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sextupole

  
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MOPCH073 A Project of a High-power FEL Driven by an SC ERL at KAERI FEL, ERL, emittance, dipole 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 dipole, quadrupole, resonance, lattice 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.  
 
MOPCH091 An Alternative Nonlinear Collimation System for the LHC collimation, LHC, optics, insertion 246
 
  • J. Resta-López, R.W. Assmann, S. Redaelli, J. Resta-López, G. Robert-Demolaize, D. Schulte, F. Zimmermann
    CERN, Geneva
  • A. Faus-Golfe
    IFIC, Valencia
  The optics design of an alternative nonlinear collimation system for the LHC is presented. We discuss an optics scheme based on a single spoiler located in between a pair of skew sextupoles for betatron collimation. The nonlinear system allows opening up the collimator gaps and, thereby reduces the collimator impedance, which presently limits the LHC beam intensity. After placing secondary absorbers at optimum locations behind the spoiler, we analyze the beam losses and calculate the cleaning efficiency from tracking studies. The results are compared with those of the conventional linear collimation system.  
 
MOPLS016 LHC IR Upgrade: A Dipole First Option with Local Chromaticity Correction LHC, dipole, 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.  
 
MOPLS017 A Low Gradient Triplet Quadrupole Layout Compatible with NbTi Magnet Technology and Betastar=0.25m LHC, luminosity, quadrupole, CERN 574
 
  • R. de Maria, O.S. Brüning
    CERN, Geneva
  The paper presents a triplet layout option with long (ca. 100 m total triplet length), low gradient (45 T/m to 70 T/m) quadrupole magnets. Assuming a maximum magnet diameter of 200mm, the peak coil field at the magnet coils still remains below 7 T which is still compatible with conventional NbTi magnet technology. The peak beta function inside the triplet magnets reaches 18 km and the configuration therefore requires an additional chromaticity correction scheme similar to a dipole first layout option. However, at the same time, the presented solution provides an interesting alternative to a high gradient triplet layout which requires the new Nb3Ti magnet technology.  
 
MOPLS040 Magnet Structure of the VEPP-2000 Electron-positron Collider quadrupole, collider, dipole, 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.  
 
MOPLS052 Luminosity Improvement at PEP-II Based on Optics Model and Beam-beam Simulation luminosity, simulation, optics, synchrotron 661
 
  • Y. Cai, W.S. Colocho, F.-J. Decker, Y. Nosochkov, P. Raimondi, J. Seeman, K.G. Sonnad, M.K. Sullivan, J.L. Turner, M. Weaver, U. Wienands, W. Wittmer, M. Woodley, Y.T. Yan, G. Yocky
    SLAC, Menlo Park, California
  The model independent analysis (MIA) has been successfully used at PEP-II to understand machine optics and improve the luminosity. However, the rate of success was limited because the improvement of optics does not necessarily lead to increase of luminosity. Recently, we were able to reconstruct MIA model in a full optics code, LEGO, and used it to calculate complete lattice and beam parameters. These parameters were fed to the beam-beam code, BBI, to understand the luminosity histories at PEP-II over the past year. Using these tools, we optimized the luminosity by varying the beam parameters such as emittance. Finally, we implemented an optimized solution with a set of asymmetric horizontal orbit bumps into the machines during a delivery shift with a few percentage gain in luminosity. The solution was retained at PEP-II machines along with the luminosity. Later, these asymmetric bumps also played a vital role in reaching 1x1034cm-2s-1 as the beam currents increased.  
 
MOPLS053 Beta-beat Correction Using Strong Sextupole Bumps in PEP-II luminosity, closed-orbit, coupling, SLAC 664
 
  • G. Yocky
    SLAC, Menlo Park, California
  A method for correcting lattice beta mismatches has been developed for the PEP-II collider using orbit offsets in strong sextupoles. The solution is first predicted in the MAD program by modeling closed orbit bumps in the plane of correction at the sextupoles strongest in that plane. The derived solution is then tested in the machine to confirm the prediction and finally dialed into the machine under high-current conditions.  
 
MOPLS094 Luminosity Tuning at the Interaction Point luminosity, simulation, linac, quadrupole 774
 
  • P. Eliasson, M. Korostelev, D. Schulte, R. Tomas, F. Zimmermann
    CERN, Geneva
  Minimisation of the emittance in a linear collider is not enough to achieve optimal performance. For optimisation of the luminosity, tuning of collision parameters such as angle, offset, waist, etc. is needed, and a fast and reliable tuning signal is required. In this paper tuning knobs are presented, and their optimisation using beamstrahlung as a tuning signal is studied.  
 
MOPLS100 CLIC Final Focus Studies CLIC, luminosity, octupole, quadrupole 792
 
  • R. Tomas, H.-H. Braun, D. Schulte, F. Zimmermann
    CERN, Geneva
  The design of the CLIC final focus system is based on the local compensation scheme proposed by P. Raimondi and A. Seryi. However, there exist important chromatic aberrations that deteriorate the performance of the system. This paper studies the optimization of the final focus based on the computation of the high orders of these aberrations using MAD-X and PTC. The use of octupole doublets to reduce the size of the halo in the locations with aperture limitations is also discussed.  
 
MOPLS117 Tuning Algorithms for the ILC Beam Delivery System luminosity, coupling, emittance, quadrupole 837
 
  • 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 (ILC) with a direct consequence on the luminosity of the machine. The Beam Delivery System represents a major problem in this respect as it produces emittance dilution effects that are difficult to correct and that have a direct effect on the emittance as seen at the interaction point, and thus upon the luminosity of the machine. Tuning algorithms for this section of the machine rely on the correction of aberrations through the use of linear and higher order knobs, using corrections magnets distributed throughout the system. Alternative systems are also discussed. The design and implementation of these tuning algorithms, and their effectiveness in a variety of cases, are investigated and estimates made for tolerances on a variety of error sources. Simulations results are also presented for models of the ATF-2 accelerator under development at KEK, with comparisons made to the ILC design.  
 
MOPLS135 Correction of Vertical Dispersion and Betatron Coupling for the CLIC Damping Ring quadrupole, emittance, dipole, 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.  
 
WEXFI03 Non-linear Collimation in Linear and Circular Colliders collimation, optics, collider, betatron 1892
 
  • A. Faus-Golfe
    IFIC, Valencia
  • J. Resta-López, F. Zimmermann
    CERN, Geneva
  We describe the concept on nonlinear collimation of beam halo in linear and circular colliders. In particular we present the application of such a concept in two different cases: the energy collimation system for CLIC at 3 TeV c.m. energy and a betatron collimation system for LHC at 14 TeV c.m. energy. For each case, the system properties, like chromatic bandwidth, collimator survival and cleaning efficiency, are evaluated and compared with those of the corresponding linear collimation system.  
slides icon Transparencies
 
WEPCH010 Beam-based Alignment for the Storage Ring Multipoles of Synchrotron SOLEIL quadrupole, alignment, SOLEIL, multipole 1939
 
  • A. Madur, P. Brunelle, A. Nadji, L.S. Nadolski
    SOLEIL, Gif-sur-Yvette
  First beam-based alignment (BBA) measurements will be carried out during the commissioning of the SOLEIL Storage Ring that will start in April 2006. The results will allow calibrating the zero reading of the 120 Beam Position Monitors (BPMs) with respect to the magnetic centre of the adjacent quadrupoles or sextupoles. BPMs being either adjacent to quadrupoles or sextupoles, we plan to resort to two different BBA methods related to each multipolar magnet. Moreover, as some BPMs are located near both quadrupole and sextupole, the use of both methods will allow us to cross-check the results. We will present here the first results and the comparison with the positions of the magnetic centres as obtained from the magnetic measurements.  
 
WEPCH026 Recent Progress of Optics Measurement and Correction at KEKB optics, KEKB, betatron, closed-orbit 1981
 
  • A. Morita, H. Koiso, Y. Ohnishi, K. Oide
    KEK, Ibaraki
  We present the progress of the optics measurement and the correction scheme of the KEKB operation for example off-momentum beta correction.  
 
WEPCH028 Position Shuffling of the J-PARC Main Ring Magnets quadrupole, resonance, lattice, betatron 1984
 
  • M. Tomizawa, K. Fan, S. Igarashi, K. Ishii, H. Kobayashi, A.Y. Molodozhentsev, K. Niki, E. Yanaoka
    KEK, Ibaraki
  • Y. Irie
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  The J-PARC 50GeV main ring has 96 dipole, 216 quadrupole with 11 families and 72 sextupole magnets with 3 families. Magnets installation in the tunnel started last year and will be planed to finish by the end of next fiscal year. Field measurements of all magnets will soon finish by this March. Deviations for BL, B'L, B"L in dipole, quadrupole and sextupole magnets make COD, beta beat and third integer stopband, respectively. They can be reduced by choosing a pair of magnets with similar field deviation and by positioning them so as to cancel each other considering betatron phase (shuffling). In this paper, we will report our shufflling scheme chosen under the given schedule for installation and field measurements and also will show performances expected by the shufflings.  
 
WEPCH038 Nonlinear Characteristics of the TME Cell emittance, betatron, resonance, lattice 2002
 
  • V.A. Kvardakov, E. Levichev
    BINP SB RAS, Novosibirsk
  The TME (Theoretical Minimum Emittance) cell is being used now for designing the lattice of different storage rings (SR sources, damping rings, FFAG accelerators, etc.). Strong sextupoles required to correct the natural chromaticity of the lattice reduce the dynamic aperture. In the paper we consider the main features of the nonlinear perturbation strength and its connection with the essential lattice parameters: horizontal emittance, betatron tunes, and natural chromaticity. The analytical results are compared with the computer simulation.  
 
WEPCH048 Measurement and Modeling of Magnetic Hysteresis in the LHC Superconducting Correctors LHC, CERN, injection, controls 2026
 
  • W. Venturini Delsolaro, L. Bottura, Y. C. Chaudhari, M. Karppinen
    CERN, Geneva
  • N.J. Sammut
    University of Malta, Faculty of Engineering, Msida
  The Large Hadron Collider, now under construction at CERN, relies heavily on superconducting magnets for its optics layout: besides the main magnets, almost all the correcting magnets are superconducting. Along with clear advantages, this brings about complications due to the effects of persistent currents in the superconducting filaments. Correcting magnets that trim key beam parameters or compensate field errors of the main magnets (among others those due to hysteresis), are in their turn hysteretic. The measured magnetic hysteresis and its possible influence on accelerator operation will be presented, in particular the real-time compensation of decay and snapback in the main magnets, and the reproducibility between runs. A detailed characterization of minor hysteresis loops is given, as well as degaussing cycles and modeling work.  
 
WEPCH050 Correction of Vertical Dispersion and Betatron Coupling for the TPS Storage Ring emittance, coupling, quadrupole, betatron 2032
 
  • H.-J. Tsai, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, M.-H. Wang
    NSRRC, Hsinchu
  A proposed 3 GeV Taiwan Photon Source (TPS) is a low emittance (1.7 nm-rad) medium energy storage ring with 24 DBA cells. The vertical emittance due to betatron coupling and spurious vertical dispersion generated by the magnet errors and off-center orbits in sextupoles and quadrupoles are analyzed. The sensitivities due to magnetic alignment errors are estimated. Using the SVD method, the result of global vertical dispersion and betatron coupling correction is presented.  
 
WEPCH060 Linear and Nonlinear Coupling Using Decoupling Transformations coupling, storage-ring, quadrupole, lattice 2059
 
  • A. Wolski, A. Sessler
    LBNL, Berkeley, California
  Linear coupling in a storage ring is conveniently analyzed in terms of transformations that put the single-turn map into block-diagonal form. Such a transformation allows us to define new variables, in which the dynamics are uncoupled. Thus, for example, the symplectic conditions are simply that the phase area in each of the uncoupled variables is preserved. In principle, a similar approach may be taken to nonlinear coupling; we discuss such an approach in this paper, giving some simple illustrations of the ideas, based on the well-known techniques of normal form analysis. We also discuss some obstacles to finding a nonlinear decoupling transformation in the general case.  
 
WEPCH061 SABER Optical Design electron, positron, linac, SLAC 2062
 
  • R.A. Erickson, K.L.F. Bane, P. Emma, Y. Nosochkov
    SLAC, Menlo Park, California
  SABER, the South Arc Beam Experimental Region, is a proposed new beam line facility designed to replace the Final Focus Test Beam at SLAC. In this paper, we outline the optical design features and beam parameters now envisioned for SABER. A magnetic chicane to compress positron bunches for SABER and a bypass line that could transport electrons or positrons from the two-thirds point of the linac to SABER, bypassing the LCLS systems, are also discussed.  
 
WEPCH067 Implementation of TPSA in the Mathematica Code LieMath lattice, COSY, octupole, linear-collider 2077
 
  • D. Kaltchev
    TRIUMF, Vancouver
  The Lie Algebra package LieMath written in the Mathematica language constructs the beamline map in a single-exponent Lie generator form. The algorithm (BCH-based map concatenation) has been recently enhanced with Truncated Power Series Algebra (TPSA) techniques.The polynomials produced by the series expansion of the Hamiltonian are replaced with arrays of coefficients (derivative structures) and the Poisson bracket and BCH are defined as operations on such structures. We have confirmed the statement that using automatic differentiation instead of symbolic operations increases the speed by least an order of magnitude. The code is equipped with a MAD parser and a normal form block allowing it to extract nonlinear chromaticity and amplitude detuning. The notebook was applied in FFAG studies and may be useful for the linear collider final focus or collimation systems.  
 
WEPCH072 The High Order Non-linear Beam Dynamics in High Energy Storage Ring of FAIR multipole, resonance, lattice, octupole 2083
 
  • A.N. Chechenin, R. Maier, Y. Senichev, E. Senicheva
    FZJ, Jülich
  The High Energy Storage Ring (HESR) is part of the international project FAIR for antiproton physics with beam in the momentum range from 1.5 to 15 GeV/c to explore the research areas of hadron structure and quark-gluon dynamics. An important feature of the project is the combination of phase space cooled beams with thick internal targets. Therefore there are two obvious reasons of beam heating: the target-beam interaction and the intra-beam scattering. Another source of the beam size growth is the higher order resonances. In the paper we investigate the non-linear beam dynamics together with different correction schemes minimizing this effect and compare with other sources of beam heating. Since the tune working point has a spread dependent on the chromaticity correction scheme and space charge, we include in our consideration both effects as well. All beam dynamics calculations are carried out with the SIMBAD code from the Unified Accelerator Library (UAL). We use 10000 macro particles, grid sizes 64x64 and 1000 turns per run.  
 
WEPCH074 Progress with Non-linear Beam Dynamic Studies of the Diamond Storage Ring lattice, injection, dynamic-aperture, DIAMOND 2089
 
  • R. Bartolini, I.P.S. Martin, B. Singh
    Diamond, Oxfordshire
  • J.K. Jones
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The conflicting requirements of high-brightness photon beams combined with adequate beam lifetime and high injection efficiency mean careful control of the non-linear lattice is crucial to achieving optimum performance. As part of the optimisation of the Diamond storage ring, studies have been made of both the Touschek lifetime and storage ring injection process, with the help of on-momentum and off-momentum frequency maps. The effect of chromaticity on Touschek lifetime has also been investigated and several new sextupole settings were identified achieving good Touschek lifetime and injection efficiency.  
 
WEPCH076 Renormalization Group Reduction of the Frobenius-Perron Operator resonance, betatron, lattice, storage-ring 2095
 
  • S.I. Tzenov
    Universita' degli Studi di Salerno, Dipartimento di Fisica E.R. Caianiello, Baronissi
  The Renormalization Group (RG) method is adopted as a tool for a constructive analysis of the properties of the Frobenius-Perron Operator. The renormalization group reduction of a generic symplectic map in the case, where the unperturbed rotation frequency of the map is far from structural resonances driven by the kick perturbation has been performed in detail. It is further shown that if the unperturbed rotation frequency is close to a resonance, the reduced RG map of the Frobenius-Perron operator (or phase-space density propagator) is equivalent to a discrete Fokker-Planck equation for the renormalized distribution function. The RG method has been also applied to study the stochastic properties of the standard Chirikov-Taylor map.  
 
WEPCH077 Particle Tracking in a Sextupole Field using the Euler Method Approximation lattice, dynamic-aperture, ELETTRA, LEFT 2098
 
  • S. Di Mitri, E. Karantzoulis
    ELETTRA, Basovizza, Trieste
  The purpose of this paper is to evaluate any differences in the single particle tracking through a magnetic lattice when sextupoles are treated either like sliced or single-kick elements. Only on-energy transverse motion is considered. Convergence and symplecticity of the method of sliced sextupoles are discussed. Dynamic apertures and transverse phase spaces applied to the Elettra synchrotron lattice are compared for the two cases.  
 
WEPCH079 Effects of Intrinsic Nonlinear Fields in the J-PARC RCS resonance, simulation, space-charge, injection 2104
 
  • H. Hotchi, Y. Irie, F. Noda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • A.Y. Molodozhentsev
    KEK, Ibaraki
  In order to accelerate a high intense proton beam with small particle losses, the J-PARC RCS, which is being constructed at JAEA, has a large acceptance. In such synchrotrons, the nonlinear motion of the beam particles, especially moving away from the axis of the elements, is a common issue, and it becomes essential to consider intrinsic field nonlinearities. The main sources of nonlinear magnetic fields in the RCS are as follows: fringes of the main dipole and quadrupole magnets, sextupole fields used for the chromatic correction, leak fields from the injection and extraction beam lines, etc. In this paper, we will discuss influences of the intrinsic field nonlinearities and a cure for the induced betatron resonances, based on single-particle and multi-particle tracking simulations.  
 
WEPCH085 Algorithms for Chromatic Sextupole Optimization and Dynamic Aperture Increase dynamic-aperture, lattice, storage-ring, betatron 2116
 
  • E. Levichev, P.A. Piminov
    BINP SB RAS, Novosibirsk
  Strong chromatic sextupoles compensating natural chromaticity of a storage ring may reduce dynamic aperture drastically. In the case of several sextupole families, one can find a lot of ways to correct chromaticity, which provides different sizes of the dynamic aperture. Finding a solution that gives the largest dynamic aperture is an important task for the storage ring design and operation. The paper discusses several approaches to sextupole arrangement optimization in order to obtain a large dynamic aperture.  
 
WEPCH096 Measurement and Correction of the 3rd Order Resonance in the Tevatron resonance, coupling, CERN, dipole 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.  
 
WEPLS010 20 - 50 GeV Muon Storage Rings for a Neutrino Factory lattice, site, injection, storage-ring 2415
 
  • G. Rees
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • C. Johnstone
    Fermilab, Batavia, Illinois
  • F. Meot
    CEA, Gif-sur-Yvette
  Muon decay ring studies are being undertaken as part of the International Scoping Study (ISS) for a Neutrino Factory. A racetrack and an isosceles triangle shaped ring are under design, initially for a muon energy of 20 GeV, but with an upgrade potential for 50 GeV. Both rings are designed with long straights to optimize directional muon decay. The neutrinos from the muon decays pass to one or two distant detectors; the racetrack ring has one very long production straight, aligned with one detector, while the triangular ring has two straights, each half as long, which can be aligned with two detectors. Lattice studies, injection, collimation, and RF system design for the large acceptance, high intensity rings are discussed and the performance of the two rings compared.  
 
WEPLS016 Studies of a Gas-filled Helical Muon Beam Cooling Channel simulation, emittance, dipole, 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.  
 
WEPLS066 Harmonic Measurement and Adjustment of Diamond Quadrupoles DIAMOND, octupole, quadrupole, alignment 2532
 
  • C.P. Bailey, N. Marks
    Diamond, Oxfordshire
  • F. Goldie, B. Leigh
    Tesla Engineering Limited, West-Sussex
  The 254 quadrupole magnets for Diamond, manufactured by Tesla Engineering Ltd, were measured for harmonic content to a level around 1 part in 104. In order to meet the demanding requirements on field quality, procedures were then developed to adjust the relative positions of the magnet quadrants such that the desired harmonic levels were achieved. This process was integrated into the analysis software so that the needed changes were specified. The measurements were performed on a seven-coil rotating coil rig, which also enabled the alignment of the magnet in five spatial degrees of freedom to the specified accuracy. In this report we describe the measurement and correction procedures and present a summary of the results that were obtained.  
 
WEPLS067 Magnets for the 3 GeV Booster Synchrotron for the Diamond Light Source dipole, quadrupole, 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.  
 
WEPLS070 The Elettra Booster Magnets Construction Status booster, dipole, 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.  
 
WEPLS072 Results of Field Measurements for J-PARC Main Ring Magnets quadrupole, multipole, optics, injection 2547
 
  • K. Niki, K. Ishii, Y. Nemoto, E. Yanaoka
    KEK, Ibaraki
  • M. Muto
    New Affiliation Request Pending, -TBS-
  The mass production of J-PARC main ring magnets had been completed till the end of fiscal year 2004. Those magnets consists of 97 bending magnets with 6-m in length, 216 quadrupole magnets with 11 families and 72 sextupole magnets. We have been measured the magnetic field for all of these magnets and we will finish it in March, 2006. The obtained distributions for the BL products of bending magnets and the GL products of quadrupole magnets are within the required tolerance limits, values of which are estimated by the beam optics for COD correction, etc. The measured multi-pole components for these magnets, and so on, will be also reported.  
 
WEPLS074 SESAME Magnets System dipole, quadrupole, 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.  
 
WEPLS080 Magnets for the Storage Ring ALBA quadrupole, multipole, dipole, 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, dipole, 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.  
 
WEPLS110 New Measurements of Sextupole Field Decay and Snapback Effect on Tevatron Dipole Magnets dipole, injection, 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.  
 
WEPLS125 Diamond Storage Ring Magnet Power Converters controls, dipole, quadrupole, 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.  
 
WEPLS126 CNAO Resonance Sextupole Magnet Power Converters controls, power-supply, proton, ion 2670
 
  • M.F. Farioli, F. Burini, S. Carrozza, M. Cavazza, S. Minisgallo, M.P.C. Pretelli, G. Taddia
    O.C.E.M. S.p.A., Bologna
  • D. Bagnara, M. Spera, A. Tilli, M. Toniato
    CASY, Bologna
  • I. De Cesaris
    CNAO Foundation, Milan
  • M. Incurvati, C. Sanelli
    INFN/LNF, Frascati (Roma)
  The CNAO Resonance Sextupole Magnet Power Converter requirements for the Storage Ring of the CNAO Project are described together with performance and initial operating experience. In particular the achieved performances will be compared with the specification and the extensive modelling that was done during the design phase. Not only the tight required performances were emphasized during the design phase but also particular attention was put on reliability and minimization of the repairing time (MTTR). Some fundamental criteria, like component de-rating and standardisation, have also been taken into account during the component choice phase. All converters adopt the switching technology with full digital control and a common control interface, that, as for the other CNAO power converters, uses the same digital controller, under licence from the Diamond Light Source.  
 
THOAFI03 Global and Local Coupling Compensation in RHIC using AC Dipoles coupling, RHIC, quadrupole, dipole 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
 
THPCH013 Study of Particle Losses Mechanism for J-PARC Main Ring resonance, injection, space-charge, emittance 2811
 
  • A.Y. Molodozhentsev, M. Tomizawa
    KEK, Ibaraki
  Detailed understanding as well as confidence in simulation modeling of long-term effects (~ 100'000 turns) of high intensity proton beam is crucial for Main Ring (MR) of the J-PARC project, where it is necessary to hold the high-intensity beam over typically ~ 2 sec with a loss level less than 1%. The major focus of such study is the combined effect of space charge and nonlinear resonances and its impact on halo formation and/or beam loss. In frame of this report, the tracking results for the injection process including realistic representation of the ring's focusing structure are discussed. Optimization of the working point during the injection process is presented. The halo formation and particle losses during the injection and acceleration for MR have been estimated for realistic magnetic field errors.  
 
THPLS007 Magnetic Measurements Results of the Dipoles, Quadrupoles and Sextupoles of the SOLEIL Storage Ring quadrupole, dipole, SOLEIL, 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, dipole, 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.  
 
THPLS021 Dynamic Aperture Studies for PETRA III dynamic-aperture, PETRA, undulator, wiggler 3320
 
  • Y.J. Li, K. Balewski, W. Decking
    DESY, Hamburg
  PETRA III is a low-emittance storage ring dedicated to synchrotron radiation. For efficient injection in the top-up mode, the dynamic aperture has to be larger than 30 mm-mrad in the horizontal plane. This paper presents the choice of tunes and the optimization of the sextupole configuration. Tracking simulations have been performed, including the non-linear effects of 20 four-meters-long damping wigglers and a representative set of undulators. Misalignment and multipole errors are considered as well, leading to specifications for the magnet design and alignment procedure.  
 
THPLS035 Next Generation Light Source Storage Ring at SPring-8 emittance, storage-ring, dynamic-aperture, coupling 3362
 
  • K. Tsumaki, N. Kumagai
    JASRI/SPring-8, Hyogo-ken
  A linac-based XFEL and an ERL are widely accepted as next-generation light sources. But they still have many technologically difficult problems to overcome. In contrast, electron beams in a storage ring are very stable. Thus, we examined the possibility of the storage ring as a next-generation light source. We designed a storage ring with an energy of 6 GeV and a circumference of 1436 m. The ring consists of 24 ten-bend achromat cells and has a natural emittance of 83 pm·rad. The circumference is equal to that of SPring-8 storage ring and the cell length is two times, which enables us to replace the existing storage ring with this new one in the SPring-8 tunnel and use the photon beam-lines without constructing new ones. Particle tracking simulation showed that the horizontal dynamic aperture at the center of a straight section is -3.7 mm and +3.4 mm and that it can be increased to -6.6 mm and +10.0 mm by changing the sextupole strength for chromaticity correction while keeping zero chromaticity. In this paper, we describe the design and the dynamic aperture of the extremely low emittance storage ring at SPring-8.  
 
THPLS063 Nonlinear Beam Dynamics of TPS lattice, dynamic-aperture, resonance, injection 3430
 
  • H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  A design study of 3.0 GeV high performance low emittance storage ring Taiwan Photon Source has been conducted recently The natural emittance of the storage ring can be as low as 1.7 nm-rad in our design and its lattice structure is a 24-cell double bend achromat type with circumference of 518.4 m, which will be located in the existing NSRRC site in Hsinchu. The strong focusing requires strong aberration correction with nonlinear sextupole magnets. The distribution of the sextupoles and number of families are studied to ensure a good dynamic aperture. The nonlinear effects in both betatron and synchrotron motions are investigated. Nonlinear beam dynamics effects in the presence of magnetic field imperfections as well as the insertion devices are simulated. The physical aperture limitations are included in the study too, and the Touschek lifetime is calculated. The tracking data are analyzed using frequency map analysis method and corresponding beam dynamics behavior can be revealed more precisely.  
 
THPLS073 Effect of Nonlinear Synchrotron Motion on TPS Energy Acceptance synchrotron, lattice, vacuum, emittance 3451
 
  • M.-H. Wang, H.-P. Chang, C.-C. Kuo, G.-H. Luo
    NSRRC, Hsinchu
  For design of new generation synchrotron light source the first order momentum compaction factor is usually small. The contribution of second order momentum compaction factor can't be neglected. The longitudinal phase space changes significantly due to the nonlinear effect. This will affect the energy acceptance of the particles and reduce the Touschek beam life time. In this paper we analyze the effect of the nonlinear synchrotron motion of TPS lattice design*. The reduction of energy acceptance is estimated. The contribution to second order momentum compaction factor is discussed. Efforts to minimize this nonlinear effect will also be addressed.

*C. C. Kuo et al., "Design of Taiwan Future Synchrotron Light Source", these proceedings.

 
 
THPLS087 A Control Theory Approach for Dynamic Aperture dynamic-aperture, lattice, controls, synchrotron 3478
 
  • J. Bengtsson
    BNL, Upton, Long Island, New York
  The dynamic aperture problem dates back to the design of the first synchrotrons. Over time, both analytical and numerical methods have been pursued. In the former case mainly by applying techniques developed for celestial mechanics to rather simplified equations of motion. Over the last decade, analysis of the Poincare map has become the method of choice. In particular, application of symplectic integrators, truncated power series algebra, and Lie series techniques has led to a complete set of tools for self-consistent numerical simulations and analytic treatment of realistic models. Nevertheless, a control theory for the general nonlinear case remains elusive. We summarize how to apply this framework to the design of modern synchrotron light sources. Moreover, we also outline how a control theory can be formulated based on the Lie generators for the nonlinear terms.  
 
THPLS088 Optimizing the Dynamic Aperture for Triple Bend Achromatic Lattices lattice, emittance, quadrupole, dipole 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, wiggler, dipole 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.  
 
THPLS091 Control of Dynamic Aperture with Insertion Devices lattice, optics, dynamic-aperture, quadrupole 3490
 
  • T.V. Shaftan, J. Bengtsson, S.L. Kramer
    BNL, Upton, Long Island, New York
  It is well known that insertion devices (IDs) perturb the linear optics in the vertical plane. In particular, that the effect can be corrected locally by a symmetric arrangement of four quadrupoles on each side of the IDs. We show how to control an arbitrary set of IDs in this configuration with the response matrix for the beta-beat and perturbation of the phase advance and SVD, i.e., to maintain the dynamic aperture. We also evaluate the residual impact on the dynamic aperture from the nonlinear terms and outline how to control these. As an example, we discuss an impact of some ID models on the NSLS-2 dynamic aperture. Results for a single ID and a set of 20 IDs with random field strengths are presented.  
 
THPLS107 Possibility of the Beam Injection Using a Single Pulsed Sextupole Magnet in Electron Storage Rings injection, electron, storage-ring, quadrupole 3526
 
  • Y. Kobayashi, K. Harada
    KEK, Ibaraki
  Recently, we succeeded in the beam injection using a single pulsed quadrupole magnet (PQM) at the Photon Factory Advanced Ring (PF-AR). The PQM enables us to inject the beam into the storage ring without the local bump by several pulsed dipole magnets. In addition, since the stored beam is not kicked when the beam passes through the magnetic center of the PQM, we can avoid the coherent beam oscillation, which is often produced by the unclosed local bump. It is important for the top-up injection in electron storage rings as synchrotron radiation sources. However, in the case of the PQM, we have the problem that the beam profile slightly changes turn-by-turn after the excitation of the PQM. In order to solve it, we investigated the possibility of the beam injection using a single pulsed sextupole magnet (PSM) instead of the PQM. Here, we will present the simulation of the beam injection using the PSM.