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dipole

       
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MOYBPA01 LHC Progress and Commissioning Plans LHC, injection, quadrupole, luminosity 14
 
  • O.S. Brüning
    CERN, Geneva
  The LHC at CERN is in its final installation phase, and the first tests with beam are planned for part of the machine for the end of 2006. The commissioning of the full machine with beam is planned for summer 2007. The talk summarizes the current status of the LHC installation and the strategy for obtaining an optimum hardware configuration. In a second part the talk outlines the main milestones for the hardware and beam commissioning and presents estimates for the expected performance levels for the commissioning phase with beam.  
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MOPCH064 The Specification, Design and Measurement of Magnets for the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory quadrupole, ERLP, linac, FEL 175
 
  • F. Bødker
    Danfysik A/S, Jyllinge
  • N. Marks, N. Thompson
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The Energy Recovery Linac Prototype (ERLP) is currently under construction at Daresbury Laboratory in the UK and will serve as a test bed for the investigation of technologies and beam physics issues necessary for the development of Daresbury Laboratory's Fourth Generation Light Source (4GLS) proposal. A number of new ERLP beam transport system magnets have been procured for the project. The magnets have been designed, manufactured and measured by Danfysik following a stringent magnetic field specification produced by Daresbury Laboratory. In this paper we summarise the magnet specification. We then present details of the magnetic and mechanical design of the magnets and finally discuss the measurement techniques used to demonstrate that the field quality of the magnets satisfied the specification.  
 
MOPCH071 Optimization of Optics at 200 MeV KEK-ERL Test Facility for Suppression of Emittance Growth Induced by CSR CSR, emittance, insertion, insertion-device 190
 
  • M. Shimada, A. Enomoto, T. Suwada, K. Yokoya
    KEK, Ibaraki
  Energy Recovery Linac (ERL) gets a lot of attention as a next period light source instrument. To produce high-brightness and short pulse synchrotoron lights, it is necessary to pass through high current and short bunch electron beams to the insertion part of ERL with keeping the low emittance and the low energy spread. However, it is challenging because Coherent Synchrotorn Radiation (CSR) generated at bending magnets is potential sources of the emittance growth which is enomous especially for high current, short bunch and a low energy beam. Therefore, it is benefit to a gradual bunch compression in the arc after accelerating the beam up to the full energy. The beam optics and lattice design of 200MeV ERL Test Facility is optimized to suppress the emittance growth caused by CSR at the arc section on two conditions, high-current mode (100mA, 1psec) and short bunch mode (0.1psec) similar to 5GeV ERL facility proposed by Cornell University.  
 
MOPCH073 A Project of a High-power FEL Driven by an SC ERL at KAERI FEL, sextupole, ERL, emittance 196
 
  • A.V. Bondarenko, S.V. Miginsky
    BINP SB RAS, Novosibirsk
  • Y.H. Han, Y.U. Jeong, B.C. Lee, S. H. Park
    KAERI, Daejon
  A project of a high-power FEL at Korea Atomic Energy Research Institute is described. The FEL is driven by a superconducting energy recovery linac. The future ERL will be connected to the existing machine without any modification. It consists of two 180-degree bents and two straight sections: one is for the FEL, another for a Compton X-rays source. One can choose the regime controlling the lenses. The total ERL is isochronous to avoid any problems with longitudinal beam instability. The total relative emittance degradation through the whole machine is ? 1.5. The FEL will be based on a 2 m helical in-vacuum undulator made of permanent magnets. One mirror of the optical cavity is blind and made of copper; the other one, the outcoupler, is semi-transparent and made of CVD diamond. The expected average power is a few kW and the tuning range 35…70 ?m.  
 
MOPCH089 Basic Aspects of the SIS100 Correction System Design quadrupole, resonance, lattice, sextupole 240
 
  • V.A. Mikhaylov, A.V. Alfeev, A.V. Butenko, A.V. Eliseev, H.G. Khodzhibagiyan, A.D. Kovalenko, O.S. Kozlov, V.V. Seleznev, A.Y. Starikov, V. Volkov
    JINR, Dubna, Moscow Region
  • E. Fischer, P.J. Spiller, J. Stadlmann
    GSI, Darmstadt
  The basic concept and the main design features of the superconducting SIS100 correction system are presented. The system comprises 84 steerer magnets consisting of two orthogonal dipole windings each for correction of the beam close orbit in vertical and horizontal planes, 48 normal sextupole windings connected in two families with opposite polarities for chromaticity correction and 12 units containing skew quadrupoles, normal and skew sextupoles and octupoles as well. The correction system should operate in a pulse mode corresponding to the accelerator cycle, i.e., up to 1 Hz. The main magnetic, geometrical and electrical parameters of the corrector magnets were specified. They are based on the beam dynamic analysis within the frames of the DF-type SIS100 lattice at different betatron tune numbers and tolerable alignment and manufacturing errors of the main lattice dipole and quadrupole magnets. The problem of reasonable unification of the corrector modules is discussed also, including their geometrical sizes, maximum supply current and cooling at 4.5 K. The concept of the SIS100 corrector magnets is based on the pulsed correctors designed for the Nuclotron.  
 
MOPCH102 A Straight Section Design in RHIC to Allow Heavy Ion Electron Cooling electron, interaction-region, RHIC, quadrupole 279
 
  • D. Trbojevic, J. Kewisch, W.W. MacKay, T. Roser, S. Tepikian
    BNL, Upton, Long Island, New York
  The Relativistic Heavy Ion Collider (RHIC) has been continuously producing exciting results. One of the major luminosity limitations of the present collider is the intra beam scattering. A path towards the higher luminosities requires cooling of the heavy ion beams. Two projects in parallel electron and stochastic cooling are progressing very well. To allow interaction between electrons and the RHIC beams it is necessary to redesign one of the existing interaction regions in RHIC to allow for the longer straight section with fixed and large values of the betatron functions. We present a new design of the interaction region for the electron cooling in RHIC.  
 
MOPCH105 A New RF Tuning Method for the End Regions of the IPHI 4-vane RFQ rfq, simulation, quadrupole, proton 285
 
  • O. Delferriere, M. Desmons, A. France
    CEA, Gif-sur-Yvette
  • R. Ferdinand
    GANIL, Caen
  The 3-MeV High Intensity Proton Injector (IPHI) RFQ is constituted by the assembly of three 2-m-long segments. The tuning of the end regions of such an accelerator with respect to the quadrupole mode is generally made by machining the thickness of the end plates. The dipole modes are moved away from the accelerator mode frequency by adding dipole rods and adjusting their length. In the case of the last IPHI RFQ segment, the tuning range given by possible plate thickness was not sufficient to adjust the frequency at 352 Mhz without modifying the notch depth, leading to serious engineering problems for the cooling, new thermo-mechanical simulations and drawings. To avoid these difficulties, a new way has been investigated by replacing the end plate thickness adjustment by a "quadrupole rod" length adjustment. These rods are situated between the beam axis and the dipole rods, and the tuning range is largely increased. The paper will describe this method applied to the IPHI RFQ and some experimental results obtained on the cold model.  
 
MOPCH107 Tuning Procedure of the 6 Meter IPHI RFQ rfq, coupling, LEFT, quadrupole 291
 
  • O. Piquet, M. Desmons, A. France
    CEA, Gif-sur-Yvette
  In the framework of the IPHI project (High Intensity Proton Injector), the RFQ cavity is divided into 6 sections of 1 meter each, and assembled in 3 segments separated by coupling plates. We will present the tuning procedure of the aluminium RFQ cold model to set the accelerating mode frequency, a flat voltage profile and to minimize the dipole components of the accelerating voltage. This tuning procedure can be divided in three steps. First, dipole mode frequencies are adjusted with rods for the 3 separated segments. Second, RFQ end cells and coupling cells are tuned by mechanical machining of tuning plates. Third, using a fully automated bead-pull for the measurement of the field distribution inside every RFQ quadrants, the RFQ is tuned with 96 plungers in a small number of iterations. Tuning this 6-meter long cold model is a comprehensive training in view of the future tuning of the copper RFQ with the variable voltage profile.  
 
MOPCH116 Electromagnetic Design of a Radio Frequency Quadrupole for the Front End Test Stand at RAL simulation, rfq, quadrupole, ion 315
 
  • A. Kurup
    Imperial College of Science and Technology, Department of Physics, London
  • A.P. Letchford
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The goal of the RAL front end test stand is to demonstrate cleanly chopped bunches of a 60mA H- ion beam at 3MeV. The acceleration of the H- ions from 65keV to 3MeV will be done using a radio frequency quadrupole (RFQ) operating at a resonant frequency of 324MHz. The two types of RFQ considered were a 4-vane and a 4-rod. The 4-vane has a higher Q-value but the post-production adjustment is limited. The 4-rod design is easier to manufacture but requires complicated cooling at 324MHz. The results of electromagnetic simulations using CST Microwave Studio are presented for the 4-vane type and 4-rod type RFQ.  
 
MOPCH137 An Anti-symmetric Lattice for High Intensity Rapid-cycling Synchrotrons injection, lattice, collimation, synchrotron 369
 
  • J. Wei, Y.Y. Lee, S. Tepikian
    BNL, Upton, Long Island, New York
  • S.X. Fang, Q. Qin, J. Tang, S. Wang
    IHEP Beijing, Beijing
  • S. Machida, C.R. Prior, G. Rees
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Rapid cycling synchrotrons are used in many high power facilities like spallation neutron sources and proton drivers. In such accelerators, beam collimation plays a crucial role in reducing the uncontrolled beam loss. Furthermore, the injection and extraction section needs to reside in dispersion-free region to avoid couplings; a significant amount of drift space is needed to house the RF accelerating cavities; orbit, tune, and chromatic corrections are needed; long, uninterrupted straights are desired to ease injection tuning and to raise collimation efficiency. Finally, the machine circumference needs to be small to reduce construction costs. In this paper, we present a lattice designed to satisfy these needs. The lattice contains a drift created by a missing dipole near the peak dispersion to facilitate longitudinal collimation. The compact FODO arc allows easy orbit, tune, coupling, and chromatic correction. The doublet straight provides long uninterrupted straights. The four-fold lattice symmetry separates injection, extraction, and collimation to different straights. This lattice is chosen for the Beijing Spallation Neutron Source synchrotron.  
 
MOPCH159 Coupler Design Considerations for the ILC Crab Cavity coupling, luminosity, higher-order-mode, damping 430
 
  • P. Goudket, C.D. Beard
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Burt
    Microwave Research Group, Lancaster University, Lancaster
  Transverse deflecting cavities, such as the ILC crab cavity, commonly operate in the TM110 dipole mode. This means that in addition to the higher order modes (HOMs), that need to be controlled for every cavity, the fundamental TM010 mode and the other polarisation of the dipole mode also need to be damped. As the resonant frequency of the fundamental mode is much lower than the cut-off frequency of the beampipe, this mode becomes trapped in the cavity and difficult to extract using conventional HOM couplers, hence a dedicated coupler is likely to be required. The ILC crab cavities will require excellent damping of all undesirable modes in order to maintain maximum luminosity at the IP.  
 
MOPCH160 A Beam-based High Resolution Phase Imbalance Measurement Method for the ILC Crab Cavities positron, linear-collider, single-bunch, electron 433
 
  • A. Kalinin, L. Ma, R.J. Smith
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A high resolution method of RF phase adjustment and test is proposed for the Crab Cavity system of the ILC. The method is based on beam as ultimate test instrument. To measure phase imbalance in the pair of crab cavities (<0.02deg at 1.3GHz is required), a low energy (~1GeV) beam is used. A bunch center-of-mass trajectory through the cavities spaced (n+1/2) RF wavelengths and excited as in the case of the ILC, is a straight line for phase-balanced cavities and gets a kick when unbalanced. The kick is measured by two spaced BPMs with reference to the initial trajectory angle measured by two other BPMs. The method is insensitive to a bunch arrival time jitter and RF phase Common Mode jitter. A prototype of the test bench based on the method, is proposed. Using a 10MeV beam, two simple dipole cavities and low RF power, the prototype can be utilized for mastering high resolution measurements, for adjustment and tests of low level electronics of the Crab Cavity system and RF systems of XFEL ERLs as well. The phase resolution of the prototype is estimated as 0.01deg and the amplitude resolution as 0.01%.  
 
MOPCH163 Analysis of Wakefields in the ILC Crab Cavity luminosity, quadrupole, TESLA, simulation 442
 
  • G. Burt, A.C. Dexter
    Microwave Research Group, Lancaster University, Lancaster
  • C.D. Beard, P. Goudket
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • L. Bellantoni
    Fermilab, Batavia, Illinois
  • R.M. Jones
    UMAN, Manchester
  The large crossing angle schemes of the ILC need a correction of bunch orientation at the IP in order to recover a luminosity loss of up to 80%. The orientation of bunches can be changed using a transverse deflecting cavity. The location of the crab cavity would be close to the final focus, and small deflections caused by wakefields in the cavities could cause misalignments of the bunches at the IP. Wakefields in the FNAL CKM cavities have been analysed and their effects studied in view of use as the ILC crab cavity. Numerical simulations have been performed to analyse the transverse wakepotentials of up to quadrupole order modes in this cavity and the effect upon bunches passing through this cavity. Trapped modes within the CKM cavity have been investigated. Perturbation tests of normal conducting models of this cavity have been launched to verify these results. The effect of the final focus quadrupole magnets on the deflection given to the bunch have also been calculated and used to calculate luminosity loss due to wakefields.  
 
MOPLS015 Quality Control Techniques Applied to the Large Scale Production of Superconducting Dipole Magnets for LHC LHC, CERN, controls, target 568
 
  • F. Savary, M. Bajko, J. Beauquis, G. De Rijk, N. Emelianenko, P. Fessia, P. Hagen, J. Miles, L. Rossi, E. Todesco, J. Vlogaert, C. Vollinger, E.Y. Wildner
    CERN, Geneva
  The LHC accelerator, under construction at CERN, is characterized by the use on a large scale of high field superconducting dipoles: the 27-km ring requires 1232 15-m long dipole magnets designed for a peak field of 9 T. The coils are wound with Rutherford-type cable based on copper-stabilized Nb-Ti superconductors and will be operated at 1.9 K in pressurized superfluid helium. The challenge that had to be faced has been an efficient, cost-effective and reproducible mass production to very tight tolerances: the field quality must be better than 10-4 and the geometry of the cold bore tube and magnet controlled to 0.1 mm over the whole length, any deviation being liable to induce delays and significant cost increase. This paper presents the main methods and tools chosen to face successfully this challenge: some methods were foreseen in the technical specification, others were implemented based on the experience gained in several years of fabrication.  
 
MOPLS016 LHC IR Upgrade: A Dipole First Option with Local Chromaticity Correction LHC, sextupole, luminosity, dynamic-aperture 571
 
  • R. de Maria, O.S. Brüning
    CERN, Geneva
  • P. Raimondi
    INFN/LNF, Frascati (Roma)
  In the framework of the LHC Luminosity Upgrade, we develop a new layout of the interaction region (IR) with betastar equal to 25cm in which the combination-separation dipoles come first with respect to the triplet assembly (dipole first) in opposition of the nominal layout (quadrupole first). The new layout presents several advantages (separate channel for multipole errors, straightforward crossing angle scheme, early separation of the beam). The payoff is a large beta function in the triplet, which enhances the chromaticity and other non-linear effects. We investigate options for local chromaticity correction and their effects on long-term stability.  
 
MOPLS023 Status of Fast IR Orbit Feedback at RHIC RHIC, feedback, power-supply, injection 589
 
  • C. Montag, J. Cupolo, J. Glenn, V. Litvinenko, A. Marusic, W. Meng, R.J. Michnoff, T. Roser, C. Schultheiss, J.E. Tuozzolo
    BNL, Upton, Long Island, New York
  To compensate modulated beam-beam offsets caused by mechanical vibrations of IR triplet quadrupoles at frequencies around 10 Hz, a fast IR orbit feedback system has been developed. We report design considerations and recent status of the system.  
 
MOPLS040 Magnet Structure of the VEPP-2000 Electron-positron Collider sextupole, quadrupole, collider, focusing 628
 
  • P.Yu. Shatunov, D.E. Berkaev, A.A. Borisov, I. Koop, N.A. Mezentsev, E. Perevedentsev, Y.M. Shatunov, D.B. Shwartz
    BINP SB RAS, Novosibirsk
  • A. Valishev
    Fermilab, Batavia, Illinois
  Electron-positron collider VEPP-2000 with beam energy up to 1 GeV is under commissioning at Budker Institute. This paper presents magnetic elements of the storage ring including 13T focusing superconducting solenoids in interaction regions. Features of magnet elements design and magnetic measurements results are given together with comparison to previously calculated data.  
 
MOPLS060 Design of an Interaction Region with Head-on Collisions for the ILC extraction, optics, quadrupole, luminosity 682
 
  • J. Payet, O. Napoly, C. Rippon, D. Uriot
    CEA, Gif-sur-Yvette
  • M. Alabau Pons, P. Bambade, J. Brossard, O. Dadoun, C. Rimbault
    LAL, Orsay
  • D.A.-K. Angal-Kalinin, F. Jackson
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Appleby
    UMAN, Manchester
  • L. Keller, Y. Nosochkov, A. Seryi
    SLAC, Menlo Park, California
  An interaction region with head-on collisions is considered an alternative to the baseline configuration of the International Linear Collider, including two interaction regions with finite crossing-angles (2 and 20 mrad). Although more challenging from the point of view of the beam extraction, the head-on scheme is favoured by the experiments because it allows a more convenient detector configuration, particularly in the forward region. The optics of the head-on extraction is revisited by separating the e+ and e- beams horizontally, first by electrostatic separators operated at their LEP nominal field and then using a defocusing quadrupole of the final focus beam line. In this way the septum magnet is protected from the beamstrahlung power. Newly optimized final focus and extraction optics are presented, including a first look at post-collision diagnostics. The influence of parasitic collisions is shown to lead to a region of stable collision parameters. Beam and beamstrahlung photon losses are calculated along the extraction elements. Issues concerning the design of the large bore superconducting final focus magnets, common to both incoming and outgoing beams, are considered.  
 
MOPLS083 Higher Order Mode Study of Superconducting Cavity for ILC Baseline KEK, polarization, pick-up, coupling 747
 
  • K. Watanabe
    GUAS/AS, Ibaraki
  • H. Hayano, E. Kako, S. Noguchi, T. Shishido
    KEK, Ibaraki
  The superconducting cavity of ILC baseline shape is being developed at KEK-STF (Superconducting RF Test Facility). The Higher Order Mode (HOM) of the cavity is one study item for the development. The purpose of the HOM study is further optimization of TTF HOM coupler and measurement of the HOM field distribution and the polarization of the main dipole modes. The result will be applied to HOM readings of beam induced signal for the purpose of cavity offset position and angle of axis measurement relative to the beam. We tried to improve of TESLA-type HOM coupler for more small size and relaxation of second stop-band. The cold-model coupler was made, and the RF characteristic was measured. After HOM couplers welded to the KEK Baseline nine-cell SC cavity, Qext of fundamental mode and each HOM, field pattern of each HOM and polarization of dipole modes were measured by the network analyzer. The results of the improved HOM coupler are presented.  
 
MOPLS091 First Design of a Post Collision Line for CLIC at 3 TeV CLIC, photon, extraction, beam-losses 765
 
  • V.G. Ziemann, T. J. C. Ekelof, A. Ferrari
    UU/ISV, Uppsala
  • P. Eliasson
    CERN, Geneva
  As part of the Post collision diagnostic task of the ILPS work-package of EuroTeV we discuss a design of the beam line between the interaction point and the beam dump for CLIC with a center-of-mass energy of 3 TeV. The design is driven by the requirement to transport the beam and all secondaries such as beamstrahlung and coherent pairs to the beam dump with minimal losses. Moreover, we discuss the integration of novel diagnostic methods into the post collision beam line based on the detection of coherent pairs and monitoring the beam profile of the primary beam.  
 
MOPLS115 A Spin Rotator for the ILC emittance, linac, polarization, coupling 831
 
  • P.O. Schmid, N.J. Walker
    DESY, Hamburg
  A spin rotator featuring an optic axis with straight vision is presented. This rotator utilizes three bends, two solenoid pairs and two correction devices. These correctors, named reflectors, are mandatory for removing the cross plane coupling introduced by the solenoids. It is shown how the solenoids have to be set up to achieve longitudinal IP polarization taking into account non-zero crossing angles at the interaction region and a linac following the curvature of the earth. Furthermore, the stability requirements for mechanical and electrical imperfections are analyzed.  
 
MOPLS116 Status Report on the Harmonic Double-sided Microtron of MAMI C linac, MAMI, vacuum, klystron 834
 
  • A. Jankowiak, K. Aulenbacher, O. Chubarov, M. Dehn, H. Euteneuer, F.F. Fichtner, F. Hagenbuck, R.H. Herr, P. Jennewein, K.-H. Kaiser, W.K. Klag, H.J. Kreidel, U.L. Ludwig-Mertin, J.R. Röthgen, S.S. Schumann, G.S. Stephan, V. Tioukine
    IKP, Mainz
  The Mainz Mikrotron MAMI is a cascade of three racetrack microtrons, delivering since 1991 a high quality 855MeV, 100muA cw electron beam for nuclear and radiation physics experiments. An energy upgrade of this machine to 1.5GeV by adding a Harmonic Double-Sided Microtron (HDSM)* as a fourth stage is well under way. Here we give a review of the experiences gained during fabrication and testing of the main components of the HDSM and report the status of its construction. Initial operation of the machine is expected for the first half of 2006. After a period of commissioning in diagnostic pulse mode with low beam power (10ns, high intensity bunch trains with a repetition rate of max. 10kHz), soon the first nuclear physics experiments will be started.

*A. Jankowiak et al. "Design and Status of the 1.5 GeV-Harmonic Double Sided Microtron for MAMI", Proceedings EPAC2002, Paris, p. 1085.

 
 
MOPLS135 Correction of Vertical Dispersion and Betatron Coupling for the CLIC Damping Ring quadrupole, emittance, sextupole, coupling 873
 
  • M. Korostelev, F. Zimmermann
    CERN, Geneva
  The sensitivity of the CLIC damping ring to various kinds of alignment errors have been studied. Without any correction, fairly small vertical misalignments of the quadrupoles and, in particular, the sextupoles, introduce unacceptable distortions of the closed orbit as well as intolerable spurious vertical dispersion and coupling due to the strong focusing optics of the damping ring. A sophisticated beam-based correction scheme has been developed to bring the design target emittances and the dynamic aperture back to the ideal value. The correction using dipolar correctors and several skew quadrupole correctors allows a minimization of the closed-orbit distortion, the cross-talk between vertical and horizontal closed orbits, the residual vertical dispersion and the betatron coupling.  
 
MOPLS140 Tuning Algorithms for the ILC Damping Rings emittance, damping, quadrupole, coupling 888
 
  • J.K. Jones
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  Emittance preservation is an important aspect in the design and running of the International Linear Collider with a direct consequence on the luminosity of the machine. One major area of concern is in the damping rings, where the extracted emittances set the effective lower limits for the rest of the machine. Algorithms for tuning this system have been investigated, and simulations have been performed to understand the design and implementation issues. The different algorithms have been applied to the various damping ring designs, and the effectiveness of each algorithm has been assessed. A preliminary recommendation of tuning algorithm, and its effectiveness under various conditions, is given.  
 
MOPLS143 Suppression of Secondary Emission in a Magnetic Field using Sawtooth Surface electron, damping, impedance, quadrupole 897
 
  • L. Wang, T.O. Raubenheimer, G.V. Stupakov
    SLAC, Menlo Park, California
  The effect of surface roughness on the secondary electron emission from a sawtooth surface in a magnetic field under electron bombardment is investigated using a Monte-Carlo method. Some of the secondary electrons emitted from the sawtooth surface return to the surface within their first few gyrations, resulting in low effective secondary electron yield. A sawtooth surface in magnetic field can significantly reduce the secondary emission yield below the multipacting threshold.  
 
TUXPA03 LHC Luminosity and Energy Upgrades luminosity, LHC, SPS, injection 910
 
  • W. Scandale
    CERN, Geneva
  LHC upgrade studies are ongoing as part of the EU CARE-HHH network and in the US-LARP collaboration. The aim is a ten-fold increase of the LHC luminosity by about 2014 and a possible upgrade of the injector complex to inject at 1 TeV and, at a later stage, to raise the collider energy. This talk will provide an overview of the beam dynamics and technological challenges associated with the LHC upgrade, including magnet R&D plans, electron cloud and beam-beam limitations, preferred scenarios to maximize the integrated luminosity, and machine experiments on beam-beam compensation or crystal collimation.  
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TUYPA02 High Precision SC Cavity Alignment Diagnostics with HOM Measurements alignment, linac, diagnostics, feedback 920
 
  • J.C. Frisch, L. Hendrickson, J. May, D.J. McCormick, S. Molloy, M.C. Ross, T.J. Smith
    SLAC, Menlo Park, California
  • N. Baboi, O. Hensler, L.M. Petrosyan
    DESY, Hamburg
  • N.E. Eddy, S. Nagaitsev
    Fermilab, Batavia, Illinois
  • O. Napoly, R. Paparella, C. Simon
    CEA, Gif-sur-Yvette
  Experiments at the TTF at DESY have demonstrated that the Higher Order Modes induced in Superconducting Cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor, and the phase of the monopole modes to measure the beam phase relative to the accelerator RF. Beam orbit feedback which minimizes the dipole HOM power in a set of structures has been demonstrated. For most SC accelerators, the existing HOM couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional BPM.  
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TUYFI01 Gantry Design for Proton and Carbon Hadrontherapy Facilities proton, ion, GSI, photon 964
 
  • U. Weinrich
    GSI, Darmstadt
  Using an isocentric gantry improves the efficiency and the flexibility of cancer treatments with ion beams (hadrontherapy). After an overview of the constraints imposed to these heavy equipments the gantries constructed for both proton and carbon ion facilities will be described. Finally, the new studies undertaken to decrease the cost of such equipments will presented.  
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TUPCH004 Commissioning of the LNLS X-ray BPMs electron, diagnostics, feedback, synchrotron 998
 
  • S.R. Marques, P.F. Tavares
    LNLS, Campinas
  We present experimental results of the commissioning of staggered-pair blade X-Ray beam position monitor (XBPM) recently developed and installed at the diagnostic beamline of the UVX electron storage ring at the Brazilian Synchrotron Light Laboratory (LNLS). The results obtained with a prototype XBPM indicate that the short-term and long-term data are both in agreement with the data from a commercially acquired XBPM installed at the same beamline, as well as with the data of the electron storage ring RF BPMs. In this paper we present the commissioning results of the LNLS XBPM.  
 
TUPCH007 High Resolution BPM for the Linear Colliders pick-up, DESY, simulation, collider 1004
 
  • C. Simon, S. Chel, M. Luong, O. Napoly, J. Novo, D. Roudier
    CEA, Gif-sur-Yvette
  • N. Rouvière
    IPN, Orsay
  The beam-based alignment and feedback systems which are essential for the operation of the future colliders use some high resolution Beam Position Monitors (BPM). In the framework of CARE/SRF, the task of CEA/DSM/DAPNIA (Saclay) is the design, the fabrication and the beam test of a BPM in collaboration with DESY. This system is composed of a RF re-entrant cavity with a beam pipe radius of 78mm and an analog electronics having several signal processing steps to reject the monopole mode. Thanks to its high position resolution (better than 1μm) and its high time-resolution (around 10ns), it is a candidate for the X-FEL at DESY and the ILC. Indeed the chosen coupling allows the bunch to bunch measurement and the separation between the monopole and dipole modes. Moreover, this BPM is designed to be used in a clean environment, at the cryogenic and room temperatures.  
 
TUPCH019 Laser-based Beam Diagnostic for the Front End Test Stand (FETS) at RAL laser, electron, ion, emittance 1037
 
  • C. Gabor
    IAP, Frankfurt-am-Main
  • D.A. Lee
    Imperial College of Science and Technology, Department of Physics, London
  • A.P. Letchford
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  • J.K. Pozimski
    CCLRC/RAL, Chilton, Didcot, Oxon
  High power proton accelerators (HPPA) are required for several future projects like spallation sources or a neutrino factory. Compared with existing machines the beam power therefore has to be increased by a factor of 30. The Front end test stand at RAL is being built to demonstrate that a chopped Hminus beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality, as required for all proposed Proton drivers, can be built. For the test stand a comprehensive set of beam diagnostics is also required. Due to the high beam energy and power non destructive diagnostic methods are favorable. Hminus beams offer the possibility to use intense laser light to detach the additional electron and use the produced particles for beam diagnostics. The principle is appropriate to determine the transversal beam density distribution as well as the transversal and longitudinal beam emittance in front and behind the RFQ. A detailed layout of the beam diagnostics including a discussion of the predicted spatial and temporal resolution and the dynamic range of the proposed devices will be presented.  
 
TUPCH035 Fine Spatial Beam Loss Monitoring for the ISIS Proton Synchrotron beam-losses, monitoring, synchrotron, acceleration 1079
 
  • S.J. Payne, S.A. Whitehead
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  Beam loss detection at the ISIS synchrotron is achieved using a series of 3 and 4 metre long argon gas ionisation tubes placed around the inside track of the main ring and along the injector and extraction sections. Even with this level of diagnostics problems have occurred, for example, inside a main dipole within the accelerator ring where small concentrated areas of loss have resulted in severe damage to the RF shield. This type of loss cannot be easily resolved using the conventional argon gas system due to the length of the detectors and their distance from the vacuum vessel (around 2m). We report here the development of a compact beam loss monoitoring system which has been installed inside a dipole between the vacuum vessel and the main body of the dipole. The system comprises of six 150 sq. cm. (BC408) plastic scintillators connected to photo-multiplier tubes via fibre optic bundles. Measurements taken demonstrate that the new system can easily resolve complex beam loss patterns along the dipole while remaining robust to the high radiation environment. We also report here details of our PXI based data collection and display system.  
 
TUPCH105 Performance of a Nanometer Resolution BPM System extraction, alignment, SLAC, linear-collider 1256
 
  • S. Walston, C.C. Chung, P. Fitsos, J.G. Gronberg
    LLNL, Livermore, California
  • S.T. Boogert
    Royal Holloway, University of London, Surrey
  • J.C. Frisch, J. May, D.J. McCormick, M.C. Ross, S. Smith, T.J. Smith
    SLAC, Menlo Park, California
  • H. Hayano, Y. Honda, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  • Y.K. Kolomensky, T. Orimoto
    UCB, Berkeley, California
  • A. Lyapin, S. Malton, D.J. Miller
    UCL, London
  • R. Meller
    Cornell University, Department of Physics, Ithaca, New York
  • M. Slater, M.T. Thomson, D.R. Ward
    University of Cambridge, Cambridge
  • V.V. Vogel
    DESY, Hamburg
  • G.R. White
    OXFORDphysics, Oxford, Oxon
  International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved – ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. The three BPMs are rigidly mounted inside an alignment frame on variable-length struts which allow movement in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a calibration algorithm which is immune to beam jitter. To date, we have been able to demonstrate a resolution of approximately 20 nm over a dynamic range of ± 20 microns. We report on the progress of these ongoing tests.  
 
TUPCH123 Dipole Stabilizing Rods System for a Four-vane RFQ: Modeling and Measurement on the TRASCO RFQ Aluminum Model at LNL rfq, quadrupole, coupling, simulation 1301
 
  • F. Grespan, A. Palmieri, A. Pisent
    INFN/LNL, Legnaro, Padova
  The Dipole Stabilizing Rods (DSR's) are devices used in order to reduce a priori the effect of perturbation on the operating mode of a four-vane RFQ caused by neighboring dipole modes by increasing the frequency spacing between the TE210 mode and dipole modes, without, in principle, affecting the quadrupole TE210 mode. They have proven to be particularly useful in the case of coupled RFQ's whose overall length is significantly greater than the operating wavelength. In this article we present a circuit model of such DSR's, that, used in combination with a transmission line model of a four vane RFQ, has allowed us to predict the dimensioning of the DSR's in the case of the aluminum model of TRASCO RFQ. The DSR parameters and, in general, the accuracy of the model have been also confirmed by HFSS simulations and by RF measurements on the above-mentioned model.  
 
TUPCH135 Characteristics of the PEFP 3 MeV RFQ rfq, electron, quadrupole, coupling 1334
 
  • H.-J. Kwon, Y.-S. Cho, J.-H. Jang, H. S. Kim, K.T. Seol
    KAERI, Daejon
  A four-vane type 3 MeV, 350 MHz RFQ (Radiofrequency Quadrupole) has been developed as a front end part of PEFP (Proton Engineering Frontier Project) 100 MeV accelerator. After the completion of field tuning and high power conditioning at reduced duty, the initial operation of the RFQ with beam was carried out. During the initial test period, several parameters related with the RF and beam were measured to characterize the performance of the RFQ. Based on these measurements, several suggestions for further system improvement were proposed. In this paper, the initial test results are discussed and the suggestions for the system improvement are summarized.  
 
TUPCH174 Vacuum Issues and Challenges of SIS18 Upgrade at GSI ion, quadrupole, vacuum, GSI 1426
 
  • H. Kollmus, M.C. Bellachioma, M. Bender, A. Kraemer, J. Kurdal, H.R. Sprenger
    GSI, Darmstadt
  For the present experiment programm and for the planned FAIR facility the heavy ion synchroton SIS18 at GSI has to reach the space charge limit for highly and intermediate charged heavy ions. For the booster mode of SIS18 the number of 1x1012 ions per second in 4 Hz operation mode is specified. To achive this requirement a dynamic vacuum in the 10-12 mbar region has to be garanteed. The poster will present the status of recent R & D work concerning the SIS18 vacuum upgrade, with a focus on the new GSI NEG coating facility and on ion-induced desorption measurements using advanced ion beam analysis.  
 
TUPCH193 Low Level RF Control System Modules for J-PARC RCS controls, acceleration, synchrotron, simulation 1465
 
  • A. Schnase, M. Nomura, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Yoshii
    KEK, Ibaraki
  After completing the design phase, the VME modules for the Low Level RF Control (LLRF) of the Rapid Cycling Synchrotron of J-PARC are now in the production and debugging phase. First all modules are tested for basic functionality, for example dual harmonic signal generation. Then sets of modules are connected together to check higher-level functions and feedback. Finally, the LLRF modules are interfaced to high voltage components like amplifiers and cavities. We present the results of these tests, the test methods and test functions on several levels. This way we simulate beam operation working conditions and gain experience in controlling all parameters.  
 
TUPLS003 A Perfect Electrode to Suppress Secondary Electrons inside the Magnets electron, positron, KEKB, quadrupole 1489
 
  • L. Wang, M.T.F. Pivi
    SLAC, Menlo Park, California
  • H. Fukuma, S.-I. Kurokawa
    KEK, Ibaraki
  • G.X. Xia
    DESY, Hamburg
  Electron cloud due to multipacting in the positron ring of B-factories is one of the limitations on the machine performance. Electron cloud in the drift region can be suppressed by solenoid. However, solenoid doesn't work inside a magnet. Numerical studies show that there is strong multipacting in the dipole magnet of the B-factory positron ring. Electrons also can be trapped inside quadrupole and sextupole magnets. The electron cloud from the dipole magnet and wiggler in the positron damping ring of the ILC is a critical limitation on the choice of damping ring circumference, which directly results in a choice of two 6km rings as the baseline for the positron damping ring. Various electrodes have been studied using the program CLOUDLAND. Our studies show that a wire type of electrode with a few hundred voltages works perfectly to kill the secondary electrons inside various magnets.  
 
TUPLS005 Preliminary Study of Using "Pipetron"-type Magnets for a Pre-accelerator for the LHC Collider LHC, injection, lattice, SPS 1493
 
  • G. De Rijk, L. Rossi
    CERN, Geneva
  • H. Piekarz
    Fermilab, Batavia, Illinois
  One of the luminosity limitations of the LHC is the rather low injection energy (0.45 TeV) with respect to the collision energy (7 TeV). The magnetic multipoles in the main dipoles at low field and their dynamic behaviour are considered to limit the achievable bunch intensity and emittance. We report on a preliminary study to increase the injection energy to 1.5 TeV using a two beam pre-accelerator (LHCI) in the LHC tunnel. The LHCI is based on "Pipetron" magnets as originally proposed for the VLHC. The aim of the study is to assess the feasibility and to identify the critical processes or systems that need to be investigated and developed to render such a machine possible.  
 
TUPLS006 Optics of a 1.5 TeV Injector for the LHC LHC, optics, injection, quadrupole 1496
 
  • J.A. Johnstone
    Fermilab, Batavia, Illinois
  A concept is being developed to install a second ring above the LHC to accelerate protons from 450 GeV to 1.5 TeV prior to injection into the LHC. The arc and dispersion suppressor optics of the LHC would be replicated in the injector using combined function 'transmission line' magnets orginally proposed for the VLHC. To avoid costly civil construction, in the straight sections housing detectors at least, the injector and LHC must share beampipes and some magnets through the detector portion of the straights. Creating the appropriate optics for these injector-LHC transition regions is very challenging: In addition to matching to the nominal LHC lattice functions at these locations, the changes in altitude of 1.1 m between the injector and LHC must be accomplished achromatically to avoid emittance blowup when the beams are transferred to the LHC.  
 
TUPLS008 A new HOM Water Cooled Absorber for the PEP-II B-factory Low Energy Ring quadrupole, scattering, coupling, impedance 1499
 
  • M. Kosovsky, N. Kurita, A. Novokhatski, J. Seeman, S.P. Weathersby
    SLAC, Menlo Park, California
  At high currents and small bunch lengths beam line components in the PEP-II B-factory experience RF induced heating from higher order RF modes (HOMs) produced by scattered intense beam fields. A design for a passive HOM water cooled absorber for the PEP-II low energy ring is presented. This device is to be situated near HOM producing beamline components such as collimators and provide HOM damping for dipole and quadrupole modes while minimizing impedance to the beam. We present a method of optimizing the impedance characteristics of such devices through the evaluation of loss factors and absorber effectiveness for specific modes using scattering parameter and wakefield analysis.  
 
TUPLS061 Design of a Low Energy Electron Cooler for the Heidelberg CSR electron, ion, CSR, target 1630
 
  • H. Fadil, M. Grieser, D. Orlov, A. Wolf
    MPI-K, Heidelberg
  The electrostatic Cryogenic Storage Ring (CSR) is currently being designed at MPI-K in Heidelberg. This ring will utilize electrostatic deflectors and focusing elements, and will store ions with kinetic energies in the range 20~300 keV (E/Q) to be mainly utilized in atomic and molecular physics experiments. The CSR will be equipped with a compact magnetic electron cooler, which will serve the double purpose of phase space compression of the stored ion beam as well as an electron target for recombination experiments. The cryogenic photocathode source, developed for the Heidelberg TSR, will be used to provide extremely cold magnetically guided electron beams. The maximum cooling electron energy is 165 eV and the usual operation energy for 20 keV protons will be about 10 eV. The cooler will fit in the 2.8 m straight section of the ring. The device will be installed inside the outer vacuum chamber of the CSR, and the magnetic confinement of the electrons will be provided with high temperature superconducting coils. The design of the magnets of the CSR electron cooler will be presented in this paper.  
 
TUPLS081 Flat Beams and Application to the Mass Separation of Radioactive Beams emittance, ion, quadrupole, heavy-ion 1687
 
  • P. Bertrand
    GANIL, Caen
  • J.-L. Biarrotte
    IPN, Orsay
  • D. Uriot
    CEA, Gif-sur-Yvette
  The notion of flat beam is now well established and has been proven theoretically and experimentally with applications for linear colliders. In this paper, we propose a new and simple demonstration of the "flat beam theorem", and a possible application in the frame of radioactive ion beams (RIB) production. It consists in using a magnetized multi-specie heavy ion beam extracted from a high frequency ECR source, decoupling the transverse phase planes in such a way to obtain a very small emittance in the horizontal one, and using a dipole to separate the isotopes. A design of such a transport and separation line will be proposed and commented.  
 
TUPLS107 Operation of the Opposite-Field Septum Magnet for the J-PARC Main-Ring Injection septum, injection, vacuum, power-supply 1750
 
  • I. Sakai, Y. Arakaki, K. Fan, Y. Saito, M. Tomizawa, M. Uota
    KEK, Ibaraki
  • A.K. Kawasaki, H. Mori, A. Tokuchi
    NICHICON, Shiga
  • Y. Morigaki, A. Nishikawa
    IHI/Yokohama, Kanagawa
  The opposite field septum magnet system has been applied to the injection system of the J-PARC 50-GeV proton synchrotron. The features of the system are a force-free structure, easy pulse excitation and the possibility of a large-aperture, thin-septum structure. The septum magnet has the structure of an inside-vacuum to eliminate the thickness of the vacuum-chamber walls and electric-insulation layer to make the septum thickness as thin as possible. However the magnet cores and return coils are outside of the vacuum to reduce the out-gassing rate of the vacuum system. Finally, the larger beam aperture than the full acceptance of the ring and larger separation angle can be obtained at the septum magnet for low-loss injection. In this paper we will introduce the methods to eliminate the error fields caused by fabrication errors and eddy current with pulse excitation and stability of high current power supply of 50 kA.  
 
TUPLS125 Spin Transport from AGS to RHIC with Two Partial Snakes in AGS AGS, RHIC, injection, extraction 1795
 
  • W.W. MacKay, A.U. Luccio, N. Tsoupas
    BNL, Upton, Long Island, New York
  • J. Takano
    RIKEN, Saitama
  The stable spin direction in the RHIC rings is vertical. With one or two strong helical Siberian snakes in the AGS, the stable spin direction at extraction is not vertical. Interleaved vertical and horizontal bends in the transport line between AGS and the RHIC rings also tend to tip the spin away from the vertical. In order to preserve polarization in RHIC, we examine several options to improve the matching of the stable spin direction during beam transfer from the AGS to each of the RHIC rings. While the matching is not perfect, the most economical method appears to be a lowering of the injection energy by one unit of G*gamma to 45.5.  
 
WEXFI01 Instabilities and Space Charge Effects in High Intensity Ring Accelerators space-charge, damping, impedance, simulation 1882
 
  • O. Boine-Frankenheim, I. Hofmann, V. Kornilov
    GSI, Darmstadt
  This presentation will review beam dynamics in circular accelerators with high beam intensity and space charge effects. The main focus will be on recent theoretical and experimental results related to collective instabilities and resonance crossing with space charge. In the first part of the presentation, the effect of space charge on collective instability thresholds and impedance budgets will be discussed. In this context the effect of space charge induced mode coupling on the longitudinal microwave instability will be illustrated. The stability of longitudinal bunched beam modes and of transverse dipole modes in the presence of space charge will be discussed. Recent work related to the transverse mode coupling instability (TMCI) with space charge will be reviewed. In the second part of the presentation, "incoherent" space charge effects on transverse nonlinear dynamics issues, like nonlinear resonance crossing, will be reviewed.  
slides icon Transparencies
 
WEPCH007 Beam Dynamics Studies for the Spiral-2 Project ion, SPIRAL2, linac, proton 1930
 
  • J.-L. Biarrotte
    IPN, Orsay
  • P. Bertrand
    GANIL, Caen
  • D. Uriot
    CEA, Gif-sur-Yvette
  The SPIRAL-2 superconducting linac driver, which aims to deliver 5 mA, 20 A.MeV deuterons and 1 mA, 14.5 A.MeV q/A=1/3 heavy ions, is now entering the construction phase. It is composed of an injector composed of two ECR sources entering a 88 MHz RFQ, followed by a superconducting section based on independently phased quarter-wave cavities with warm focusing. This paper presents the status of the beam dynamics studies recently performed during this construction phase: consolidation and freezing of the linac design, update of the mass separation system or analysis of the proton capability.  
 
WEPCH009 Loss Management in the Beta-beam Decay Ring ion, collimation, injection, lattice 1936
 
  • A. Chancé, J. Payet
    CEA, Gif-sur-Yvette
  The aim of the beta-beams is to produce pure electronic neutrino and anti-neutrino highly energetic beams, coming from beta radioactive disintegration of the 18Ne10+ and 6He2+, both at gamma = 100, directed towards experimental halls situated in the Frijus tunnel. The high intensity ion beams are stored in a ring, until the ions decay. Consequently, all the injected particles will be lost anywhere around the ring generating a high level of losses. In order to keep a constant neutrino flux, the losses due to the decay of the radioactive ions are compensated with regular injections. The new ion beam is then merged with the stored beam with a specific RF program Two sources of losses have been considered: -The beta-decay products: their magnetic rigidity being different from the reference one, they are bent differently and lost. -The losses during the injection merging process. The first one needs a particular ring design in order to insert appropriate beam stoppers at the right place. The second one needs a specific collimation system which allows beam longitudinal halo cleaning between two successive injections.  
 
WEPCH033 Single Particle Beam Dynamics Design of CSNS/RCS lattice, collimation, injection, extraction 1996
 
  • S. Wang, S.X. Fang, Q. Qin, J. Tang
    IHEP Beijing, Beijing
  • J. Wei
    BNL, Upton, Long Island, New York
  Rapid Cycling Synchrotron (RCS) is a key component of Beijing Spallation Neutron Source (BSNS). It accumulates and accelerates protons to design energy of 1.6 GeV and extracts high energy beam to the target. As a high beam density and high beam power machine, low beam loss is also a basic requirement. An optimal lattice design is essential for the cost and the future operation. The lattice design of BSNS is presented, and the related dynamics issues are discussed. The injection/extraction scheme and the beam collimation system design are introduced.  
 
WEPCH046 Design and Validation with Measurements of the LEIR Injection Line optics, ion, quadrupole, linac 2020
 
  • F. Roncarolo, C. Carli, M. Chanel, L.D. Dumas, R. Scrivens
    CERN, Geneva
  The CERN Low Energy Ion Ring (LEIR) commissioning started in the year 2005. O4+ and Pb54+ 4.2 MeV/nucleon ion beams are transferred from Linac 3 to LEIR through a low energy transfer line, for which the constraints and the resulting optics design are presented. First trajectory and dispersion measurements agreed only poorly with the theoretical model. Iterations of a refined optics model and further measurements improved the agreement between experimental observations and expectations. In particular, the effect of quadrupolar errors in the line dipole magnets is discussed.  
 
WEPCH049 Closed Orbit Correction of TPS Storage Ring closed-orbit, quadrupole, synchrotron, emittance 2029
 
  • H.-J. Tsai, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, M.-H. Wang
    NSRRC, Hsinchu
  A 3 GeV synchrotron storage ring is proposed in Taiwan to serve the synchrotron light users, especially for the x-ray community. The ring consists of 24 double-bend cells with 6-fold symmetry and the circumference is 518.4 m. The designed natural emittance with slightly positive dispersion in the straight sections is less than 2 nm-rad. This low emittance lattice structure needs strong quadrupoles and sextupoles and the closed orbit distortions are sensitive to the alignment errors in the quadrupoles and sextupoles as well. The closed orbit distortions due to tolerable magnetic errors are simulated and the correction scheme is proposed. Using singular value decomposition method, the closed orbit distortions are corrected and corrector strengths as well as the residual closed orbit distortions are obtained.  
 
WEPCH051 Isochronous Magneto-optical Structure of the Recirculator SALO injection, quadrupole, recirculation, site 2035
 
  • I.S. Guk, A. Dovbnya, S.G. Kononenko, F.A. Peev, A.S. Tarasenko
    NSC/KIPT, Kharkov
  • J.I.M. Botman, M.J. Van der Wiel
    TUE, Eindhoven
  With the goal to provide low energy spread of electron beam, the magneto-optical structure of the recirculator SALO has been modified. All of its parts (an injection tract and arcs) were made isochronous and achromatic. Besides, with the purpose of the accelerating structure arrangement, the length of straight sections was enlarged. The amplitude and dispersion functions on various recirculator sections and design characteristics of the beam are submitted.  
 
WEPCH063 Measurements and Modeling of Eddy Current Effects in BNL's AGS Booster vacuum, booster, quadrupole, AGS 2068
 
  • K.A. Brown, L. Ahrens, C.J. Gardner, J. Glenn, M. Harvey, W. Meng, K. Zeno
    BNL, Upton, Long Island, New York
  Recent beam experiments at BNL's AGS Booster have enabled us to study in more detail the effects of eddy currents on the lattice structure and our control over the basic lattice parameters of betatron tune and chromaticity. The Booster is capable of operating at ramp rates as high as 8 T/sec. At these ramp rates eddy currents in the vacuum chambers have significant effects on the fields and gradients seen by the beam as it is accelerated. The Booster was designed with these effects in mind and to help control the field uniformity and linearity in the Booster Dipoles special vacuum chambers were designed with current windings to negate the effect of the induced eddy currents. In this report results from measurements of these effects will be presented. Results from modeling and comparisons to the measurements will also be presented.  
 
WEPCH065 Lattices for High-power Proton Beam Acceleration and Secondary Beam Collection, Cooling, and Deceleration lattice, synchrotron, secondary-beams, proton 2074
 
  • S. Wang
    IHEP Beijing, Beijing
  • K.A. Brown, C.J. Gardner, Y.Y. Lee, D.I. Lowenstein, S. Peggs, N. Simos, J. Wei
    BNL, Upton, Long Island, New York
  Rapid-cycling synchrotrons are used to accelerate high-intensity proton beams to energies of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: a) flexible momentum compaction to avoid transition and to facilitate RF gymnastics b) long straight sections for low-loss injection, extraction, and high-efficiency collimation c) dispersion-free straights to avoid longitudinal-transverse coupling, and d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.  
 
WEPCH068 6-D Beam Dynamics Studies in EMMA FFAG LEFT, acceleration, electron, quadrupole 2080
 
  • F. Meot
    CEA, Gif-sur-Yvette
  Extensive simulations of 6-D transmission simulations in linear, non-scaling FFAGs, based on gutter rapid acceleration, are reported. They concern two different on-going projects: the 20~GeV muon accelerators in the Neutrino Factory (NuFact) with ISS parameters* and a 20~MeV electron model of these machines, EMMA**.

*http://www.hep.ph.ic.ac.uk/iss/**http://hepunx.rl.ac.uk/uknf/wp1/emodel/

 
 
WEPCH092 Dynamical Aperture Studies for the CERN LHC: Comparison between Statistical Assignment of Magnetic Field Errors and Actual Measured Field Errors LHC, quadrupole, simulation, optics 2128
 
  • M. Giovannozzi, S.D. Fartoukh, S.S. Gilardoni, J.-B. Jeanneret, A.M. Lombardi, Y. Papaphilippou, T. Risselada, R. de Maria
    CERN, Geneva
  It is customary to evaluate the performance of a circular particle accelerator by computing the dynamical aperture, i.e., the domain in phase space where bounded single-particle motion occurs. In the case of the LHC the dynamical aperture computation is performed by assuming a statistical distribution of the magnetic field errors of various magnets' classes: the numerical computations are repeated for a given set of realisations of the LHC ring. With the progress in the magnet production and allocation of the available positions in the ring, the statistical approach has to be replaced by the computation of one single configuration, namely the actual realisation of the machine. Comparisons between the two approaches are presented and discussed in details.  
 
WEPCH093 Parameter Scans and Accuracy Estimates of the Dynamic Aperture of the CERN LHC LHC, dynamic-aperture, simulation, CERN 2131
 
  • M. Giovannozzi, E. McIntosh
    CERN, Geneva
  Techniques to make use of large distributed computing facilities allow for denser parameter scans of the dynamical aperture, i.e., the domain in phase space where bounded single-particle motion prevails. Moreover, one can also increase the number of 'seeds' each of which represents a possible realisation of multipolar components around the machine. In this paper the dependence of the dynamical aperture on the step size of the grid of initial conditions and on the number of seeds is studied. Estimates on the accuracy of the dynamic aperture are derived and the definition of an improved protocol for numerical simulations is presented.  
 
WEPCH094 An Early Beam Separation Scheme for the LHC luminosity, LHC, separation-scheme, beam-beam-effects 2134
 
  • J.-P. Koutchouk, G. Sterbini
    CERN, Geneva
  The high nominal luminosity of the LHC requires a large number of bunches spaced by about 7.5 m. To prevent more than one head-on collision in each interaction region, a crossing angle of 0.285 mrad is necessary. A side effect of this crossing angle is the increase of the effective transverse beam cross-section, thereby decreasing the luminosity by some 16%. For the LHC upgrade, depending on the focusing scenarios, this loss significantly increases and largely offsets the potential gain of a stronger focusing. In this paper we analyze a strategy to circumvent this difficulty, based an early beam separation using small dipoles placed at a few meters from the interaction point, deep inside the detectors. This allows quasi co-linear head-on collisions at the crossing point only. From the beam dynamics point of view, the essential constraint is to control the long-range beam-beam interactions in a scenario where the normalized beam separation is not constant. In this paper the criteria of the analysis and the performance improvement obtained with the scheme are discussed. The strength of the dipoles is estimated as well as the impact on the detectors structure.  
 
WEPCH096 Measurement and Correction of the 3rd Order Resonance in the Tevatron sextupole, resonance, coupling, CERN 2140
 
  • F. Schmidt
    CERN, Geneva
  • Y. Alexahin, V.A. Lebedev, D. Still, A. Valishev
    Fermilab, Batavia, Illinois
  At Fermilab Tevatron BPM system has been recently upgraded resulting much better accuracy of beam position measurements and improvements of data acquisition for turn-by-turn measurements. That allows one to record the beam position at each turn for 8000 turns for all BPMs (118 in each plane) with accuracy of about 10-20 μm. In the last decade a harmonic analysis tool has been developed at CERN that allows relating each FFT line derived from the BPM data with a particular non-linear resonance in the machine. In fact, one can even detect the longitudinal position of the sources of these resonances. Experiments have been performed at the Tevatron in which beams have been kicked to various amplitudes to analyze the 3rd order resonance. It was possible to address this rather large resonance to some purposely powered sextupoles. An alternative sextupole scheme allowed the suppression of this resonance by a good factor of 2. Lastly, the experimental data are compared with model calculations.  
 
WEPCH123 Large Simulation of High Order Short Range Wakefields simulation, higher-order-mode, SLAC, DESY 2209
 
  • A. Bungau
    Cockcroft Institute, Warrington, Cheshire
  • R.J. Barlow
    UMAN, Manchester
  We present a formalism for incorporating intra-bunch wake fields into particle-by-particle tracking codes, such as MERLIN and BDSIM. Higher order wake field effects are incorporated in a manner which is computationally efficient. Standard formulae for geometric, resistive and dielectric wake fields are included for various apertures, particularly those relevant for ILC collimators. Numerous examples are given.  
 
WEPCH152 Comment on Healy's Symplectification Algorithm BNL, AGS, CERN 2281
 
  • W.W. MacKay
    BNL, Upton, Long Island, New York
  For long-term tracking, it is important to have symplectic maps for the various electromagnetic elements in an accelerator ring. While many standard elements are handled well by modern tracking programs, new magnet configurations (e.g., a helical dipole with a superimposed solenoid) are being used in real accelerators. Transport matrices and higher terms may be calculated by numerical integration through model-generated or measured field maps. The resulting matrices are most likely not quite symplectic due to numerical errors in the integrators as well as the field maps. In his thesis*, Healy presented a simple algorithm to symplectify a matrix. This paper presents a discussion of limitations of this method.

*L. M. Healy, "Lie Algebraic Methods for Treating Parameter Errors in Particle Accelerators", Doctoral Thesis. University of Maryland, unpublished (1986).

 
 
WEPCH153 Symplectic Interpolation coupling, AGS, resonance, BNL 2284
 
  • W.W. MacKay, A.U. Luccio
    BNL, Upton, Long Island, New York
  It is important to have symplectic maps for the various electromagnetic elements in an accelerator ring. For some tracking problems we must consider elements which evolve during a ramp. Rather than performing a complicated numerical integration for every turn, it should be possible to integrate the trajectory for a few sets of parameters, and then interpolate the transport map as a function of one or more parameters, such as energy. We present two methods for interpolation of symplectic matrices as a function of parameters: one method is based on the logarithm of the matrix, and the other is based on the related but simpler Healy symplectification method.  
 
WEPCH160 A Novel Proton and Light Ion Synchrotron for Particle Therapy synchrotron, extraction, septum, injection 2305
 
  • S.P. Møller, F.S. Albrechtsen, T. Andersen, A. Elkjaer, N. Hauge, T. Holst, I. Jensen, S.M. Madsen
    Danfysik A/S, Jyllinge
  • K. Blasche, B. Franczak
    GSI, Darmstadt
  A compact and simple synchrotron for a cancer particle therapy system has been designed and is presently under construction. A lattice with six regular superperiods, twelve dipole and twelve quadrupole magnets, is used. The optimized lattice configuration, including the design of injection and extraction systems, provides large transverse phase space acceptance with minimum magnet apertures. The result is a synchrotron for PT with light magnets (5t dipoles), low values of peak power for pulsed operation and minimum dc power consumption. In addition, industrial production principles are used, keeping ease of construction, installation, and operation in mind. The beam, injected at 7 MeV/amu, can be accelerated to the maximum magnetic rigidity of 6.6 Tm in less than 1 s. A beam of 48-250 MeV protons and 88-430 MeV/u carbon ions can be slowly extracted during up to 10s. The intensity for protons and carbon ions will be well beyond the needs of scanning beam applications. The design and performance specifications of the synchrotron will be described in detail.  
 
WEPCH162 Magnet Simulations for Medical FFAG simulation, magnet-design, CERN 2310
 
  • E. Froidefond
    LPSC, Grenoble
  • B. Autin
    CERN, Geneva
  Studies have been undertaken concerning magnet design in the frame of the RACCAM FFAG project (this conference). This contribution reports on the objectives of the project in that matter, on the working methods and calculation tools developments, magnetic field modeling and simulations, and on the present status of this work.  
 
WEPCH180 A Dramatically Reduced Size in the Gantry design for the Proton-Carbon Therapy betatron, hadron, focusing, quadrupole 2352
 
  • D. Trbojevic, R.C. Gupta, B. Parker
    BNL, Upton, Long Island, New York
  • E. Keil
    CERN, Geneva
  • A. Sessler
    LBNL, Berkeley, California
  Gantries in the proton/carbon cancer therapy machines represent the major cost and are usually very large. This report explains a new way for the gantry design. The size and cost of the gantries are reduced, and their use is simplified by using the fixed magnetic field. The "new" gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. The strong focusing magnets following the gantry have to be adjustable as well to provide the required spot size. The adjustable dipoles provide the radial scanning. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.  
 
WEPLS007 A Six-dimensional Muon Beam Cooling Experiment emittance, collider, simulation, beam-cooling 2409
 
  • R.P. Johnson, M. Alsharo'a, M.A.C. Cummings, M. Kuchnir, K. Paul, T.J. Roberts
    Muons, Inc, Batavia
  • D.M. Kaplan
    Illinois Institute of Technology, Chicago, Illinois
  • V.S. Kashikhin, V. Yarba, K. Yonehara
    Fermilab, Batavia, Illinois
  Ionization cooling, a method for shrinking the size of a particle beam, is an essential technique for the use of muons in future particle accelerators. Muon colliders and neutrino factories, examples of such future accelerators, depend on the development of robust and affordable ionization cooling technologies. A 6D cooling experiment has been proposed, incorporating a novel configuration of helical and solenoidal magnets in a prototype cooling channel. This Helical Cooling Channel (HCC) experiment is being designed with simulations and prototypes to provide an affordable and striking demonstration that 6D muon beam cooling is understood well enough to enable intense neutrino factories and high-luminosity muon colliders. Because of the large amount of expected beam cooling, helium instead of hydrogen can be used for the initial experiment, avoiding the safety complications of hydrogen. Cryostats are currently being developed using internal heat exchangers for simple, effective and safe hydrogen absorber systems to use in later cooling experiments and real cooling channels. The experimental design choices and corresponding numerical simulations are reviewed.  
 
WEPLS016 Studies of a Gas-filled Helical Muon Beam Cooling Channel simulation, emittance, sextupole, quadrupole 2424
 
  • R.P. Johnson, K. Paul, T.J. Roberts
    Muons, Inc, Batavia
  • Y.S. Derbenev
    Jefferson Lab, Newport News, Virginia
  • K. Yonehara
    Fermilab, Batavia, Illinois
  A helical cooling channel (HCC) can quickly reduce the six dimensional phase space of muon beams for muon colliders, neutrino factories, and intense muon sources. The HCC is composed of solenoidal, helical dipole, and helical quadrupole magnetic fields to provide the focusing and dispersion needed for emittance exchange as the beam follows an equilibrium helical orbit through a continuous homogeneous absorber. We consider liquid helium and liquid hydrogen absorbers in HCC segments that alternate with RF accelerating sections and we also consider gaseous hydrogen absorber in pressurized RF cavities imbedded in HCC segments. In the case of liquid absorber, the possibility of using superconducting RF in low magnetic field regions between the HCC segments may provide a cost effective solution to the high repetition rate needed for an intense neutrino factory or high average luminosity muon collider. In the gaseous hydrogen absorber case, the pressurized RF cavities can be operated at low temperature to improve their efficiency for higher repetition rates. Numerical simulations are used to optimize and compare the liquid and gaseous HCC techniques.  
 
WEPLS023 The Two-beam Test-stand in CTF3 CLIC, CTF3, diagnostics, linac 2445
 
  • V.G. Ziemann, T. J. C. Ekelof, M. A. Johnson
    UU/ISV, Uppsala
  • H.-H. Braun, S. Doebert, G. Geschonke, J.P.H. Sladen, W. Wuensch
    CERN, Geneva
  The acceleration concept for CLIC, based on the two-beam acceleration scheme, where the 30 GHz RF power needed to accelerate the high energy beam is generated by a high-intensity but rather low energy drive beam, will be tested in the two-beam test-stand in CTF3. There RF-structures will be tested at full pulse length. The extreme power levels of up to 640 MW warrant a careful diagnostic system to analyze RF breakdown by observing the effect on both probe- and drive-beam but also the RF signals and secondary effects such as emitted light, vibrations, vacuum, temperatures. We describe the experimental setup and the diagnostic system planned to be installed in CTF3 for 2007.  
 
WEPLS064 Wiggler for ILC Cooler wiggler, emittance, quadrupole, focusing 2526
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represented the concept of a wiggler with linear piecewise field dependence. This eliminates nonlinearities in wiggler. This type of wiggler can be recommended for usage in ILC cooler.  
 
WEPLS065 The Effect of Vaccum Vessel Permeability on the Field Quality within Dipole and Quadrupole Magnets at the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory vacuum, quadrupole, ERLP, linac 2529
 
  • N. Thompson
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The Energy Recovery Linac Prototype (ERLP) is currently under construction at Daresbury Laboratory in the UK and will serve as a test bed for the investigation of technologies and beam physics issues necessary for the development of Daresbury Laboratory's Fourth Generation Light Source (4GLS) proposal. To assist with the material specification of the vacuum vessels, analyses have been done on the effect of vessel permeability on the magnetic field quality within quadrupole and dipole magnets. It is found that for dipoles where the specified maximum relative dipole field variation over the good field region is ± 1x 10-4 or for quadrupoles where the specified maximum relative gradient variation is ±1 1x10-3, the transverse size of the good field region decays unacceptably for relative permeability > 1.006. However, for the dipoles where the specified maximum relative dipole field variation is ± 1x10-3, the decay of the good field region is more gradual and would safely permit a material with relative permeability >1.006 to be used for the vacuum vessel within these dipoles.  
 
WEPLS067 Magnets for the 3 GeV Booster Synchrotron for the Diamond Light Source quadrupole, sextupole, booster, DIAMOND 2535
 
  • S.P. Mhaskar, C.P. Bailey, G.M.A. Duller, V.C. Kempson, N. Marks
    Diamond, Oxfordshire
  • F. Bødker, N. Hauge, L.H. Helmersen
    Danfysik A/S, Jyllinge
  The Diamond Booster is a full energy injector for the Diamond Storage Ring. It is designed to accelerate electrons from 100 MeV to 3 GeV at a 5 Hz repetition rate. The lattice is a missing dipole FODO lattice consisting of 22 unit cells with 36 dipoles, 44 quadrupoles, 28 sextupoles and 44 correctors, distributed around a circumference of 158.4 m. The dipole field will be ramped from 0.026 T at injection to 0.809 T at 3 GeV; the quadrupoles will have a maximum operating gradient of 15T/m. The initial design of pole tip profiles was carried at Diamond, with the magnets then manufactured by DANFYSIK A/S as part of preassembled girder units (44 in total), complete with vacuum vessels. High quality was required to meet the accelerator physics requirements of alignment, positioning accuracies and field tolerances over the required good field apertures. Materials, ramp rates and field range have been selected to obtain almost linear response during magnet ramping. This paper describes the main features of the magnetic designs and measurement results; the magnets have now been delivered and installed at Diamond.  
 
WEPLS068 The IASA Magnetic Field Mapping (MFM) Project electron, controls, resonance, TESLA 2538
 
  • E.P. Pournaras, A. Karabarbounis, C.N. Papanicolas, E. Stiliaris
    IASA, Athens
  The design and development of an automatic magnetic field mapping device as supporting equipment for the 10 MeV CW-Linac and its transport system at the Institute of Accelerating Systems and Applications (IASA) is presented. The MFM project aims to totally automate the operation of mapping room temperature magnetic field sources, reconstruct the 3D-field shape and reveal nonlinearities in the fridge field regions. The positioning system covers an area of 50x50 cm2 with an accuracy of less than 20 ?m in both axes; magnetic field measurements, mainly based on a Hall probe, can reach in precision the 1x 10-4 value. Several software tools for the visualization of the measured fields and for a direct comparison with theoretical estimates are also presented.  
 
WEPLS070 The Elettra Booster Magnets Construction Status sextupole, booster, quadrupole, ELETTRA 2541
 
  • D. Zangrando, D. Castronovo, F. Iazzourene, M. Svandrlik
    ELETTRA, Basovizza, Trieste
  The third generation light source ELETTRA has been in operation since 1993. A new 2.5 GeV full energy booster injector has been approved and founded last year. It will replace the existing linear injector limited to a maximum energy of 1.2 GeV. During last year, after having completed the specifications and the preliminary magnetic and mechanical design, the orders for all the magnets were assigned to two European firms. The paper reports on the magnets' construction status and the requested specifications.  
 
WEPLS074 SESAME Magnets System quadrupole, sextupole, focusing, storage-ring 2553
 
  • S. Varnasseri
    SESAME, Amman
  In this paper the SESAME storage ring magnet system is described. The storage ring consists of 16 bending magnets with a maximum field of 1.455 T and vertical gradient of 2.79 T/m, 32 focusing quadrupoles with a maximum gradient of 16.92 T/m, 32 defocusing quadrupoles with a maximum gradient of 10.23 T/m, 32 focusing sextupoles with a maximum differential gradient of 200 T/m2 and 32 defocusing sextupoles with the maximum differential gradient of 300 T/m2. The horizontal/vertical correctors will be embedded inside focusing/defocusing sextupoles. For the quadrupole and sextupole, a design similar to ANKA has been adopted. The magnetic and electrical design of dipoles and correctors, field profile and higher order multipoles optimization will be presented.  
 
WEPLS077 Considerations on the Design of the Bending Magnet for Beam Extraction System of PEFP extraction, proton, focusing, target 2556
 
  • Y.-H. Kim, Y.-S. Cho, J.-H. Jang
    KAERI, Daejon
  The PEFP is designed to have two beam extraction lines at the 20 MeV end and 100MeV end for beam utilization. So, the bending magnet to extract the beam from the beam line is located among the MEBT. This implies that there is a long drift space between the focusing structures, while, from the beam dynamics study, it is recommended to make the drift space shorter. In this study, we design and compare some bending magnets to satisfy the beam dynamics requirements.  
 
WEPLS080 Magnets for the Storage Ring ALBA quadrupole, sextupole, multipole, storage-ring 2562
 
  • M. Pont
    ALBA, Bellaterra
  • E. Boter, M.L. Lopes
    CELLS, Bellaterra (Cerdanyola del Vallès)
  The Storage Ring ALBA is a 3.0 GeV synchrotron light source under construction in Barcelona (Spain). The Storage Ring, has a circumference of 268.8 m and comprises 32 combined magnets, 112 quadrupoles, and 120 sextupoles. This paper will describe the design and the present state of these magnets. The combined magnet has a central field of 1.42 T and a large gradient of 5.65 T/m, since most of the vertical focusing happens at these combined magnets. The 112 quadrupoles have been designed for a maximum gradient of 22 T/m. The bore diameter will be 61 mm and the lengths range from 200 to 500 mm. Each quadrupole will be individually powered. The 120 sextupoles are divided in 9 families. There are two lengths of sextupoles 150 and 220 mm and the maximum sextupole gradient is 600 T/m2. The bore diameter is 76 mm. The sextupole magnets will also be equipped with additional coils for vertical steering, horizontal steering and quadrupolar skew correction.  
 
WEPLS084 AC Field Measurements of Fermilab Booster Correctors Using a Rotating Coil System booster, sextupole, synchrotron, quadrupole 2574
 
  • G. Velev, J. DiMarco, D.J. Harding, V.S. Kashikhin, M.J. Lamm, A. Makulski, D.F. Orris, P. Schlabach, C. Sylvester, M. Tartaglia, J. Tompkins
    Fermilab, Batavia, Illinois
  The first prototype of a new corrector package for the Fermilab Booster Synchrotron is presently in production. This water-cooled package includes normal and skew dipole, quadrupole and sextupole magnets to control orbit, tune and chromaticity of the beam over the full range of Booster energies (400 MeV-8 GeV). These correctors must make rapid excursions from the 15 Hz excitation cycle of the main synchrotron magnets, in some cases even switching polarity in approximately 1 ms at transition crossing. To measure the dynamic changes in the field during operation, a new method based on a relatively slow rotating coil system is proposed. The method pieces together the measured flux from successive current cycles to reconstruct the field harmonics. This paper describes the method and presents initial field quality measurements from the corrector prototype.  
 
WEPLS087 Status of the Development of the FAIR Superconducting Magnets superconducting-magnet, GSI, quadrupole, ion 2577
 
  • G. Moritz
    GSI, Darmstadt
  For the planned 'Facility for Antiprotons and Ion Research' (FAIR), a variety of superconducting magnets is foreseen. The synchrotrons SIS 100 and SIS 300 will use fast-pulsed superferric and superconducting cos (theta) magnets. The storage ring CR and the SuperFRS will be equipped with large-scale superferric magnets, while in the storage ring HESR RHIC-type magnets are foreseen. The status of the R&D activities will be presented.  
 
WEPLS089 Feasibility Study of a Permanent Magnet Made from High-Tc Bulk Superconductor LEFT, permanent-magnet, superconductivity, shielding 2580
 
  • M. Masuzawa, K. Egawa, K. Tsuchiya
    KEK, Ibaraki
  A field trapping experiment using a magnetic field up to ~1.5 T was performed using high-Tc bulk superconductors. Applications of bulk high-Tc superconductors have been investigated in various fields. High-Tc superconductors are attractive since they can trap higher magnetic fields than conventional permanent magnets. The trapping experiment was done with a field of above 1 T, which can be easily produced by conventional magnets. However, achieving the desired field distribution and understanding the characteristics of the trapped field and its decay process would open up the possibility of high-Tc bulk superconductor applications in the design of magnets for particle accelerators The distribution of the trapped field and its decay process was monitored by an array of Hall sensors for different shapes of the bulk superconductors. The observations are reported on in this paper.  
 
WEPLS090 Full Length Superferric Dipole and Quadrupole Prototype Magnets for the SIS100 at GSI: Status of the Design and Manufacturing quadrupole, GSI, synchrotron, ion 2583
 
  • A.D. Kovalenko, N.N. Agapov, A.V. Alfeev, H.G. Khodzhibagiyan, G.L. Kuznetsov, V.V. Seleznev, A.Y. Starikov
    JINR, Dubna, Moscow Region
  • E. Fischer, G. Moritz, C. Muehle, P.J. Spiller
    GSI, Darmstadt
  • A.K. Kalimov
    St. Petersburg State Polytechnic University, St. Petersburg
  • A.V. Shabunov
    JINR/LHE, Moscow
  The SIS100, one of the two basic accelerators of the future Facility for Antiproton and Ion Research FAIR at GSI, should provide acceleration of U28+ and proton beams for 0.5 s with a pulse repetition rate of 1 Hz. In the accelerator magnetic system superferric 2 T dipoles of about 3 m length and 35 T/m quadrupoles of about 1 m length will be used. The magnet coils are made from hollow NbTi composite cable cooled with two-phase helium flow at 4.5 K. The maximum operating current of 7500 A is supposed. The lattice comprises 108 dipoles and 168 quadrupoles. The elliptic beam pipe inner sizes have been fixed to 130x60 mm2 for the dipole and 135x65 mm2 for the quadrupole The design approach is based on the improved versions of the Nuclotron fast-cycling magnets that provide significant less AC loss at 4.5 K, better quality of the magnetic field and a higher long-term mechanical stability of the magnet coils. The AC losses in the magnets for the strongest SIS100 operating cycle at 4.5 K are expected to be about 13 W/m and 17 W/m in the full length prototype dipole and quadrupole magnets respectively.  
 
WEPLS091 Analysis of the Superferric Quadrupole Magnet Design for the SIS100 Accelerator of the FAIR Project quadrupole, GSI, synchrotron, ion 2586
 
  • E. Fischer, G. Moritz
    GSI, Darmstadt
  • H.G. Khodzhibagiyan, A.D. Kovalenko
    JINR, Dubna, Moscow Region
  • R.V. Kurnyshov, P.A. Shcherbakov
    IHEP Protvino, Protvino, Moscow Region
  The heavy ion fast-cycling synchrotron SIS100 is the "workhorse", of the future Facility for Antiproton and Ion Research FAIR at GSI in Darmstadt. The main lattice parameters of the accelerator are defined now so the main engineering problems of the new superferric magnets should be analyzed and solved too. We present the results of finite element calculations and compare them with the experimental data from investigation of the model magnets to characterize the expected AC loss properties of the full length prototype quadrupole. We discuss the appropriate new coil structure aimed at minimizing the heat releases at 4.5 K, but providing the requested long-term mechanical stability against dynamic Lorentz forces and thermal cooling cycles as well.  
 
WEPLS093 3D Field Computation for the Main Prototype Magnets of the SIS100 Accelerator of the FAIR Project quadrupole, multipole, magnet-design, GSI 2592
 
  • P.A. Shcherbakov
    IHEP Protvino, Protvino, Moscow Region
  • E. Fischer
    GSI, Darmstadt
  • R.V. Kurnyshov
    Electroplant, Moscow
  Fast cycling superferric magnets are planned for use in the new international accelerator Facility for Antiprotons and Ion Research (FAIR) at GSI, Darmstadt. The dipoles and quadrupoles have to provide the required field quality from the injection field of 0.25T and 4.3T/m up to the maximum values of 2.1T and 35T/m respectively. The complex 3D magnetic field distribution due to the longitudinal component Bz near the yoke end regions and the presence of eddy currents also in the bulk construction elements as well as in a mechanical stable beam pipe design can create unacceptable static and dynamic nonlinearities. The detailed knowledge of these effects is necessary to control the field quality for all operating cycles to be provided by the SIS100 accelerator. We discuss the methodical problems of 3D finite element calculations (ANSYS) of the local and the integral nonlinearities, considering also the problems caused by the various nonlinear and anisotropic material properties and by the structure elements of the yoke and beam pipe. The calculated integral static and the affected by eddy currents harmonic coefficients are presented.  
 
WEPLS094 3D Magnetic Field and Eddy Current Loss Calculations for Iron Dominated Accelerator Magnets using ANSYS Compared with Results of Noncommercial Codes GSI, simulation, synchrotron, quadrupole 2595
 
  • P.A. Shcherbakov
    IHEP Protvino, Protvino, Moscow Region
  • E. Fischer
    GSI, Darmstadt
  • R.V. Kurnyshov
    Electroplant, Moscow
  The design of fast ramped superferric magnets with repetition rates in the order of 1Hz requires reliable software tools to calculate the complex 3D magnetic field quality as well as the impact of eddy current and hysteresis loss. Various technological construction details should be taken into account to obtain a high field quality. We present a methodical study of these questions based on ANSYS calculations for simplified dipole models. The details of these analysis are compared with recently published results obtained by different special codes, i.e. an integral and the FIT method. The time dependences of eddy current power due to longitudinal magnetic field component at the yoke ends, the transient field distribution in the yoke volume and the total eddy current loss are investigated, choosing the identical geometry with the same magnetic and electric properties of the lamination steel used by the other codes. The conclusions for the application potential of the different methods are discussed.  
 
WEPLS096 Design and Calculation of a Superferric Combined Magnet for XFEL quadrupole, XFEL, DESY, background 2598
 
  • F. Toral, P. Abramian, J.L. Gutierrez, E. Rodriguez, I. Rodriguez, S. Sanz, C. Vazquez
    CIEMAT, Madrid
  • R. Bandelmann, H. Brueck
    DESY, Hamburg
  • J. Calero, L. García-Tabarés
    CEDEX, Madrid
  • J. Lucas
    Elytt Energy, Madrid
  A planned European X-ray Free Electron Laser so-called XFEL is being developed within the framework of an international collaboration. The design and fabrication of a prototype of a combined magnet is part of the Spanish contribution to this project. This magnet consists of a superferric quadrupole for focusing and two dipoles (horizontal and vertical) for steering, glued around the beam tube. The magnet will be operated in a superfluid helium bath. The aperture is 78 mm. The quadrupole gradient is 35 T/m whereas each dipole field is about 0.04 T. The magnetic saturation is limited to 5% at nominal current, which is quite a challenging specification for such aperture and gradient. As the overall length of the helium vessel is just 300 mm, the calculation of the magnetic field is a pure 3-D problem which has been solved and optimized using two different FEM codes to cross-check the results. This paper also gives some guidelines about the fabrication techniques most suitable for the first prototype, which is now under construction.  
 
WEPLS097 Random Errors in Superconducting Dipoles LHC, multipole, RHIC, simulation 2601
 
  • B. Bellesia, E. Todesco
    CERN, Geneva
  • C. Santoni
    Université Blaise Pascal, Clermont-Ferrand
  The magnetic field in a superconducting magnet is mainly determined by the position of the conductors. Hence, the main contribution to the random field errors comes from random displacement of the coil with respect to its nominal position. Using a Monte-Carlo method, we analyze the measured random field errors of the main dipoles of the LHC, Tevatron, RHIC and HERA projects in order to estimate the precision of the conductor positioning reached during the production. The method can be used to obtain more refined estimates of the random components for future projects.  
 
WEPLS098 Experience with the Quality Assurance of the Superconducting Electrical Circuits of the LHC Machine LHC, pick-up, quadrupole, octupole 2604
 
  • D. Bozzini, V. Chareyre, K.H. Mess, S. Russenschuck
    CERN, Geneva
  • A. Kotarba, S. Olek
    HNINP, Kraków
  The coherence between the powering reference database and the Electrical Quality Assurance (ELQA) is guaranteed on the procedural level. However, a challenge remains the coherence between the database, the magnet test and assembly procedures, and the connection of all superconducting circuits of the LHC. In this paper, the methods, tooling, and procedures for the ELQA during the assembly phase of the LHC will be presented in view of the practical experience gained in the LHC tunnel. The parameters measured at ambient temperature such as the dielectric insulation and the impedance transfer function of assembled circuits will be discussed. Some examples of detected polarity errors and the treatment of non-conformities will be presented.  
 
WEPLS100 Performance of LHC Main Dipoles for Beam Operation LHC, CERN, target, controls 2610
 
  • G. De Rijk, M. Bajko, L. Bottura, M.C.L. Buzio, V. Chohan, L. Deniau, P. Fessia, J. Garcia Perez, P. Hagen, J.-P. Koutchouk, J. Kozak, J. Miles, M. Missiaen, M. Modena, P. Pugnat, V. Remondino, L. Rossi, S. Sanfilippo, F. Savary, A.P. Siemko, N. Smirnov, A. Stafiniak, E. Todesco, D. Tommasini, J. Vlogaert, C. Vollinger, L. Walckiers, E.Y. Wildner
    CERN, Geneva
  At present about 75% of the main dipoles for the LHC have been manufactured and one of the three cold mass assemblers has already completed the production. More than two third of the 1232 dipoles needed for the tunnel have been tested and accepted. In this paper we mainly deal with the performance results: the quench behavior, the magnetic field quality, the electrical integrity quality and the geometry features will be summarized. The variations in performance associated with different cold mass assemblers and superconducting cable origins will be discussed.  
 
WEPLS101 First Computation of Parasitic Fields in LHC Dipole Magnet Interconnects LHC, CERN, quadrupole, multipole 2613
 
  • A. Devred, B. Auchmann, Y. Boncompagni, V. Ferapontov, J.-P. Koutchouk, S. Russenschuck, T. Sahner, C. Vollinger
    CERN, Geneva
  The Large Hadron Collider (LHC), now under construction at CERN, will rely on about 1600 main superconducting dipole and quadrupole magnets and over 7400 superconducting corrector magnets distributed around the eight sectors of the machine. Each type of magnets is powered by dedicated superconducting busbars running along each sector and passing through the iron yokes of the main dipole and quadruple magnets. In the numerous magnet interconnects, the busbars are not magnetically shielded from the beam pipes and produce parasitic fields that can affect beam optics. We review the 3D models which have been built with the ROXIE software package to evaluate these parasitic fields and we discuss the computation results and their potential impacts on machine performance.  
 
WEPLS104 The Dependence of the Field Decay on the Powering History of the LHC Superconducting Dipole Magnets LHC, injection, CERN, collider 2622
 
  • N.J. Sammut, L. Bottura, S. Sanfilippo
    CERN, Geneva
  • J. Micallef
    University of Malta, Faculty of Engineering, Msida
  The decay amplitude of the allowed multipoles in the LHC dipoles is expected to perturb the beam stability during the injection phase and is strongly dependent on the powering history of the magnet. The effect is particularly large for the pre-cycle nominal flat-top current and duration. With possible prospects of having different genres of cycles during the LHC operation, the powering history effect must be taken into account in the Field Description Model for the LHC (FIDEL) and must hence be corrected for during machine operation. This paper presents the results of the modelling of this phenomenon. We also discuss the statistic of magnetic measurements required to guarantee that the current history effect is predicted within the specified accuracy.  
 
WEPLS105 Performance of the LHC Arc Superconducting Quadrupoles towards the End of their Series Fabrication quadrupole, CERN, LHC, factory 2625
 
  • T. Tortschanoff, P. Hagen, M. Modena, L. Rossi, S. Sanfilippo, K. M. Schirm, E. Todesco, E.Y. Wildner
    CERN, Geneva
  • R. Burgmer, H.-U. Klein, D. Krischel, B. Schellong, P. Schmidt
    ACCEL, Bergisch Gladbach
  • M. Durante, A. Payn, F. Simon
    CEA, Gif-sur-Yvette
  The fabrication of the 408 main arc quadrupole magnets and their cold masses will come to an end in summer 2006. A rich collection of measurement and test data has been accumulated and their analysis is presented in this paper. These data cover the fabrication and the efficiency in the use of the main components, the geometrical measurements and the achieved dimensional precision, the warm magnetic measurements in the factory and the performance at cold conditions, especially the training behaviour. The scrap rate of the NbTi/Cu conductor as well as that of other components turned out to be acceptably low and the quench performance measured was in general very good. Most quadrupoles measured so far exceeded the operating field gradient with one or no quench. The multipole content at cold was measured for a limited numbers of quadrupoles as far as needed for verifying the warm-to-cold correlation. From the point of view of field quality, all quadrupoles could be accepted for the machine and the measures taken to overcome the problem of a too high permeability of a batch of collars are discussed.  
 
WEPLS107 Comparative Study of Inter-strand Coupling Current Models for Accelerator Magnets coupling, LHC, CERN, GSI 2631
 
  • R. de Maria, B. Auchmann, S. Russenschuck
    CERN, Geneva
  "Inter-Strand Coupling Currents" (ISCCs) contribute to field errors and losses in Rutherford-type superconducting cables in the time- transient regime. The field change induces eddy currents in loops formed by the superconducting twisted strands and the resistive matrix. In the ROXIE program two models are implemented to simulate ISCCs in a magnet cross-section: A network model uses an electric circuit to represent the geometry of the twisted strands and their resistive contacts; an analytical model simplifies the network equations to determine an equivalent cable magnetization from an average field sweep over the cable. The implementation of the models in ROXIE allows to combine them with models for "Persistent Currents" and "Inter-Filament Coupling Currents". The non-linear iron yoke can be taken into account as well. The predictions of different ISCC models with regard to losses and field errors are compared for two design versions of the LHC main dipole. We find that as far as field quality is concerned, the models perform equally well. As for losses, however, the analytical model cannot capture the complexity of the problem and computes lower losses than the network model.  
 
WEPLS110 New Measurements of Sextupole Field Decay and Snapback Effect on Tevatron Dipole Magnets injection, sextupole, LHC, LEFT 2640
 
  • G. Velev, P. Bauer, R.H. Carcagno, J. DiMarco, M.J. Lamm, D.F. Orris, P. Schlabach, C. Sylvester, M. Tartaglia, J. Tompkins
    Fermilab, Batavia, Illinois
  To perform detailed studies of the dynamic effects in superconducting accelerator magnets, a fast continuous harmonics measurement system based on the application of a digital signal processor (DSP) has been built at Fermilab. Using this new system the dynamic effects in the sextupole field, such as the field decay during the dwell at injection and the rapid subsequent "snapback" during the first few seconds of the energy ramp, are evaluated for more than ten Tevatron dipoles from the spares pool. The results confirm the previously observed fast drift in the first several seconds of the sextupole decay and provided additional information on a scaling law for predicting snapback duration. The presented information can be used for an optimization of the Tevatron and for future LHC operations.  
 
WEPLS118 The 3Hz Power Supplies of the SOLEIL Booster booster, SOLEIL, synchrotron, power-supply 2652
 
  • P. Gros, S. Bobault, A. Loulergue
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a 2.75 GeV new third generation synchrotron radiation facility under construction near Paris. The injector system is composed of a 100 MeV electron Linac pre-accelerator followed by a full energy (2.75 GeV) booster synchrotron. A repetition rate of 3Hz is required for the booster for the filling of the Storage Ring together with the need for discontinuous operation for top-up filling mode. Based on digital regulation loop, the four power supplies (2 for the dipoles 600 A x 1000 V and 2 for the quadrupoles 250 A x 450 V) reach the current tracking tolerance specification of 10-3. The aim of this paper is to describe the main issues from the loads to the mains network through the power converters that are essential to reach the required performances.  
 
WEPLS124 Diamond Booster Magnet Power Converters booster, controls, DIAMOND, quadrupole 2664
 
  • J.A. Dobbing, C.A. Abraham, R.J. Rushton
    Diamond, Oxfordshire
  • F. Cagnolati, M.P.C. Pretelli, L. Sita
    O.C.E.M. S.p.A., Bologna
  • G. Facchini
    CERN, Geneva
  • C. Rossi
    CASY, Bologna
  This paper will describe the design, factory tests, commissioning and early operation of the Diamond Booster Power Converters. The Power Converters covered are the Dipole, Quadrupole with two outputs, two bi-polar Sextupoles and 44 Steerers. The actual achieved performance will be compared with the specification and the extensive modelling that was carried out during the design phase. The design includes measures to enhance the reliability of the power converters, such as redundancy, plug-in modularity, component de-rating and component standardisation. All the Diamond power converters use the same digital controller, manufactured under licence from the Paul Scherrer Institute.  
 
WEPLS125 Diamond Storage Ring Magnet Power Converters controls, quadrupole, sextupole, power-supply 2667
 
  • R.J. Rushton, C.A. Abraham, J.A. Dobbing
    Diamond, Oxfordshire
  • F. Cagnolati, G. Facchini, M.P.C. Pretelli, V.R. Rossi, L. Sita
    O.C.E.M. S.p.A., Bologna
  • C. Rossi
    CASY, Bologna
  The DC Magnet Power Converter requirements for the Storage Ring of the Diamond Project are described together with performance, commissioning and initial operating experience. In addition to meeting the required performance, emphasis during the design phase was placed on reliability and minimising the mean time to repair a power converter. A modular design, built-in redundancy, EMC filtering and testing, component de-rating and standardisation have all been adopted. The power modules for the 200A supplies were subject to highly accelerated stress screening. All converters are switched mode with full digital control and a common control interface. Every power converter appears identical to the Controls Network, from the lowest power corrector up to the 800 kW Storage Ring Dipole Converter.  
 
WEPLS127 CNAO Storage Ring Dipole Magnet Power Converter 3000A / ±1600V controls, power-supply, synchrotron, simulation 2673
 
  • M.P.C. Pretelli, F. Burini, S. Carrozza, M. Cavazza, M.F. Farioli, S. Minisgallo, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  • F. Ronchi, C. Rossi, M. Spera, M. Toniato
    CASY, Bologna
  This paper will describe the design and simulations of the CNAO Dipole Power Converter rated 3000A / ±1600V. The Power Converter will feed the 16+1 synchrotron bending dipole magnets of the CNAO Storage Ring. The actual design confirms how the choice of a 24-pulses, 4 bridges series-parallel connected, active filter, bipolar voltage, meets the stringent requested technical specification ( 10-5 of maximum current for the output current residual ripple and setting resolution). The extensive modelling will also be presented. The design includes the strength of the topology design, component de-rating and component standardisation. As the other CNAO power converters, the Storage Ring Dipole Power Converter uses the same digital controller, under licence from the Diamond Light Source.  
 
WEPLS128 The Italian Hadrontherapy Center (CNAO): A Review of the Power Supply System for Conventional Magnets synchrotron, power-supply, quadrupole, controls 2676
 
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  • L. Balbo, N. Balbo, A. Tescari
    EEI, Vicenza
  • F. Burini, S. Carrozza, M. Cavazza, M.F. Farioli, S. Minisgallo, M.P.C. Pretelli, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  A hadron (Carbon/Proton) medical centre based on a synchrotron accelerator dedicated to the cure of deep tumours is under construction in Pavia (Italy) under the joint responsibility of CNAO (Centro Nazionale di Adroterapia Oncologica) and INFN (Istituto Nazionale di Fisica Nucleare). This paper describes the power supply system, made up of about 200 units designed by LNF, and whose converters for the synchrotron ring and related low, medium and high energy transfer lines are now under construction by the major Italian companies. The power supplies requirements and electrical characteristics will be reported describing the most interesting topologies that fulfill the requested performances together with the main features of each power supply topology. Synchrotron dipoles, quadrupoles, sextupoles and resonance sextupole power supplies have tight characteristics with respect to precision class (current resolution, residual ripple, short-long term stability, etc.) that range from 5 ppm to 500 ppm, fast dynamical response with bandwidth up to some hundreds hertz, high power from tens of kW to many MW and output current ranging from hundreds of A to 3 kA.  
 
WEPLS141 Operational Experience with the LHC Waveguide Mode Reflectometer LHC, quadrupole, CERN, insertion 2709
 
  • T. Kroyer, P. Borowiec, F. Caspers, Z. Sulek, L.R. Williams
    CERN, Geneva
  The LHC microwave mode reflectometer (assembly version) reached operational status by the end of 2005. It is now routinely used in the LHC tunnel to take data on the beam-screen of the individual LHC magnets and also groups of magnets with lengths up to 200 meter. The reflectometer operates in the frequency range from about 4GHz to 8 GHz and employs mode selective launchers. Data traces of typically 16000 data points are taken in the frequency domain with subsequent Fourier transformation into the time domain and numerical waveguide mode dispersion compensation. This paper discusses the operational aspects of the system as well as methods for clutter (fake reflection) elimination and procedures for cross-checks in case of a suspected obstacle or other fault.  
 
THXFI01 State of the Art in EM Field Computation simulation, gun, SLAC, TESLA 2763
 
  • C.-K. Ng, V. Akcelik, A.E. Candel, S. Chen, N.T. Folwell, L. Ge, A. Guetz, H. Jiang, A.C. Kabel, K. Ko, L. Lee, Z. Li, E.E. Prudencio, G.L. Schussman, R. Uplenchwar, L. Xiao
    SLAC, Menlo Park, California
  This presentation will provide an up-to-date survey of the methods and tools for the computation of electromagnetic fields in accelerator systems and components.  
slides icon Transparencies
 
THOAFI03 Global and Local Coupling Compensation in RHIC using AC Dipoles coupling, RHIC, quadrupole, sextupole 2774
 
  • R. Calaga
    BNL, Upton, Long Island, New York
  • F. Franchi
    GSI, Darmstadt
  • R. Tomas
    CERN, Geneva
  Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techique using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling matrix and resonance driving terms with the aid of RHIC ac dipoles.  
slides icon Transparencies
 
THPCH005 Considerations for the High-intensity Working Point of the SIS100 resonance, beam-losses, LEFT, synchrotron 2793
 
  • G. Franchetti, O. Boine-Frankenheim, I. Hofmann, V. Kornilov, P.J. Spiller, J. Stadlmann
    GSI, Darmstadt
  In the FAIR project the SIS100 synchrotron is foreseen to provide high-intensity beams of U 28+, including slow extraction to the radioactive beam experimental area, as well as high-intensity p beams for the production of antiprotons. In this paper we discuss the proposal of three different working points, which should serve the different needs: (1) a high intensity working point for U28+; (2) a slow extraction working point (also U28+); (3) a proton operation working point to avoid transition crossing. The challenging beam loss control for all three applications requires a careful account of the effects of space charge, lattice nonlinearities and chromaticity, which will be discussed in detail in this paper. Since tunes are not split by an integer and the injected emittances are different, the Montague stop-band needs to be avoided. Moreover, final bunch compression for the U beam requires a sufficiently small momentum spread, and the risk of transverse resisitive wall instabilities poses further limitations on our choice of working points.  
 
THPCH016 Transfer Matrix of Linear Focusing System in the Presence of Self-field of Intense Charged Particle Beam focusing, electromagnetic-fields, quadrupole, ion 2817
 
  • Yu. Kazarinov
    JINR, Dubna, Moscow Region
  Within the framework of moments method, the computation algorithm of the transfer matrix in the presence of self-field of the intense charged particle beam is given. The transfer matrix depends on both the linear external electromagnetic field parameters and the initial value of the second order moments of the beam distribution function. In the case of coupled degrees of freedom, the independent 2D subspaces of the whole phase space are found by means of the linear transformation of the phase space variables. The matrix of this transformation connects with second order moments of the beam distribution function. The momentum spread of the beam is taken into account also.  
 
THPCH028 Crystalline Beams at High Energies lattice, focusing, luminosity, quadrupole 2841
 
  • J. Wei
    BNL, Upton, Long Island, New York
  • S. Machida
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • S. Ochi, H. Okamoto
    HU/AdSM, Higashi-Hiroshima
  • A. Sessler
    LBNL, Berkeley, California
  • Y. Yuri
    JAEA, Takasaki, Takasaki
  Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams*. On the other hand, crystalline beams can only be formed at energies below the transition energy of the circular accelerators**. In this paper, we investigate the formation of crystals in two types of high-transition-energy lattices, one realized by three-cell missing dipole modules and the other with negative bends. The latter type satisfies the maintenance condition for a crystalline beam***.

*J. Wei and A.M. Sessler, “Colliding crystalline beams”, EPAC98, p. 862. **J. Wei et al. Physical Review Letters, 73 (1994) p. 3089.***J. Wei et al. Physical Review Letters, 80 (1998) p. 2606.

 
 
THPCH041 Alternate Cavity Designs to Reduce BBU BBU, recirculation, TESLA, ERL 2874
 
  • E. Wooldridge
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  An investigation was carried out on alternate cavity designs to decrease the effect of the higher order modes (HOMs) whilst maintaining the cavity accelerating gradient. The cavities were modelled in Microwave Studio and the number of cells per cavity and the number of cells per unit length were examined. HOM data from these models was used in beam break up (BBU) codes to calculate the threshold and the results are presented here. The cells of each cavity were slightly deformed alternately in the x and y planes so that the fundamental frequency of the cavity remained unperturbed, whilst minimising the HOM coupling between consecutive cells. Other patterns, such as alternating each deformed cell by several degrees, were also investigated. The data from these e-m models was also used in BBU calculations and their thresholds calculated.  
 
THPCH051 The Effect of the Solenoid Field in Quadrupole Magnets on the Electron Cloud Instability in the KEKB LER electron, quadrupole, simulation, KEKB 2901
 
  • H. Fukuma, J.W. Flanagan, T. Kawamoto, T. Morimoto, K. Oide, M. Tobiyama
    KEK, Ibaraki
  • F. Zimmermann
    CERN, Geneva
  The electron cloud instability which causes vertical beam blowup in the KEKB LER is largely suppressed by applying a weak solenoid field to vacuum chambers in the drift region. However the blowup is still observed when the bunch spacing is reduced to 3.27 rf buckets or shorter. A question is where the remaining electron clouds are. To investigate the electron clouds in the quadrupole magnets, solenoids made of flat cables were developed and installed in 88 quadrupole magnets. The field strength of the solenoid is 17 Gauss. The effect of the solenoid field on the blowup is now under beam study. So far no clear effect of the solenoids on the luminosity and the sideband accompanied by the blowup is found. We report on the solenoid system, the results of the experiments and comparison of the experimental results with simulations.  
 
THPCH071 Coupling Impedances of Small Discontinuities for Non-ultrarelativistic Beams impedance, coupling, vacuum, LANL 2949
 
  • S.S. Kurennoy
    LANL, Los Alamos, New Mexico
  The beam coupling impedances of small discontinuities of an accelerator vacuum chamber have been calculated (e.g., * and references therein) for ultrarelativistic beams using Bethe's diffraction theory. Here we extend the results for an arbitrary beam velocity. The vacuum chamber is assumed to have an arbitrary, but fixed, cross section. The longitudinal and transverse coupling impedances are derived in terms of series over cross-section eigenfunctions, while the discontinuity shape enters via its polarizabilities. Simple explicit formulas for the circular and rectangular cross sections are presented. The impedance dependence on the beam velocity exhibits some unusual features. For example, the reactive impedance, which dominates in the ultrarelativistic limit, can vanish at a certain beam velocity, or its magnitude can exceed the ultrarelativistic value many times.

*S. S. Kurennoy et al. Phys. Rev. ·1052 (1995) 4354.

 
 
THPCH167 Commissioning of the Diamond Pre-injector Linac linac, emittance, single-bunch, DIAMOND 3185
 
  • C. Christou, V.C. Kempson
    Diamond, Oxfordshire
  • K. Dunkel, C. Piel
    ACCEL, Bergisch Gladbach
  Commissioning of the linac for the Diamond Light Source (DLS) was completed in October 2005. The linac was supplied by Accel Instruments as a complete system, with DLS providing beam diagnostics, beam analysis software, control system hardware and standard vacuum components. Much of the beam analysis was carried out using the first part of the Linac to Booster transfer line (LTB), which was designed and built by DLS. Operation of the linac and LTB at 100 MeV in long-pulse and short-pulse modes of operation was demonstrated, and all operational parameters were measured to be within specification.  
 
THPCH180 Equipment for Tunnel Installation of Main and Insertion LHC Cryo-magnets LHC, acceleration, monitoring, quadrupole 3218
 
  • K. Artoos, S. Bartolome-Jimenez, O. Capatina, T. Feniet, J.L. Grenard, M. Guinchard, K. Kershaw
    CERN, Geneva
  The installation of about 1700 superconducting dipoles and quadrupoles in the Large Hadron Collider (LHC) is now well underway. The transport and installation of the LHC cryo-magnets in the LEP tunnels originally designed for smaller, lighter LEP magnets have required development of completely new handling solutions. The severe space constraints combined with the long, heavy loads have meant that solutions had to be very sophisticated. The paper describes the procedure of the installation of the main cryo-magnets in the arc as well as the more specific insertion cryo-magnets. The logistics for the handling and transport are monitored with tri-axial acceleration monitoring devices that are installed on each cryo-magnet to ensure their mechanical and geometric integrity. These dynamic results are commented. The paper includes conclusions and some lessons learned.  
 
THPLS006 The Machine Installation at SOLEIL alignment, SOLEIL, vacuum, quadrupole 3275
 
  • J.C. Besson, X. Deletoille, J.-F. Lamarre, D. Lefebvre, H. Rozelot
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a third generation Synchrotron radiation Source, under construction in France near Paris. The 357 m circumference storage ring is mainly composed of (32 +1) dipoles, 160 quadrupoles, 120 sextupoles, 2 RF cryomodules, ~ 200 vacuum chambers, 6 injection equipment; 12 beamline front-ends and 4 insertion devices (initially). The 157 m circumference Booster comprises 36 dipoles, 44 quadrupoles, 28 sextupoles, 1 RF cavity and 8 injection/extraction equipment. Before the beginning of the Process installation, a general planning was established detailing the various stages of the equipment installation and their assembly protocols before their on-site installation. In reality, many unknown factors, delays on the buildings, delays on the equipment deliveries, technical problems encountered during the construction, have constrained us to significantly and frequently amend and adapt this initial planning. Due to the various delays, it was also necessary to manage the cohabitation with the various building trades. However, the work made on the initial planning paid off as without its detailed protocols, we could not have carried out the Process installation within correct deadline.  
 
THPLS007 Magnetic Measurements Results of the Dipoles, Quadrupoles and Sextupoles of the SOLEIL Storage Ring quadrupole, SOLEIL, sextupole, storage-ring 3278
 
  • P. Brunelle, C. Benabderrahmane, P. Berteaud, F. Briquez, A. Dael, L. Dubois, M. Girault, A. Madur, F. Marteau, A. Nadji, F. Paulin, J. Vétéran
    SOLEIL, Gif-sur-Yvette
  During the magnetic measurement campaign, from May 2004 to August 2005, the 326 electro-magnets of the SOLEIL Storage Ring have been characterized in terms of magnetic axis centering and field properties. For the dipoles, two types of measurements have been performed at SOLEIL: field mapping in the mid plan using a Hall probes bench, and field integral comparison with a reference magnet using a stretched wire bench. For the quadrupoles, a rotating coil bench has been built and optimized at SOLEIL in order to reach magnetic center and tilt angle adjustments within ± 25 μm and ± 0.1 mrad respectively. For the sextupoles, magnetic measurements have been performed by the SIGMAPHI Company. This paper will present the main features of the SOLEIL benches, the results of magnetic measurements in terms of reproducibility, field identity between magnets, magnetic axis centering, and harmonic content versus current. Moreover, the origin of some unexpected harmonic field components will be discussed, as well as the magnetic compensation scheme used to minimize some of them.  
 
THPLS013 The Magnets of the Metrology Light Source in Berlin-Adlershof quadrupole, sextupole, storage-ring, octupole 3296
 
  • P. Budz, M. Abo-Bakr, K. Buerkmann-Gehrlein, V. Duerr, J. Kolbe, D. Krämer, J. Rahn, G. Wüstefeld
    BESSY GmbH, Berlin
  • I.N. Churkin, E.R. Rouvinsky, E.P. Semenov, S.V. Sinyatkin, A.G. Steshov
    BINP SB RAS, Novosibirsk
  • R. Klein, G. Ulm
    PTB, Berlin
  PTB, the German National Metrology Institute in close cooperation with BESSY II, is currently carrying out the project of constructing the low-energy "Metrology Light Source" (MLS) as a synchrotron radiation facility situated in the close vicinity of BESSY II. Construction of the MLS housing is in progress and nearly finished. The user operation is scheduled to begin in 2008. Dedicated to metrology and technology development in the UV and EUV spectral range, the MLS will bridge the gap that is existent since the shutdown of BESSY I. A 100 MeV microtron delivered by Danfysik A/S will provide the electrons for the MLS with a structure of asymmetric double bend achromat. The total circumference of the MLS is 48 m. The electron energy is ramped to the desired value between 200 MeV and 600 MeV. The MLS magnetic lattice, consisting of 8 bending magnets, 24 quadrupole magnets, 24 sextupole magnets and 4 octupole magnets, is laid out to facilitate this operation. The contract for the MLS magnets is awarded to the Budker Institute for Nuclear Physics. A description of the MLS magnets based on the results of the factory acceptance tests should be presented.  
 
THPLS029 Commissioning of the Booster Synchrotron for the Diamond Light Source booster, DIAMOND, injection, extraction 3344
 
  • V.C. Kempson, R. Bartolini, C. Christou, J.A. Dobbing, G.M.A. Duller, M.T. Heron, I.P.S. Martin, G. Rehm, J.H. Rowland, B. Singh
    Diamond, Oxfordshire
  The Diamond booster is a 158 m circumference, 5 Hz synchrotron which accelerates the 100 MeV electron beam from a linac to 3 GeV for full-energy injection into the Diamond storage ring. The booster has been commissioned in the first few months of 2006, following successful initial 100 MeV trials at the very end of 2005. The injection and ramping process, orbit correction and essential beam physics measurements are discussed as are extraction and beam transport to the storage ring.  
 
THPLS033 Elettra New Full Energy Injector Status Report booster, ELETTRA, quadrupole, storage-ring 3356
 
  • M. Svandrlik, S. Bassanese, F.C. Cargnello, A. Carniel, K. Casarin, D. Castronovo, P. Craievich, G. D'Auria, R. De Monte, S. Di Mitri, A. Fabris, R. Fabris, M. Ferianis, A. Gambitta, F. Giacuzzo, M. Giannini, F. Iazzourene, G.L. Loda, M. Lonza, F.M. Mazzolini, D.M. Morelli, G. Pangon, C. Pasotti, G. Penco, L.P. Pivetta, L. Rumiz, C. Scafuri, G. Tromba, A. Vascotto, R. Visintini, D. Zangrando
    ELETTRA, Basovizza, Trieste
  The Elettra new full energy injector will be based on a 100 MeV linac pre-injector, a 2.5 GeV booster synchrotron and two new beam transfer lines. It will replace the existing 1.2 GeV linac injector and transfer line. Full funding was finally available in 2005, which allowed to start, or in some cases to re-start, the construction activities. The status of the project will be presented in this paper, in particular the progress of the fabrication of various components, like magnets, power supplies, vacuum chambers; also the status of the construction of the building and technical plants will be given. Results of recent optimization studies will also be outlined. The commissioning of the new injector is scheduled to start in Spring 2007, while the first ELETTRA operation for user's with the new full energy injector is expected for the last quarter of 2007.  
 
THPLS043 Status of SESAME vacuum, lattice, power-supply, storage-ring 3383
 
  • G. Vignola, A. Amro, M. Attal, H. Azizi, A. Kaftoosian, F. Makahleh, M.M. Shehab, H. Tarawneh, S. Varnasseri
    SESAME, Amman
  An overview of the status of SESAME is presented. SESAME is a third generation light source facility, with an e-beam energy of 2.5 GeV, located in Allan, Jordan. The emittance is 26 nm.rad and 12 straights are available for insertion devices. The injector consists of a 22.5 MeV microtron and 800 MeV booster synchrotron, with a repetition rate of 1 Hz. The conceptual design of the accelerator complex has been frozen, and the engineering design is in progress. The phase I scientific program for SESAME has also been finalized, and it foresees 6 beam lines, including 2 IR ports. The construction of the SESAME building is in progress, and the beneficial occupancy is expected by the end of 2006. The completion of the accelerators complex construction is scheduled for the end of 2009.  
 
THPLS052 The Vacuum System for the Spanish Synchrotron Light Source (ALBA) vacuum, storage-ring, synchrotron, photon 3398
 
  • E. Al-Dmour, D. Einfeld, M. Q. Quispe, L. Ribó
    ALBA, Bellaterra
  ALBA will be a 3GeV, third generation synchrotron light facility to be built near Barcelona (Spain). The design phase of ALBA is almost completed and the main components have been ordered, which includes the vacuum chambers for the storage ring. Commissioning of the storage ring is foreseen to start at the end of 2008. The circumference of the storage ring of ALBA is 268.8 m, and it will be divided into 16 vacuum sections by ultra high vacuum (UHV) gate valves. The vacuum chamber will be made of stainless steel with an internal vertical aperture of 28 mm and 72 mm width. The vacuum chamber will be connected to an antechamber with a slot of 10 mm height and 20 mm width. The antechamber will have the discrete absorbers, which will absorb the unwanted synchrotron radiation. The pumping will be by sputter ion pumps (SIP) and NEG pumps, with an overall pumping speed from SIP of 57400 l/s. This will maintain an average dynamic pressure of around 1.0·10-9 mbar to achieve a beam lifetime > 15 hours at the designed current. No in-situ bakeout is foreseen, as the vacuum section will be conditioned ex-situ and installed under vacuum to the storage ring.  
 
THPLS057 Injector Design for ALBA booster, linac, quadrupole, storage-ring 3413
 
  • M. Pont, G. Benedetti, D. Einfeld, A. Falone, U. Iriso, M.L. Lopes, M. Muñoz
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • E. Al-Dmour, F. Pérez
    ALBA, Bellaterra
  • W. Joho
    PSI, Villigen
  The storage ring ALBA is a 3rd generation synchrotron light source under construction in Barcelona (Spain). The facility is based on a 3.0 GeV storage ring of 268.8 m circumference with a beam emittance under 5 nm.rad. Top-up operation is foreseen from the start. The injector complex for ALBA will consist of a 100 MeV linac and a full energy booster. The linac will be a turn-key system which has already been ordered to the industry and delivery is expected in the second half of 2007. The full energy booster will be placed in the same tunnel as the storage ring and will have a circumference of 249.6 m. The lattice of the booster is a modified FODO lattice providing an emittance as low as 9 nm.rad. The magnet system comprises 40 combined magnets and 60 quadrupoles. Chromaticity correction relies on the sextupole component built-in the combined magnets and the quadrupoles. In this paper a description of the booster design including the present status of the different components will be given.  
 
THPLS058 MAX III Commissioning vacuum, injection, electron, betatron 3416
 
  • M. Eriksson, M. Bergqvist, M. Brandin, L.-J. Lindgren, M. Sjöström, S. Thorin
    MAX-lab, Lund
  Some of the features of the 700 MeV MAX III synchrotron radiation storage ring are presented, and the commissioning of this ring is described.  
 
THPLS083 Implementation of the Double-waist Chicane Optics in SPEAR 3 optics, lattice, quadrupole, vacuum 3472
 
  • W.J. Corbett, M. Cornacchia, T. Dao, D. Dell'Orco, D. Harrington, R.O. Hettel, X. Huang, Y. Nosochkov, T. Rabedeau, F.S. Rafael, H. Rarback, A. Ringwall, J.A. Safranek, B. Scott, J.J. Sebek, J. Tanabe, A. Terebilo, C. Wermelskirchen, M. Widmeyer
    SLAC, Menlo Park, California
  • M. Yoon
    POSTECH, Pohang, Kyungbuk
  The SPEAR 3 upgrade produced two new 7.6 m racetrack straight sections in the 18 cell, 234 m magnet lattice. One of these straights houses four PEP-II style mode-damped RF cavities. The other straight will accommodate two new small-gap insertion devices separated by 10mrad in a magnetic chicane configuration. A quadrupole triplet has been installed at the midpoint of the chicane and the vertical tune has been raised by an integer to create a 'double waist' optics with betay = 1.6m in the center of each ID. Furthermore, as part of the optics upgrade, betay in the four straights adjacent to the racetrack sections was reduced from 5m to 2.5m. In this paper, we describe the physical implementation of the double-waist chicane optics and initial operational results.  
 
THPLS088 Optimizing the Dynamic Aperture for Triple Bend Achromatic Lattices lattice, emittance, quadrupole, sextupole 3481
 
  • S.L. Kramer, J. Bengtsson
    BNL, Upton, Long Island, New York
  The Triple Bend Achromatic (TBA) lattice has the potential for lower natural emittance per period than the Double Bend Achromatic (DBA) lattice for high brightness light sources. However, the DBA has been chosen for 3rd generation light sources more often due to the higher number of undulator straight section available for a comparable emittance. The TBA has considerable flexibility in linear optics tuning while maintaining this emittance advantage. We have used the tune and chromaticity flexibility of a TBA lattice to minimize the lowest order nonlinearities using a high order achromatic tune condition, while maintaining a constant emittance. This frees the geometric sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the TBA as a proposed lattice for the NSLS-II facility. The flexibility of the TBA lattice will also provide for future upgrade capabilities of the beam parameters.  
 
THPLS089 Comparison of Double Bend and Triple Bend Achromatic Lattice Structures for NSLS-II lattice, emittance, sextupole, wiggler 3484
 
  • S.L. Kramer, J. Bengtsson, S. Krinsky
    BNL, Upton, Long Island, New York
  The Double Bend Achromatic (DBA) and the Triple Bend Achromatic (TBA) lattice have been studied rather extensively for use for the NSLS-II storage ring. The well known advantage of the TBA compared to the DBA is that the emittance per period has the potential to be considerably lower. However, the DBA has been chosen more often due to the greater number of ID straight sections for the users for a desired emittance. We present a comparison of these lattice structures based on the optimization of the non-linear driving terms from the chromatic sextupole and the ease of compensation of these terms using the higher order achromatic cancellation.  
 
THPLS092 Nb-Pb Superconducting RF-Gun cathode, DESY, laser, emittance 3493
 
  • J.S. Sekutowicz, J.I. Iversen, D. Klinke, D. Kostin, W.-D. Möller
    DESY, Hamburg
  • I. Ben-Zvi, A. Burrill, T. Rao, J. Smedley
    BNL, Upton, Long Island, New York
  • M. Ferrario
    INFN/LNF, Frascati (Roma)
  • P. Kneisel
    Jefferson Lab, Newport News, Virginia
  • K. Ko, L. Xiao
    SLAC, Menlo Park, California
  • J. Langner, P. Strzyzewski
    The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock
  • R.S. Lefferts, A.R. Lipski
    SBUNSL, Stony Brook, New York
  • J.B. Rosenzweig
    UCLA, Los Angeles, California
  • K. Szalowski
    University of Lodz, Lodz
  We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.  
 
THPLS138 Fast Polarization Switching at the SLS Microspectroscopy Beamline POLLUX SLS, coupling, feedback, polarization 3610
 
  • M. Böge, U. Flechsig, J. Raabe, T. Schilcher
    PSI, Villigen
  POLLUX is a new microspectroscopy facility which will be operated at a bending magnet at the Swiss Light Source (SLS). It offers spectroscopy with sub-micrometer spatial resolution for polymer science and magnetism. First user operation is scheduled for summer 2006. One of the novel envisaged options of the beamline is the usage of circular polarized light. The circular polarization will be generated by a localized angular steering of the electron beam within the bending magnet. This is accomplished by means of the global fast orbit feedback system of the SLS which allows to stabilize the electron beam to the sub-micrometer level up to frequencies of ~100 Hz. Due to the adapting coupling compensation involving dedicated adjacent skew quadrupoles, this steering becomes practically transparent to the other beamlines. Polarization switching rates of a few Hz are within reach.