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multipole

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MOPA001 Advances in the Understanding and Operations of Superconducting Colliders dipole, sextupole, injection, coupling 54
 
  • P. Bauer, G. Annala, M.A. Martens, V.D. Shiltsev, G. Velev
    Fermilab, Batavia, Illinois
  • L. Bottura, N.J. Sammut
    CERN, Geneva
  Chromaticity drift is a well-known and more or less understood phenomenon in superconducting colliders such as the Tevatron. Less known is the effect of tune and coupling drift, also observed in the Tevatron during injection. Recently, in the context of the Tevatron collider run II, extensive studies of chromaticity, tune and coupling drifts were conducted to improve Tevatron performance. The studies included not only beam studies but also extensive off-line magnetic measurements on spare Tevatron dipoles. Some of these measurements were conducted in collaboration with Cern. Cern’s interest in multipole drifts is related to the future LHC, which will have similar issues. The following will report on the results of these studies. A new result, which will be presented here also, is related to fast drifts occurring in the first few seconds of the injection porch. These fast drifts were observed first in the Tevatron and efforts are underway to explain them. The author will also attempt to broaden the discussion to include the discussion of drift effects in the accelerating fields of superconducting linear accelerators.  
 
MOPA008 On the Feasibility of a Tripler Upgrade for LHC dipole, photon, synchrotron, injection 634
 
  • P.M. McIntyre, A. Sattarov
    Texas A&M University, College Station, Texas
  Funding: This work is supported by the U.S. Dept. of Energy, grant #DE-FG03-95ER40924.

Recent developments in the performance of superconductors and the design of high-field superconducting dipoles have opened the possibility to extend dipole field strength to ~25 Tesla in the arc dipoles of a future hadron collider. Design issues are presented for a concept of a Tripler upgrade of LHC, in which a second dual ring would be installed over the LHC ring in the same tunnel. Proton beams from LHC would be transferred to the Tripler midway through the LHC cycle and accelerated to ~20 TeV/beam for collisions. A number of obvious issues are explored. Synchrotron radiation power would be 80 times greater, but the critical energy would come as soft X-rays rather than hard UV, and so could be absorbed locally on ~150 K photon stops following each dipole so that total refrigeration power could perhaps be no more than that for LHC. Synchrotron damping would be dramatically enhanced in the Tripler compared to LHC, with damping times of ~one hour. Alternatives for beam transfer and low-beta insertions will be discussed. Like LHC, the Tripler would access new mass scales primarily through gluon fusion. The Tripler should reach about twice the mass scale attainable with LHC.

 
 
MPPE004 Evaluation of Nonlinear Effects in the 3GeV Rapid Cycling Synchrotron of J-PARC resonance, dipole, sextupole, simulation 916
 
  • H. Hotchi, F. Noda, N. Tani
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • J. Kishiro, S. Machida, A.Y. Molodojentsev
    KEK, Ibaraki
  In order to accelerate an ultra-high intense beam with small particle losses, the 3GeV Rapid Cycling Synchrotron (RCS) of J-PARC, which is being constructed at JAERI, has a large acceptance. In this case the nonlinearity associated with the motion of particles at large amplitude and large momentum deviation plays a significant role. The sources of nonlinear magnetic fields in RCS are mainly connected with the fringe of the main dipole and quadrupole magnets and with the sextupole magnets used for the linear chromaticity correction. In this paper, we will present simulation results including such nonlinear effects. In addition, the possible correction scheme for the induced transverse resonances will be discussed.  
 
MPPE009 2003-2004 Nonlinear Optics Measurements and Modeling for the CERN SPS optics, dipole, simulation, quadrupole 1171
 
  • A. Faus-Golfe
    IFIC, Valencia
  • G. Arduini, F. Zimmermann
    CERN, Geneva
  • R. Tomas
    CELLS, Bellaterra (Cerdanyola del Vallès)
  In 2003 and 2004 nonlinear chromaticity, amplitude detuning, chromatic phase advance, resonance driving terms and off-energy orbits were measured in the CERN SPS at 14 GeV/c and 26 GeV/c, respectively. From the nonlinear chromaticity, the SPS optics model has been updated, by adjusting the strength of nonlinear field errors in dipoles and quadrupoles. Furthermore, we have added to the model the effect of the displacement of all main bends and the voluntary misalignments of all the other elements of the machine. We compare the field errors with those founded in 2002, 2001 and 2000. The tune shifts with transverse amplitude, driving terms, etc., predicted by this nonlinear optics model are compared with direct measurements.  
 
MPPE025 Dynamical Effects Due to Fringe Field of the Magnets in Circular Accelerators quadrupole, resonance, dynamic-aperture, dipole 1907
 
  • Y. Cai, Y. Nosochkov
    SLAC, Menlo Park, California
  Funding: Work supported by the Department of Energy under Contract No. DE-AC02-76SF00515.

The leading Lie generators, including the chromatic effects, due to hard edge fringe field of single multipole and solenoid are derived from the vector potentials within a Halmitonian system. These nonlinear generators are applied to the interaction region of PEP-II to analyze the linear errors due to the feed-down from the off-centered quadrupoles and solenoid. The nonlinear effects of tune shifts at large amplitude, the synchro-betatron sidebands near half integer and their impacts on the dynamic aperture are studied in the paper.

 
 
MPPE039 A C++ Framework for Conducting High-speed, Long-term Particle Tracking Simulations lattice, insertion, quadrupole, factory 2565
 
  • A.C. Kabel
    SLAC, Menlo Park, California
  High-resolution tracking studies such as the ones presented in*,** require unprecented amounts of CPU power. Usually, flexibility of a simulation code compromises performance; we have developed a C++ framework for parallel simulation of circular accelerators which provides a high degree of flexibility and programmability (parsing of MAD beamline descriptions, manipulation of beamlines and interfaces, optimization and matching of beamlines, tracking of particles or differential-algebraic objects) while achieving raw tracking speeds comparable to and surpassing hand-coded Fortran code. We describe some of the techniques used, such as compile-time polymorphism, meta-programming, and present benchmarking results.

*A. Kabel, Y. Cai, this conference. **A. Kabel, Y. Cai, T. Sen, V. Shiltsev, this conference.

 
 
MPPE052 Study on Coupling Issues in the Recycler at Fermilab coupling, injection, simulation, lattice 3209
 
  • M. Xiao, Y. Alexahin, D.E. Johnson, M.-J. Yang
    Fermilab, Batavia, Illinois
  We have been working and trying to answer the following questions: where are the coupling sources in the Recycler and is the existing correcting system working fine? In this paper, we report the analysis on the sources from both modeling by code MAD based on nonlinear lattice and real machine. From the first turn flesh orbit, we fit the off-plane orbits by third order polynomial, then separate 1st, 2nd and 3rd order coefficients to see different effects. On the other hand, we present the analysis from turn by turn data, which is to verify the phase of two skew quads families are more or less orthogonal, and to make sure the minimum tune split is small enough, and is consistent with the measurement.  
 
MPPE083 Harmonic Decomposition of Orbit Data for Multipole Analysis coupling, extraction, dipole, sextupole 4120
 
  • M.-J. Yang
    Fermilab, Batavia, Illinois
  The unprecedented position resolution provided by the newly commissioned Recycer BPM system is opening up a new chapter of beam based multipole analysis at Fermilab. The closed orbit data, taken with circulating beam and averaged over many consecutive turns, has been shown to have the resolution of a few microns. The result of polynomial fit to BPM position data, as a function of dipole kick sizes, is used to separate orbit data into first, second, and third order. Combining both the in-plane and cross-plane orbit data it is possible to determine the multipole content within each half cell. This paper presents the algorithm behind the procedure, the data collected from the Fermilab Recycler Ring, and the final analysis result.  
 
MPPE084 Multipole error Analysis Using Local 3-Bump Orbit Data in Fermilab Recycler coupling, quadrupole, dipole, closed-orbit 4144
 
  • M.-J. Yang, M. Xiao
    Fermilab, Batavia, Illinois
  The magnetic harmonic errors of the Fermilab Recycler ring were examined using circulating beam data taken with closed local orbit bumps. Data was first parsed into harmonic orbits of first, second, and third order. Each of which was analyzed for sources of magnetic errors of corresponding order. This study was made possible only with the incredible resolution of a new BPM system that was commissioned after June of 2003.  
 
MPPP025 The Impedance of the Ceramic Chamber in J-PARC impedance, space-charge, electron 1898
 
  • Y. Shobuda
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y.H. Chin, K. Ohmi, T. Toyama
    KEK, Ibaraki
  The ceramic chamber is adopted at the RCS (rapid cycling synchrotron) in J-PARC. The copper stripes are on the outer surface of the chamber in order to shield the electro-magnetic field produced by the beam. The inner surface of the chamber is coated by TiN to suppress the secondary electron emission. In this paper, we calculate the strength of electro-magnetic field produced by the beam and evaluate the impedance of this ceramic chamber.  
 
MPPP028 The Code MBIM1 for the Calculation of the Multibunch Beams Coherent Oscillations Stability (in Approach of Short Bunches) synchrotron, electron, storage-ring, positron 2009
 
  • N. Mityanina
    BINP SB RAS, Novosibirsk
  The code MBIM1 for the calculation of the coherent oscillations stability for multibunch beams in storage rings is presented. The multibunch beams with arbitrary charges of bunches are considered, including counterrotating bunches (in approach of short bunches in comparison with minimal wavelength of considered environment RF spectrum), with the account of beams coupling with the environment (i.e. RF cavities or/and smooth vacuum chamber with walls of finite conductivity). The code uses the approach of small shifts of coherent frequencies, when different multipole types of synchrotron oscillations can be treated as independent from each other.  
 
MPPP029 The Code MBIM2 for the Calculation of the Arbitrary Multibunch Beams Longitudinal Coherent Oscillations Stability (in the Case of Long Bunches) synchrotron, damping, impedance, single-bunch 2110
 
  • N. Mityanina
    BINP SB RAS, Novosibirsk
  The presented code is an advanced version of the code MBIM1 also presented at this conference and dealing with short bunches. The code MBIM2 analyses the stability of longitudinal coherent motion for arbitrary multibunch beams in storage rings without limitations on the bunch length or RF cavities wavelength, which is especially important for higher types of multipole synchrotron oscillations. The code implies also the possibility to consider coupling between different types of multipole synchrotron oscillations and Landau damping. In considered approach, the problem reduces to the eigenvalue problem for the linear algebraic equation system. The order of this system is equal to the number of bunches times number of multipole types times approximation order wich appears to be small (a few units) in most cases.  
 
MPPP030 Analytic Evaluation of the Series over Azimuthal Harmonics at the Analysis of the Stability of Bunched Beams Coherent Oscillations impedance, synchrotron, coupling, RF-structure 2149
 
  • N. Mityanina
    BINP SB RAS, Novosibirsk
  At the analysis of the stability of coherent motion of multibunch beams including counterrotating beams) one should deal with expressions analogous to the effective impedance - the serieses over harmonics of revolution frequency of the RF structure impedance at the side frequencies to these harmonics, with certain factors depending on the harmonic number, such as the bunch line density spectrum, the phase factor and the factor describing the order of multipole synchrotron oscillations. In this paper, we present the method for analytic summation of these serieses for resonant impedance, which seems not to be made before in the common case including all mentioned factors. Comparison of obtained expressions with formulae used in previous papers shows the limits of validity of simpler approaches. The obtained expressions are used in the computer codes MBIM1 and MBIM2 presented at this conference, which calculate coherent oscillations stability for arbitrary multibunch beams.  
 
MPPP051 Transverse Impedance of Two-Layer Tube impedance, vacuum, dipole, undulator 3138
 
  • M. Ivanyan, A.V. Tsakanian
    CANDLE, Yerevan
  The exact analytical expressions for the multipole longitudinaland transverse impedances of two-layer tube with finite wall thickness areobtained. The numerical examples for the impedances of the vacuum chamberwith laminated walls are given.  
 
MPPT002 Design and Experiment of the BEPCII IR Conventional Dual Aperture Quadrupole quadrupole, septum, interaction-region, magnet-design
 
  • Z. Yin, Y. Wu, J.F. Zhang
    IHEP Beijing, Beijing
  The quadrupole magnet Q1a is one of the final horizontal focus quadrupoles for the Beijing Electron-Positron Collider Interaction Region (BEPCII IR). The BEPCII IR lattice design specification calls for a very high field quality for the quadrupole magnet. The Q1a is a conventional dual apertures quadrupole magnet. The required integral quadrupole strengths in two apertures are the same. This magnet is a septum quadrupole with high current density and solid core. 2D pole contour optimization and pole end chamfers are used to minimize harmonic error. The design methods, experiment results and magnet performances are described in this paper.  
 
MPPT004 End Chamfer Study and Field Measurements of the BEPCII Dipoles dipole, sextupole, quadrupole, factory 919
 
  • W. Chen, C. Cao, C. Shi, Z. Yin
    IHEP Beijing, Beijing
  The new BEPCII double ring will be added in the existing BEPC tunnel. There are more than 40 bending magnets named 67B in the new ring. The 67B is conventional ‘C’-type dipole magnet. The magnetic filed properties are dominated by the magnet end effect. The end effect have been studied and minimized by a proper end chamfer. Magnetic measurements of the prototype and productions were carried out using long coil. The developing process of the pole end chamfers and the measurement results of the 67B prototype and batch productions are described in the paper.  
 
MPPT010 A New Correction Magnet Package for the Fermilab Booster Synchrotron quadrupole, sextupole, dipole, booster 1204
 
  • V.S. Kashikhin, D.J. Harding, J.A. John, J.R. Lackey, A. Makarov, W. Pellico, E. Prebys
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76CH03000.

Since its initial operation over 30 years ago, most correction magnets in the Fermilab Booster Synchrotron have only been able to fully correct the orbit, tunes, coupling, and chromaticity at injection (400MeV). We have designed a new correction package, including horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles, to provide control up to the extraction energy (8GeV). In addition to tracking the 15Hz cycle of the main, combined function magnets, the quadrupoles and sextupoles must swing through their full range in 1ms during transition crossing. The magnet is made from 12 water-cooled racetrack coils and an iron core with 12 poles, dramatically reducing the effective magnet air gap and increasing the corrector efficiency. Magnetic field analyses of different combinations of multipoles are included.

 
 
MPPT017 Design of Switching Magnet for 20-MeV Beamlines at PEFP vacuum, proton, extraction, simulation 1575
 
  • H.S. Suh, H.S. Han, S.-H. Jeong, Y.G. Jung, H.-S. Kang, H.-G. Lee, K.-H. Park, C. K. Ryu
    PAL, Pohang, Kyungbuk
  Funding: Ministry of Science and Technology.

The PEFP(Proton Engineering Frontier Project) proton linac is designed to have two proton beam extraction lines at the 20-MeV and 100-MeV end. The 20-MeV extraction line is branched out into 5 beamlines by using the switching magnet. The magnet bends the proton beam by +20, +10, 0, -10, -20 degrees, respectively, and has an AC frequency of 5 Hz with a programmable ac power supply. It employs an H-shape, 0.45 T magnetic field, 0.5 m effective magnet length, 30x5 cm bore aperture. The pole shape is optimized for the field levels. Laminated steel of 0.5 mm is enough to suppress the eddy current effect in the yoke. This paper presents the magnet specification and primary design.

 
 
MPPT021 Magnetic Measurement System for the NSLS Superconducting Undulator Vertical Test Facility undulator, vacuum, survey, instrumentation 1730
 
  • D.A. Harder, G. Rakowsky, J. Skaritka
    BNL, Upton, Long Island, New York
  One of the challenges of small-gap superconducting undulators is measurement of magnetic fields within the cold bore to characterize the device performance and to determine magnetic field errors for correction or shimming, as is done for room-temperature undulators. Both detailed field maps and integrated field measurements are required. This paper describes a 6-element, cryogenic Hall probe field mapper for the NSLS Superconducting Undulator Vertical Test Facility (VTF). The probe is designed to work in an aperture only 3 mm high. A pulsed-wire insert is also being developed, for visualization of the trajectory, for locating steering errors and for determining integrated multi-pole errors. The pulsed-wire insert will be interchangeable with the Hall probe mapper. The VTF and the magnetic measurement systems can accommodate undulators up to 0.4 m in length.

*J. Skaritka et al., MEDSI’04.

 
 
MPPT023 A New Magnetic Field Integral Measurement System photon, acceleration, insertion, insertion-device 1808
 
  • J.Z. Xu, I. Vasserman
    ANL, Argonne, Illinois
  Funding: Work supported by U.S. Department of Energy Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

In order to characterize the insertion devices at the Advanced Photon Source (APS) more efficiently, a new stretched-coil magnetic field integral measurement system has been developed. The system uses the latest state-of-the-art field programmable gate array (FPGA) technology to compensate the speed variations of the coil motions. Initial results demonstrate that the system achieves the system measurement accuracy of 0.15 Gauss centimeter (G-cm) in a field integral measurement of 600 G-cm, probably the world’s best accuracy of its kind.

 
 
MPPT024 Rotating Coil Magnetic Measurement System and Measurement Results of Quadrupole Prototype for BEPCII Storage Ring quadrupole, pick-up, dipole, storage-ring 1844
 
  • L. Li, W. Chen, G. Ni, X.J. Sun
    IHEP Beijing, Beijing
  A normal quadrupole prototype magnet with 266-mm long, 105-mm aperture has been designed and fabricated by IHEP. Total of 88 quadrupole magnets are under fabrication. The multipole components, magnetic field gradient and transfer function of the quadrupole magnets were measured in September 2004, using an updated measurement system, which includes a rotating coil measurement system and a Hall probe measurement system. This paper mainly describes the updated harmonic coil magnetic field measurement system and provides the measurement results for BEPC II quadrupole magnets.  
 
MPPT025 Field Quality and Magnetic Center Stability Achieved in a Variable Permanent Magnet Quadrupole for the ILC quadrupole, permanent-magnet, alignment, linear-collider 1913
 
  • Y. Iwashita, T. Mihara
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • C.M. Spencer
    SLAC, Menlo Park, California
  Funding: Work supported in part by Department of Energy contract DE–AC03–76SF00515 and by the Ministry of Education, Science, Sports and Culture, Japan, Grant-in-Aid for Scientific Research (A) 14204023.

The precise tolerances on the last two quadrupoles before the interaction point of the proposed, superconducting e+e- collider (ILC) have not been determined yet. These quads will be aligned with a beam-based alignment (BBA) process during which their integrated strengths will be decreased by 20%. Their magnetic centers must move by less than a few microns during the BBA else a systematic error will be introduced, yielding an increase in the beam spot size. These strong quads must be small to fit in the tight space. A compact, variable, superstrong permanent magnet quad (PMQ) has been fabricated and tested. The PMQ has inner and outer rings of NEOMAX; the outer ring is subdivided along its length and each section can rotate. By rotating different lengths one can vary the integrated strength in small steps. Because of the fixed inner ring and tight mechanical tolerances, the sensitivities of the magnetic center and pole angles to the rotation of the outer rings are largely suppressed. Measurements of the PMQ will be presented, plus how observed small center and angle shifts were further reduced by adjustments to the stopping angles of the rotating rings and by shimming these rings.

 
 
MPPT028 An Air Bearing Rotating Coil Magnetic Measurement System quadrupole, resonance, dipole, permanent-magnet 2038
 
  • S.C. Gottschalk, K.W. Kangas, D.J. Taylor, W.J. Thayer
    STI, Washington
  This paper describes a rotating coil magnetic measurement system supported on air bearings. The design is optimized for measurements of 0.1micron magnetic centerline changes on long, small aperture quadrupoles. Graphite impregnated epoxy resin is used for the coil holder and coil winding forms. Coil holder diameter is 11 mm with a length between supports of 750mm. A pair of coils is used to permit quadrupole bucking during centerline measurements. Coil length is 616mm, inner radius 1.82mm, outer radius 4.74mm. The key features of the mechanical system are simplicity; air bearings for accurate, repeatable measurements without needing warm up time and a vibration isolated stand that uses a steel-topped Newport optical table with air suspension. Coil rotation is achieved by a low noise servo motor controlled by a standalone Ethernet servo board running custom servo software. Coil calibration procedures that correct wire placement errors, tests for mechanical resonances, and other system checks will also be discussed.  
 
MPPT032 Construction and Performance of Superconducting Magnets for Synchrotron Radiation electron, wiggler, radiation, synchrotron 2218
 
  • C.-S. Hwang, C.-H. Chang, C.-K. Chang, H.-P. Chang, C.-T. Chen, H.-H. Chen, J. Chen, J.-R. Chen, Y.-C. Chien, T.-C. Fan, G.-Y. Hsiung, K.-T. Hsu, S-N. Hsu, M.-H. Huang, C.-C. Kuo, F.-Y. Lin
    NSRRC, Hsinchu
  Two superconducting magnets, one wavelength shifter (SWLS) with a field of 5 T and one wiggler (SW6) with a field of 3.2 T, were constructed and routinely operated at NSRRC for generating synchrotron x-rays. In addition, three multipole wigglers (IASW) with fields of 3.1 T will be constructed and installed each in the three achromatic short straight sections. A warm beam duct of 20 mm inner gap and a 1.5 W GM type cryo-cooler were chosen for the SWLS to achieve cryogen-free operation. For the SW6, a cold beam duct of 11 mm inner gap was kept at 100 K temperature and no trim coil compensation is necessary for its operation. Meanwhile, no beam loss was observed when the SW6 was quenched. A cryogenic plant with cooling power of 450 W was constructed to supply the liquid helium for the four superconducting wigglers. The design concept, magnetic field quality, the commissioning results, and the operation performance of these magnets will be presented.  
 
MPPT037 Design Study of Superconducting Magnets for the Super-KEKB Interaction Region quadrupole, superconducting-magnet, interaction-region, luminosity 2470
 
  • N. Ohuchi, Y. Funakoshi, H. Koiso, K. Oide, K. Tsuchiya
    KEK, Ibaraki
  The KEKB accelerator has achieved the highest luminosity of 1.39E1034cm-2s-1 at June-03-2004. For getting the higher luminosity over 1E1035cm-2s-1, the KEKB accelerator group continues to study the upgraded machine of the KEKB, that is the Super-KEKB. The designed machine parameters for this Super-KEKB are the vertical beta of 3 mm at the interaction point (IP), the LER and HER currents of 9.4 A and 4.1 A, and the half crossing angle of 15 mrad for the target luminosity of 1-5E1035cm-2s-1. For achieving these beam parameters, the superconducting magnets (final focus quadrupoles and compensation solenoids) are newly required to design. The magnet-cryostats have very tight spatial constraints against the Belle particle detector and the beam pipe so that the beam and the synchrotron light do not have any interference with the beam pipe. In this design, the final focus quadrupoles generate the field gradient of 42.3 T/m and their effective magnetic lengths are 0.30m and 0.36m in each side with respect to the IP, respectively. The compensation solenoids are overlaid with the quadrupoles. We will report the design of these magnets in detail and show the difficulties for the Super-KEKB-IR.  
 
MPPT042 Field Quality and Alignment of the Series Produced Superconducting Matching Quadrupoles for the LHC Insertions quadrupole, insertion, alignment, dipole 2738
 
  • N. Catalan-Lasheras, G. Kirby, R. Ostojic, J.C. Perez, H. Prin, W.  Venturini Delsolaro
    CERN, Geneva
  The production of the superconducting quadrupoles for the LHC insertions is advancing well and about half of the magnets have been produced. The coil size and field measurements performed on individual magnets both in warm and cold conditions are yielding significant results. In this paper we present the procedures and results of steering the series production at the magnet manufacturers and the assembly of cold masses at CERN. In particular, we present the analysis of warm-cold correlations and hysteresis of the main field multipoles, the correlation between coil sizes and geometrical field errors and the effect of permeability of magnet collars. The results are compared with the target errors for field multipoles and alignment.  
 
MPPT043 Low-Beta Quadrupole Designs for the LHC Luminosity Upgrade quadrupole, luminosity, insertion, dipole 2795
 
  • R. Ostojic, N. Catalan-Lasheras, G. Kirby
    CERN, Geneva
  Several candidate scenarios are considered for the upgrade of the LHC insertions in view of increasing the luminosity in excess of 1034 cm-2s-1. In all cases, superconducting low-beta quadrupoles with apertures in the range of 90-110 mm are required in view of increased heat loads and beam crossing angles. We present possible low-beta quadrupole designs based on Nb3Sn and NbTi superconducting cables, including existing LHC-class superconductors, present scaling laws for the magnet parameters and discuss relative advantages of the underlying triplet layouts.  
 
MPPT044 The Construction of the Low-Beta Triplets for the LHC quadrupole, insertion, vacuum, dipole 2798
 
  • R. Ostojic, M. Karppinen, T.M. Taylor, W.  Venturini Delsolaro
    CERN, Geneva
  • R. Bossert, J. DiMarco, SF. Feher, J.S. Kerby, M.J. Lamm, T.H. Nicol, A. Nobrega, T.M. Page, T. Peterson, R. Rabehl, P. Schlabach, J. Strait, C. Sylvester, M. Tartaglia, G. Velev
    Fermilab, Batavia, Illinois
  • N. Kimura, T. Nakamoto, T. Ogitsu, N. Ohuchi, t.s. Shintomi, K. Tsuchiya, A. Yamamoto
    KEK, Ibaraki
  The performance of the LHC depends critically on the low-beta triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was set up in 1996 to design and build the triplet systems, and after nine years of joint effort the production will be completed in 2005. We retrace the main events of the project and present the design features and performance of the low-beta quadrupoles, built by KEK and Fermilab, as well as of other vital elements of the triplet. The experience in assembly of the first triplet at CERN and plans for tunnel installation and commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-beta triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of physics experiment collaborations, and rarely before achieved in accelerator building.  
 
MPPT064 Elements of Magneto-Optics Acting in One Direction octupole, wiggler, focusing, quadrupole 3618
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We describe here the way to use quadrupole, octupole lenses so they are acting in one direction only. The beam is running across the lens in contrast with usual axis running.  
 
MPPT068 A Compact High Gradient Pulsed Magnetic Quadrupole quadrupole, ion, heavy-ion, induction 3771
 
  • D. Shuman, A. Faltens, G. Ritchie, P.A. Seidl
    LBNL, Berkeley, California
  • M. Kireeff Covo
    LLNL, Livermore, California
  Funding: This work was supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Features include a five turn eddy current compensated solid conductor coil design which theoretically eliminates the first four higher order multipole field components, a single layer "non-spiral bedstead" coil design which both minimizes utilization of radial space and maximizes utilization of axial space, and allows incorporation of steering and correction coils within existing radial space. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends, simplifying fabrication and assembly.

 
 
MPPT072 3D Simulation Studies of SNS Ring Doublet Magnets simulation, SNS, quadrupole, dipole 3865
 
  • J.-G. Wang
    ORNL, Oak Ridge, Tennessee
  • N. Tsoupas
    BNL, Upton, Long Island, New York
  • M. Venturini
    LBNL, Berkeley, California
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The accumulator ring of the Spallation Neutron Source (SNS) at ORNL employs in its straight sections closely packed quadrupole doublet magnets with large aperture of R=15.1 cm and relatively short iron-to-iron distance of 51.4 cm.* The magnetic interference among the magnets in the doublet assemblies is not avoidable due to the fringe fields. Though each magnet in the assemblies has been individually mapped to high accuracy of delta(B)/B~1x10-4, the experimental data including the magnet interference effect in the assemblies will not be available. We have performed 3D computer simulations on a quadrupole doublet model in order to assess the degree of the interference and to obtain relevant data which should be very useful for the SNS commissioning and operation. This paper reports our simulation results.

*N. Tsoupas et al. "A Large-aperture Narrow Quadrupole for the SNS Accumulator Ring," Proc. EPAC 2002, p.1106, Paris, June 3-7, 2002.

 
 
MPPT073 Field Distribution of Injection Chicane Dipoles in SNS Ring simulation, dipole, SNS, injection 3907
 
  • J.-G. Wang
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

3D computing simulations have been performed to study the magnetic field distribution of the injection chicane dipoles in the SNS ring.* The simulation studies have yielded the performance characteristics of the magnets and generated the magnetic field data in three dimensional grids, which can be used for detailed investigation of beam dynamics. Based on the simulation data, a 3D multipole expansion of the chicane dipole field, consisting of generalized gradients and their derivatives, has been made. The harmonic and pseudo-harmonic components in the expansion give much insight into the magnet physics. The expansion is quasi-analytical by fitting numeric data into a few interpolation functions. A 5th-order representation of the field is generated, and the effects of even higher order terms on the field representation are discussed.

*The injection chicane dipoles were designed at BNL by Y.Y. Lee, W. Meng, et al. See "Injection into the SNS Accumulator Ring: Minimizing Uncontrolled Losses and Dumping Stripped Electrons," D.T. Abell, Y.Y. Lee, W. Meng, EPAC 2000.

 
 
MPPT075 Analysis and Design of Backing Beam for Multipole Wiggler (MPW14) at PLS wiggler, synchrotron, synchrotron-radiation, radiation 3940
 
  • H.-G. Lee, C.W. Chung, H.S. Han, Y.G. Jung, D.E. Kim, W.W. Lee, K.-H. Park, H.S. Suh
    PAL, Pohang, Kyungbuk
  Pohang Accelerator Laboratory (PAL) had developed and installed a Multipole Wiggler (MPW14) to utilize high energy synchrotron radiation at Pohang Light Source (PLS). The MPW14 is a hybrid type device with period of 14 cm, minimum gap of 14 mm, maximum flux density of 2.02 Tesla and total magnetic structure length of 2056 mm. The support locations and structure of an insertion device are optimized to achieve a minimum deflection due to the magnetic loads. A Finite Element Analysis (FEA) is performed to find out the amount of maximum deflection and optimal support positions on the backing beam, the support and drive structures of the MPW14 under expected magnetic load of 14 tons. To reduce the deflection effect further, two springs are designed and installed to compensate the gap dependent magnetic loads. The optimized deflection is estimated to be about 20.6 ? while the deflection before optimization is 238 ?.  
 
MPPT090 Design, Construction and Field Characterization of a Variable Polarization Undulator for SOLEIL undulator, polarization, permanent-magnet, synchrotron 4242
 
  • B. Diviacco, R. Bracco, C. Knapic, D. Millo, D.Z. Zangrando
    ELETTRA, Basovizza, Trieste
  • O.V. Chubar, A. Dael, M. Massal
    SOLEIL, Gif-sur-Yvette
  • Z. Martí
    LLS, Bellaterra (Cerdanyola del Vallès)
  Two variable polarization undulators (HU80) are being designed and constructed in the framework of an ELETTRA-SOLEIL collaboration. The four-quadrant permanent magnet structure, of the APPLE-II type, will produce various polarization modes by means of parallel or anti-parallel displacement of two diagonally opposite magnet arrays. In this paper the main aspects of the magnetic and mechanical design will be summarized. The post-assembly field quality optimization methods will be described in some detail, discussing our approach to the correction of phase, trajectory and multipole errors. Finally the magnetic measurement results on the completed device will be presented.  
 
TOAA003 Survey of Superconducting Insertion Devices for Light Sources wiggler, undulator, radiation, electron 256
 
  • N.A. Mezentsev, E. Perevedentsev
    BINP SB RAS, Novosibirsk
  The first Superconducting Insertion devices were designed, fabricated and installed on electron storage rings more than 25 years ago for generation of synchrotron radiation. For these years wide experience of manufacturing and use of such superconducting insertion devices as superconducting wave length shifters, multipolar wigglers and undulators is accumulated. Review of various types of Superconducting Insertion Devices for Light Sources is given in the report. Their basic characteristics as SR sources are discussed.  
 
TOAA010 Serpentine Coil Topology for BNL Direct Wind Superconducting Magnets quadrupole, dipole, octupole, superconducting-magnet 737
 
  • B. Parker, J. Escallier
    BNL, Upton, Long Island, New York
  Funding: Work supported by the U.S. Department of Energy under contract DE-AC-02-98-CH10886.

BNL direct wind technology, with the conductor pattern laid out without need for extra tooling (no collars, coil presses etc.) began with RHIC corrector production. RHIC patterns were wound flat and then wrapped on cylindrical support tubes. Later for the HERA-II IR magnets we improved conductor placement precision by winding directly on a support tube. To meet HERA-II space and field quality goals took sophisticated coil patterns, (some wound on tapered tubes). We denote such patterns, topologically equivalent to RHIC flat windings, "planar patterns." Multi-layer planar patterns run into trouble because it is hard to wind across existing turns and magnet leads get trapped at poles. So we invented a new "Serpentine" winding style, which goes around 360 degrees while the conductor winds back and forth on the tube. To avoid making solenoidal fields, we wind Serpentine layers in opposite handed pairs. With a Serpentine pattern each turn can have the same projection on the coil axis and integral field harmonics then closely follow the 2D cross section. This and other special Serpentine coils properties are discussed in this paper and applied to a variety of direct wind magnet projects.

 
 
TPAT028 TRACK: The New Beam Dynamics Code linac, simulation, space-charge, ion 2053
 
  • B. Mustapha, V.N. Aseev, E.S. Lessner, P.N. Ostroumov
    ANL, Argonne, Illinois
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. W-31-109-ENG-38.

The new ray-tracing code TRACK was developed* to fulfill the special requirements of the RIA accelerator systems. The RIA lattice includes an ECR ion source, a LEBT containing a MHB and a RFQ followed by three SC linac sections separated by two stripping stations with appropriate magnetic transport systems. No available beam dynamics code meet all the necessary requirements for an end-to-end simulation of the RIA driver linac. The latest version of TRACK was used for end-to-end simulations of the RIA driver including errors and beam loss analysis.** In addition to the standard capabilities, the code includes the following new features: i) multiple charge states ii) realistic stripper model; ii) static and dynamic errors iii) automatic steering to correct for misalignments iv) detailed beam-loss analysis; v) parallel computing to perform large scale simulations. Although primarily developed for simulations of the RIA machine, TRACK is a general beam dynamics code. Currently it is being used for the design and simulation of future proton and heavy-ion linacs at TRIUMF, Fermilab, JLAB and LBL.

*P.N. Ostroumov and K.W. Shepard. Phys. Rev. ST. Accel. Beams 11, 030101 (2001). **P.N. Ostroumov, V. N. Aseev, B. Mustapha. Phys. Rev. ST. Accel. Beams, Volume 7, 090101 (2004).

 
 
TPAT079 Importance of the Linear Coupling and Multipole Compensation of Long-Range Beam-Beam Interactions In Tevatron emittance, coupling, beam-beam-effects, simulation 4039
 
  • J. Shi, B. Anhalt
    KU, Lawrence, Kansas
  Funding: The US Department of Energy under Grant No. DE-FG02-04ER41288.

In Tevatron, serious long-range beam-beam effects are due to many parasitic collisions that are distributed around the ring. Because of this non-localized nature of long-range beam-beam interactions, the multipole compensation with one-turn or sectional maps aims a global compensation of long-range beam-beam interactions. Since nonlinear beam dynamics in a storage ring can usually be described by a one-turn map that contains all global information of system nonlinearities, by minimizing nonlinear terms of the maps order-by-order with a few groups of multipole correctors, one could reduce the nonlinearity globally. Since a large beam separation is typical at parasitic points, in the phase-space region that is relevant to the beam, long-range beam-beam interactions can be expanded into a Taylor series around the beam separation and be included into the one-turn map for the global compensation. To examine the effect of this multipole compensation scheme, the emittance growth of both p and pbar beam in Tevatron were studied with a beam-beam simulation. The result showed that the multipole compensation can significantly reduces the emittance growth of the pbar beam due to long-range beam-beam interactions.

 
 
TPPP041 Recent Developments on the Muon-Facility Design Code ICOOL simulation, emittance, focusing, factory 2651
 
  • R.C. Fernow
    BNL, Upton, Long Island, New York
  Funding: Work supported by U.S. Department of Energy.

Current ideas for designing neutrino factories and muon colliders require unique configurations of fields and materials to prepare the muon beam for acceleration. We have continued the development of the 3D tracking code ICOOL for examining possible system configurations. Development of the ICOOL code began in 1996 in order to simulate the process of ionization cooling. This required tracking in magnetic focusing lattices, together with interactions in shaped materials that must be placed in the beam path.* The most important particle interactions that had to be simulated were energy loss and straggling. Since the optimum way of designing a cooling channel was not known, the code had to have a flexible procedure for specifying field and material geometries. Eventually the early linear cooling channels evolved into cooling rings. In addition the designs require many other novel beam manipulations besides ionization cooling, such as pion collection in a high field solenoid, rf phase rotation, and acceleration in FFAG rings. We describe new features that have been incorporated in ICOOL for handling these new requirements. A suite of auxilliary codes have also been developed for pre-processing, post-processing, and optimization.

*R.C. Fernow, ICOOL: a simulation code for ionization cooling of muon beams, Proc. 1999 Part. Accel. Conf., New York, p. 3020.

 
 
TPPT031 Coupler Design for the LCLS Injector S-Band Structures quadrupole, dipole, emittance, linac 2176
 
  • Z. Li, L.D. Bentson, J. Chan, D. Dowell, C. Limborg-Deprey, J.F. Schmerge, D.C. Schultz, L. Xiao
    SLAC, Menlo Park, California
  Funding: Work supported by the U.S. DOE Contract No. DE-AC03-76SF00515.

The LCLS injector is required to provide a 1-nC, 10-ps bunch with a normalized rms transverse projected emittance of less than 1.0-μm. The LCLS beam is generated and accelerated in a 1.6-cell S-band RF gun to 6-MeV followed by two SLAC 3-m S-band accelerator structures to further accelerate the beam to 135 MeV to move it out of the space-charge dominated regime. In the SLAC S-band structures, the RF power feed is through a single coupling-hole (single-feed coupler) which results in a field asymmetry. The time dependent multipole fields in the coupler induce a transverse kick along the bunch and cause the emittance to increase above the LCLS specification. To meet the stringent emittance requirements for the injector, the single-feed couplers will be replaced by a dual-feed racetrack design to minimize the multipole field effects. We will present detailed studies of the multipole fields in the S-band coupler and the improvements with the dual-feed racktrack design using the parallel finite element eigenmode solver Omega3P.

 
 
WPAE015 High Heat-Load Slits for the PLS Multipole Wiggler wiggler, storage-ring, synchrotron, synchrotron-radiation 1449
 
  • K.H. Gil, J.Y. Choi, C.W. Chung, Y.-C. Kim, H.-S. Lee
    PAL, Pohang, Kyungbuk
  The HFMX (High Flux Macromolecular X-ray crystallography) beamline under commissioning at Pohang Accelerator Laboratory uses beam from a multipole wiggler for MAD experiment. Two horizontal and vertical slits relevant to high heat load are installed at its front-end. In order to treat high heat load and to reduce beam scattering, the horizontal slit has two glidcop blocks with 10° of vertical inclination and its tungsten blades defining beam size are bolted on backsides of both blocks. The blocks of the slit are adjusted on fixed slides by two actuating bars, respectively. Water through channels machined along the actuating bars cool down the heat load of both blocks. The vertical slit has the same structure as the horizontal slit except its installation direction and angle of vertical inclination. The installed slits show stable operation performance and no alignment for the blocks is required by virtue of a pair of blocks translating on slides. The cooling performance of two slits is also shown to be acceptable. In this article, the details of the design and manufacture of the two slits are presented and its operation performance is reported.  
 
WPAE034 Fast Neutron Damage Studies on NdFeB Materials radiation, radioactivity, permanent-magnet, hadron 2351
 
  • J.E. Spencer, S.D. Anderson, R. Wolf
    SLAC, Menlo Park, California
  • A. Baldwin, D.E. Pellet
    UCD, Davis, California
  • M. Boussoufi
    UCD/MNRC, McClellan, California
  • J.T. Volk
    Fermilab, Batavia, Illinois
  Funding: Support of this work was under U.S. Dept. of Energy contracts DE-AC02-76SF00515, DE-AC02-76CH03000 and LCRD contract DE-FG02-03ER41280.

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) where the accelerator and detectors will be subjected to large fluences of hadrons, leptons and gammas over the life of the facility. Although the linacs will be superconducting, there are still many potential uses for NdFeB in the damping rings, injection and extraction lines and final focus. Our understanding of the radiation damage situation for rare earth permanent magnet materials was presented at PAC2003 and our first measurements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented at EPAC2004 where the damage appeared proportional to the distances between the effective operating points and Hc. Here we have extended those doses and included more commercial samples together with the induced radioactivities associated with their respective dopants. Hall probe data for the external induction distributions are compared with vector magnetization measurements for the different materials.

 
 
WPAE053 Neutronics Assessments for a RIA Fragmentation Line Beam Dump Concept radiation, heavy-ion, proton, ion 3227
 
  • J.L. Boles, L. Ahle, S. Reyes, W. Stein
    LLNL, Livermore, California
  Funding: Work performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

Heavy ion and radiation transport calculations are in progress for conceptual beam dump designs for the fragmentation line of the proposed Rare Isotope Accelerator (RIA). Using the computer code PHITS, a preliminary design of a motor-driven rotating wheel beam dump and adjacent downstream multipole has been modeled. Selected results of these calculations are given, including neutron and proton flux in the wheel, absorbed dose and displacements per atom in the hub materials, and heating from prompt radiation and from decay heat in the multipole.

 
 
WOAC001 Aberration Correction in Electron Microscopy electron, quadrupole, sextupole, acceleration 44
 
  • H.H. Rose, W. Wan
    LBNL, Berkeley, California
  The resolution of conventional electron microscopes is limited by spherical and chromatic aberrations. Both defects are unavoidable in the case of static rotationally symmetric electromagnetic fields (Scherzer theorem). Multipole correctors and electron mirrros have been designed and built, which compensate for these aberrations. The principles of correction will be demonstrated for the tetrode mirror, the quadrupole-octopole corrector and the hexapole corrector. Electron mirrors require a magnetic beam separator free of second-order aberrations. The multipole correctors are highly symmetric telescopic systems compensating for the defects of the objective lens. The hexapole corrector has the most simple structure yet eliminates only the spherical aberration, whereas the mirror and the quadrupole-octopole corrector are able to correct for both aberrations. Chromatic correction is achieved in the latter corrector by cossed electric and magnetic quadrupoles acting as first-order Wien filters. Micrographs obtained with aberration-corrected electron microscopes will be shown demonstrating the improvement in resolution to better than 1 Angstroem.  
 
WOAC002 Chromatically Corrected Imaging Systems for Charged-Particle Radiography proton, dipole, quadrupole, sextupole 225
 
  • B. Blind, A.J. Jason
    LANL, Los Alamos, New Mexico
  In proton radiography, imaging with systems consisting of quadrupole magnets is an established technique for viewing the material distribution and composition of objects, either statically or during fast events such as explosions. With the most favorable magnet configuration, the –I lens, chromatic aberrations generally dominate the image blur. Image resolution can be improved, and largely decoupled from the input-beam parameters, by using a second-order achromatic bend with some additional higher-order aberration correction. The aberration-correction approach is discussed. For a given resolution, such a bend allows use of much lower-energy imaging particles than a –I lens. Each bend design represents a set of equivalent systems; an 800-MeV proton design and its equivalent 40-MeV electron system are presented. The electron system is useful for imaging small objects. Magnet errors in the achromatic bends must be tightly controlled to preserve image quality, but not beyond feasibility of present technology. System performance is verified by particle tracking. Configurations alternative to the canonical achromatic bend are also discussed.  
 
WOAC007 Beam-Based Nonlinear Optics Corrections in Colliders sextupole, octupole, coupling, resonance 601
 
  • F.C. Pilat, Y. Luo, N. Malitsky, V. Ptitsyn
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the US Department of Energy

A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, which gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 3 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non linear correction techniques.

 
 
RPAE006 Feasibility Study on Introducing a Superconducting Wiggler to Saga Light Source lattice, dynamic-aperture, quadrupole, wiggler 1021
 
  • S. Koda, Y. Iwasaki, T. Okajima, H. Setoyama, Y. Takabayashi, T. Tomimasu, K. Yoshida
    Saga Synchrotron Light Source, Industry Promotion Division, Saga City
  • H. Ohgaki
    Kyoto IAE, Kyoto
  • M. Torikoshi
    NIRS, Chiba-shi
  Saga light source (SAGA-LS) is the synchrotron radiation facility, which consists of 250 MeV electron linac and 1.4 GeV storage ring. We have a plan to introduce an existing superconducting wiggler, which has been developed for other project by National Institute of Radiological Sciences. The superconducting wiggler consists of a main pole of 7T and two side poles of 4T. Each pole is composed of a racetrack-shaped coil and an iron core. We have examined the effects of the wiggler on the beam optics when it is introduced into SAGA-LS. The distribution of multipole components in the planes perpendicular to the electron orbit, which is deformed by the wiggler fields, have been calculated using magnetic field calculation code RADIA. Then the lattice function and the dynamic aperture of the ring have been calculated by the lattice calculation code SAD. The results show that the tune shift due to the quadrupole component of the wiggler field is as large as to make horizontal beam orbit unstable. The dynamic aperture after the tune correction becomes small by about 20%. These effects due to multipole field are considered to be tolerable for the SAGA-LS.  
 
RPAE051 Multipole Design for CAMD Storage Ring sextupole, power-supply, quadrupole, storage-ring 3161
 
  • V.P. Suller
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M.G. Fedurin, P. Jines, T.A. Miller
    LSU/CAMD, Baton Rouge, Louisiana
  The CAMD storage ring has been in operation more than 12 years with only sextupole elements in the lattice for correction of nonlinear beam dynamics. To compensate for coupling arising from the integrated effect of skewed elements around the ring, and to improve beam lifetime, a multipole element is required which can be operated in active mode. The design of a magnetic multipole is presented as well as power and control systems designs. The strength and effect and of this element are calculated.  
 
FPAE024 Studies Performed in Preparation for the Spallation Neutron Source Accumulator Ring Commissioning injection, target, beam-losses, proton 1859
 
  • S.M. Cousineau, V.V. Danilov, S. Henderson, J.A. Holmes, M.A. Plum
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos, and Oak Ridge.

The Spallation Neutron Source accumulator ring will compress 1.5?1014, 1 GeV protons from a 1 ms bunch train to a single 695 ns proton bunch for use in neutron spallation. Due to the high beam power, unprecedented control of beam loss will be required in order to control radiation and allow for hands-on maintenance in most areas of the ring. A number of detailed investigations have been performed to understand the primary sources of beam loss and to predict and mitigate problems associated with radiation hot spots in the ring. The ORBIT particle tracking code is used to perform realistic simulations of the beam accumulation in the ring, including detailed modeling of the injection system, transport through the measured magnet fields including higher order multipoles, and beam loss and collimation. In this paper we present the results of a number of studies performed in preparation for the 2006 commissioning of the accumulator ring.

 
 
FPAT079 Data Base Extension for the Ensemble Model Using a Flexible Implementation simulation, quadrupole, sextupole, space-charge 4036
 
  • W. Ackermann, T. Weiland
    TEMF, Darmstadt
  Funding: Work supported by DESY, Hamburg.

To guarantee an adequate design and a proper functionality of various machine components it is of great importance to perform detailed studies of charged particle transport. However, it is often not necessary to initiate individual kinetic simulations. When the evolution of integral quantities is of research interest, it is worth treating an investigated particle ensemble as a whole and applying a macroscopic formulation. Using a collision-less kinetic approach, the simplified model is derived from the well-known Vlasov equation. Instead of solving directly this equation, one can use moments of the density function obtained by means of an averaging process. This formalism had been implemented into the beam dynamics simulation program V-Code and a fundamental database of various beam line elements like cavities, drift spaces, solenoids, quadrupoles and steerers was set up. A flexible realization of the C++ code representing the cavities and the drift spaces can be automatically used for an arbitrary order of moments applying a symbolic algebra program. A useful extension to the remaining beam line elements together with appropriate simulation results is presented in the paper.