrier bucket. The performance of this system is reviewed. In addition, a study of the cooling rates and asymmptotic emittances as a function of beam intensity is presented.  
 
MOPLT111 On using NEA Cathodes in an RF Gun wiggler, radiation, electron, luminosity 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.  
 
MOPLT112 Optimizing Non-Scaling FFAG Lattices for Rapid Acceleration wiggler, radiation, luminosity, beamloading 800
 
  • C. Johnstone
    Fermilab, Batavia, Illinois
  • S.R. Koscielniak
    TRIUMF, Vancouver
  A linear approach to fixed field acceleration was first proposed [*,**] and successfully developed to support the rapid and large-emittance acceleration of muons for a Neutrino Factory or Muon Collider. Lattices have evolved from a simple F0D0-cell base as first proposed to a slightly more complex layout that has been referred to as a triplet configuration. In this work a methodology is developed for optimizing nonscaling lattices which demonstrates that the appropriate description is minimum momentum compaction, alpha=(dL/L)/(dp/p). Further, the triplet configuration is not used conventionally as a focusing telescope, but rather its optics is shown to resemble that of a F0D0-cell. This methodology is then used to propose and compare lattices for muon acceleration. Specifically a 2.5-5, 5-10, and 10-20 GeV/c lattice is proposed for muon acceleration and also one for a small, 10-20 MeV/c electron prototype machine.

* C. Johnstone, "FFAG Non-scaling Lattice Design", talk, Proc 4th Int Conf on the Physics Potential and Development of the m+ m- Colliders, San Francisco, CA Dec.10-12, 1997, pgs 696-698** F. Mills, "Linear Orbit Recirculators", ibid, pgs 693-696

 
 
MOPLT114 Modeling of Beam Loss in Tevatron and Backgrounds in the BTeV Detector wiggler, radiation, luminosity, beamloading 803
 
  • A. Drozhdin, N. Mokhov
    Fermilab, Batavia, Illinois
  Detailed STRUCT simulations are performed of beam loss rates in the vicinity of the BTeV detector in the Tevatron C0 interaction region due to beam-gas nuclear elastic interactions, outscattering from the collimator jaws and an accidental abort kicker prefire. Corresponding showers induced in the machine components and background rates on the BTeV Detector are modeled with the MARS14 code. It is shown that a steel mask located in front of the last four dipoles upstream the C0 can reduce the accelerator-related background rates in the detector by an order of magnitude.  
 
MOPLT115 Numerical Simulations and Analyses of Beam-Induced Damage to the Tevatron Collimators wiggler, radiation, luminosity, beamloading 806
 
  • A. Drozhdin, N. Mokhov, D. Still
    Fermilab, Batavia, Illinois
  • V. Samulyak
    BNL, Upton, Long Island, New York
  Numerical simulations are performed to analyze the Tevatron collimator damage happened in December 2003 that was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench are studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident.  
 
MOPLT117 An Electron Front End for the Fermilab Multi-species 8 GeV SCRF Linac wiggler, electron, 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 wiggler, electron, 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 vacuum, wiggler, electron, 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 vacuum, wiggler, electron, 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 vacuum, wiggler, electron, 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 vacuum, electron, 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 vacuum, damping, electron, 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, vacuum, electron, 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, vacuum, injection, electron 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, vacuum, injection, electron 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, vacuum, injection, electron 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.  
 
MOPLT130 Bunch Pattern with More Bunches in PEP-II luminosity, damping, vacuum, beamloading 842
 
  • F.-J. Decker, S. Colocho, A. Novokhatski, M.K. Sullivan, U. Wienands
    SLAC, Menlo Park, California
  The number of bunches in the PEP-II B-Factory has increased over the years. The luminosity followed roughly linear that increase or even faster since we also lowered the spot size at the interaction point. The recent steps from 933 in June of 2003 to about 1320 in February 2004 should have been followed by a similar rise in luminosity from 6.5·1033 1/cm2 1/s to 9.2·1033 1/cm2 1/s. This didn't happen so far and a peak luminosity of only 7.3·1033 1/cm2 1/s was achieved. By filling the then partially filled by-3 pattern to a completely filled by-3 pattern (1133 bunches) should even give 7.9·1033 1/cm2 1/s with scaled currents of 1400 mA (HER) and 1900 mA (LER). We are typically running about 1300 mA and 1900 mA with 15% more bunches. The bunch pattern is typically by-2 with trains of 14 bunches out of 18. The parasitic beam crossings or electron cloud effects might play a role in about a 10% luminosity loss. Also the LER x-tune could be pushed further down to the ? integer in the by-3 pattern. On the other hand we might not push the beam-beam tune shift as hard as in June of 2003 since we started trickle injection and therefore might avoid the highest peak luminosity with a higher background. A mixed pattern with a by2-by3 setup (separation of 2, 3, 2, 3 ?) would give totally filled a slightly higher number of bunches (1360), but near the interaction point there would be only one parasitic crossing per beam lowering the tune shift by two.  
 
MOPLT131 Emittance Dilution Simulations for Normal Conducting and Superconducting Linear Colliders luminosity, damping, vacuum, beamloading 845
 
  • R.M. Jones, T.O. Raubenheimer
    SLAC, Menlo Park, California
  • N. Baboi
    DESY, Hamburg
  An electron (or positron) multi-bunch train traversing several thousand accelerator structures can be distorted by long-range wakefields left behind the accelerated bunches. These wakefields can at the very least, give rise to a dilution in the emittance of the beam and, at worst can lead to a beam break up instability. We investigate the emittance dilution that occurs for various frequency errors (corresponding to small errors made in the design or fabrication of the structure) for the GLC/NLC (Global Linear Collider/Next Linear Collider) and for TESLA (Terra Electron Superconducting Linear Accelerator). Resonant effects, which can be particularly damaging, are studied for X-band and L-band linacs. Simulations are performed with the computer codes LIAR[1] and L-MAFIA[2].

[1] R. Assman et al, LIAR, SLAC-PUB AP-103[2] The MAFIA Collaboration, MAFIA: L - The Linear Accelerator Tracking Code, CST GmbH, Darmstadt (1994)

 
 
MOPLT133 Beam Loading and Higher-band Longitudinal Wakes in High Phase Advance Traveling Wave Accelerator Structures for the GLC/NLC luminosity, damping, vacuum, beamloading 848
 
  • R.M. Jones, V.A. Dolgashev, Z. Li, T.O. Raubenheimer
    SLAC, Menlo Park, California
  A multi-bunch beam traversing traveling wave accelerator structures, each with a 5pi/6 phase advance is accelerated at a frequency that is synchronous with the fundamental mode frequency. As per design, the main interaction occurs at the working frequency of 11.424 GHz. However, modes with frequencies surrounding the dominant accelerating mode are also excited and these give rise to additional modal components to the wakefield. Here, we consider the additional modes in the context of X-band accelerator structures for the GLC/NLC (Global Linear Collider/Next Linear Collider). Finite element simulations, mode-matching and circuit models are employed in order to calculate the wakefield.  
 
MOPLT134 X-Band Linear Collider R&D in Accelerating Structures through Advanced Computing luminosity, damping, vacuum, dipole 851
 
  • Z. Li, N.T. Folwell, L. Ge, A. Guetz, V. Ivanov, K. Ko, M. Kowalski, L. Lee, C.-K. Ng, G. Schussman, R. Uplenchwar
    SLAC, Menlo Park, California
  • M. Wolf
    University of Illinois, Urbana
  The X-band linear collider design, GLC/NLC, requires accelerating structures in the main linac to operate at 65 MV/m and to be able to control emittance growth due to dipole wakefields generated by 100 micron bunch trains. The approach to high gradient has focused mainly on testing structures for acceptable breakdown rates at the desired gradient through experiments since the problem is analytically challenging. In suppressing dipole wakefields, the damped, detuned structure (DDS) has shown capable of meeting design requirements but the analysis using equivalent circuits has thus far been limited to the lowest two dipole bands. This paper describes a computational approach that addresses these design issues through large-scale simulations, using a suite of parallel electromagnetic codes developed under the DOE SciDAC Accelerator Simulation Project. Numerical results on peak field calculation, dark current generation, and wakefield computation will be presented on the H60VG4S17 DDS structure, considered to be the baseline design for the NLC.  
 
MOPLT135 Damping the High Order Modes in the Pumping Chamber of the PEP-II Low Energy Ring luminosity, damping, dipole, beamloading 854
 
  • A. Novokhatski, S. Debarger, F.-J. Decker, A. Kulikov, J. Langton, M. Petree, J. Seeman, M.K. Sullivan
    SLAC, Menlo Park, California
  The Low Energy Ring of the PEP-II B-factory operates with extremely high currents and short positron bunches. Any discontinuity in the vacuum chamber can excite a broad-band spectrum of the High Order Modes. A temperature rise has been found in the vacuum chamber elements in one transition from straight section to arc. The power in the wake fields was high enough to char beyond use the feed-through for the Titanium Sublimation Pump. This pumping section consists of the beam chamber and an ante-chamber. Fields, excited in the beam chamber penetrate to the ante-chamber and then through the heater wires of the TSP come out. A small ceramic tile was placed near the TSP feed-through to absorb these fields. A short wire antenna was also placed there. HOM measurements show a wide spectrum with a maximum in the 2-3 GHz region. A special water cooled HOM absorber was designed and put inside the ante-chamber part of the section. As a result, the HOM power in the section decreased and the temperature rise went down. The power loss is 750 W for a beam current of 2 A. Measurements of the HOM impedance for different bunch patterns, bunch length and transverse beam position will be presented.  
 
MOPLT136 Reliability Simulations for a Linear Collider luminosity, dipole, beamloading, lattice 857
 
  • N. Phinney, T.M. Himel, M.C. Ross
    SLAC/NLC, Menlo Park, California
  • P. Czarapata, H. Edwards, M. Huening
    Fermilab, Batavia, Illinois
  A new flexible tool for evaluating accelerator reliability was developed as part of the US Linear Collider Technology Comparison Study. The linear collider designs considered were based on the GLC/NLC X-band and TESLA Superconducting proposals, but modified to meet the US physics requirements. To better model some of the complexities of actual operation, a simulation program was written, which included details such as partial fixes or workarounds, hot-swappable repairs, multiple simultaneous repairs, cooldown periods before access, staged recovery from an outage, and both opportunistic and scheduled machine development. The main linacs and damping rings were modeled in detail with component counts taken from the designs, and using MTBFs and MTTRs from existing accelerator experience. Other regions were assigned a nominal overall failure rate. Variants such as a single tunnel or conventional positron source were also evaluated, and estimates made of the sensitivity to recovery or repair times. While neither design was predicted to be sufficiently reliable given present experience, the required improvements were estimated to increase the overall project cost by only a few percent.  
 
MOPLT137 Beam Delivery Layout for the Next Linear Collider dipole, beamloading, lattice, undulator 860
 
  • A. Seryi, Y. Nosochkov, M. Woodley
    SLAC, Menlo Park, California
  We present the latest design and layout of the NLC Beam Delivery System (BDS) for the first and second interaction region (IR). This includes the beam switchyard, skew correction and emittance diagnostics section, collimation system integrated with the final focus, the primary and post linac tune-up beam dumps, and arcs of the second interaction region beamline. The layout and optics are optimized to deliver the design luminosity in the entire energy range from 90GeV to 1.3TeV CM, with the first IR BDS also having the capabilities for multi-TeV extension.  
 
MOPLT138 Vibrational Stability of GLC/NLC Linear Collider: Status and R&D Plans dipole, beamloading, lattice, undulator 863
 
  • A. Seryi, F. Asiri, F. Le Pimpec
    SLAC, Menlo Park, California
  • K. Fujii, T. Matsuda, T. Tauchi, H. Yamaoka
    KEK, Ibaraki
  Luminosity stability of the X-band linear collider will be provided by beam-based train by train steering feedbacks in the linac and at the IP, optional active stabilization of the final doublet, being developed to counteract possible excessive vibration of the detector, and optional fast intratrain feedback that would allow delivering major part of the luminosity while other systems are being commissioned. Control and reduction of the beam jitter originating from vibration of collider components is part of our strategy described in this paper.  
 
MOPLT139 Beam-based Alignment and Beta Function Measurements in PEP-II quadrupole, dipole, beamloading, undulator 866
 
  • G. Yocky, J. Nelson, M.C. Ross, T.J. Smith, J.L. Turner, M. Woodley
    SLAC, Menlo Park, California
  Careful optics studies and stringent lattice control have been identified as two key components to increasing PEP-II luminosity. An accurate, trusted BPM system is required for both of these strategies. To validate the existing BPM system and to better understand some optical anomalies in the PEP-II rings, an aggressive program of beam-based alignment (BBA) has been initiated. Using a quad-shunt BBA procedure in which a quadrupole?s field strength is varied over a range of beam positions, relative offsets are determined by the BPM readings at which quadrupole field changes no longer induce a closed orbit shift. This procedure was verified in the HER and is well underway in the LER IR. We have found many surprisingly large BPM offsets, some over one centimeter, as well as a number of locations where the current nominal orbit is several millimeters from the quadrupole center. Tune versus quadrupole field data were taken during the BBA process in the LER IR, and the non-linear response in each case is compared to simulation to infer local beta functions.  
 
MOPLT141 IR Upgrade Plans for the PEP-II B-Factory luminosity, quadrupole, beamloading, undulator 869
 
  • M.K. Sullivan, S. Ecklund, N. Kurita, A. Ringwall, J. Seeman, U. Wienands
    SLAC, Menlo Park, California
  • M.E. Biagini
    INFN/LNF, Frascati (Roma)
  PEP-II, the SLAC, LBNL, LLNL B-factory has achieved a peak luminosity of over 7e33, more than twice the design luminosity, and plans to obtain a luminosity of over 1·1034 in the next year. In order to push the luminosity performance of PEP-II to even higher levels an upgrade to the interaction region is being designed. In the present design, the interaction point is a head-on collision with two strong horizontal dipole magnets (B1) located between 20-70 cm from the IP that bring the beams together and separate the beams after the collision. The first parasitic crossing (PC) is at 63 cm from the IP in the present by2 bunch spacing. The B1 magnets supply all of the beam separation under the present design. Future improvements to PEP-II performance include lowering the beta y * values of both rings. This will increase the beta y value at the PCs which increases the beam-beam effect at these non-colliding crossings. Introducing a horizontal crossing angle at the IP quickly increases the beam separation at the PCs but recent beam-beam studies indicate a significant luminosity reduction occurs when a crossing angle is introduced at the IP. We will discuss these issues and describe the present interaction region upgrade design.  
 
MOPLT142 Analysis of KEK-ATF Optics and Coupling Using LOCO luminosity, quadrupole, beamloading, undulator 872
 
  • M. Woodley, J. Nelson, M.C. Ross
    SLAC/NLC, Menlo Park, California
  • A. Wolski
    LBNL/AFR, Berkeley, California
  LOCO is a computer code for analysis of the linear optics in a storage ring based on the closed orbit response to steering magnets. The analysis provides information on focusing errors, BPM gain and rotation errors, and local coupling. Here, we discuss the details of the LOCO implementation at the KEK-ATF Damping Ring, and report the initial results. Some of the information obtained, for example on the BPM gain and coupling errors, has not previously been determined. We discuss the possibility of using the data provided by the LOCO analysis to reduce the vertical emittance of the ATF beam.  
 
MOPLT143 Results and Plans of the PEP-II B-Factory luminosity, quadrupole, beamloading, undulator 875
 
  • J. Seeman, J. Browne, Y. Cai, S. Colocho, F.-J. Decker, M.H. Donald, S. Ecklund, R.A. Erickson, A.S. Fisher, J.D. Fox, S.A. Heifets, R.H. Iverson, A. Kulikov, A. Novokhatski, M.T.F. Pivi, M.C. Ross, P. Schuh, T.J. Smith, K. Sonnad, M. Stanek, M.K. Sullivan, P. Tenenbaum, D. Teytelman, J.L. Turner, D. Van Winkle, U. Wienands, M. Woodley, Y.T. Yan, G. Yocky
    SLAC, Menlo Park, California
  • M.E. Biagini
    INFN/LNF, Frascati (Roma)
  • J.N. Corlett, C. Steier, A. Wolski, M.S. Zisman
    LBNL, Berkeley, California
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • G. Wormser
    IPN, Orsay
  PEP-II is an e+e- B-Factory Collider located at SLAC operating at the Upsilon 4S resonance. PEP-II has delivered, over the past four years, an integrated luminosity to the BaBar detector of over 175 fb-1 and has reached a luminosity over 7.4x1033/cm2/s. Steady progress is being made in reaching higher luminosity. The goal over the next few years is to reach a luminosity of at least 2x1034/cm2/s. The accelerator physics issues being addressed in PEP-II to reach this goal include the electron cloud instability, beam-beam effects, parasitic beam-beam effects, trickle injection, high RF beam loading, lower beta y*, interaction region operation, and coupling control.  
 
MOPLT144 Design for a 1036 Super-B-factory at PEP-II quadrupole, beamloading, undulator, lepton 878
 
  • J. Seeman, Y. Cai, F.-J. Decker, S. Ecklund, A.S. Fisher, J.D. Fox, S.A. Heifets, A. Novokhatski, M.K. Sullivan, D. Teytelman, U. Wienands
    SLAC, Menlo Park, California
  Design studies are underway to arrive at a complete parameter set for a very high luminosity e+e- Super B-Factory (SBF) in the luminosity range approaching 1036/cm2/s. The design is based on a collider in the PEP-II tunnel but with an upgraded RF system (higher frequency), magnets, vacuum system, and interaction region. The accelerator physics issues associated with this design are reviewed as well as the site and power constraints. Near term future studies will be discussed.  
 
MOPLT146 Trickle-charge: a New Operational Mode for PEP-II luminosity, quadrupole, beamloading, undulator 881
 
  • J.L. Turner, S. Colocho, F.-J. Decker, S. Ecklund, A.S. Fisher, R.H. Iverson, C. O'Grady, J. Seeman, M.K. Sullivan, M. Weaver, U. Wienands
    SLAC, Menlo Park, California
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In regular top-up-and-coast operation, PEP-II average luminosity is about 70…75% of the peak luminosity due to detector ramp-down and ramp-up times plus the time it takes to top-up both beams. We recently commissioned a new operational mode where the Low Energy Ring is injected continuously without ramping down the detector. The benefits?increased luminosity lifetime and roughly half the number of top-ups per shift?were expected to give an increase in delivered luminosity of about 15% at the same peak luminosity; this was confirmed in test runs. In routine trickle operation, however, it appears that the increase in delivered luminosity is more than twice that due to an increase in availability credited to the more stable operating conditions during trickle operation. In this paper we will present our operational experience as well as some of the diagnostics we use to monitor and maintain tuning of the machine in order to control injection background and protect the detector. Test runs are planned to extend trickle-charge operation to the High Energy Ring as well.  
 
MOPLT147 SPEAR 3 Commissioning Software luminosity, quadrupole, beamloading, undulator 884
 
  • W.J. Corbett, G.J. Portmann, J.A. Safranek, A. Terebilo
    SLAC/SSRL, Menlo Park, California
  In order to meet the tight SPEAR 3 accelerator commissioning schedule, a software package was assembled to streamline experimental measurements and data analysis. At the heart of the software is a MATLAB "middle layer" with an element definition database and channel access link for fast and easy communication with the EPICS control system. Originally adapted from work at the ALS, the middle layer allows direct control from the MATLAB command line, use in the form of short "scripts" for specific experiments and integration into high-level application programs. The revised software is also machine-independent. This paper outlines the software architecture and provide examples with results from the SPEAR 3 accelerator commissioning effort.  
 
MOPLT148 Progress of the eRHIC Electron Ring Design electron, 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.  
 
MOPLT151 Study of Arc-related RF Faults in the CEBAF Cryomodules vacuum, quadrupole, beamloading, undulator 890
 
  • E. Daly, D. Curry, J. Musson, G. Myneni, T. Powers, H. Wang, T.E. Whitlatch
    Jefferson Lab, Newport News, Virginia
  • I.E. Campisi
    ORNL/SNS, Oak Ridge, Tennessee
  A series of measurements has been conducted on two superconducting radio-frequency cavity pairs, installed in cryomodules and routinely operated in the Continuous Electron Beam Accelerator Facility, in order to study the RF-vacuum interaction during an RF fault. These arc-related fault rates increase with increasing machine energy, contribute to system downtime and directly affect the accelerator?s availability. For this study, the fundamental power coupler waveguides have been instrumented with vacuum gauges, additional arc detectors, additional infrared sensors and temperature sensors in order to measure the system response during both steady-state operations and RF fault conditions. Residual gas analyzers have been installed on the waveguide vacuum manifolds to monitor the gas species present during cooldown, RF processing and operation. Simultaneous measurements of the signals are presented, a comparison with analysis is shown and results are discussed. The goal of this study is to characterize the RF-vacuum interaction during normal operations. With a better understanding of the installed system response, methods for reducing the fault rate may be devised, ultimately leading to improvements in availability.  
 
MOPLT153 Electron-Ion Collider at CEBAF: New Insights and Conceptual Progress ion, luminosity, vacuum, quadrupole 893
 
  • Y.S. Derbenev, A. Afanasev, K. Beard, S.A. Bogacz, P. Degtiarenko, J.R. Delayen, A. Hutton, G.A. Krafft, R. Li, L. Merminga, M. Poelker, B.C. Yunn, Y. Zhang
    Jefferson Lab, Newport News, Virginia
  • P.N. Ostroumov
    ANL/Phys, Argonne, Illinois
  We report on progress in conceptual development of the proposed high luminosity (up to 1035/cm2s) and efficient spin manipulation (using figure 8 boosters and collider rings) Electron-Ion Collider at CEBAF based on use of polarized 5-7 GeV electrons in superconduction energy recovering linac (ERL with circulator ring, kicker-operated) and 30-150 GeV ion storage ring (polarized p, d. He3, Li and unpolarized nuclei up to Ar, all totally stripped). Ultra-high luminosity is envisioned to be achievable with short ion bunches and crab-crossing at 1.5 GHz bunch collision rate interaction points. Our recent studies concentrated on simulation of beam-beam interaction, preventing the electron cloud instability, calculating luminosity lifetime due to Touschek effect in ion beam and background scattering of ions, experiments on energy recovery at CEBAF, and other. These studies have been incorporated in the development of the luminosity calculator and in formulating minimum requirements to the polarized electron and ion sources  
 
MOPLT155 Study of Beam-beam Effects at PEP-II ion, luminosity, vacuum, quadrupole 896
 
  • I.V. Narsky, F.C. Porter
    CALTECH, Pasadena, California
  • Y. Cai, J. Seeman
    SLAC, Menlo Park, California
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  Using a self-consistent, three-dimensional simulation program running on parallel supercomputers, we have simulated the beam-beam interaction at the PEP II asymmetric e+e- collider. In order to provide guidance to luminosity improvement in PEP-II, we have scanned the tunes and other machine parameters in both rings, and computed their impact on the luminosity and particle loss. Whenever possible, the code has been benchmarked against experimental measurements, at various beam currents, of luminosity and luminous-region size using the BaBar detector. These studies suggest that three-dimensional effects such as bunch lengthening may be important to understand a steep drop of luminosity near the peak currents.  
 
MOPLT156 High Brightness Electron Guns for Next-Generation Light Sources and Accelerators gun, ion, luminosity, vacuum 899
 
  • H. Bluem, M.D. Cole, J. Rathke, T. Schultheiss, A.M.M. Todd
    AES, Princeton, New Jersey
  • I. Ben-Zvi, T. Srinivasan-Rao
    BNL, Upton, Long Island, New York
  • P. Colestock, D.C. Nguyen, R.L. Wood, L. Young
    LANL, Los Alamos, New Mexico
  • D. Janssen
    FZR, Dresden
  • J. Lewellen
    ANL, Argonne, Illinois
  • G. Neil, H.L. Phillips, J.P. Preble
    Jefferson Lab, Newport News, Virginia
  Advanced Energy Systems continues to develop advanced electron gun and injector concepts. Several of these projects have been previously described, but the progress and status of each will be updated. The project closest to completion is an all superconducting RF (SRF) gun, being developed in collaboration with the Brookhaven National Laboratory, that uses the niobium of the cavity wall itself as the photocathode material. This gun has been fabricated and will shortly be tested with beam. The cavity string for a closely-coupled DC gun and SRF cavity injector that is expected to provide beam quality sufficient for proposed ERL light sources and FELs will be assembled at the Jefferson Laboratory later this year. We are also collaboration with Los Alamos on a prototype CW normal-conducting RF gun with similar performance, that will undergo thermal testing in late 2004. Another CW SRF gun project that uses a high quantum efficiency photocathode, similar to the FZ-Rossendorf approach, has just begun. Finally, we will present the RF design and cold test results for a fully axisymmetric, ultra-high-brightness x-band RF gun.  
 
TUYACH01 Laser-acceleration and Laser-cooling for Ion Beams gun, vacuum, focusing, laser 54
 
  • M. Roth, A. Blazevic, E. Brambrink, M. Geissel
    TU Darmstadt, Darmstadt
  • P. Audebert
    LULI, Palaiseaux
  • M. Bussmann, D. Habs, U. Schramm, J. Schreiber
    LMU, München
  • R. Clarke, S. Karsch, D. Neely
    CCLRC/RAL, Chilton, Didcot, Oxon
  • J.A. Cobble, J. Fernandez, M. Hegelich, S. Letzring
    LANL, Los Alamos, New Mexico
  • T.E. Cowan, J. Fuchs, A. Kemp, H. Ruhl
    University of Nevada, Reno, Reno, Nevada
  • K. Ledingham, P. McKenna
    Strathclyde University, Glasgow
  The acceleration or cooling of particles with lasers has been the subject of growing interest over the last years. Because of the huge difference in mass, the acceleration of ions was so far limited to thermal expansion from laser plasmas, driven by the hot electron temperature. In recent years, due to the development of short-pulse ultra-intense lasers, the manipulation of ions has now become possible. Especially the generation of high quality, intense ion beams from laser solid interaction has attracted large attention and is investigated at many laboratories world-wide. For the first time, intense, directed, low emittance beams of ions have been observed, having several MeV of particle energy right from the source. A wealth of applications including next generation ion sources can be envisioned. The talk will give an overview of the status of laser cooling and ion acceleration including the last experimental results. In addition, an overview of the current and future research activities will be presented.  
Video of talk
Transparencies
 
TUZACH01 Positron Source Options for Linear Colliders gun, positron, focusing, synchrotron 69
 
  • K. Floettmann
    DESY, Hamburg
  Linear colliders require sources delivering particle intensities much higher than sources for storage rings and even several orders of magnitude larger than the SLC positron source, the highest intensity positron source operated so far. A fundamental limitation for the intensity of a positron source is set by the thermal stress in the target. Besides improvements of conventional positron sources, i.e. sources where an electron beam creates electron position pairs in an electromagnetic cascade, new concepts based on the direct conversion of gamma radiation offer possibilities for increased particle intensities. In these sources the hard gamma radiation has to be produced either in an undulator or by backscattering of laser light off an electron beam. An additional advantage of gamma radiation based sources is the possibility to produce polarized positrons. The talk will give an overview of the developments of high intensity unpolarized and polarized positron sources for linear colliders.  
Video of talk
Transparencies
 
TUPKF035 RF System for Compact Medical Proton Synchrotron positron, focusing, plasma, impedance 1039
 
  • Z. Fang, K. Egawa, K. Endo, S. Yamanaka
    KEK, Ibaraki
  • Y. Cho, T. Fusato, T. Hirashima
    DKK, Kanagawa
  The rf system has been developed for the compact medical proton synchrotron. The rf system will be operated in pulse mode with the fundamental rf frequency sweeping from 1.6 to 15 MHz during the acceleration time of 5 ms. The required rf cavity voltage is a function of acceleration time too, with the voltage of fundamental varying from 13 to 6 kV. Besides, high order harmonics are also considered to apply to the rf system, and the cavity peak voltage varying from 20 to 9 kV during the acceleration time is expected. The performance of the rf system is being studied and will be presented.  
 
TUPKF036 RF Property of the Prototype Cryomodule for ADS Superconducting Linac positron, focusing, plasma, impedance 1042
 
  • E. Kako, S. Noguchi, N. Ohuchi, T. Shishido
    KEK, Ibaraki
  • N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno
    JAERI/LINAC, Ibaraki-ken
  • H. Hara, M. Matsuoka, K. Sennyu
    MHI, Kobe
  A prototype cryomodule containing two 9-cell superconducting cavities of beta=0.725 and frequency=972MHz is being constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Design and performance of RF components will be reported.  
 
WEODCH01 1.5-GeV FFAG Accelerator as Injector to the BNL-AGS radiation, focusing, kicker, bunching 159
 
  • A. Ruggiero, M. Blaskiewicz, T. Roser, D. Trbojevic, N. Tsoupas, W. Zhang
    BNL, Upton, Long Island, New York
  A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) Accelerator has been recently proposed as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). It is being considered as a replacement of the present 1.5-GeV AGS Booster. The substitution will enhance the performance of the AGS accelerator facility in a variety of ways. It would still allow acceleration of all hadronic particles: protons, and heavy-ions. The major benefit is that it would considerably shorten the typical combined AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power. The paper describes a compact FFAG design for acceleration of protons from 200 MeV to 1.5 GeV. The circumference is about 250 m. The lattice is a periodic sequence of FDF triplets of combined-function magnets. An adjusted field profile has been calculated to compensate the variation of the main lattice functions with momentum. At injection, a beam pulse 130 μs long of negative-ions (H?) is stacked with the charge-exchange method. Acceleration of one pulse with 2.5 x 1013 protons takes about 130 μs, if harmonic-jump scheme is used in conjunction with the choice of 201.25 MHz. Four of such beam pulses are required to fill entirely the AGS. The entire filling process thus takes less than one millisecond.  
Video of talk
Transparencies
 
WEPLT014 Mechanical Dynamic Load of the LHC Arc Cryo-magnets during the LHC Installation focusing, bunching, beamloading, monitoring 1846
 
  • O. Capatina, K. Artoos, G. Huet, B. Nicquevert
    CERN, Geneva
  About 1700 LHC main superconducting dipoles and quadrupoles will have to be transported and handled between the assembly, the magnet measurements and the storage that precedes the final installation in the LHC tunnel. To ensure the required mechanic and geometric integrity of the cryo-magnets, transport specifications and allowed acceleration loads were defined after detailed dynamic analysis. A large number of cryo-magnets are now arriving at CERN on a regular basis. The logistics for the handling and transport are monitored with tri-axial acceleration monitoring devices that are installed on each cryo-magnet. Measurements are made to commission new equipment like overhead cranes, tunnel transport and handling devices to guarantee that the defined acceleration limits are respected. The results from the acceleration monitoring that are stored in the same quality assurance system as the cryo-magnets allowed to give a first idea of the level of the mechanical dynamic load on each magnet throughout the logistics chain and were used to detect details such as out-of-specification accelerations that needed improvement.  
 
WEPLT015 Proposal for the Creation and Storage of Long Bunches in the LHC focusing, bunching, luminosity, beamloading 1849
 
  • H. Damerau, R. Garoby
    CERN, Geneva
  Long bunches with a uniform longitudinal line density held by barrier buckets are considered for a future luminosity upgrade of the Large Hadron Collider (LHC). With such bunches, the luminosity is maximised for a fixed number of particles. Instead of conventional barrier buckets, periodic barriers are proposed. These are generated with multiple RF harmonics (e.g. multiples of 40 MHz). A possible scheme to create and hold long flat bunches in the LHC is described, and the resulting gain in luminosity is estimated.  
 
WEPLT016 Logistics of LHC Cryodipoles: from Simulation to Storage Management focusing, bunching, luminosity, beamloading 1852
 
  • K. Foraz, B. Nicquevert, D. Tommasini
    CERN, Geneva
  The particles traveling in the Large Hadron Collider are guided by superconducting magnets. The main magnets (cryodipoles) are 16 m long, 30 tons objects placed with accuracies of few tenths of mm and therefore imposing challenging requirements for handling and transportation. Numerous contracts are constraining the production and installation of these cryodipoles. These contracts have been rated according to the baseline schedule, based on a "just in time" scheme. However the complexity of the construction and the time required to fully test the cryodipoles before installation in the LHC required to decouple as much as possible each contract from the others' evolutions and imposed temporary storage between different assembly and test steps. Therefore a tool simulating the logistics was created in order to determine the number of cryodipoles to store at the various stages of their production. In this paper the organization of cryodipole flow and the main challenges of logistics are analyzed on the basis of the planning of each main step before installation. Finally the solutions implemented for storage, handling and transportation are presented and discussed.  
 
WEPLT017 Numerical Studies of the Impact of the Separation Dipoles and Insertion Quadrupoles Field Quality on the Dynamic Aperture of the CERN LHC focusing, bunching, insertion, beamloading 1855
 
  • M. Giovannozzi, O.S. Brüning, S.D. Fartoukh, T. Risselada, F. Schmidt
    CERN, Geneva
  A wide range of magnets, both warm and superconducting, will be used in the LHC. In addition to main dipoles, quadrupoles are used to focus the beam in regular arcs. Special dipoles separate or merge the two beams in insertion regions. A few very strong superconducting quadrupoles squeeze the beam to achieve the required luminosity, while warm quadrupoles are used in the collimation insertions. At injection the main dipoles largely dominate beam dynamics, but contributions from smaller classes of magnets should not be neglected. Peculiar optical configurations may dramatically enhance beam dynamics effects of few magnetic elements. This paper will focus on the effect of insertion quadrupoles, e.g. wide-aperture, and warm quadrupoles, as well as separation dipoles presenting on the dynamic aperture of the LHC machine.  
 
WEPLT018 Nonlinear Dynamics Studies at the CERN Proton Synchrotron: Precise Measurements of Islands Parameters for the Novel Multi-turn Extraction focusing, bunching, insertion, beamloading 1858
 
  • M. Giovannozzi, P. Scaramuzzi
    CERN, Geneva
  Recently, a novel approach to perform multi-turn extraction from a circular accelerator was proposed. It is based on adiabatic capture of particles into islands of transverse phase space generated by nonlinear resonances. Sextupole and octupole magnets are used to generate these islands, while an appropriate slow variation of the linear tune allows particles to be trapped inside the islands. Intense experimental efforts showed that the approach is indeed performing rather well. However, good knowledge of the islands properties is a key ingredient for the success of this extraction type. In this paper, a series of measurements are presented dealing with the study of islands' parameters for the fourth-order resonance, such as detuning with amplitude, fixed points' position, betatron frequency, as well as detuning with amplitude inside the islands.  
 
WEPLT019 Towards a Unified General Purpose CAD System at CERN focusing, bunching, insertion, beamloading 1861
 
  • T. Hakulinen, C. Andrews, B. Feral, P.-O. Friman, M. Mottier, T. Pettersson, C. Sorensen, E. Van Uytvinck
    CERN, Geneva
  Several different CAD systems are in use at CERN today. Most of the 3D design work for the LHC is being done using Euclid from MDTVision. For 2D design work AutoCAD is widely used. Also, various special design tools exist for tasks such as electrical design and schematics. Even though LHC design will be finished with Euclid, it has been clear since several years that a new 3D CAD system will be needed in the future. For this reason CERN carried out a comparison between the currently available 3D CAD software using a set of selection criteria important for CERN. The selected system was CATIA from Dassault together with local data base system SmarTeam. The aim is to use CATIA as a multi-disciplinary general purpose CAD tool which could eventually replace almost all of the other CAD systems at CERN. For this purpose, CATIA and SmarTeam are being integrated with the existing CAD utilities and data base systems developed in-house. Pilot users are using the system for real designs and the digital mock-up features of CATIA are used for integration studies of LHC experiments. The feature list of CATIA and SmarTeam is impressive and experience with the software has so far been almost exclusively positive. This is promising for software with which CERN will likely have to live for the next 20 years or more.  
 
WEPLT020 Installation of A Particle Accelerator: from Theory to Practice. The LHC Example focusing, bunching, insertion, beamloading 1864
 
  • C. Hauviller, S. Weisz
    CERN, Geneva
  Installing and commissioning the thousands of equipments constituting a Particle Accelerator is a lengthy and complex process. A large number of multidisciplinary teams are involved over a long period lasting usually many years. Diverse boundary constrains must be taken into account: space, a long and narrow tunnel with few accesses, time, with milestones set many years in advance, and obviously budget. A strict organisation associated with the management tools and the right people is the only way to arrive to a success. The keywords are: Knowledge: A unique and up-to-date database of all the elements and their location, Integration: Study the physical position of the elements, suppress the interferences and define the installation methodology, Prevision: Schedule all the activities and update on-line, In-situ management and supervision: Teams dedicated to follow-up, corrective actions and orphan jobs, Safety. After presenting the planned overall organization, the paper will present practical achievements with the example of the LHC machine installation.  
 
WEPLT021 Towards an Ontology Based Search Mechanism for the EDMS at CERN focusing, bunching, insertion, beamloading 1867
 
  • A. Jimeno Yepes, B. Rousseau
    CERN, Geneva
  CERN is building its new accelerator, the LHC. All the data flow generated during its lifecycle is stored in the EDMS (Engineering Data Management System) developed at CERN. For such a system it is compulsory to have a performant search mechanism to guarantee that the involved people gets the data at the required time. Due to the size of the collection and the diversity of people, organizations, divisions . To overcome this problem, an approach based on a hand-crafted domain specific ontology has been tested in order to improve the information retrieval task within the technical documentation for the LHC Equipment Catalog. The experiments have shown that using the ontology an improvement on the base line has been produced and encorages IE techniques to refine the base ontology.  
 
WEPLT022 Transport and Installation of Cryo-magnets in CERN's Large Hadron Collider Tunnel focusing, bunching, insertion, beamloading 1870
 
  • K. Kershaw, K. Artoos, O. Capatina, A.Y. Coin, M. Gielen, C. Hauviller
    CERN, Geneva
  The arcs of the Large Hadron Collider (LHC) will contain around 1700 main superconducting dipoles and quadrupoles. The long and heavy magnets are supported on fragile composite support posts inside a cryostat to reduce the heat in-leak to the magnets' super fluid helium bath. The presence of fragile components and the need to avoid geometry changes make the cryo-magnets very difficult to handle and transport. The transport and installation of the LHC cryo-magnets in the LEP tunnels originally designed for smaller, lighter LEP magnets has required development of completely new handling solutions. The paper explains the constraints imposed by the cryo-magnet characteristics, the existing tunnel infrastructure and schedule considerations. The development and realisation of transport and handling solutions are described, starting from conceptual design, through manufacture and testing to the installation of the first cryo-magnet. Integration studies to verify and reserve space needed for manoeuvre and the preparation of the infrastructure for transport and installation operations are also presented. The paper includes conclusions and some of the lessons learned.  
 
WEPLT023 Transverse Resistive Wall Impedance and Wake Function with Inductive Bypass focusing, bunching, insertion, beamloading 1873
 
  • A. Koschik, F. Caspers, E. Métral, L. Vos
    CERN, Geneva
  • B. Zotter
    Honorary CERN Staff Member, Grand-Saconnex
  We analyze the resistive wall impedance with an "inductive bypass" due to alternate current paths in the outer vacuum chamber proper. Also the corresponding wake function has been obtained which is useful for the simulation of beam stability in the time domain. Results are presented for the LHC.  
 
WEPLT024 Scheduling the Installation of the LHC Injection Lines focusing, bunching, insertion, beamloading 1876
 
  • L. Lari, H. Gaillard, V. Mertens
    CERN, Geneva
  The installation of the two LHC injection lines has to fit within tight milestones of the LHC project and of CERN?s accelerator activity in general. For instance, the transfer line from the SPS to LHC point 8 (to fill the anti-clockwise LHC ring) should be tested with beam before the end of 2004 since the SPS will not run in 2005. It will first serve during the LHC sector test in 2006. Time constraints are also very strong on the installation of the transfer line from the SPS to LHC point 2 (for the clockwise LHC ring): its tunnel is the sole access for the LHC cryo-magnets and a large part of the beam line can only be installed once practically all LHC cryo-magnets are in place. Of course, the line must be operational when the LHC starts. This paper presents the various constraints and how they are taken into account for the logistics and installation planning of the LHC injection lines.  
 
WEPLT025 LHC Reference Database : Towards a Mechanical, Optical and Electrical Layout Database focusing, bunching, insertion, beamloading 1879
 
  • P. Le Roux, S. Chemli, A. Jimeno Yepes, B. Maire, H. Prin, A. Vergara-Fernández, M. Zerlauth
    CERN, Geneva
  The LHC project has entered a phase of integration and installation of thousands of diverse components. The Hardware Commissioning work has also started. Collecting and distributing reliable and coherent information on the equipments and their layout becomes a crucial requirement in the lifecycle of the project. Existing database tools had to evolve to a more generic model to cover not only optical layout, but also the mechanical and the electrical aspects. This paper explains the requirements, the implementation and the benefits of this new database model.  
 
WEPLT026 Dynamic Aperture Reduction from the Dodecapole Component in the LHC Main Quadrupoles and its Mechanism. focusing, bunching, insertion, beamloading 1882
 
  • A.M. Lombardi, O.S. Brüning, S.D. Fartoukh, T. Risselada, F. Schmidt, A. Verdier
    CERN, Geneva
  The systematic dodecapole component in the Main Quadrupoles of the LHC lattice has a strong influence on the machine dynamic aperture at injection. In this paper we quantify this effect with the help of tracking studies, explain the mechanism for the loss in dynamic aperture and look into potential correction schemes. Finally, we provide an estimate for the maximum allowed systematic dodecapole component in the MQ.  
 
WEPLT027 Connection Cryostats for LHC Dispersion Suppressors focusing, bunching, insertion, beamloading 1885
 
  • S. Marque, T. Colombet, M. Genet, B. Skoczen
    CERN, Geneva
  The lattice of the Large Hadron Collider (LHC) being built at CERN is based on 8 standard arcs of 2.8 km length. Each arc is bounded on either side by Dispersion Suppressors connected to the arc by connection cryostats providing 15m long drift spaces. As for a dipole magnet, the connection cryostat provides a continuity of beam and insulation vacuum, electrical powering, cryogenic circuits, thermal and radiation shielding. In total 16 modules will be constructed. The stringent functional specification has led to various analyses. Among them, a light mechanical structure has been developed to obtain a stiffness comparable to a dipole magnet, for alignment purpose. Thermal studies, included λ front propagation, have been performed to ensure a cooling time down to 1.9K within the time budget. A special cooling scheme around the beam tubes has been chosen to cope with heat loads produced during operation. We will report on the general design of the module and on the manufacturing process adopted to guarantee the tight alignment of the beam tubes once the module installed in the machine. Special emphasis will be given on thermo-mechanical analysis, λ front propagation and on beam-tubes cooling scheme.  
 
WEPLT028 High-intensity and High-density Charge-exchange Injection Studies into the CERN PS Booster at Intermediate Energies injection, focusing, booster, bunching 1888
 
  • M. Martini
    CERN, Geneva
  • C.R. Prior
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  For the high brilliance LHC ultimate beam and the high intensity CNGS beam, single batch injections into the CERN Proton Synchrotron (PS) will be used to increase the overall machine intensity compared with the present double batch injections. Charge-exchange injection into the PS Booster with a new linac at intermediate energies is thus examined. A key parameter to consider is the energy dependence of beam incoherent tune shifts at injection. Increasing the linac energy from the present 50 MeV to 160 MeV should yield a safer tune shift. For each PS Booster ring, a charge-exchange injection scheme is envisaged inside a proper straight section, redesigned with new bends to make a local bump and using the existing fast bump magnets for horizontal phase-space painting. ACCSIM simulations for charge-exchange injection at 160 MeV have been investigated for both LHC and CNGS beams. After optimizing the parameters that are used for the space charge tracking routines, the results of the simulations agree well with expectations, signifying that the LHC ultimate and CNGS beams may be provided with single PS Booster batches within the required emittances. For assessment, simulation of injection at 50 MeV for the current LHC beam has been performed, yielding a fairly good agreement with measured performance. Concurrently, similar charge-exchange injection simulations have been carried out using an alternative programme developed at the Rutherford Appleton Laboratory.  
 
WEPLT029 Intensity Dependent Emittance Transfer Studies at the CERN Proton Synchrotron injection, focusing, resonance, booster 1891
 
  • E. Métral, C. Carli, M. Giovannozzi, M. Martini, R.R. Steerenberg
    CERN, Geneva
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  • J. Qiang
    LBNL, Berkeley, California
  • R.D. Ryne
    LBNL/CBP, Berkeley, California
  An intensive study has been undertaken since the year 2002 to understand better the various high-intensity bottlenecks of the CERN Proton Synchrotron machine. One of these limitations comes from the so-called Montague resonance. High-intensity proton synchrotrons, having larger horizontal than vertical emittance, may suffer from this fourth-order coupling resonance driven by space charge only. In particular, such resonance may lead to emittance sharing and, possibly, beam loss due to vertical acceptance limitation. Experimental observations made in the 2002 and 2003 runs on the Montague resonance are presented in this paper and compared with 3D particle-in-cell simulation results and theoretical predictions.  
 
WEPLT030 Stability Diagrams for Landau Damping with Two-dimensional Betatron Tune Spread from Both Octupoles and Non-linear Space Charge applied to the LHC at Injection focusing, resonance, booster, bunching 1894
 
  • E. Métral, F. Ruggiero
    CERN, Geneva
  The joint effect of space-charge non-linearities and octupole lenses is discussed for the case of a quasi-parabolic transverse distribution of a monochromatic beam. The self-consistent non-linear space-charge tune shift corresponding to the above distribution function is first derived analytically. The exact dispersion relation is also given but not solved. Instead, noting that a good approximation of the non-linear space-charge tune shift is obtained considering only linear terms in the action variables, the dispersion relation is solved analytically in this approximate case. As expected, in the absence of external (octupolar) non-linearities, the result of Möhl and Schönauer is recovered: there is no stability region. In the absence of space charge, the stability diagrams of Berg and Ruggiero are also recovered. Finally, the new result is applied to the LHC at injection.  
 
WEPLT031 The LHC Access Control System focusing, resonance, booster, bunching 1897
 
  • P. Ninin, L. Scibile
    CERN, Geneva
  The LHC complex is divided into a number of zones with different levels of access controls. Inside the interlocked areas, the personnel protection is ensured by the LHC Access System. This system is made of two parts: the LHC Access Safety System and the LHC Access Control System. During machine operation, the LHC Access Safety System ensures the collective protection of the personnel against the hazards arising from the operation of the accelerator. By interlocking the LHC key safety elements, it will permit access to authorised personnel in the underground premises during the accelerator shutdowns and will deny access during accelerator operation. On the other hand, the LHC Access Control System, regulates the access to the accelerator and the numerous support systems. It allows a remote, local or automatic operation of the access control equipment that verifies the users? authorization, identifies them, locks and unlocks access control equipment and restricts the number of users working simultaneously in the interlocked areas. This paper introduces the main functions, architecture, technologies and methodology used to realise the LHC Access system.  
 
WEPLT033 The LHC Radiation Monitoring System for the Environment and Safety radiation, focusing, resonance, booster 1900
 
  • L. Scibile, D. Forkel-Wirth, H.G. Menzel, D. Perrin, G. Segura Millan, P. Vojtyla
    CERN, Geneva
  A state of the art radiation monitoring and alarm system is being implemented at CERN for the LHC. The RAdiation Monitoring System for the Environment and Safety (RAMSES) comprises about 350 monitors and provides ambient dose equivalent rates measured in the LHC underground areas as well as on the surface inside and outside the CERN perimeter. In addition, it monitors air and water released from the LHC installations. Although originally conceived for radiation protection only, RAMSES also integrates some conventional environmental measurements such as physical and chemical parameters of released water and levels of non-ionizing radiation in the environment. RAMSES generates local radiation warnings, local alarms as well as remote alarms on other monitored variables, which are transmitted to control rooms. It generates operational interlocks, allows remote supervision of all measured variables as well as data logging and safe, long-term archiving for off-line data analysis and reporting. Requirements of recent national and international regulations in combination with CERN's specific technical needs were translated into the RAMSES specifications. This paper outlines the scope, the organization, the main system performance and the system design.  
 
WEPLT035 Capture Loss of the LHC Beam in the CERN SPS radiation, focusing, resonance, booster 1903
 
  • E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar, J. Tuckmantel
    CERN, Geneva
  The matched voltage of the LHC beam at injection into the SPS is 750 kV. However, even with RF feedback and feed forward systems in operation, the relative particle losses on the flat bottom for nominal LHC parameters with this capture voltage can reach the 30% level. With voltages as high as 2 MV these losses are still around 15% pushing the intensity in the SPS injectors to the limit to obtain nominal intensity beam for the LHC. Beam losses grow with intensity and are always asymmetric in energy (lost particles are seen main in front of the batch). The asymmetry can be explained by the energy loss of particles due to the SPS impedance which is also responsible for a non-zero synchronous phase on the flat bottom leading to large gaps between buckets. In this paper the measurements of the dependence of particles loss on the beam and machine parameters are presented and discussed together with possible loss mechanisms.  
 
WEPLT036 Energy Loss of a Single Bunch in the CERN SPS radiation, focusing, resonance, booster 1906
 
  • E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar, J. Tuckmantel
    CERN, Geneva
  • A. Hofmann
    Honorary CERN Staff Member, Grand-Saconnex
  The dependence of energy loss on bunch length was determined experimentally for a single proton bunch in the SPS at 26 GeV/c. This was done from measurements of the synchronous phase as a function of intensity for different capture voltages. The results are compared with the expected dependence calculated from the resistive part of the SPS impedance below 1 GHz. Two impedance sources, the cavities of the 200 MHz RF system and the extraction kickers, give the main contributions to particle energy loss in very good agreement with experiment. The results obtained allow a better understanding of some mechanisms leading to capture loss of the high intensity LHC beam in the SPS.  
 
WEPLT037 A J2EE Solution for Technical Infrastructure Monitoring at CERN radiation, focusing, resonance, booster 1909
 
  • J. Stowisek, R.M. Martini, P. Sollander
    CERN, Geneva
  The Technical Infrastructure Monitoring project (TIM) will design and implement the future control system for CERN's technical infrastructure. The control system will be built using standard components including industrial PLCs, Java Enterprise Edition (J2EE) including Enterprise Java Beans and the Java Message Service and relational databases. This paper describes how these standard technologies are used to build a flexible, scalable, robust and reliable control system.  
 
WEPLT038 Betatron Resonance Studies at the CERN PS Booster by Harmonic Analysis of Turn-by-turn Beam Position Data radiation, resonance, focusing, bunching 1912
 
  • P. Urschütz, M. Benedikt, C. Carli, M. Chanel, F. Schmidt
    CERN, Geneva
  High brightness and high intensity beams are required from the PS Booster for LHC, CNGS and ISOLDE operation. The large space charge tune spreads associated with these beams, especially at injection, require an optimized resonance compensation scheme to avoid beam blow-up and subsequent beam losses. For this a detailed knowledge on strength and phase of resonance driving terms is needed. A new measurement system has been installed to determine resonance driving terms from turn-by-turn bpm data using fast Fourier transform. The multi-turn acquisition system as well as the specific measurement conditions at the PS Booster are discussed. As an example, the measurement and compensation of the linear coupling resonance driving term is presented. Excellent agreement between measurement and simulation for resonance phase and strength was found.  
 
WEPLT039 Measurement and Compensation of Second and Third Order Resonances at the CERN PS Booster radiation, focusing, resonance, bunching 1915
 
  • P. Urschütz
    CERN, Geneva
  Space charge effects at injection are the most limiting factor for the production of high brightness beams in the CERN PS Booster. The beams for LHC, CNGS and ISOLDE feature incoherent tune spreads exceeding 0.5 at injection energy and thus cover a large area in the tune diagram. Consequently these beams experience the effects of transverse betatron resonances and efficient compensation is required. Several measurements have been performed at the PS Booster in 2003, aiming at a detailed analysis of all relevant second and third order resonances and an optimisation of the compensation scheme. Special attention was paid to the systematic 3Qy=16 resonance. To avoid this particularly dangerous resonance an alternative working point was tested. A comparison of resonance driving terms and compensation settings for both working points was made and important differences in the strengths of the resonances were found. The peculiarities when measuring third order coupling resonance driving terms are also mentioned.  
 
WEPLT040 Layout Drawings of the LHC Collider radiation, focusing, resonance, bunching 1918
 
  • A. Vergara-Fernández, S. Chemli, B. Maire, Y. Muttoni
    CERN, Geneva
  • A. Kournossenko, R. Zalyalov
    IHEP Protvino, Protvino, Moscow Region
  The team in charge of the LHC integration largely uses 3D scenes combining functional positions of equipments and the 3D CAD model issued from the Cern Drawing Directory (CDD) repository. This is made possible through the Digital Mock-Up tool developed at CERN. Giving dimensions in 3D context is a challenge with the current 3D CAD tools used at CERN. Requirements from users groups have made clear a need for automatic production of 2D layout drawings. This paper presents the retained solution to create on-request dimensioned drawings, to publish them, while maintaining coherence and consistency with the 3D integration scenes. Reliability of the information, on-line availability of the latest layout changes on dimensions and positions of equipments, and the maintenance of the facility will also be described.