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dipole

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MOXAGM01 Status of the Large Hadron Collider (LHC) cryogenics, quadrupole, controls, collider 1
 
  • F. Bordry
    CERN, Geneva
  The status of the LHC commissioning is presented. Preparation for smooth beam commissioning is going on since several years:
  1. very thorough commissioning of the highly complex hardware systems started already in 2005
  2. preparation of the LHC beam commissioning, resulting in detailed procedures for various commissioning phases with increasing beam intensity and performance
  3. preparation of the injector complex, with beam up to the end of the transfer lines between SPS and LHC.
 
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MOYCGM01 FAIR: Challenges Overcome and Still to be Met antiproton, superconducting-magnet, ion, vacuum 17
 
  • H. Stöcker
    GSI, Darmstadt
  FAIR will be one of the leading accelerator facilities worldwide making use of a highly sophisticated and cost-effective accelerator concept. The intensity frontier will be pushed by several orders of magnitude for the primary and especially for the secondary beams. To reach the unprecedented beam parameters several technical challenges such as operation with high brightness, high current beams, control of the dynamic vacuum pressure or the design of rapidly cycling superconducting magnets have to be mastered. For most of those challenges solutions have been found and prototypes are being built. The remaining open questions are addressed in close collaborations with the partners of FAIR.  
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MOZCM01 Commissioning and Operation of the 1.5 GeV Harmonic Double Sided Microtron at Mainz University linac, injection, recirculation, microtron 51
 
  • A. Jankowiak, K. Aulenbacher, D. Bender, O. Chubarov, M. Dehn, H. Euteneuer, F. Fichtner, B. Gutheil, F. Hagenbuck, R. H. Herr, P. Jennewein, K.-H. Kaiser, W. Klag, H. J. Kreidel, U. Ludwig-Mertin, A. Nuck, J. R. Röthgen, B. Seckler, G. S. Stephan, V. Tioukine, G. Woell, Th. Zschocke
    IKP, Mainz
  In December 2006 the 4th stage of the Mainz Microtron MAMI has been succesfully set into operation expanding the 855MeV output energy of the existing three racetrack microtron cascade (MAMI B) to 1508MeV. This new recirculating cw electron accelerator is realised as a worldwide unique Harmonic Double Sided Microtron (HDSM, [*]). Since February 2006, after only 14 day of commissioning, the HDSM serves as part of the MAMI C accelerator cascade in routine 24h a day operation for nuclear physics experiments. We will give a brief overview of the design and construction of the HDSM and describe in detail the experiences gained during commissioning and the first year of operation.

[*] A. Jankowiak et al., "Status Report on the Harmonic Double Sided Microtron of MAMI C", Proceedings EPAC2006, Edinburgh, p. 834

 
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MOZDM01 LHC Hardware Commissioning Summary extraction, controls, cryogenics, instrumentation 56
 
  • R. I. Saban
    CERN, Geneva
  The presentation summarizes the main phases of the LHC hardware commissioning and discusses especially the powering of one completer sector to the nominal current.  
slides icon Slides  
 
MOPC059 BBU Limitations for ERLs linac, beam-transport, recirculation, lattice 199
 
  • E. Wooldridge, C. D. Beard, P. A. McIntosh, B. D. Muratori, S. L. Smith
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The BBU threshold in ERLs is a limitation on the maximum beam current due to the interaction of the electron bunches and the Higher Order Modes (HOMs) contained within the RF cavities. Several factors are involved in determining the threshold current; from the cavity the Q, R/Q and degeneracy of the modes all play an important part. From the beam transport the values of the lattice functions α, β and μ have an effect. We will discuss the limits on these variables to provide a BBU current threshold greater than 100 mA for a multiple cavity machine and what will be required to provide higher currents. Also three different cavity profiles were investigated with the aim of reducing the BBU threshold. The TESLA 9-cell cavity was used as a baseline for comparison against possible 7-cell cavity designs, using the TESLA cell shape for their inner cells. The ends of the 7-cell cavities join to different sized beampipes, with radii of 39 mm and 54 mm, to allow the most of the HOMs to propagate to a broadband HOM absorber. Two different beampipe to cavity to transitions were investigated. The optimised 7-cell cavity will be shown to provide an increase in the BBU threshold.  
 
MOPC100 Design Status of the FAIR Synchrotrons SIS100 and SIS300 and the High Energy Beam Transport System extraction, synchrotron, acceleration, beam-losses 298
 
  • P. J. Spiller, U. B. Blell, O. Boine-Frankenheim, E. S. Fischer, G. Franchetti, F. Hagenbuck, I. Hofmann, J. E. Kaugerts, M. Kauschke, M. Kirk, H. Klingbeil, A. Kraemer, D. Krämer, G. Moritz, C. Omet, N. Pyka, H. Ramakers, S. Ratschow, A. Saa-Hernandez, M. Schwickert, J. Stadlmann, H. Welker
    GSI, Darmstadt
  • A. D. Kovalenko
    JINR, Dubna, Moscow Region
  The present status of system- and technical design and R&D for the new heavy ion synchrotrons SIS100 and SIS300 and the HEBT system is summarized. The overall machine planning and the general layout has been completed and the detailed technical machine design has been started. Device and component specifications, technical parameter lists and technical design reports are in preparation with the goal to enable international partners or industry to finalize the component design to achieve production readiness. In the frame of international working groups the distribution and sharing of the work packages, especially of the cryomagnetic system is under discussion.  
 
MOPC103 Short Circuit Tests: First Step of LHC Hardware Commissioning Completion controls, extraction, quadrupole, monitoring 304
 
  • B. Bellesia, E. Barbero-Soto, F. Bordry, M. P. Casas Lino, G.-J. Coelingh, G. Cumer, K. Dahlerup-Petersen, J.-C. Guillaume, J. Inigo-Golfin, V. Montabonnet, D. Nisbet, M. Pojer, R. Principe, F. Rodriguez-Mateos, R. I. Saban, R. Schmidt, H. Thiesen, A. Vergara-Fernández, M. Zerlauth
    CERN, Geneva
  • A. Castaneda, I. Romera Ramirez
    CIEMAT, Madrid
  The Large Hadron Collider operation relies on 1232 superconducting dipoles with a field of 8.33T and 400 superconducting quadrupoles with a strength of 220 T/m powered at 12kA, operating in superfluid He at 1.9K. For dipoles and quadrupoles as well as for many other magnets more than 1700 power converters are necessary to feed the superconducting circuits. Between October 2005 and September 2007 the so-called short circuit tests were carried-out in the 15 underground areas where the power converters of the superconducting circuits are located. The tests were aimed at the qualification of the normal conducting components of the circuits: the power converters, the normal conducting DC cables between the power converters and the LHC cryostat, the interlocks and energy extraction systems. In addition, the correct functioning of the infrastructure systems (AC distribution, water and air cooling, control system) were validated. The final validation test for each underground area was the powering of all converters at ultimate current during 24h. This approach highlighted a few problems that were solved long before the beginning of magnet commissioning and beam operation.  
 
MOPC118 Coordination of the Commissioning of the LHC Technical Systems controls, collider, cryogenics, quadrupole 340
 
  • R. I. Saban, B. Bellesia, M. P. Casas Lino, C. Fernandez-Robles, M. Pojer, R. Schmidt, M. Solfaroli Camillocci, A. Vergara-Fernández
    CERN, Geneva
  The Large Hadron Collider operation relies on 1232 superconducting dipoles with a field of 8.33T and 400 superconducting quadrupoles with a strength of 220 T/m powered at 12kA, operating in superfluid He at 1.9K. For dipoles and quadrupoles as well as for many other magnets more than 1700 power converters are necessary to feed the superconducting circuits. A sophisticated magnet protection system is crucial to detect a quench and safely extract the energy stored in the circuits (about 1GJ only in one of the dipole circuits) after a resistive transition. Besides, in such complex architecture, many technical services (e.g. cooling and ventilation, technical network, electrical distribution, GSM network, controls system, etc.) have to be reliably available during commissioning. Consequently, the commissioning of the technical systems and the associated infrastructures has been carefully studied. Procedures, automatic control and analysis tools, repositories for test data, management structures for carrying out and following up the tests have been put in place. This paper briefly describes the management structure and the tools created to ensure safe, smooth and rapid commissioning.  
 
MOPC124 Ion Optical Design of SIS100 and SIS300 ion, lattice, extraction, quadrupole 358
 
  • J. Stadlmann, G. Franchetti, B. J. Franczak, M. Kirk, N. Pyka, A. Saa-Hernandez, P. J. Spiller
    GSI, Darmstadt
  The ion optical layout of the two synchrotrons SIS100/300 of the FAIR project is presented. SIS100 will provide high intensity ion beams of all species from H to U up to a magnetic rigidity of 100 Tm. To minimize the space charge effects and to reach the necessary ion intensities for the FAIR project SIS100 will be operated with intermediate charge state heavy ions (U28+). The ion optical layout of SIS100 has been optimized for this purpose. The layout assures the separation of beam particles which are ionized by collisions with residual gas molecules from the circulating beam. Since SIS100 and SIS300 will be installed in the same tunnel, the lattice layout of SIS300 has to follow precisely the geometry of SIS100. SIS300 will provide beams of highly charged heavy ions with a maximum rigidity of 300 Tm. In addition, it will function as a stretcher ring for SIS100. The beam transfer system from SIS100 to SIS300 is designed to fit in a single straight section of the two machines. The effect of dynamic field errors in SIS300 has been considered and the maximum tolerable error levels for the operation of SIS100, such as tracking errors and power supply ripples have been investigated.  
 
MOPC129 Lattice without Transition Energy for the Future PS2 lattice, betatron, quadrupole, sextupole 370
 
  • D. Trbojevic, S. Peggs
    BNL, Upton, Long Island, New York
  • Y. Papaphilippou, R. de Maria
    CERN, Geneva
  The Large Hadron Collider (LHC) will be commissioned very soon. Improvements of the LHC injection complex are considered in the upgrade possibilities. In the injection complex it is considered that the aging Proton Synchrotron (PS) would be replaced with a new fast cycling synchrotron PS2. The energy range would be from 5-50 GeV with a repetition rate of 0.3 Hz. This is a report on the PS2 lattice design using the Flexible Momentum Compaction (FMC) method*. The design is trying to fulfill many requirements: high compaction factor, racetrack shape with two long zero dispersion straight sections, circumference fixed to a value of 1346 meters (CPS2=15/77 CPS), using normal conducting magnets and avoiding the transition energy.

*D. Trbojevic et al. ”Design Method for High Energy Accelerator Without Transition Energy”, EPAC 90, Nice, June 12-16 (1990) pp. 1536-1538.

 
 
MOPP001 Beam-Based Alignment for the CLIC Decelerator alignment, quadrupole, simulation, lattice 547
 
  • E. Adli, D. Schulte
    CERN, Geneva
  The CLIC Drive Beam decelerator requires the beam to be transported with very small losses. Beam-based alignment is necessary in order to achieve this, and various beam-based alignment schemes have been tested for the decelerator lattice. The decelerator beam has an energy spread of up to 90%, which impacts the performance of the alignment schemes. We have shown that Dispersion-Free-Steering works well for the decelerator lattice. However, because of the transverse focusing approach, modifications of the normal DFS schemes must be applied. Tune-up scenarios for the CLIC decelerator using beam-based alignment are also discussed.  
 
MOPP007 Wakefield Calculations - Comparison between Simulations and Experimental Data simulation, emittance, collider, impedance 562
 
  • A. Bungau, R. J. Barlow
    UMAN, Manchester
  In linear colliders the collimator wakefields have a significant effect on emittance growth, beam jitter and background estimates. Each simulation code models the collimator wakefields using a different approach and a discussion of the formalism for incorporating wakefields into the particle tracking code Merlin is included in this paper. Using simple collimator types we present the different predictions for bunch shape effects, and also for the wakefield kicks. These kicks are also compared with experimental results from SLAC End Station A.  
 
MOPP009 Copper Prototype Measurements of the HOM, LOM and SOM Couplers for the ILC Crab Cavity simulation, polarization, coupling, damping 568
 
  • G. Burt, P. K. Ambattu, A. C. Dexter
    Cockcroft Institute, Lancaster University, Lancaster
  • L. Bellantoni
    Fermilab, Batavia, Illinois
  • P. Goudket, P. A. McIntosh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • Z. Li, L. Xiao
    SLAC, Menlo Park, California
  The ILC Crab Cavity is positioned close to the IP and hence is very sensitive to the wakefields induced by the beam. A set of couplers were designed to couple to and hence damp the spurious modes of the crab cavity. As the crab cavity is a deflecting mode cavity, it operates using a dipole mode and has different damping requirements than an accelerating mode cavity. A separate coupler is required for the monopole modes below the operating frequency of 3.9 GHz, known as the LOMs, the opposite polarization of the operating mode, the SOM, and the modes above the operating frequency, the HOMs. Each of these couplers have been manufactured out of copper and measured attached to an aluminium nine cell prototype of the cavity and their external Q factors were measured. The results were found to agree well with numerical simulations.  
 
MOPP015 Continuously Adjustable Permanent Magnet Quadrupole for a Final Focus quadrupole, coupling, permanent-magnet, multipole 583
 
  • T. Sugimoto, M. Ichikawa, Y. Iwashita, M. Yamada
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • S. Kuroda, T. Tauchi
    KEK, Ibaraki
  A permanent magnet quadrupole with continuous strength adjustability has been fabricated. It has a five-ring-singlet structure, which was proposed by R. L.Gluckstern. Its small overall diameter allows an outgoing beamline to pass closeby. Since the permanent magnet pieces do not have any vibration source in themselves, this magnet could be used as a quadrupole in a final focus doublet. Such a quadrupole system is described.  
 
MOPP030 ATF2 Final Focus Orbit Correction and Tuning Optimisation sextupole, quadrupole, linear-collider, collider 613
 
  • A. Scarfe, R. Appleby
    UMAN, Manchester
  • D. Angal-Kalinin, J. K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  ATF2 is an upgrade to the ATF facility at KEK, Japan consisting of a replacement to the current ATF extraction line and the addition of a final focus section. The final focus system has been designed, and is aiming to test, the local chromaticity correction scheme as proposed for future linear colliders. The final focus system focuses the ultra-low emittance beams at the collision point in the linear collider. To provide the required small beam sizes and to maintain the beam sizes to nanometer level requires optimised orbit correction and tuning procedures. In this paper, the optimisation of the orbit correction using a global SVD method is discussed, along with the progress on final focus tuning knob analysis. The tuning algorithms used at ATF2 will provide an important feedback for future linear colliders (including the ILC and CLIC).  
 
MOPP034 Large Scale Linac Simulations Using a Globalised Scattering Matrix Approach scattering, simulation, linac, electromagnetic-fields 619
 
  • I. R.R. Shinton, R. M. Jones
    UMAN, Manchester
  A globalised cascaded scattering matrix scheme serves as practical method to simulate the electromagnetic (e.m.) fields in the groups of cavities which constitute the main accelerating structures of a linac. The cascaded scattering matrix technique is a well-proven method which allows realistic fabrication errors to be incorporated in an efficient manner without the necessity to re-mesh the entire geometry. Once the unit cell structures have been determined using a numerical scheme, such as finite element method utilized here, the overall cascaded scattering matrix calculation requires little in the way of computational resources or time and is consequently an efficient means of characterizing the e.m. field. Details of the e.m. field, shunt impedance and trapped modes for large scale linac simulations applied to the baseline and alternate high gradient cavities for the ILC and applications to XFEL are presented.  
 
MOPP045 Study of the Validity of K. Bane's Formulae for the CLIC Accelerating Structure impedance, RF-structure, target, luminosity 646
 
  • R. Zennaro
    CERN, Geneva
  The comprehension of short range wake is essential for the design of CLIC. Useful tools are the Karl Bane's formulae which predict the short range wake for periodic 2D symmetry structures. The comparison of 2D computations based on ABCI with predicted results and the study of the range of validity of these formulae are the subjects of this paper. A new fitting of the computational results is proposed for structures with very small aperture. A model for rounded iris structures is also proposed.  
 
MOPP057 ILC DR Vacuum Design and E-cloud electron, vacuum, photon, positron 673
 
  • O. B. Malyshev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • W. Bruns
    WBFB, Berlin
  An electron cloud parameters and vacuum design are tightly bounded to each other. Input parameters for the e-cloud depend on shape of vacuum chamber and surface property (material, roughthness, coatings, etc.), electron multipacting in the vacuum chamber causes the electron stimulated gas desorption and may require modification of vacuum system to deal with it. This paper describes the e-cloud modelling performed in a way to optimise ILC DR vacuum design in positron ring and to have clear understanding what modification in vacuum chamber are required. Three parameters of e-cloud were varied in turn: photo-electron emission, secondary electron yield and gas pressure. It was found all three parameter should not exceed certain value to keep the e-cloud density to an acceptable level. The energy and intensity of electron bombardment of the vacuum chamber walls and electron stimulated gas desorption were also calculated. It was found that electron stimulated gas desorption is comparable or larger than the photon stimulated desorption and should be considered in vacuum design.  
 
MOPP063 A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders electron, resonance, simulation, vacuum 688
 
  • M. T.F. Pivi, D. Arnett, F. D. Cooper, D. Kharakh, F. King, R. E. Kirby, B. Kuekan, J. J. Lipari, M. Munro, J. S.T. Ng, J. Olszewski, T. O. Raubenheimer, J. Seeman, B. Smith, C. M. Spencer, L. Wang, W. Wittmer
    SLAC, Menlo Park, California
  • C. M. Celata, M. A. Furman
    LBNL, Berkeley, California
  Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC. Possible remedies for the electron cloud effect include thin-film coatings, surface conditioning, antechamber, clearing electrodes, and chamber with grooves or slots. The effect is expected to be particularly severe in magnetic field regions. To test this and possible mitigation methods, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER). We have also installed test chambers in straight field free regions. The associated chamber consists of bare aluminum and TiN-coated inner surface sections. Each section is instrumented with arrays of readout electrodes and retarding grids. Installation of a grooved chamber is also planned. In this paper, we describe the ongoing R&D effort at SLAC to reduce the electron cloud effect in linear colliders. We present the design of the chicane, the chambers and diagnostics, as well as the experimental results obtained.  
 
MOPP065 Microwave Transmission Measurement of the Electron Cloud Density in the Positron Ring of PEP-II electron, plasma, vacuum, simulation 694
 
  • M. T.F. Pivi, A. Krasnykh
    SLAC, Menlo Park, California
  • J. M. Byrd, S. De Santis, K. G. Sonnad
    LBNL, Berkeley, California
  • F. Caspers, T. Kroyer, F. Roncarolo
    CERN, Geneva
  Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation of these machines at high currents. Because of the size of these accelerators, it is difficult to probe the low energy electron clouds over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave which is independently excited and transmitted over a section of the accelerator. We infer the absolute phase shift with relatively high accuracy from the phase modulation of the transmission due to the modulation of the electron cloud density from a gap in the positively charged beam. We have used this technique for the first time to measure the average electron cloud density over a 50 m straight section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center. We have also measured the variation of the density by using low field solenoid magnets to control the electrons.  
 
MOPP071 Intense Stopping Muon Beams target, background, proton, scattering 712
 
  • M. A.C. Cummings, R. J. Abrams, R. P. Johnson, C. Y. Yoshikawa
    Muons, Inc, Batavia
  • C. M. Ankenbrandt, M. A. Martens, D. V. Neuffer, K. Yonehara
    Fermilab, Batavia, Illinois
  The study of rare processes using stopping muon beams provides access to new physics that cannot be addressed at energy frontier machines. The flux of muons into a small stopping target is limited by the kinematics of the production process and by stochastic processes in the material used to slow the particles. Innovative muon beam cooling techniques are being applied to the design of stopping muon beams in order to increase the event rates in such experiments. Such intense stopping beams will also aid the development of applications such as muon spin resonance and muon-catalyzed fusion.  
 
MOPP128 Comparison of Stretched-wire, Bead-pull and Numerical Impedance Calculations on 3.9 GHz Dipole Cavities impedance, simulation, higher-order-mode, radio-frequency 859
 
  • P. Goudket, C. D. Beard, P. A. McIntosh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Burt, A. C. Dexter
    Cockcroft Institute, Lancaster University, Lancaster
  • R. M. Jones
    Cockcroft Institute, Warrington, Cheshire
  In order to verify detailed impedance and wakefield simulations, the resonant modes in an aluminium model of the 9-cell ILC crab cavity were investigated using a stretched-wire frequency domain measurement, as well as frequency-domain bead-pull measurements. These measurements were compared to numerical simulations in order to verify that the complete cavity mode spectrum could be experimentally characterised for this high frequency structure. The analysis of the results and the accuracy and/or limitations of each method is presented.  
 
MOPP140 Status and Test Results of High Current 5-cell SRF Cavities Developed at JLAB damping, impedance, simulation, quadrupole 886
 
  • F. Marhauser, G. Cheng, G. Ciovati, W. A. Clemens, E. Daly, D. Forehand, J. Henry, P. Kneisel, S. Manning, R. Manus, R. A. Rimmer, C. Tennant, H. Wang
    Jefferson Lab, Newport News, Virginia
  A new compact CW cryomodule development for use in future ERLs and FELs is underway at JLAB. Five-cell SRF cavities have been built at 1497 MHz for moderate RF input power scenarios with waveguide endgroups to efficiently transfer the beam induced HOM energy to room temperature loads. Effort has been made as well to provide a good real-estate gradient, cryogenic efficiency and HOMs tuned to safe frequencies to minimize HOM power extracted from the beam. Preliminary tests carried out earlier for two single-cell cavities at 1497 MHz cavity -one with a waveguide endgroup- and a bare 1497 MHz five-cell cavity have exceeded gradient and Qo specifications with no signs of multipacting and encouraged us to built two fully equipped 1497 MHz five-cell cavities. We report on the latest test results and the HOM impedance budget of the cavity used to evaluate BBU limits based on special machine optics.  
 
MOPP155 Superconducting RF Deflecting Cavity Design and Prototype for Short X-ray Pulse Generation damping, simulation, coupling, collider 913
 
  • J. Shi, H. Chen, C.-X. Tang
    TUB, Beijing
  • G. Cheng, G. Ciovati, P. Kneisel, R. A. Rimmer, G. Slack, L. Turlington, H. Wang
    Jefferson Lab, Newport News, Virginia
  • D. Li
    LBNL, Berkeley, California
  • A. Nassiri, G. J. Waldschmidt
    ANL, Argonne, Illinois
  Deflecting RF cavities are proposed to be used in generating short x-ray pulses (on ~1-picosecond order) at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL)* using a novel scheme by Zholents**. To meet the required deflecting voltage, impedance budget from higher order, lower order and the same order modes (HOM, LOM and SOM) of the APS storage ring, extensive deflecting cavity design studies have been conducted with numerical simulations and cavity prototypes. In this paper, we report recent progress on a single cell S-band (2.8-GHz) superconducting deflecting cavity design with waveguide damping. A copper and a niobium prototype cavity were fabricated and tested, respectively to benchmark the cavity and damping designs. A new damping scheme has been proposed which provides stronger damping to both HOM and LOM by directly coupling to a damping waveguide on the cavity equator.

* A. Nassiri, private communication, 2007
** A. Zholents et al. NIM, 1999, A425:385-389.

 
 
TUOBG03 Electron Beam Dynamics in the Long-pulse, High-current DARHT-II Linear Induction Accelerator electron, induction, impedance, focusing 968
 
  • C. Ekdahl, E. O. Abeyta, P. Aragon, R. D. Archuleta, G. V. Cook, D. Dalmas, K. Esquibel, R. J. Gallegos, R. W. Garnett, J. F. Harrison, E. B. Jacquez, J. Johnson, B. T. McCuistian, N. Montoya, S. Nath, K. Nielsen, D. Oro, L. J. Rowton, M. Sanchez, R. D. Scarpetti, M. Schauer, G. J. Seitz, H. V. Smith, R. Temple
    LANL, Los Alamos, New Mexico
  • H. Bender, W. Broste, C. Carlson, D. Frayer, D. Johnson, C.-Y. Tom, C. P. Trainham, J. T. Williams
    NSTec, Los Alamos, New Mexico
  • T. C. Genoni, T. P. Hughes, C. H. Thoma
    Voss Scientific, Albuquerque, New Mexico
  • B. A. Prichard, M. E. Schulze
    SAIC, Los Alamos, New Mexico
  We are now operating the full-scale DARHT-II linear induction accelerator (LIA) at its rated energy, accelerating 2-kA electron beams to more than 17 MeV. The injector produces a beam pulse with a full-width at half maximum (FWHM) greater than 2.5 microseconds, and a ~0.5 microsecond rise time. This long risetime is deliberately scraped off in a special beam-head cleanup zone (BCUZ) before entering the 68-cell main accelerator. The accelerated electron beam pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. We will discuss the tuning of the injector, BCUZ, and accelerator; and we will present data for the resulting beam transport and dynamics. We will also present beam stability data, which we will relate to previous stability experiments at lower current and energy*.

*Carl Ekdahl et al. "Long-pulse beam stability experiments on the DARHT-II linear induction accelerator," IEEE Trans. Plasma. Sci. Vol. 34, 2006, pp. 460-466.

 
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TUOBG04 A Vlasov-Maxwell Solver to Study Microbunching Instability in the FERMI@ELETTRA First Bunch Compressor System quadrupole, electron, synchrotron, emittance 971
 
  • G. Bassi
    Liverpool University, Science Faculty, Liverpool
  • G. Bassi
    Cockcroft Institute, Warrington, Cheshire
  • J. A. Ellison, K. A. Heinemann
    UNM, Albuquerque, New Mexico
  Microbunching can cause an instability which degrades beam quality. This is a major concern for free electron lasers where very bright electron beams are required. A basic theoretical framework for understanding this instability is the 3D Vlasov-Maxwell system. However, the numerical integration of this system is computationally too intensive at the moment. As a result, investigations to date have been done using very simplified analytical models or numerical solvers based on simple 1D models. We have developed an accurate and reliable 2D Vlasov-Maxwell solver which we believe improves existing codes. Our solver has been successfully tested against the Zeuthen benchmark bunch compressors*. In the present contribution we apply our self-consistent, parallel solver to study the microbunching instability in the first bunch compressor system of FERMI@ELETTRA. This system was proposed as a benchmark for testing codes at the September'07 workshop on microbunching instability in Trieste**.

*PAC2007, papers TUZBC03 and THPAN084.
**https://www.elettra.trieste.it/FERMI/index.php?n=Main. MicrobProgram

 
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TUPC005 Simulation Study of Laser-wires as a Post-linac Diagnostic for CLIC and ILC background, linac, electron, simulation 1047
 
  • G. A. Blair, L. Deacon, S. Malton
    Royal Holloway, University of London, Surrey
  • I. V. Agapov, A. Latina, D. Schulte
    CERN, Geneva
  Realistic CLIC and ILC bunch trains are simulated in the linac, including intra-train collective effects, and then analysed via a realistic simulation of a laser-wire system, including effects of laser-wire signal extraction, detection and deconvolution. Implications are drawn for the use of laser-wires as a post-linac machine diagnostic.  
 
TUPC007 Numerical and Experimental Investigation of the Contamination of X-ray Beam Position Monitors by Bending Magnet Edge Radiation radiation, undulator, synchrotron, photon 1053
 
  • C. Bloomer, G. Rehm, C. A. Thomas
    Diamond, Oxfordshire
  The details of an investigation into bending magnet edge radiation at Diamond are discussed, reviewing the effects of this radiation on X-ray Beam Position Monitoring (XBPM) equipment. For some time it has been recognized that there are difficulties using XBPMs for determining the centre of mass position of an undulator beam due to contamination from bending magnet radiation. While the geometry of the XBPM blades is designed to help reduce background dipole interference, this radiation is known to account for approximately 1% of the signal received, skewing the calculated beam position by several micrometres. We made detailed models of the bending magnet edge radiation using the SRW program and used Matlab to analyse the data. We present this model and compare our prediction to experimental results obtained at Diamond.  
 
TUPC009 Vertical Beam Profile Measurement and Analysis with X-ray Pinhole emittance, synchrotron, alignment, lattice 1059
 
  • M. J. Boland, M. J. Spencer
    ASP, Clayton, Victoria
  Imaging the electron beam profile at a synchrotron light source is commonly performed in the x-ray regime using a pinhole camera system. However, with machines pushing down the vertical emittance, including errors in source point optical parameters, pinhole manufacturing limitations and error analysis difficulties associated with diffraction and image capture, the pinhole imaging system has large errors, up to 50% for an emittance of a few picometre. An analysis has been done at the Australian Synchrotron (AS) looking at the effects of errors in determining the x-ray pinhole source point parameters.  
 
TUPC012 MICE: The International Muon Ionization Cooling Experiment: Diagnostic Systems emittance, factory, quadrupole, diagnostics 1068
 
  • A. D. Bross
    Fermilab, Batavia, Illinois
  • T. L. Hart
    IIT, Chicago, Illinois
  The Muon Ionization Cooling Experiment will make detailed measurements of muon ionization cooling using a new constructed low-energy muon beam at the Rutherford Appleton Laboratory. The experiment is a single-particle experiment and utilizes many detector techniques from High-Energy Physics experiments. To characterize and monitor the muon beam line, newly developed scintillating fiber profile monitors will employed. In order to monitor the purity of the beam and tag the arrival time of individual muons, a dual Aerogel Cerenkov system and a plastic scintillator time-of-flight system will be used. The 4-momenta of the muons will be measured by two identical spectrometer systems (one before and one after the cooling apparatus) which employ a fiber tracker that utilizes 350 micron diameter scintillator fiber. An additional time-of-flight system and electron and muon calorimeters are used to tag outgoing muons. We will discuss the design of the MICE diagnostic systems, the operation and give the first results from beam measurements in the MICE experimental hall.

A. Bross on behalf of the MICE collaboration.

 
 
TUPC026 Simulating a UMER Beam Position Monitor simulation, coupling, electron, quadrupole 1104
 
  • K. Fiuza
    IF-UFRGS, Porto Alegre
  • S. Bernal, I. Haber, R. A. Kishek
    UMD, College Park, Maryland
  We have investigated numerically and experimentally a beam position monitor (BPM), using the WARP code* to study image charge effects for an off-axis beam. In order to apply the theory of image charge, we calibrated the BPM response for the University of Maryland Electron Ring**. We studied the BPM linearity using several WARP simulations with different transverse offsets. The simulations were also compared with offsets measured employing a phosphor screen. In this paper we report the methodology used and results of this work.

* D. P. Grote et. all "New Developments in WARP Progress Toward End-to-End Simulation", Fus. Eng. & Des. 32-33 (1996) 193.
** J. Harris et. all "A fast beam position monitor for UMER", PAC'01, p 1387.

 
 
TUPC072 Design and Fabrication of an X-band Traveling Wave Deflection Mode Cavity for Longitudinal Characterization of Ultra-short Electron Beam Pulses electron, diagnostics, simulation, betatron 1215
 
  • A. Y. Murokh, R. B. Agustsson, S. Boucher, P. Frigola
    RadiaBeam, Marina del Rey
  • D. Alesini
    INFN/LNF, Frascati (Roma)
  • R. J. England, J. B. Rosenzweig, G. Travish
    UCLA, Los Angeles, California
  • V. Yakimenko
    BNL, Upton, Long Island, New York
  An X-band Traveling wave Deflector mode cavity (XTD) has been developed at Radiabeam Technologies to perform longitudinal characterization of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. An XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, fabrication procedure, and commissioning plans are presented. An experimental program at ATF to utilize the deflector for compressed beam characterization is discussed, including proposed measurements of the phase space filamentation due to non-linear processes in a chicane compressor.  
 
TUPC076 TTF HOM Data Analysis with Curve Fitting Method polarization, linac, simulation, optics 1227
 
  • S. Pei, C. Adolphsen, K. L.F. Bane, Z. Li, J. C. Smith
    SLAC, Menlo Park, California
  To investigate the possibility of using HOM signal induced in SC cavities as beam and cavity diagnostics, experiments and analyses based on SVD have been done, which are very successful. In this paper, we described one new method based on curve fitting to analyze the HOM signal data, some results have been obtained. The new method can be used to extract the HOM mode frequency, Q and relative phase from the data. On the other hand, this method can also be used to find the HOM mode center, polarization axis, mode axis along the cavity, while careful handling of beam timing information need to be considered in analysis. Comparing with SVD, this method is more physical, and can also be used in the beam diagnostic data analysis to obtain the beam position and beam trajectory angle.  
 
TUPC083 A Diagnostics Plate for the IFMIF-EVEDA Accelerator diagnostics, emittance, radiation, quadrupole 1248
 
  • I. Podadera Aliseda, B. Brañas, J. M. Carmona, A. Ibarra, C. Oliver
    CIEMAT, Madrid
  • P.-Y. Beauvais, J. Marroncle, A. Mosnier
    CEA, Gif-sur-Yvette
  The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. It is essential then to implement the necessary instrumentation for the commissioning, operation and correct characterization of the beam properties of the accelerator prototype. To achieve this goal, a complete set of instrumentation will be installed in the last part of the accelerator, just before the beam dump, in the so-called Diagnostics Plate (DP). It must allow the measurement of the main parameters of the beam: current, phase, position, transverse profile, energy, transverse halo, transverse emittance and longitudinal profile. The main challenges of such a measurement are the high damage power of the low-energy cw 125 mA beam, which precludes the use of interceptive instrumentation. In addition, the DP will not only be used during operation but also during the commissioning of the different accelerating structures at 5 and 9 MeV. In this contribution, the requirements imposed to the instrumentation, the type of techniques that will be used and a first conceptual design will be presented.  
 
TUPC105 Slice Emittance Measurements at SPARC Photoinjector with a RF Deflector emittance, quadrupole, diagnostics, linac 1305
 
  • C. Vaccarezza, D. Alesini, E. Chiadroni, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, G. Gatti, B. Marchetti, E. Pace
    INFN/LNF, Frascati (Roma)
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma
  • A. Mostacci
    Rome University La Sapienza, Roma
  The SPARC photoinjector is a R&D facility performing beam dynamics studies and driving a SASE-FEL. The RF deflector, completely designed and built by the SPARC team, allows measurements of the longitudinal properties of the beam bunch. Using it and the well know technique of the quadrupoles scan, the slice emittance has been measured in different conditions and benchmarked with the simulations.  
 
TUPC119 Corrector Based Determination of Quadrupole Centres quadrupole, closed-orbit, storage-ring, feedback 1347
 
  • M. Sjöström, M. Eriksson, L.-J. Lindgren, E. J. Wallén
    MAX-lab, Lund
  A corrector magnet based method to determine the quadrupole magnet centres for storage rings has been tested on the MAX III synchrotron light source. The required corrector magnet strengths for the corrected beam orbit are used to determine the quadrupole magnet centre positions. This method is the most effective for an optimal distribution of beam position monitors and corrector magnets in the storage ring and will be used as a basis for the MAX IV storage rings.  
 
TUPC134 Results from Commissioning of the Energy Extraction Facilities of the LHC Machine extraction, superconducting-magnet, quadrupole, simulation 1383
 
  • K. H. Mess, G.-J. Coelingh, K. Dahlerup-Petersen
    CERN, Geneva
  The risk of damage to the superconducting magnets, busbars and current leads of the LHC machine in case of a resistive transition (quench) is being minimized by adequate protection. The protection is based on early quench detection, bypassing the quenching magnets by cold diodes, energy density dilution in the quenching magnets using heaters and, eventually, energy extraction. For two hundred and twenty-six LHC circuits (600 A and 13 kA) extraction of the stored magnetic energy to external dump resistors was required. All these systems are now installed in the machine and the final hardware commissioning has been undertaken. After a short description of the topology and definitive features, layouts and parameters of these systems the paper will focus on the results from their successful commissioning and an analysis of the system performance.  
 
TUPD017 Design of Main Ring Dipole Power Supply for HIRFL-CSR power-supply, controls, feedback, heavy-ion 1464
 
  • Y. X. Chen, X. M. Feng, D. Q. Gao, Y. L. Gao, Y. Z. Huang, Y. Tang, J. J. Wang, J. W. Xia, H. B. Yan, H. H. Yan, Y. J. Yuan, Z. D. Yuan, S. Zhang, X. L. Zhang, Z. Z. Zhou
    IMP, Lanzhou
  This paper introduces the main circuit topologic, control method and double reference setting system of a dipole power supply which is the pivotal device of the HIRFL-CSR(Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring). The power supply works at the pulse mode, with the peak output power of 3.15MW (3000A, 1045V). To fulfill difficult requirements especially for the tracking error, which is needed less than 300ppm, a special topologic is adopted. The power supply has two parts: SCR rectifier provides the most energy and PWM converter provides correcting current and perfect reaction for tracking current setting. Now the dipole power supply is performing well during the CSR commissioning, with the perfect tracking error, well long-time stability and low ripple current.  
 
TUPP030 A Formula for the Electron Cloud Map Coefficient in the Presence of a Magnetic Field electron, simulation, vacuum, cyclotron 1601
 
  • T. Demma
    INFN/LNF, Frascati (Roma)
  • S. Petracca
    U. Sannio, Benevento
  The evolution of the electron density during multibunch electron cloud formation can be reproduced using a bunch-to-bunch iterative map formalism. The reliability of this formalism has been proved for RHIC* and LHC**. The coefficients that parameterize the map function are readily obtained by fitting the results of compute-intensive electron cloud simulations. An analytic expression for the linear map coefficient that describes weak cloud behaviour from first principles has been derivied for the case of staight sections of RHIC***. In this paper we generalize the model presented in *** to the case of electron cloud evolution in presence of a dipolar magnetic field and compare the results with numerical simulations.

*U. Iriso and S. Pegg. Phys. Rev. ST Accel. Beams 9, 071002 (2006).
**T. Demma et al. Phys. Rev. ST Accel. Beams 10,114401 (2007).
***U. Iriso and S. Pegg. Proc. of EPAC06, pp. 357-359.

 
 
TUPP076 Longitudinal and Transverse Impedances of XFEL Kicker Vacuum Chamber impedance, vacuum, kicker, resonance 1712
 
  • A. V. Tsakanian, J. Rossbach
    Uni HH, Hamburg
  • M. Ivanyan
    CANDLE, Yerevan
  In European XFEL project beam delivery system the kicker magnet vacuum chamber design is composed of the ceramic pipe coated with Titanium Stabilized High Gradient Steel. In this paper the results of the study for the longitudinal and transverse impedances for such a laminated vacuum chamber are presented. The field matching technique is used to calculate the vacuum chamber impedances. The loss and kick factors are given.  
 
TUPP082 Longitudinal Stability of Flat Bunches with Space-charge or Inductive Impedance impedance, damping, synchrotron, space-charge 1721
 
  • F. Zimmermann
    CERN, Geneva
  • I. Santiago Gonzalez
    University of the Basque Country, Bilbao
  We study the loss of Landau damping for the longitudinal plane via the ''Sacherer formalism''. Stability limits are calculated for several longitudinal beam distributions, in particular for two types of flat bunches, which could be of interest to the LHC upgrade. The resulting Landau stability diagrams are computed and displayed for different azimuthal modes. A general recipe is given for calculating the threshold intensity in the case of a capacitive impedance below transition or, equivalently, for a purely inductive impedance above transition. Specific results are finally presented for the case of the PS Booster, as an example of space-charge impedance below transition, and for the SPS, as an example of inductive impedance above transition.  
 
TUPP089 Implementation of Fringe Field Dipole Magnets into the V-Code Beam Dynamics Simulation Tool simulation, focusing, multipole, vacuum 1738
 
  • S. S. Franke, W. Ackermann, B. Steiner, T. Weiland
    TEMF, Darmstadt
  • J. Enders, C. Hessler, Y. Poltoratska
    TU Darmstadt, Darmstadt
  Fast online beam dynamics simulations can advantageously assist the machine operators at various particle accelerator machines because they provide a more detailed insight into the actual machine status. Based on the moment approach a fast tracking code named V-Code has been implemented at TEMF. Within the SFB 634 project the V-Code beam dynamics simulation tool is supposed to be installed at the Superconducting Darmstadt LINear ACcelerator S-DALINAC which is designed as a re-circulating linear accelerator. In order to be able to simulate the entire beam line, an implementation of fringe field dipole magnets is mandatory. Unlike a hard edged field approach the fringe fields influence the beam focusing and its inhomogeneity results in a non-circular bunch motion. For an accurate reproduction of the transverse motion specialized techniques to obtain and to handle the reference path in V-Code together with the 3D-field data along the curved trajectory had to be developed. In the paper a summary of implementation details together with simulation results will be provided.  
 
TUPP105 Theoretical Field Analysis for Superferric Accelerator Magnets Using Elliptic Multipoles and its Advantages multipole, synchrotron, simulation, magnet-design 1773
 
  • P. Schnizer, E. S. Fischer
    GSI, Darmstadt
  • P. G. Akishin
    JINR, Dubna, Moscow Region
  • B. Schnizer
    TUG/ITP, Graz
  FAIR will build a set of accelerators and storage rings at GSI Darmstadt. Nearly all of them transport beams of elliptical shape (SIS 100, CR, NESR, RESR, SuperFRS). Magnetic field calculations as well as magnetic measurements provide precise field information, which is used to improve the properties of machine using numerical simulations. We had developed elliptical multipoles fulfilling the Laplace equation which enable us to describe the field within the whole aperture consistently. Now the representation of these has been simplified considerably as compared to earlier ones. Meanwhile we found analytical expressions to derive circular multipoles directly from the elliptic multipoles. We illustrate the advantage of this data representation on SIS 100 magnet data and show how a concise set of harmonics can be derived from rotating coil measurements.  
 
TUPP110 Rotative Systems for Dose Distribution in Hadrontherapy (Gantries) ion, cryogenics, superconducting-magnet, proton 1779
 
  • M. J. Bajard
    UCBL, Villeurbanne
  • F. A. Kircher
    CEA, Grenoble
  Tumour treatments with high velocity ion beams or protons are characterised by a great depth precision (Bragg pic) and a low divergence for dose delivery in very small volumes. In order to spare normal tissues before and around the tumour it is necessary to have the choice of the beam incidence because the patient cannot be moved. Different devices have been built mainly exocentric and isocentric. Many others are being studied. Cryogenic solutions are analysed to reduce the total mass in rotation. For example it would be very interesting to choose a superconductive solution for the last 90° dipole.  
 
TUPP124 Status of the Particle Therapy Accelerator System Built by DANFYSIK A/S synchrotron, vacuum, ion, quadrupole 1815
 
  • S. P. Møller, T. Andersen, F. Bødker, A. Baurichter, M. Budde, P. A. Elkiaer, C. E. Hansen, N. Hauge, T. Holst, I. Jensen, L. K. Kruse, S. M. Madsen, M. Schmidt
    Danfysik A/S, Jyllinge
  • K. Blasche
    BTE Heidelberg, Ingeniurbüro, Schriesheim
  • B. J. Franczak
    GSI, Darmstadt
  Danfysik and Siemens have entered a cooperation to market and build Particle Therapy* systems for cancer therapy. The accelerators will consist of an injector (7 MeV/u proton and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u in less than 1s. These beams can be slowly extracted over a period of up to 10s and delivered to treatment rooms through a choice of fixed-angle horizontal and semi-vertical beamlines and Gantry Systems. The intensity for protons and carbon ions will be sufficient for the needs of scanning beam applications. The design of a particular system, with three horizontal beamlines and one semi-vertical (45°) beamline, will be described. At the time of EPAC08, most components have been manufactured and hardware tested. The detailed layout of the facility will be presented, together with some of the components and their performance.

*Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.

 
 
WEOBM01 R&D Activities Aimed at Developing a Curved Fast Ramped Superconducting Dipole for FAIR SIS300 synchrotron, coupling, ion, antiproton 1950
 
  • P. Fabbricatore, S. Farinon, R. Musenich
    INFN Genova, Genova
  • F. Alessandria, G. Bellomo, G. Volpini
    INFN/LASA, Segrate (MI)
  • U. Gambardella
    INFN/LNF, Frascati (Roma)
  • J. E. Kaugerts, G. Moritz
    GSI, Darmstadt
  • R. Marabotto
    ASG, Genova
  • M. Sorbi
    Universita' degli Studi di Milano & INFN, Segrate
  One of the basic components of the FAIR facility, under development at GSI, is the synchrotron SIS300 (300 Tm rigidity). In order to reach the required high intensities of proton and heavy ion beams, the magnets of this synchrotron have to be pulsed from the injection magnetic field of 1.5 T up to 4.5 T maximum field at the rate of 1 T/s. These 7.8 m long, cos-teta shaped coils with a 100 mm bore have the particular characteristic to be curved (the sagitta is 114 mm). All these aspects demand for a challenging R&D, aimed at the development of a low loss conductor and of a suitable winding technology for curved coil. Further design issues are related to the optimization of the stress distribution involving materials able to hold 107 cycles and to the maximization of the heat transfer to coolant (supercritical helium at 4.7 K). At the present time, design activities are going on with the aim to design, construct and test a 3.8 m long prototype within 2009. In order to achieve this objective, several intermediate milestones are included in the R&D program. One of the most challenging is the industrial development of a method for winding a curved cos-teta dipole.  
slides icon Slides  
 
WEPC011 Using Multi-bend Achromats in Synchrotron Radiation Sources lattice, vacuum, emittance, sextupole 2007
 
  • M. Eriksson, A. Hansson, S. C. Leemann, L.-J. Lindgren, M. Sjöström, E. J. Wallén
    MAX-lab, Lund
  • L. Rivkin, A. Streun
    PSI, Villigen
  Multi-bend achromats offer small electron beam emittance, large energy acceptance and a good dynamic aperture. Two examples are discussed in the article, each using 7-bend achromats; a 12 achromat lattice and a 20 achromat one. Some possible technical solutions associated with the dense lattices are discussed: magnet technology, vacuum system and RF system. Some characteristics of the two rings are also presented; effects of Intra Beam Scattering, Touschek life-time and the electron beam parameter values.  
 
WEPC040 Commissioning of the SSRF Booster booster, linac, electron, synchrotron 2073
 
  • H. H. Li, Q. Gu, D. M. Li, L. G. Liu, D. Wang, Z. T. Zhao
    SINAP, Shanghai
  The SSRF Booster, designed to accelerate the electrons from 150MeV to 3.5GeV, is a FODO structure synchrotron with 180m circumference and 2Hz repetition rate. The commissioning of the SSRF booster from the LTB transfer line started on Sept. 30th evening, 2007, the first turns of beam in the booster was obtained in 20 hours. With about 60 hours effective commissioning effort, the electrons were accelerated to 3.5GeV on October 5th morning, 2007. And then the first 3.5GeV beam was extracted to BTS transfer line on October 30th, 2007. In this paper, the SSRF booster is introduced and its commissioning results are presented.  
 
WEPC056 Emittance Reduction by Longitudinally Varying Dipole Field emittance, dynamic-aperture, optics, radiation 2118
 
  • K. Tsumaki
    JASRI/SPring-8, Hyogo-ken
  One of the most important matters for synchrotron radiation source is decreasing the beam emittance to increase the brightness. The electron beam emittance is almost determined by electron energy and the average H-function. For further improvement of the emittance, we can change the damping partition number by radially varying dipole field and can reduce the emittance. However, this method is not effective for a small emittance lattice due to its small dispersion function. We have studied the emittance reduction by longitudinally varying magnetic field in a bending magnet. The radius of curvature is assumed to vary with the function of nth degree (n=1,2,3,4). The emittance is calculated numerically for minimum emittance and achromat configuration. In this paper, we describe the details of calculated results and discuss the effectiveness of the method.  
 
WEPC057 Preparation for Top-up Operation at Diamond radiation, injection, storage-ring, controls 2121
 
  • R. P. Walker, P. T. Bonner, F. Burge, Y. S. Chernousko, C. Christou, J. A. Dobbing, M. T. Heron, V. C. Kempson, I. P.S. Martin, G. Rehm, R. J. Rushton, S. J. Singleton, M. C. Wilson
    Diamond, Oxfordshire
  • R. Bartolini
    JAI, Oxford
  We report on progress towards top-up operation of Diamond. We describe the extensive safety assessment that has carried out, including the measurements and simulations to assess the potential radiation doses in the case of poor injection efficiency or a top-up "accident", and the various levels of safety measures - procedures, software limits and personnel safety system interlocks - that have been implemented. We describe the top-up control algorithm, the technique used to maintain a given arbitrary filling pattern and the performance in practise. The work carried out to reduce the effect of the injection kickers on the stored beam is described, and the effect of the residual disturbance on user operation is discussed. The modifications to the timing system to provide hardware and software gating signals, and experience with the use of these, are also described.  
 
WEPC066 The Transport Line Upgrade Proposal of Hefei Light Source quadrupole, injection, storage-ring, coupling 2145
 
  • L. Wang, G. Feng, W.-W. Gao, W. Li, L. Liu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  The injector of Hefei Light Source is a 200 MeV linac. A 55m transport line transfer beam to injection point of storage ring. At current stage, the mismatch of phase space is a potential source limiting the injection efficiency and stable operation of light source. A new focusing configuration of transport line was put forward, where the Twiss parameters matching was implemented. A skew quadrupole was introduced to make horizontal dispersion function matching. This matching between transport line and storage ring would be helpful to improve injection efficiency of HLS storage ring.  
 
WEPC067 Optics for the ALBA Booster Synchrotron booster, sextupole, quadrupole, lattice 2148
 
  • G. Benedetti, D. Einfeld, Z. Martí, M. Munoz, M. Pont
    ALBA, Bellaterra
  The ALBA booster is a full energy injector of 3 GeV for top-up operation that will be installed in the same tunnel as the Storage Ring. Its large circumference of 249.6 m and the magnetic lattice with combined function bending magnets provide an equilibrium emittance as low as 9 nm rad. In this paper the linear optics functions, the aperture requirements and the gradient error tolerances in the dipoles and quadrupoles are discussed. The closed orbit correction scheme consists of 44 horizontal and 28 vertical correctors and 44 BPMs. A solution that requires a reduced number of BPMs has been studied as well. Chromaticity correction and dynamic aperture during the ramping have been also investigated. Finally, the injection and extraction schemes are described.  
 
WEPC083 Status of the SSRF Booster booster, injection, extraction, power-supply 2189
 
  • D. M. Li, H. W. Du, H. H. Li, Z. T. Zhao
    SINAP, Shanghai
  The SSRF booster is a 2Hz electron synchrotron. It accelerates electrons, coming from a 150 MeV linac, to a final energy of 3.5 GeV in 250ms and extracts them into the storage ring. The booster lattice is based on a FODO structure with missing dipoles, forming 28 cells with 8 straight sections of a 2-folder symmetry and 180m circumference. The SSRF injector (Include 150 MeV linac, booster and two transport lines) was designed for Top-Up injection, which has single-bunch and multi-bunch beam modes. After 9 months installation and pre-commissioning, the SSRF booster commissioning started on September 30, 2007. The first 3.5GeV beam was obtained On Oct.5, and the first extracted beam was obtained on Oct.29, 2007. The booster serves as a injector for storage ring from Dec. 21, 2007. In this paper, the design, installation and commissioning of the SSRF booster and transport lines are described.  
 
WEPC092 A Pulsed Quadrupole Magnet Injection at the PF-AR Storage Ring injection, beam-losses, quadrupole, factory 2207
 
  • H. Takaki, N. Nakamura
    ISSP/SRL, Chiba
  • K. Harada, Y. Kobayashi, T. Miyajima, S. Nagahashi, T. Obina, A. Ueda, K. Umemori
    KEK, Ibaraki
  We have examined a beam injection system that used a pulsed quadruple magnet (PQM) at the PF-AR storage ring since the spring of 2004. The system is operating well and the accumulation of the beam up to 60mA in the single bunch operation is possible by the current state. The beam injection system that uses the PQM does not require a conventional injection bump orbit, and has the feature that only one PQM in the injection part is needed. An injected beam is kicked to be proportional to the distance from the center and captured afterwards. On the other hand, the pulse kick hardly influences the stored beam at the magnetic field center of the PQM. We report on the result of collecting the basic data of the influence on the PQM beam injection at the PF-AR storage ring.  
 
WEPC096 APPLE Undulator for PETRA III undulator, polarization, emittance, radiation 2219
 
  • J. Bahrdt, H.-J. Baecker, W. Frentrup, A. Gaupp, M. Scheer, B. Schulz
    BESSY GmbH, Berlin
  • U. Englisch, M. Tischer
    DESY, Hamburg
  Currently, the storage ring PETRA is being rebuilt to a light source with an ultra low emittance of only 1nm rad. The undulator radiation will take full advantage of this high performance. PETRA III will also provide circularly polarized light and linearly polarized light under arbitrary angles (inclined mode) within the energy range of 250-3000eV. The light will be produced with an APPLE II undulator which is under construction at BESSY at present. The total length of 5m and a minimum gap of only 11mm cause strong 3D forces. Due to the small good field region in an APPLE undulator and a small stay clear between the magnets and the vacuum chamber a sophisticated mechanical layout is required. The design will be presented, the expected residual mechanical deformations will be given and the consequences for the spectral performance will be discussed.  
 
WEPC144 Test Results of the AC Field Measurements of Fermilab Booster Corrector Magnets booster, quadrupole, sextupole, pick-up 2347
 
  • J. DiMarco, D. J. Harding, V. S. Kashikhin, S. Kotelnikov, M. J. Lamm, A. Makulski, R. Nehring, D. F. Orris, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, G. Velev
    Fermilab, Batavia, Illinois
  Multi-element corrector magnets are being produced at Fermilab that will enable correction of orbits and tunes through the entire cycle of the Booster, not just at injection. The corrector package includes six different corrector elements - normal and skew orientations of dipole, quadrupole, and sextupole - each independently powered. The magnets have been tested during typical AC ramping cycles at 15Hz using a fixed coil system to measure the dynamic field strength and field quality. The fixed coil is comprised of an array of inductive pick-up coils around the perimeter of a cylinder which are sampled simultaneously at 100kHz with 24-bit ADC’s. The performance of the measurement system and a summary of the field results are presented and discussed.  
 
WEPC145 A Fast-sampling, Planar Array for Measuring the AC Field of Fermilab Pulsed Extraction Magnets linac, extraction, pick-up, booster 2350
 
  • J. DiMarco, C. Johnstone, O. Kiemschies, S. Kotelnikov, M. J. Lamm, A. Makulski, R. Nehring, D. F. Orris, A. D. Russell, M. Tartaglia, G. Velev, D. G.C. Walbridge, A. Yuan
    Fermilab, Batavia, Illinois
  A system employing a planar array of inductive pick-up coils has been developed for measurements of the rapidly changing dipole field in pulsed extraction magnets of the Fermilab MuCool project. The magnets are of C-type design, and have a peak field of 0.65 T during 8.33 millisecond half-sine pulse with 15 Hz repetition rate. The coils of the measurement system are fabricated on a single, 97.5 mm wide, 2-layer circuit board. The top layer of the circuit board has 15 unbucked coils distributed over its width. The bottom layer has a similar arrangement of coils, except each is bucked against the central winding to suppress the main dipole field and allow for more sensitive measurements of higher-order harmonics across the magnet mid-plane. The array of coils is simultaneously sampled at data rates of up to 100kHz with 10kHz bandwidth using 24-bit ADC’s. A detailed overview of the system and data analysis is presented, along with a characterization of results and system performance.  
 
WEPC153 Dipole Magnet for Use of RHIC EBIS HEBT Line multipole, sextupole, quadrupole, octupole 2365
 
  • T. Kanesue
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
  • M. Okamura, D. Raparia, J. Ritter
    BNL, Upton, Long Island, New York
  We present the design optimization of a dipole magnet for use of RHIC EBIS HEBT line. This magnet provides a total bending angle of 145 degrees by two identical magnets and it is used to guide H+ to Au32+ beam with energy of 2 MeV/amu. Magnetic field is required to change within 1 second corresponding to the ion species, so magnet body has the laminated structure to suppress eddy current. Effective length and field quality within a radius of 5 cm was optimized separately. Effective length was optimized by adjusting end shape not to change the beam orbit between low and high field operation more than 1 mm from intended beam orbit after bending. Then field quality was optimized by changing the shim position and additional bump. After modification, all multipole coefficients along the beam trajectory were reduced to within 10x10-4.  
 
WEPC155 Experimental Characterization of Permanent Magnet Harmonic Corrector Rings permanent-magnet, quadrupole, insertion, insertion-device 2371
 
  • A. Madur, S. Marks, S. Prestemon, D. Schlueter
    LBNL, Berkeley, California
  A total of three permanent magnet chicane magnets have been installed at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The magnet design incorporates counter-rotating permanent magnet pairs with trim coils. The purpose is to provide a fixed angular separation between two successive elliptically polarizing undulator (EPU) photon fans and to correct steering perturbation resulting from EPU polarization state and gap changes. This paper presents a method for the determination of the permanent magnets parameters and setting relative orientations of the rotors by performing magnetic measurements with rotating coils. The measurement method will be developed and illustrated with experimental data from the measurement of a 16 cylinder permanent magnet harmonic corrector ring.  
 
WEPC156 Development and Adjustment of the EMMA Quadrupole Magnets quadrupole, multipole, electron, controls 2374
 
  • N. Marks, B. J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M. J. Crawley, F. T.D. Goldie, B. Leigh
    Tesla Engineering Limited, West-Sussex
  The non-scaling FFAG EMMA, now under construction at STFC’s Daresbury Laboratory, requires 84 quadrupoles. Because of the unusual nature of these magnets*, prototypes for the F and the D type quadrupoles were required. These magnets were ordered from and constructed and measured by Tesla Engineering. Subsequently, design changes have been made and modifications to the prototypes carried out. The paper will give engineering details of these prototypes, of the measurement results obtained using a rotating coil magnetometer and subsequent adjustments to clamp plates and pole profiles needed to obtain optimum three dimensional gradient quality. As a result of these developments, the construction of the magnets for the complete ring is now underway.

*B. J.A. Shepherd & N. Marks, “Quadrupole Magnets For The 20MeV FFAG, ‘EMMA’”, PAC 2007 (MOPAN107).

 
 
WEPC160 Eddy-current Effect on Field Multipoles Arising in Dipole Magnets with Elliptic and Rectangular Beam Pipe multipole, vacuum, quadrupole, coupling 2383
 
  • E. Perevedentsev, A. L. Romanov
    BINP SB RAS, Novosibirsk
  We present an analytical evaluation of the field-distortion effect from eddy currents induced by variation of magnetic field of dipole magnets with elliptic or rectangular beam pipe of finite conductivity. The pipe sizes and aspect are arbitrary except that for practical reasons we assume the pipe wall thickness is small as compared to the skin depth. Handy formulas are presented for the field multipoles arising from non-round shape of the beam pipe.  
 
WEPC161 Some Remarks about Characterization of Magnetic Blocks with Helmholtz Coil insertion, insertion-device, synchrotron, induction 2386
 
  • G. Tosin, R. A. Pimenta
    LNLS, Campinas
  The use of Helmholtz coils for magnetic block characterization is a widespread technique because of its small sensitivity to block positioning errors and high precision. In this paper we present some calculations related to the influence of block positioning for the cases where the Helmholtz condition is not exactly satisfied. Also the comparison between a model based on point dipolar magnetic moment and magnetized blocks with real dimensions is analyzed, as well as the corrections associated to the effect of self-demagnetization of the blocks.  
 
WEPC164 Development of Modulating Permanent Magnet Sextupole Lens for Focusing of Cold Neutrons sextupole, focusing, scattering, permanent-magnet 2392
 
  • M. Yamada, M. Ichikawa, Y. Iwashita, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • T. Ino, S. Muto, H. M. Shimizu
    KEK, Ibaraki
  A modulating permanent magnet sextupole lens that can focus pulsed cold neutrons is under development. It is based on the extended Halbach configuration to generate stronger magnetic field. In order to adjust the strength, the magnet is divided into two co-axial nested rings, where the inner ring is fixed and the outer ring can be rotated. Synchronizing the period of the modulation with that of pulsed neutron beam suppress the chromatic aberration. We have fabricated a half-scale model and studied the strength, the torque and the temperature rise caused by eddy current. Now we are developing the full-scale model improving such problems. These two scale models of magnet are described.  
 
WEPC165 Magnetic Measurements of the SSRF Storage Ring Magnets quadrupole, sextupole, storage-ring, multipole 2395
 
  • J. D. Zhang, Q. G. Zhou
    SINAP, Shanghai
  The SSRF storage ring comprises a total of 460 magnets which has four types and eight different effective magnetic lengths. The magnetic measurements of all the production magnets including 40 bending magnets with a maximum field of 1.2726 T, 200 quadrupoles divided in Three families with a maximum gradient of 20 T/m, 140 sextupoles with a maximum second order differential of 460 T/m, and 80 correctors with a maximum kick capability of 1.2 mrad. For the dipoles a long coil system has been used to measure the magnetic field while for the quadrupoles and sextupoles a rotating coil system has been used to determine the magnitude of the high order multipoles. In this paper the analysis of these data is discussed and results for measured magnets are presented.  
 
WEPD006 Conceptual Design of Superferric Magnets for PS2 cryogenics, quadrupole, magnet-design, injection 2410
 
  • L. Bottura, G. De Rijk, M. Karppinen, G. Kirby, R. Maccaferri, C. Maglioni, V. Parma, L. Rossi, W. Scandale, L. Serio, D. Tommasini
    CERN, Geneva
  We analyze feasibility and cost of a superferric magnet design for the PS2, the novel 50 GeV ring that should replace the PS in the CERN injector chain. Specifically, we provide the conceptual design of dipole and quadrupoles, including considerations on cryogenics and powering. The magnets have warm iron yoke, and cryostated superconducting coils embedded in the magnet, which reduces AC loss at cryogenic temperature. The superconductor has large operating margin to endure beam loss and operating loads over a long period of time. Although conservative, and without any critical dependence on novel technology developments, this superconducting option appears to be attractive as a low-power alternative to the normal-conducting magnets that are the present baseline for the PS2 design. In addition it provides flexibility in the selection of flat-top duration at no additional cost.  
 
WEPD008 Automatic System for the DC High Voltage Qualification of the Superconducting Electrical Circuits of the LHC Machine controls, monitoring, cryogenics, power-supply 2416
 
  • D. Bozzini, V. Chareyre, S. Russenschuck
    CERN, Geneva
  • M. Bednarek, P. Jurkiewicz, A. Kotarba, J. Ludwin, S. Olek
    HNINP, Kraków
  A system has been developed to verify automatically with the application of a DC high voltage, the insulation resistance between circuits to circuit and circuit to ground. In the most complex case of the LHC machine up to 72 circuits share the same volume inside the cryogenic lines and each circuit can have an insulation fault versus any other circuit or versus ground. The system can connect up to 80 circuits and apply a voltage up to 2 kV DC. The leakage of current flowing through each circuit is measured within a range of 1 nA to 2 mA. The matrix of measurements characterizes the paths taken by the currents and recognizes weak points of the insulation between circuits. The system is composed of a DC voltage source, a data acquisition card that measures with precision currents and voltages and drives up to 5 high voltage switching modules offering each 16 channels. A LabVIEW based application controls the system for an automatic and safe operation. This paper describes the hardware and software design, the testing methodology and the results obtained during the qualification of the LHC superconducting circuits.  
 
WEPD009 The CERN High Field Magnet Program luminosity, quadrupole, radiation, insertion 2419
 
  • G. De Rijk
    CERN, Geneva
  With the LHC, magnets of 10T peak field Nb-Ti technology were developed and this technology reached full maturity. The next step in field level, with a peak field in the range of 15T, will be needed for the LHC phase II upgrade. For this upgrade the temperature margin and radiation resistance of the Nb-Ti coil technology is not sufficient. Begin 2008 CERN starts a program to develop high field magnets for LHC upgrades and other future programs. For this mostly Nb3Sn conductors will be employed but also HTS conductors will be considered. In this paper an overview will be presented of the projects for which this HFM technology will be needed. The the program will be presented in terms of R&D chapters and work packages. The need and opportunities for collaborations with other institutes will be discussed.  
 
WEPD010 Electronic Systems for the Protection of Superconducting Devices in the LHC extraction, insertion, quadrupole, power-supply 2422
 
  • R. Denz, K. Dahlerup-Petersen, K. H. Mess
    CERN, Geneva
  The Large Hadron Collider LHC incorporates an unprecedented amount of superconducting components: magnets, bus-bars, and current leads. Most of them require active protection in case of a transition from the superconducting to the resistive state, the so-called quench. The electronic systems ensuring the reliable quench detection and further protection of these devices have been developed and produced over the last years and are currently being put into operation. The paper will describe the various protection devices and hereby focus on the final test and commissioning phase of the system. First results from operation will be presented as well as an analysis of the system performance.  
 
WEPD011 Development Work for a Short Curved Superconducting Dipole Magnet for the HESR at FAIR storage-ring, antiproton, synchrotron, lattice 2425
 
  • F. M. Esser, R. Greven, G. Hansen, F. Klehr, J. Schillings, H. Soltner, R. Tölle
    FZJ, Jülich
  Forschungszentrum Juelich has taken the leadership of a consortium being responsible for the design of the High-Energy Storage Ring (HESR) going to be part of the FAIR project at GSI. Within these activities a design for a short cosine-theta superconducting dipole has been carried out together with industry partners. Its length will be approximately one third of the original HESR dipole whereas all other design parameter will be the same. The main design criterion is the short bending radius of 15.3 m of the magnet implying that the coil itself has a curved shape. Beside the geometrical design of the cold mass, this paper will focus particularly on the finite element calculations from the assembly through the cool down to the operating temperature of the magnet. First manufacturing tests as well as a status report on the achievements so far will be presented and future plans will be discussed.  
 
WEPD013 Four-Coil Superconducting Helical Solenoid Model for Muon Beam Cooling beam-cooling, controls, quadrupole, superconducting-magnet 2431
 
  • V. S. Kashikhin, N. Andreev, A. N. Didenko, V. Kashikhin, M. J. Lamm, A. V. Makarov, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. P. Johnson, S. A. Kahn
    Muons, Inc, Batavia
  Novel configurations of superconducting magnets for helical muon beam cooling channels and demonstration experiments are being designed at Fermilab. The magnet system for helical cooling channels has to generate longitudinal solenoidal and transverse helical dipole and helical quadrupole fields. This paper discusses the Helical Solenoid model design and manufacturing of a 0.6 m diameter, 4-coil solenoid prototype to prove the design concept, fabrication technology, and the magnet system performance. Results of magnetic and mechanical designs with the 3D analysis by TOSCA, ANSYS and COMSOL will be presented. The model quench performance and the test setup in the FNAL Vertical Magnet Test Facility cryostat will be discussed.  
 
WEPD014 Magnets for the MANX 6-D Muon Cooling Demonstration Experiment quadrupole, multipole, simulation, superconductivity 2434
 
  • V. S. Kashikhin, N. Andreev, V. Kashikhin, M. J. Lamm, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • M. Alsharo'a, R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
  MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a helical cooling channel (HCC) for muon beam emittance reduction for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components, which diminish as the beam loses energy as it slows down in the liquid helium absorber inside the magnet. The proposed magnet system design is comprised of coil rings positioned along a helical path, which will provide the desired solenoidal and helical dipole and quadrupole fields. Additional magnets that provide emittance matching between the HCC and the upstream and downstream spectrometers are also described. The results of a G4Beamline simulation of the beam cooling behavior of the magnet and absorber system will be presented.  
 
WEPD015 Design Studies of Magnet Systems for Muon Helical Cooling Channels beam-cooling, quadrupole, target, superconductivity 2437
 
  • V. Kashikhin, V. S. Kashikhin, M. J. Lamm, M. L. Lopes, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • M. Alsharo'a, R. P. Johnson, S. A. Kahn
    Muons, Inc, Batavia
  Helical cooling channels consisting of a magnet system with superimposed solenoid, helical dipole and quadrupole fields, and a pressurized gas absorber in the aperture, promise high efficiency in providing 6D muon beam cooling for a future Muon Collider and some other applications. Two alternative designs of the magnet system for the helical cooling channel are being investigated at the present time. The first one is based on a straight, large aperture solenoid with helical dipole and quadrupole coils. The other one is based on a spiral solenoid which generates the main solenoid field and the helical dipole and quadrupole components. Both concepts have been developed and compared for the MANX experiment. In this paper we continue design studies and comparison of these two concepts for the high field sections of a helical cooling channel. The results of magnetic and mechanical analysis as well as the superconductor choice and specifications will be presented and discussed.  
 
WEPD016 Electrical Quality Assurance of the Superconducting Circuits during LHC Machine Assembly cryogenics, pick-up, controls, quadrupole 2440
 
  • S. Russenschuck, D. Bozzini, V. Chareyre, O. Desebe, K. H. Mess
    CERN, Geneva
  • M. Bednarek, D. P. Dworak, E. Gornicki, P. Jurkiewicz, P. J. Kapusta, A. Kotarba, J. Ludwin, S. Olek, M. Talach, M. Zieblinski
    HNINP, Kraków
  • M. Klisch, B. Prochal
    AGH, Cracow
  Based on the LHC powering reference database, all-together 1712 superconducting circuits have been electrically wired and interconnected in the various cryogenic lines of the LHC machine. Continuity, magnet polarity, and the quality of the electrical insulation have been the main objectives of the Electrical Quality Assurance (ELQA) activities during the LHC machine assembly. Another activity aimed at ensuring the coherence between the reference database on one side, and the polarity conventions used for beam simulation and magnetic measurements. With the assembly of the LHC now completed, the paper reviews the methods and procedures established for the ELQA, as well as the employed time and resources. The qualification results will be presented with the emphasis on the detected electrical non-conformities and their possible impact on the performance of the LHC machine.  
 
WEPD017 Full Size Prototype Magnets for Heavy Ion Superconducting Synchrotron SIS100 at GSI: Status of Manufacturing and Test at JINR quadrupole, synchrotron, ion, antiproton 2443
 
  • A. D. Kovalenko, N. N. Agapov, A. V. Alfeev, A. V. Bychkov, A. V. Gromov, H. G. Khodzhibagiyan, G. L. Kuznetsov, A. Y. Starikov
    JINR, Dubna, Moscow Region
  • E. S. Fischer, G. Moritz, P. J. Spiller
    GSI, Darmstadt
  • A. V. Shabunov
    JINR/LHE, Moscow
  The SIS100 synchrotron is designed for acceleration of high intensity beams with a pulse repetition rate of 1 Hz. The use of superferric Nuclotron-type dipoles, quadrupoles and corrector magnets is planned in the accelerator magnetic system. The magnet coils are made of hollow NbTi composite cable cooled with two-phase helium flow at 4.5 K. The lattice comprises 108 dipoles, 168 quadrupoles and necessary set of steerer and multipole corrector magnets. We present recent results from the design and optimization of the SIS100 magnetic elements parameters. The status of manufacturing full size prototypes is presented. The essential features of the magnets production and the new test results are discussed.  
 
WEPD018 Commissioning of the LHC Current Leads cryogenics, quadrupole, controls, instrumentation 2446
 
  • A. Ballarino, S. A. March, K. H. Mess
    CERN, Geneva
  The powering of the LHC superconducting magnets relies on more than 3000 leads transporting the current from/to the cryogenic environment and rated at currents ranging from 60 A to 13000 A. The design of these leads, about 1000 of which are based on high temperature superconducting material, was entirely done at CERN, where prototype assemblies were also assembled and tested, while the series production was done in external laboratory and companies on the basis of build-to-print specification. This report summarizes the results of the tests performed during the commissioning of the LHC machine, when the leads underwent the thermal and electrical cycles necessary for the powering of the LHC superconducting circuits.  
 
WEPD020 Stability of Superconducting Wire in Magnetic Field superconducting-magnet, cryogenics, power-supply 2449
 
  • K. Ruwali
    GUAS/AS, Ibaraki
  • K. Hosoyama, K. Nakanishi
    KEK, Ibaraki
  • Y. Teramoto, A. Yamanaka
    Toyobo Research Institute, Shiga
  Main cause of premature quench in superconducting magnet is the heat generated due to superconducting wire motion. The wire motion occurs where electromagnetic force to conductors exceeds frictional force on surfaces of the conductors. Hence, frictional properties of the conductors and winding structures are important parameters for characterizing stability of the superconducting windings. An experimental setup was prepared to detect wire movement by observing spike in voltage of the superconducting sample wire. A detailed study was carried out in order to study superconducting wire motion under different experimental conditions such as varying applied load to specimen wire, back up field, varying the interface of superconductor and base material. The base materials used are polyimide film and Dyneema. The Dyneema has low frictional coefficient and negative thermal expansion. In the case of Dyneema, it is found that amplitude of voltage generated due to wire motion reduces and also relatively smooth motion of wire is observed. These effects are attributed to the low frictional coefficient. The experimental observation will be discussed in detail.  
 
WEPD021 Magnetic Field Characteristics of a SIS 100 Full Size Dipole vacuum, multipole, injection, synchrotron 2452
 
  • P. Schnizer, E. S. Fischer
    GSI, Darmstadt
  • P. G. Akishin
    JINR, Dubna, Moscow Region
  • R. V. Kurnyshov
    Electroplant, Moscow
  • B. Schnizer
    TUG/ITP, Graz
  • P. A. Shcherbakov
    IHEP Protvino, Protvino, Moscow Region
  • G. Sikler, W. Walter
    BNG, Würzburg
  FAIR will feature two superconducting fast ramped synchrotrons. The dipole magnets for one of them, SIS 100, have been designed and prototypes were built. The properties of the magnetic field were analysed using OPERA (for DC operation) and ANSYS for dynamic calculations. Elliptic multipoles fulfilling the Laplace Equation in plane elliptic coordinates describe the field within the whole aperture consistently within a single expansion. Further circular multipoles, valid within the ellipse, can be calculated analytically from the elliptic multipoles. The advantage of this data representation is illustrated on the FEM calculation performed for SIS 100 dipoles and quadrupoles currently foreseen for the machine. The magnetic field of one of these prototypes was measured using a mole. We compare the results of the calculation to the measurement for the static as well as the dynamic mode.  
 
WEPD025 A Feasibility Study of Superconducting Dipole for the Early Separation Scheme of SLHC luminosity, separation-scheme, shielding, simulation 2461
 
  • G. Sterbini, D. Tommasini
    CERN, Geneva
  In the framework of the LHC luminosity upgrade an early separation scheme is being studied for the final phase (L~1035 cm-2 s-1 with substantial changes in the IR). In this paper we compare a Nb3Sn and a Nb-Ti cos(θ) design: the aim is to explore the benefits and the limits of a compact solution with respect to the detector's constraints and the energy deposition issues. We propose to put the dipole system (cryostat and magnet) at a location starting at 6.8 m from the IP. The preliminary cross section, the achievable integrated field, the energy deposition on the magnet are presented and discussed.  
 
WEPD027 A new cable insulation scheme improving heat transfer in Nb-Ti superconducting accelerator magnets superconducting-magnet, quadrupole, interaction-region, collider 2467
 
  • D. Tommasini, D. Richter
    CERN, Geneva
  The next applications of superconducting magnets for interaction regions of particle colliders or for fast cycled accelerators require dealing with large heat fluxes generated or deposited in the coils. Last year* we have anticipated the theoretical potential for a large improvement of heat transfer of state of the art Nb-Ti cable insulations in superfluid helium, such as the one used for the LHC superconducting magnets. In this paper we present and discuss new experimental results, confirming that a factor of 5 increase of the allowed heat flux from coil to coolant can be obtained with the new insulation topology while keeping a sound margin in the dielectric performance.

*M. La China, D. Tommasini. “Cable Insulation Scheme to Improve Heat Transfer to Superfluid Helium in Nb-Ti Accelerator Magnets,” MT-20, Philadelphia, USA, August 2007.

 
 
WEPD029 Performance of the Main Dipole Magnet Circuits of the LHC during Commissioning extraction, cryogenics, target, instrumentation 2473
 
  • A. P. Verweij, V. Baggiolini, A. Ballarino, B. Bellesia, F. Bordry, A. Cantone, M. P. Casas Lino, A. Castaneda, C. CastilloTrello, N. Catalan-Lasheras, Z. Charifoulline, G.-J. Coelingh, G. D'Angelo, K. Dahlerup-Petersen, G. De Rijk, R. Denz, M. Gruwe, V. Kain, B. Khomenko, G. Kirby, S. L.N. Le Naour, A. Macpherson, A. Marqueta Barbero, K. H. Mess, M. Modena, R. Mompo, V. Montabonnet, D. Nisbet, V. Parma, M. Pojer, L. Ponce, A. Raimondo, S. Redaelli, H. Reymond, D. Richter, A. Rijllart, I. Romera, R. I. Saban, S. Sanfilippo, R. Schmidt, A. P. Siemko, M. Solfaroli Camillocci, H. Thiesen, Y. Thurel, W. Venturini Delsolaro, A. Vergara-Fernández, R. Wolf, M. Zerlauth
    CERN, Geneva
  • SF. Feher, R. H. Flora
    Fermilab, Batavia, Illinois
  During hardware commissioning of the Large Hadron Collider, 8 main dipole circuits and 16 main quadrupole circuits are tested at 1.9 K and up to their nominal current. Each dipole circuit contains 154 magnets of 15 m length, and has a total stored energy of up to 1.1 GJ. Each quadrupole circuit contains 47 or 51 magnets of 5.4 m length, and has a total stored energy of up to 20 MJ. All magnets are wound from Nb-Ti superconducting Rutherford cables, and contain heaters to quickly force the transition to the normal conducting state in case of a quench, and hence reduce the hot spot temperature. In this paper the performance of these circuits is presented, focusing on the quench current and quench behaviour of the magnets. Quench detection, heater performance, operation of the cold bypass diodes, cryogenic recovery time, electrical joints, and possible magnet-to-magnet quench propagation will be dealt with. The results as measured on the entire circuits will be compared to the test results obtained during the reception tests of the individual magnets.  
 
WEPD030 Feasibility Study of Combined Function Magnets for a NS-FFAG for Medical Applications quadrupole, proton, lattice, ion 2476
 
  • H. Witte, J. H. Cobb
    OXFORDphysics, Oxford, Oxon
  • K. J. Peach
    JAI, Oxford
  Non-scaling fixed field alternating gradient (NS-FFAG) accelerators combine a number of advantages, such as rapid particle acceleration and large acceptance. These features make NS-FFAGs particularly interesting for medical applications. NS-FFAGs could be used for cancer therapy, which may lead to significant size and cost reductions in comparison to other accelerator types. Cancer therapy with protons or carbon ions is advantageous in comparison to conventional radiation treatment amongst other things due to the higher biological effectiveness. This paper discusses the basic magnet design issues for the PAMELA project. PAMELA is a prototype proton/carbon-ion therapy facility.  
 
WEPD031 Dependence of the Static and Dynamic Field Quality of the LHC Superconducting Dipole Magnets on the Pre-cycle Ramp Rate injection, sextupole, multipole, acceleration 2479
 
  • N. J. Sammut, L. Bottura, G. Deferne, W. Venturini Delsolaro, R. Wolf
    CERN, Geneva
  • N. J. Sammut
    University of Malta, Faculty of Engineering, Msida
  The allowed multipoles in the Large Hadron Collider (LHC) superconducting dipole magnets decay whilst on a constant current plateau. It is known that the decay amplitude is largely affected by the powering history of the magnet, and particularly by the pre-cycle flat top current and duration and the pre-injection preparation duration. Recently, it was observed that the decay amplitude is also highly dependent on the pre-cycle ramp rate, which has an indirect effect also on the sample of data taken at constant field along the magnet loadlines. This is an important consideration to be included in the Field Description for the LHC (FiDeL), to cope with the difference between the test procedure followed for series tests and the expected cycles during the machine operation. This paper presents the results of the measurements performed to investigate this phenomenon and describes the method included in FiDeL to represent this dependence.  
 
WEPD033 A Demonstration Experiment for the Forecast of Magnetic Field and Field Errors in the Large Hadron Collider sextupole, controls, multipole, quadrupole 2482
 
  • N. J. Sammut, R. Alemany-Fernandez, L. Bottura, G. Deferne, M. Lamont, J. Miles, S. Sanfilippo, M. Strzelczyk, W. Venturini Delsolaro, P. Xydi
    CERN, Geneva
  • N. J. Sammut
    University of Malta, Faculty of Engineering, Msida
  In order to reduce the burden on the beam-based feedback, the Large Hadron Collider (LHC) control system is embedded with the Field Description for the LHC (FiDeL) which provides a forecast of the magnetic field and the multipole field errors. FiDeL has recently been extensively tested at CERN to determine main field tracking, multipole forecasting and compensation accuracy. In this paper we describe the rationale behind the tests, the procedures employed to characterize and power the main magnets and their correctors, and finally, we present the results obtained. We also give an indication of the prediction accuracy that the system can deliver during the operation of the LHC and we discuss the implications that these will have on the machine performance.  
 
WEPD034 Main Field Tracking Measurement in the LHC Superconducting Dipole and Quadrupole Magnets controls, quadrupole, instrumentation, injection 2485
 
  • P. Xydi, R. Alemany-Fernandez, L. Bottura, G. Deferne, M. Lamont, J. Miles, R. Mompo, M. Strzelczyk, W. Venturini Delsolaro
    CERN, Geneva
  • N. J. Sammut
    University of Malta, Faculty of Engineering, Msida
  One of the most stringent requirements during the energy ramp of the Large Hadron Collider (LHC) is to have a constant ratio between dipole-quadrupole and dipole-dipole field so as to control the variation of the betatron tune and of the beam orbit throughout the acceleration phase, hence avoiding particle loss. To achieve the nominal performance of the LHC, a maximum variation of ±0.003 tune units can be tolerated. For the commissioning with low intensity beams, acceptable bounds are up to 30 times higher. For the quadrupole-dipole integrated field ratio, the above requirements translate in the tight windows of 6 ppm and 180 ppm, while for dipole differences between sectors the acceptable error is of the order of 10-4. Measurement and control at this level are challenging. For this reason we have launched a dedicated measurement R&D to demonstrate that these ratios can be measured and controlled within the limits for machine operation. In this paper we present the techniques developed to power the magnets during the current ramps, the instrumentation and data acquisition setup used to perform the tracking experiments, the calibration procedure and the data reduction employed.  
 
WEPD037 Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade quadrupole, optics, luminosity, coupling 2491
 
  • A. V. Zlobin, J. A. Johnstone, V. Kashikhin, N. V. Mokhov, I. L. Rakhno
    Fermilab, Batavia, Illinois
  • S. Peggs, G. Robert-Demolaize, P. Wanderer, R. de Maria
    BNL, Upton, Long Island, New York
  After some years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. At the present time it is planned to perform the IR upgrade in two phases with the target luminosity for Phase I of ~2.5· 1034 cm-2s-1 and up to 1035 cm-2s-1 for Phase II. In Phase I the baseline 70-mm NbTi low-beta quadrupoles will nominally be replaced with larger aperture NbTi magnets and in Phase II with higher performance Nb3Sn magnets. U. S.-LARP is working on the development of large aperture high-performance Nb3Sn magnet technologies for the LHC Phase II luminosity upgrade. Recent progress also suggests the possibility of using Nb3Sn quadrupoles in the Phase I upgrade, improving the luminosity through an early demonstration of Nb3Sn magnet technology in a real accelerator environment. This paper discusses the possible hybrid optics layouts for Phase I upgrades with both NbTi and Nb3Sn quadrupoles, introducing magnet parameters and issues related to using Nb3Sn quadrupoles including magnet length and aperture limitations, field quality, operation margin, etc. Possible transition scenarios to Phase II are also discussed.  
 
WEPP005 Measurements and Effects of the Magnetic Hysteresis on the LHC Crossing Angle and Separation Bumps simulation, beam-beam-effects, controls, cryogenics 2530
 
  • N. J. Sammut, H. Burkhardt, C. Giloux, W. Venturini Delsolaro, S. M. White
    CERN, Geneva
  • N. J. Sammut
    University of Malta, Faculty of Engineering, Msida
  The superconducting orbit corrector magnets (MCBC and MCBY) in the Large Hadron Collider (LHC) at CERN will be used to generate parallel separation and crossing angles at the interaction points during the different phases that will bring the LHC beams into collision. However, the field errors generated by the inherent hysteresis in the operation region of the orbit correctors may lead to unwanted orbit perturbations that could have a critical effect on luminosity. This paper presents the results obtained from dedicated cryogenic measurements on the orbit correctors from the simulated results on the impact of the hysteresis on the LHC orbit.  
 
WEPP012 Analysis of Optical Layouts for the Phase 1 Upgrade of the CERN Large Hadron Collider Insertion Regions optics, insertion, quadrupole, dynamic-aperture 2551
 
  • M. Giovannozzi, F. Borgnolutti, O. S. Brüning, U. Dorda, S. D. Fartoukh, W. Herr, M. Meddahi, E. Todesco, R. Tomas, F. Zimmermann
    CERN, Geneva
  • R. de Maria
    EPFL, Lausanne
  In the framework of the studies for the upgrade of the insertions of the CERN Large Hadron Collider, four optical layouts were proposed with the aim of reducing the beta-function at the collision point down to 25 cm. The different candidate layouts are presented. Results from the studies performed on mechanical and dynamic aperture are summarized, together with the evaluation of beam-beam effects. Particular emphasis is given to the comparison of the optics performance, which led to retain two promising layouts for further investigation and development.  
 
WEPP013 Increasing the Integrated Luminosity of SLHC by Levelling via the Crossing Angle luminosity, simulation, separation-scheme, beam-beam-effects 2554
 
  • J.-P. Koutchouk, G. Sterbini
    CERN, Geneva
  • K. Ohmi
    KEK, Ibaraki
  With an increase of luminosity by a factor of 10, the luminosity lifetime in an upgraded LHC would be limited to a few hours. Furthermore, schemes relying on stronger focusing and reduced beam current increase (which are intrisically less dangerous for machine protection) are penalized by a very short lifetime of around 2 hours. We show in this paper that the "early separation" scheme and/or crab cavities scheme lend themselves to a very efficient luminosity leveling scheme. It allows constant luminosity over many hours as well as a significant increase of integrated luminosity above the performance announced so far. This is achieved by adjusting the crossing angle rather than the beam size by means of a bump closed inside the experimental straight section, i.e. operationally simple. The initially large crossing angle reduces the beam-beam tune shift, allowing an increased beam current and higher performance for lower pile-up in the detector and lower energy deposition in the triplet. The impact of the required large Piwinski angle is investigated.  
 
WEPP025 Optics Correction in the LHC quadrupole, closed-orbit, optics, betatron 2572
 
  • R. Tomas, M. Aiba, G. Vanbavinckhove
    CERN, Geneva
  • R. Calaga
    BNL, Upton, Long Island, New York
  • A. Morita
    KEK, Ibaraki
  Optics correction in the LHC is challenged by the tight aperture constrains and the demand of a highly performing BPM system. To guarantee that the LHC optics remains within a maximum allowable beta-beating of 20% several methods are being investigated through computer simulations and experiments at existing hadron machines. A software package to consolidate the implementation of the various techniques during LHC operation is underway (or nearing completion)  
 
WEPP026 Reliable Operation of the AC Dipole in the LHC resonance, emittance, simulation, injection 2575
 
  • R. Tomas, S. D. Fartoukh, J. Serrano
    CERN, Geneva
  The AC dipole in the LHC will not only provide transverse oscillations without emittance growth but also with a safety guarantee. These two features are due to the adiabaticity of the excitation. However chromaticity and non-linear fields spoil this adiabaticity. This paper assesses the margins of the relevant parameters for a reliable and safe operation of AC dipoles in the LHC.  
 
WEPP030 LHC Luminosity Upgrade: Protecting Insertion Region Magnets from Collision Debris shielding, insertion, luminosity, cryogenics 2584
 
  • E. Y. Wildner, F. Cerutti, A. Ferrari, M. Mauri, A. Mereghetti
    CERN, Geneva
  The Large Hadron Collider built at CERN now enters a starting-up phase where with the present design luminosities up to 1034 cm-2 s-1 will be reached after the running in phase. A possible upgrading of the machine to luminosities up to 1035 cm-2 s-1 requires a completely new insertion region design, and will be implemented in essentially two phases. The energy from collision debris is deposited in the insertion regions and in particular in the superconducting magnet coils with a possible risk of quench. We describe here how to protect the interaction region magnets against this irradiation to keep the energy deposition below critical values estimated for safe operation. The constraint is to keep the absorber size as small as possible to leave most of the magnet aperture available for the beam. This can be done by choosing a suitable material and design minimizing the load on the cryogenic system. We will describe a proposal of a design for the phase I upgrade lay-out (i.e., luminosities up to 2.5 1034 cm-2 s-1).  
 
WEPP032 Parametric Study of Energy Deposition in the LHC Inner Triplet for the Phase 1 Upgrade quadrupole, interaction-region, insertion, luminosity 2590
 
  • E. Y. Wildner, F. Borgnolutti, F. Cerutti, M. Mauri, A. Mereghetti, E. Todesco
    CERN, Geneva
  To be able to make a global parametric analysis and to have some basic understanding of the influence of critical parameters, scaling laws may be of help. For the design of the LHC collision insertion regions, one of the critical parameters is the energy deposited in the insertion superconducting magnet coils, to avoid magnet quench, too heavy load on the cryogenic system, and degradation of the superconductor due to radiation. The influence on energy deposition of some key parameters for magnet design, such as the magnet apertures, the magnet lengths and positions, has been studied for some specified optical beta-value at the collision point.  
 
WEPP056 Aperture Restriction Localisation in the LHC Arcs using an RF Mole and the LHC Beam Position Measurement System vacuum, monitoring, radio-frequency, quadrupole 2644
 
  • O. R. Jones, J. Albertone, S. Bartolome-Jimenez, C. Boccard, T. Bogey, P. B. Borowiec, E. Calvo, F. Caspers, M. Gasior, J. L. Gonzalez, B. Jenninger, L. K. Jensen, T. Kroyer, S. Weisz
    CERN, Geneva
  Ensuring that the two 27km beam pipes of the LHC do not contain aperture restrictions is of utmost importance. Most of the ring is composed of continuous cryostats, so any intervention to remove aperture restrictions when the machine is at its operating temperature of 1.9K will require a substantial amount of time. On warming-up the first cooled sector, several of the sliding contacts which provide electrical continuity for the image current between successive sections of the vacuum chamber were found to have buckled into the beam pipe. This led to a search for a technique to verify the integrity of a complete LHC arc (~3km) before any subsequent cool-down. In this paper the successful results from using a polycarbonate ball fitted with a 40MHz RF transmitter will be presented. Propulsion of the ball is achieved by sucking filtered air through the entire arc, while its progress is traced every 54m via the LHC beam position measurement system which is auto-triggered by the RF transmitter on passage of the ball. Reflectometry at frequencies in the 4-8 GHz range can cover the gaps between beam position monitors and could therefore be used to localise a ball blocked by an obstacle.  
 
WEPP068 Impact Distribution of the Beam Losses at the LHC Collimators in Case of Magnet Failures injection, quadrupole, simulation, collimation 2674
 
  • A. Gomez Alonso
    CERN, Geneva
  During LHC operation, magnet failures may affect the beam optics leading to proton losses in the collimators. These losses, with about 360MJ of stored energy per beam at nominal collision operation, are potentially dangerous for the accelerator equipment. The LHC Machine Protection Systems ensure that the beam is extracted safely before these losses can produce any damage. As a magnet failure develops, so does the distribution of the lost particles, longitudinally along the ring as well as transversally at each collimator. The transversal impact distributions of lost particles at the most affected collimators and their evolution with time have been studied for representative magnet failures in the LHC. It has been found that the impact distribution at a given collimator can be approximated by an exponential function with time-dependent parameters. The average impact parameter ranges from about 7 to 620 μm for the cases studied.  
 
WEPP085 RF Coupler Kicks and Wake-fields in SC Accelerating Cavities simulation, linac, coupling, higher-order-mode 2719
 
  • N. Juntong, R. M. Jones, I. R.R. Shinton
    UMAN, Manchester
  • C. D. Beard
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • G. Burt
    Cockcroft Institute, Warrington, Cheshire
  The main accelerating cavities of the ILC provide acceleration of both positron and electron beams to 250 GeV per beam and 500 GeV per beam in a proposed upgrade. The wake-field excited by each ultra-relativistic beam in the accelerating cavities can seriously dilute the emittance of the particles within the beams. Each cavity is supplied with both fundamental and higher order mode couplers. The geometrical configuration of these RF couplers results in an asymmetrical field and this gives rise to both an RF kick being applied to the beam and transverse wake-field. Detailed e.m. fields are simulated in the vicinity of the couplers in order to assess the impact on the beam dynamics. We investigate modified geometries with a view to alleviating the emittance dilution resulting from the e.m. field associated with the RF couplers.  
 
WEPP087 Observation and Mitigation of Multipass BBU in CEBAF linac, damping, recirculation, optics 2722
 
  • R. Kazimi, A. Freyberger, C. Hovater, G. A. Krafft, F. Marhauser, T. E. Plawski, C. E. Reece, J. S. Sekutowicz, C. Tennant, M. G. Tiefenback, H. Wang
    Jefferson Lab, Newport News, Virginia
  The CEBAF recirculating accelerator at Jefferson Lab consists of two linacs carrying beam for up to five passes of acceleration. The Beam Break-Up (BBU) phenomenon was anticipated during design of the accelerator. The threshold beam current to induce BBU was calculated to be approximately 20 milliamperes, far above operational current. No sign of BBU was ever seen in more than a decade of operation. A specially designed acceleration cavity in a recently installed cryomodule was found to cause a BBU instability under special conditions with as low as 40 uA of injected beam current. This presented an opportunity to study BBU in a five-pass accelerator. In this paper we will discuss multipass BBU, show observational data, and discuss the ways we have developed to maintain the instability threshold current to values above those required for operation.  
 
WEPP089 Wake-field Suppression in the CLIC Main Linac damping, coupling, emittance, positron 2725
 
  • V. F. Khan, R. M. Jones
    UMAN, Manchester
  The CLIC linear collider aims at accelerating multiple bunches of electrons and positrons and colliding at a centre of mass energy of 3 TeV. These bunches are accelerated through X-band linacs operating at an accelerating frequency of 12 GHz. Each beam readily excites wake-fields in the accelerating cavities of each linac. The transverse components of the wake-fields, if left unchecked, can dilute the beam emittance. The present CLIC design relies on heavy damping of these wake-fields in order to ameliorate the effects of the wake-field on the beam emittance. Here we present initial results on a modified design which combines both damping and detuning of the cell frequencies of each cavity structure in order to enhance the overall decay of the wake-field. Interleaving of cell frequencies is explored as a means to improve the damping.  
 
WEPP108 The MICE Diffuser System emittance, controls, optics, target 2761
 
  • M. Apollonio, J. H. Cobb, T. Handford, P. Lau, W. Lau, J. Tacon, M. Tacon, S. Q. Yang
    OXFORDphysics, Oxford, Oxon
  • M. Dawson
    JAI, Oxford
  The MICE experiment at RAL will measure the performance of a cooling channel in a variety of configurations of momentum and initial emittance. Coverage in phase space relies on the MICE diffuser, a system with five different thickness lead degraders, remotely operated in a high magnetic field. Technical issues and degrader optimisation for beam matching are discussed.  
 
WEPP122 Commissioning Status of the MICE Muon Beamline target, proton, quadrupole, emittance 2782
 
  • K. Tilley
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  It is planned to install a Muon Ionisation Cooling Experiment (MICE) at the ISIS facility at Rutherford Appleton Laboratory. This experiment will be the first demonstration of ionisation cooling as a means to reduce the large transverse emittances expected in the early stages of a Neutrino Factory. A new muon beamline has been installed on ISIS, in order to supply muons of characteristic energy and emittance to the experiment. This paper gives an overview of the goals and design of the beamline, the detectors used to characterise the beam, and the techniques and results which have been obtained during its first operating periods in 2008.

K. Tilley on behalf of the MICE Collaboration.

 
 
WEPP123 Isochronous Pion Decay Channel for Enhanced Muon Capture target, factory, collider, quadrupole 2785
 
  • C. Y. Yoshikawa, C. M. Ankenbrandt, D. V. Neuffer, M. Popovic, K. Yonehara
    Fermilab, Batavia, Illinois
  • R. J. Abrams, M. A.C. Cummings, R. P. Johnson
    Muons, Inc, Batavia
  • Y. S. Derbenev
    Jefferson Lab, Newport News, Virginia
  Intense muon beams have many potential applications, including neutrino factories and muon colliders. However, muons are produced in tertiary beams into a diffuse phase space. To make useful beams, the muons must be rapidly cooled before they decay. A promising new concept for the collection and cooling of muon beams is being investigated, namely, the use of a nearly Isochronous Helical Transport Channel (IHTC) to facilitate capture of muons into RF bunches. Such a distribution could be cooled quickly and coalesced into a single bunch to optimize the luminosity of a muon collider. We describe the IHTC and provide simulations demonstrating isochronicity, even in the absence of RF and absorber.  
 
WEPP131 RF-breakdown Experiments at the CTF3 Two-beam Test-stand ion, electron, extraction, vacuum 2800
 
  • M. Johnson, T. J.C. Ekelöf, R. J.M. Y. Ruber, V. G. Ziemann
    UU/ISV, Uppsala
  • H.-H. Braun
    CERN, Geneva
  The Two-beam Test-stand (TBTS) in the CLIC Test Facility CTF3 offers unique possibilities to conduct RF-breakdown related experiments on the accelerating structures and the power extraction and transfer structures with beam. We report on the set-up of two such experiments, one for the measurement of the transverse kick and the other for the measurement of positive ion currents. The purpose of the transverse kick measurements is to determine the effects of a RF-breakdown event on the beam. Five BPMs in the TBTS will be used to study the trajectory of a pulse train after a RF-breakdown event, with important implications for the operation of CLIC. Ion currents ejected from accelerating structures during RF-breakdown events have already been observed at the 30 GHz test stand at the present test facility. Results and their implications for RF-breakdown physics are presented, as well as plans for similar measurements at the TBTS.  
 
WEPP139 The CTF3 Two-beam Test-stand Installation and Experimental Program acceleration, vacuum, quadrupole, diagnostics 2821
 
  • V. G. Ziemann, T. J.C. Ekelöf, M. Johnson, R. J.M. Y. Ruber
    UU/ISV, Uppsala
  • H.-H. Braun, S. Doebert, G. Geschonke, G. Riddone, J. P.H. Sladen, I. Syratchev, W. Wuensch
    CERN, Geneva
  The Two-beam Test-stand in CTF3 will be used to investigate the power-generation and accelerating structures for the Compact Linear Collider CLIC. We report on its design and construction which was recently completed and discuss the imminent commissioning phase as well as the following experimental program that initially will be devoted to the test of power generation structures in the drive-beam.  
 
WEPP140 X-band PASER Experiment acceleration, electron, resonance, laser 2824
 
  • A. Kanareykin, P. Schoessow
    Euclid TechLabs, LLC, Solon, Ohio
  • S. P. Antipov
    ANL, Argonne, Illinois
  • L. Schächter
    Technion, Haifa
  The PASER concept for particle acceleration entails the direct transfer of energy from an active medium to a charged particle beam. The PASER was originally formulated for optical (laser) media; we are pursuing a PASER demonstration experiment based on an optically pumped paramagnetic medium active in the X-band. We report on the development of a relatively high energy density microwave active medium consisting of a fullerene (C60) derivative in a toluene solution. We discuss both the bench test of an amplifier and a beam acceleration experiment under construction that employ this medium as a power source. Applications of the technology to accelerators and microwave components will be presented.  
 
WEPP147 Aberration-free Muon Transport Line for Extreme Ionization Cooling: a Study of Epicyclic Helical Channel resonance, simulation, cyclotron, collider 2833
 
  • A. Afanasev, R. P. Johnson
    Muons, Inc, Batavia
  • Y. S. Derbenev
    Jefferson Lab, Newport News, Virginia
  Once the normalized transverse emittances of a muon beam have been cooled to some hundreds of microns, new techniques such as Parametric-resonance Ionization Cooling and Reverse Emittance Exchange can be used to focus the beam very tightly on beryllium energy absorbers for further transverse emittance reduction. The transport lines for these techniques have stringent requirements for the betatron tunes so that resonance conditions are properly controlled and for the dispersion function so that the longitudinal emittance can be controlled by emittance exchange using wedge-shaped absorbers. The extreme angular divergence of the beam at the absorbers implies large beam extension between the absorbers such that these techniques are very sensitive to chromatic and spherical aberrations. In this work we describe general and specific solutions to the problem of compensating these aberrations for these new muon cooling channels.  
 
WEPP153 Status of the MANX Muon Cooling Experiment emittance, simulation, collider, beam-cooling 2844
 
  • K. Yonehara, D. R. Broemmelsiek, M. Hu, A. Jansson, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, M. L. Lopes, V. D. Shiltsev, V. Yarba, M. Yu, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. J. Abrams, M. A.C. Cummings, R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
  MANX is an experiment to prove that effective six-dimensional (6D) muon beam cooling can be achieved a Helical Cooling Channel (HCC) using ionization-cooling with helical and solenoidal magnets in a novel configuration. The aim is to demonstrate that 6D muon beam cooling is understood well enough to plan intense neutrino factories and high-luminosity muon colliders. The experiment consists of the HCC magnets that envelop a liquid helium energy absorber, upstream and downstream instrumentation to measure the particle or beam parameters before and after cooling, and emittance matching sections between the detectors and the HCC. Studies are presented of the effects of detector resolution and magnetic field errors on the beam cooling measurements.  
 
WEPP166 Comparison of Collimator Wakefields Formulae impedance, quadrupole, electron, vacuum 2877
 
  • A. M. Toader, R. J. Barlow
    UMAN, Manchester
  There is an extensive literature on transverse wakefield kick factors in collimators. We present a compendium of the formulae and discuss their agreement and disagreement with each other and with experimental results.  
 
THYG03 Ionization Cooling and Muon Colliders collider, emittance, factory, luminosity 2917
 
  • R. P. Johnson
    Muons, Inc, Batavia
  Recent developments in the field of muon beam cooling are reviewed. A view of the impact of new cooling concepts on the overall design of muon colliders is included, as are the prospects for the experimental verification of the required muon beam cooling concepts and technology.  
slides icon Slides  
 
THPC016 Beam Optics of the PEFP Modified Beam Lines proton, quadrupole, optics, linac 3011
 
  • J.-H. Jang, Y.-S. Cho, B. Chung, H.-J. Kwon
    KAERI, Daejon
  The 100 MeV Linac of the Proton Engineering Frontier Project (PEFP) is designed to supply 20 MeV and 100 MeV proton beams to user groups. In order to extract 20 MeV proton beams, a 45 degrees bending magnet is installed after 20 MeV DTL tank. The extracted proton beams are separated into five target rooms via a AC bending magnets. For 100 MeV beams, we use the same distribution schemes. Recently, the layout of the beam lines are modified to be short and compact. The work summaries the beam optics calculation of the modified beam lines.  
 
THPC027 Pulsed RF Accelerator of Electrons with Beam Recirculation linac, electron, simulation, acceleration 3038
 
  • V. V. Mytrochenko, M. I. Ayzatskiy, P. Gladkikh, V. A. Kushnir, A. Opanasenko, A. Y. Zelinsky
    NSC/KIPT, Kharkov
  • S. Chemerisov, D. Ehst
    ANL, Argonne, Illinois
  We discuss the project of upgrading existent 20 MeV L-band electron linac at Argonne National Laboratory aimed at electron energy increasing. It is shown that the proposed beam recirculation will provide on the accelerator output an electron beam with a pulse current 0.5 A and energy of particles 45 MeV. Problems of stability of recirculating beam are discussed.  
 
THPC028 High Energy Beam Transport Line for the IFMIF-EVEDA Accelerator quadrupole, diagnostics, emittance, beam-transport 3041
 
  • C. Oliver, B. Brañas, A. Ibarra, I. Podadera Aliseda
    CIEMAT, Madrid
  • N. Chauvin, A. Mosnier, D. Uriot
    CEA, Gif-sur-Yvette
  The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which will verify the validity of the design of the future IFMIF accelerator. A transport line is necessary to handle the high current beam from the DTL exit up to the beam dump. This line must produce the beam expansion to obtain an acceptable power density at the beam dump. Therefore the design of the transport line must consider the geometry and power handling capacity of the beam dump, the space requirements for diagnostics and the restrictions on the maximum length of the line. In addition, a bending magnet is required in order to avoid excessive irradiation of the diagnostics and line elements by neutrons and gammas produced at the beam dump and to perform energy spread measurements. In this contribution, the preliminary design of the high energy beam transport line will be presented. The results of a sensitivity study to the input beam and line elements errors will also be discussed.  
 
THPC034 Correction the Round Beam Lattice of VEPP-2000 Collider Using Orbit Response Technique closed-orbit, lattice, quadrupole, multipole 3053
 
  • A. L. Romanov, D. E. Berkaev, A. N. Kirpotin, I. Koop, E. Perevedentsev, Yu. A. Rogovsky, P. Yu. Shatunov, D. B. Shwartz
    BINP SB RAS, Novosibirsk
  Round colliding beams option in VEPP-2000 puts a number of strict requirements on the collider lattice. Orbit Response Matrix (ORM) technique is a versatile tool for lattice analysis and correction. For linear optical function study and correction, the orbit response to the dipole correctors is collected and processed, while for the orbit correction the quadrupole trimming is used. Theoretical and experimental responses of closed orbit on the same perturbations are compared to determine the most probable deviations of chosen parameters from its project values.  
 
THPC036 Model Based Orbit Correction in a Diagnostics Deficient Region linac, controls, beam-losses, diagnostics 3056
 
  • A. P. Shishlo, A. V. Aleksandrov
    ORNL, Oak Ridge, Tennessee
  A method is presented for an orbit correction in a region where the number of beam position monitors is much less than the number of possible trajectory distortions points (quads). The method was developed for the Coupled Cavities Linac (CCL) part of the Spallation Neutron Source (SNS) linac. The orbit correction is very important in this region to minimize losses and activation, but the usual orbit correction method did not work here. The new method is based on a usage of a realistic online model. The parameters of the model were defined by multidimensional fitting procedure with a substantial array of measured trajectories in CCL. The procedure of parameters finding, model, and results are discussed.  
 
THPC041 Closed Orbit Correction and Orbit Stabilization Control for TPS Storage Ring quadrupole, emittance, closed-orbit, radiation 3068
 
  • H.-J. Tsai, H.-P. Chang, H. C. Chao, P. J. Chou, K. T. Hsu, C.-C. Kuo, W. T. Liu, J. W. Tsai
    NSRRC, Hsinchu
  TPS is a 3 GeV synchrotron storage ring proposed in Taiwan. The designed natural emittance with slightly positive dispersion in the straight sections is less than 2 nm-rad. With 1% emittance coupling, the beam size in horizontal and vertical plane are 120/5 micron in the short straight sections, respectively. The beam position stability requirements are 10% of the beam sizes, i.e., 12/0.5 micron in the horizontal/vertical plane. The closed orbit distortions due to alignment displacement and magnetic field errors are simulated. The distribution of beam position monitors and the location of slow and fast correctors are proposed and the level of achievement is shown.  
 
THPC042 Uncoupled Achromatic Tilted S-bend quadrupole, electron, controls, coupling 3071
 
  • N. Tsoupas, A. Kayran, V. Litvinenko, W. W. MacKay
    BNL, Upton, Long Island, New York
  A particular section of one of the electron beam transport lines, to be used in the e-cooling project* of the Relativistic Heavy Ion Collider (RHIC), is constrained to bend the beam simultaneously in both the horizontal and vertically planes and also be achromatic in both planes. The simultaneous horizontal and vertical achromatic bend is accomplished by rotating, about the longitudinal axis of the beam, the dipole and quadrupole elements of this section of the line. However such a rotation of the magnetic elements may couple the transported beam through the first order beam transfer matrix (linear coupling). In this paper we investigate for a sufficient condition, that the first order transport matrix (R-matrix) can satisfy, under which such a section of a beam transfer line is both achromatic and also constrains the beam at the exit of the line to emerge linearly uncoupled. We also provide a complete solution for the beam optics, of this part of the beam transfer line, which satisfies achromaticity and no first order beam coupling.

*htpp://www.bnl.gov/cad/eRhic/Documents/AD_Position_Paper_2007.pdf

 
 
THPC048 Study of Beam Losses at Transition Crossing at the CERN PS quadrupole, optics, beam-losses, proton 3086
 
  • S. S. Gilardoni, S. Aumon, M. Martini
    CERN, Geneva
  A series of studies has been carried out to understand and alleviate the beam losses in the CERN PS proton Synchrotron. In particular, losses appear at transition crossing during the pulsing of special quadrupoles used to create a gamma jump scheme and which causes a large optics and orbit distortion. After a brief summary of the gamma jump scheme at the PS, experimental and simulation results about the loss studies and reduction are presented.  
 
THPC054 Transportation of Decay Products in the Beta-beam Decay Ring ion, lattice, beam-transport, quadrupole 3104
 
  • A. Chancé, J. Payet
    CEA, Gif-sur-Yvette
  The principle of the neutrino production in the beta-beams relies on the beta-decay of the radioactive ions Neon 18 and Helium 6 in a storage ring. After decaying, the daughter particles have their magnetic rigidity significantly changed (-33% for Helium and +11% for Neon). Therefore, the decay products will be quickly lost on the walls of the decay ring after entering a dipole. Absorbers have been inserted in the decay ring in order to collect most decay products. Their optimization implies to calculate the trajectories of the decay products in the dipoles for very large momentum differences with a good accuracy. For pure dipoles without fringe field as in the decay ring, an analytic treatment can be used to simulate the transportation. It is then possible to obtain the equivalent dipole which gives the beam sizes of the daughter particles. In a first part, we will describe the analytic treatment of the central trajectory and the motion of the ions around. In a second part, we will compare this treatment with the one with matrices for different orders in the case of the beta-beam decay ring.  
 
THPC057 Field Interference of Magnets in the Large Acceptance Storage Ring CR of the Fair Project quadrupole, multipole, simulation, dynamic-aperture 3113
 
  • O. E. Gorda, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck
    GSI, Darmstadt
  The large acceptance storage ring CR is planned to be used for accumulation and cooling of rare isotope and antiproton beams at the future FAIR accelerator facility. The huge apertures as well as the close arrangement of the dipoles and quadrupoles make overlapping between the end fields of the magnets unavoidable. In addition, corrector magnets are planned to be installed in the drift sections between the dipoles and quadrupoles for closed orbit corrections. The presence of additional iron can have a significant influence on the magnetic field distribution. This interference can lead to a reduction of the integral field quality decline that is undesirable since it can affect the beam dynamics. In this contribution we present the results of 3D magnetic field simulations performed using the OPERA computer code. The field maps were derived and further analyzed. The corresponding sets of multipole components were calculated and were then implemented into one of the codes for the beam dynamics calculations. The MAD code was used to calculate the dynamic aperture and to estimate the effect of the field interference on the beam dynamics of the ring.  
 
THPC060 Spin Flip of Deuterons in COSY - Spink Tracking resonance, simulation, polarization, betatron 3122
 
  • A. U. Luccio
    BNL, Upton, Long Island, New York
  • A. Lehrach
    FZJ, Jülich
  The spin tracking code Spink, as recently overhauled*, has been used to study the deuteron spin resonances and spin flipping induced by a RF dipole and a RF solenoid. The modifications of the code followed extended discussions on the formalism used to model spin evolution in a synchrotron. The simulation shows a good agreement with published results of the measurements**.

*A. U. Luccio et al. See another contribution to this Conference.
**A. D. Krisch et al. PR-STAB 10, 07100-1, 2007.

 
 
THPC068 Effect of Magnetic Multipoles on the ALBA Dynamic sextupole, multipole, dynamic-aperture, quadrupole 3143
 
  • P. A. Piminov, E. B. Levichev
    BINP SB RAS, Novosibirsk
  • D. Einfeld
    ALBA, Bellaterra
  For modern synchrotron light sources the main limitation of dynamic aperture is due to the strong chromatic sextupoles. However, small multipole errors in magnetic elements can reduce the original dynamic aperture by generating high order resonances at the aperture boundary. For the ALBA synchrotron light source a dynamic aperture in the presence of magnetic multipoles in the main magnets was simulated by tracking code. Both systematic and random magnetic errors were taken into account. In this paper we report on the results of our considerations.  
 
THPC069 Impact of Magnet Misalignment in an ERL for Electron Cooling in RHIC emittance, electron, linac, space-charge 3146
 
  • V. H. Ranjbar, D. T. Abell, K. Paul
    Tech-X, Boulder, Colorado
  • I. Ben-Zvi, J. Kewisch
    BNL, Upton, Long Island, New York
  • R. D. Ryne
    LBNL, Berkeley, California
  The MaryLie/IMPACT code was recently upgraded to include magnet errors. We have used the code to assess the sensitivity of final emittance of an ERL injector for the proposed RHIC electron cooler to up-stream magnetic element misalignments. This calculation will help determine the error tolerance for the construction of the ERL.  
 
THPC076 Closed Orbit Correction and Sextupole Compensation Schemes for Normal-conducting HESR sextupole, closed-orbit, electron, lattice 3161
 
  • D. M. Welsch, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, R. Tölle
    FZJ, Jülich
  The High Energy Storage Ring (HESR) will be part of the future Facility for Antiproton and Ion Research (FAIR) located at GSI in Darmstadt, Germany. The HESR will be operated with antiprotons in the momentum range from 1.5 to 15 GeV/c, which makes a long beam life time and a minimum of particle losses crucial. This and the demanding requirements of the PANDA experiment lead to the necessity of a good orbit correction and an effective multipole compensation. We developed a closed orbit correction scheme and tested it with Monte Carlo simulations. We assigned different sets of angular and spatial errors to all elements (magnets, bpms, etc.) within the lattice of the HESR. For correction we applied the orbit response matrix method. We carried out investigations concerning higher-order multipoles and created a scheme for chromaticity correction and compensation of arising resonances utilising analytic formulae and dynamic aperture calculations. In this presentation we give an overview of the correction and compensation schemes and of the corresponding results.  
 
THPC089 Electron-cloud Intrabunch Density Modulation electron, simulation, proton, resonance 3197
 
  • G. Franchetti
    GSI, Darmstadt
  • F. Zimmermann
    CERN, Geneva
  During the passage of a proton bunch through an electron cloud a complicated electron density modulation arises, with characteristic ring and stripe patterns of high density regions that move radially outward along the bunch. We present simulation results as well as a simple analytical model to reveal the morphology and main features of this phenomenon as well as its dependence on key parameters like bunch length, beam size, and bunch charge.  
 
THPC102 Image Simulations on the ISIS Synchrotron simulation, closed-orbit, vacuum, lattice 3215
 
  • B. G. Pine, C. M. Warsop
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a loss-limited 50 Hz proton synchrotron, which accelerates ~3·1013 ppp from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. A significant proportion of beam loss is attributable to space charge effects. One such effect is the image field which forms in the beam pipe. Off-centre beams resulting from closed orbit errors generate fields, which can perturb the beam and cause loss. Of particular interest on ISIS is the rectangular, varying aperture, vacuum vessel, as compared with the more usual constant aperture circular or elliptical geometries. A new 2D space charge code, Set, was developed to study these effects. The code simulates the effects of space charge using a 2D particle-in-cell model of the beam distribution, including an appropriate treatment of the rectangular beam pipe, and details of the ISIS lattice. The effects of images on closed orbits, driving terms, and the evolution of beam distributions at ISIS operational intensities were explored.  
 
THPC144 A Beam Quality Monitor for LHC Beams in the SPS extraction, luminosity, injection, pick-up 3324
 
  • G. Papotti
    CERN, Geneva
  The SPS Beam Quality Monitor (BQM) system monitors the longitudinal parameters of the beam before extraction to the LHC to prevent losses and degradation of the LHC luminosity by the injection of low quality beams. It is implemented in two priority levels. The highest level is related to machine protection, e.g. verifying SPS-LHC synchronization and global beam structure. If the specifications are not met, the beam is dumped in the SPS before extraction. On the second level, individual bunch position, length and stability are checked for beam quality assessment. Tolerances are adapted to the mode of operation and extraction to the LHC can also be inhibited. Beam parameters are accessed by acquiring bunch profiles with a longitudinal pick up and fast digital oscilloscope. The beam is monitored for instabilities during the acceleration cycle and thoroughly checked a few ms before extraction for a final decision on extraction interlock. Dedicated hardware and software components implementing fast algorithms are required. In this paper the fast algorithms and their possible implementations are presented.  
 
THPP006 Injection and Extraction for the EMMA NS-FFAG extraction, injection, quadrupole, diagnostics 3386
 
  • B. D. Muratori, S. L. Smith, S. I. Tzenov
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • C. Johnstone
    Fermilab, Batavia, Illinois
  EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG to be hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. It also represents a possible active element for an ADSR (Accelerator Driven Sub-critical Reactor). This paper will summarize the design of the extraction and injection transfer lines of the NS-FFAG. In order to operate EMMA, the Energy Recovery Linac Prototype (ERLP) shall be used as injector and the energy will range from 10 to 20 MeV. Because this would be the first non-scaling FFAG, it is important that as many of the bunch properties are studied as feasible, both at injection and at extraction. To do this, a complex injection line was designed consisting of a dogleg to extract the beam from ERLP, a matching section, a tomography section and some additional dipoles and quadrupoles to transport the beam to the entrance of EMMA. Further, an equivalent tomography module was placed in the extraction line together with several other diagnostic devices including the possibility of using a transverse deflecting cavity.  
 
THPP028 Beam Tests of the PEFP 20 MeV Accelerator rfq, proton, ion-source, ion 3434
 
  • H.-J. Kwon, Y.-S. Cho, I.-S. Hong, J.-H. Jang, D. I. Kim, H. S. Kim, B.-S. Park, K. T. Seol, Y.-G. Song, S. P. Yun
    KAERI, Daejon
  PEFP (Proton Engineering Frontier Project) 20 MeV proton accelerator has been installed and tested at KAERI (Korea Atomic Energy Research Institute) site. After the radiation license was issued, some parts were modified to increase a beam current above 1mA. Both an ion source and a LEBT (Low Energy Beam Transport) were modified for better matching of the beam into the 3 MeV RFQ. The field profile of the RFQ was measured to check the dipole field effect. In addition, control mechanisms to improve the RF properties of 20 MeV DTL were newly adopted. In this paper, the modifications of the 20MeV accelerator are summarized and the test results are presented.  
 
THPP091 One Nano-second Bunch Compressor for High Intense Proton Beam proton, linac, kicker, target 3578
 
  • L. P. Chau, M. Droba, N. S. Joshi, O. Meusel, U. Ratzinger, C. Wiesner
    IAP, Frankfurt am Main
  About ten bunches of 2MeV proton rf-linac with an average current of 150mA at 175 MHz will be deflected by kicker on different paths into a magnetic bending system. Passing this optimized geometry they approach each other longitudinaly (βλ = 0.114m) and arrive at the same time at the focus of the dipole system. For longitudinal focussing of the merged bunches a rebuncher cavity is included in the bending system. The motivation and the layout of the whole project, "Frankfurter Neutronen Quelle am Stern-Gerlach Zentrum" (FRANZ), were presented in details in previous conferences*,**. More accurate investigation results in a revision of the preliminary concept. For a theoretical proof of principle one trajectory with the biggest path length of a new geometry is calculated by a multi particle beam dynamics program (LORASR). Preliminary investigations showed, that magnetic fringing fields and bunch-bunch interactions have to be included as detailed as posible in the beam simulations. In this paper the beam dynamics results from LORASR-simulations, the new geometry and the code development for the bunch compressor are discussed in details.

*L. P. Chau et al. Proc. of the Eur. Part. Acc. Conf., Edinburgh (2006), 1690-1692.
**O. Meusel et al. Proc. of the Lin. Acc. Conf., Knoxville (2006), MOPO51, 159-161.

 
 
THPP104 The High Energy Beam Transport System for FAIR beam-transport, extraction, diagnostics, ion 3608
 
  • S. Ratschow, F. Hagenbuck, P. J. Spiller
    GSI, Darmstadt
  The High Energy Beam Transport System of FAIR, with a total length of more than 2350 m, forms a complex system connecting seven accelerator- and storage-rings, the experimental caves, beam dumps, stripping stations, the antiproton target and the Super-FRS. The variety of beams to be transported is considerable, ranging from slow extracted beams with long spills of up to 100 s to short intense bunches with lengths of a few nanoseconds and a momentum spread of up to ±1%. The range of beam intensity covers more than six orders of magnitude. The SIS100/300 rings are located 13.5 m under ground while the rest of the facility is essentially on ground level necessitating a 3-dimensional layout of the beam line system. Most of the beam transport system consists of normal conducting magnets. However, the SIS300 beam line system has to be built with superconducting magnets. Due to the large variety of beam parameters, a careful planning of the beam diagnostics system is important. The paper summarizes the design fundamentals and the current status of the system design.  
 
THPP120 Measurements on an A/D Interface Used in the Power Supply Control System of the Main Dipoles of CNAO synchrotron, power-supply, pick-up, controls 3638
 
  • G. Franzini, D. Pellegrini, M. Serio, A. Stella
    INFN/LNF, Frascati (Roma)
  • M. Donetti, M. Pezzetta, M. Pullia
    CNAO Foundation, Milan
  The CNAO (the Italian Centre of Oncological Hadrontherapy, near Pavia) is in its final step of construction and is about to be fully operative. It is based on a synchrotron that can accelerate protons up to 250MeV and carbon ions up to 400MeV/u for the treatment of patients. In this paper we describe an A/D interface, used in the power supply control system of the synchrotron main dipoles, called B-Train. The field is measured in a dedicated dipole connected in series with the sixteen ones of the synchrotron and is then fed back to the power supply. The field is obtained integrating and digitizing the voltage induced on a pickup coil inserted in the gap of the seventeenth dipole. The A/D interface under study is based on a 64-channel current to frequency converter ASIC, in CMOS 0.35 μm technology, followed by a counter and uses a recycling integrator technique. The digital signal obtained is then used to generate a feedback signal for control system of the dipoles power supply. We present the electronic structure, the lab measurements and the behavior for various setups of the A/D interface described.  
 
THPP121 The SSRF Storage Ring Dipole and Sextupole Magnet Power Supplies power-supply, controls, sextupole, storage-ring 3641
 
  • C. L. Guo, Z. M. Dai, D. M. Li, H. Liu, T. J. Shen, W. F. Wu
    SINAP, Shanghai
  SSRF is a third generation synchrotron radiation light source. It has a full energy injection storage ring of 3.5GeV. The storage ring dipole magnet string and sextupole magnets strings are powered by 10 large magnet power supplies. The power supply output current ranges from 250A to 800A, and the output voltage ranges from 140V to 840V. These power supplies are digital controlled, with bridge topology, and diode rectifiers with step-down transformers. In this paper, the commissioning results of these power supplies are presented, together with the circuit topology and the control schemes.  
 
THPP122 Fast High-Power Power Supply for Scanning Magnets of CNAO Accelerator controls, power-supply, booster, synchrotron 3643
 
  • M. Incurvati
    OCEM spa, San Giorgio di Piano Bologna
  • F. Burini, M. F. Farioli, G. Taddia
    O. C.E. M. S.p. A., Bologna
  • I. De Cesaris, C. Sanelli, F. Voelker
    INFN/LNF, Frascati (Roma)
  • M. Donetti, S. Toncelli
    CNAO Foundation, Milan
  • S. Giordanengo, F. Marchetto
    INFN-Torino, Torino
  • G. Venchi
    University of Pavia, Pavia
  The paper presents the design aspects and performance measurements of the CNAO Scanning Magnets’ power supply (PS) rated ±550A/±660V and developed in collaboration between OCEM SpA and INFN-CNAO. CNAO is a medical synchrotron producing carbon ions and protons for the cure of deep tumours. The Scanning Magnets are dipole magnets used to move the beam in an x-y plane at the very end of the beam extraction line. The PS current will be set in order to cover the targeted tumour area. To accomplish such a task the specifications of the PS are very stringent: current ramp speed is required to be as fast as 100 kA/s with an overall precision class of 100 ppm. Moreover the wide (20x20 cm2) area to be covered by the beam requires a wide current range. High voltage peaks are required during transients whereas low voltage is needed during steady state. The above characteristics are challenging design issues both with respect to topology and control optimization.  
 
THPP123 Ramping Power Supplies for the SSRF Booster power-supply, controls, booster, feedback 3646
 
  • R. Li, H. G. Chen, D. M. Li, S. L. Lu, T. J. Shen, D. X. Wang
    SINAP, Shanghai
  The SSRF booster magnetic field ramped with a 250ms ramp, 2Hz cycle rate, and biased quasi-sinusoidal wave shape is successfully realized. Two Digital Switch-mode Power Supplies (DSPS) separately deliver currents to all dipoles, and other four DSPS deliver to the quadrupoles and sextupoles in families. Tracking precision and reducing line power fluctuation requirements are particularly challenging because of the fast ramp and high inductance load. In order to meet the requirements, the magnetic energy recycle, digital regulation and novel PID correction circuit are used. On Oct. 5th 2007, after a few days commissioning of the SSRF booster, the beam was boosted up to 3.5GeV firstly in SSRF, it proved that the design of ramping power supplies was correct and the manufacture was successful. The power supply system and its performance are described in this paper.  
 
THPP125 Performance Evaluation of the Switching Mode AC Power Supply power-supply, booster, controls, impedance 3652
 
  • C.-Y. Liu, Y.-C. Chien, H. M. Shih
    NSRRC, Hsinchu
  In order to improve the injection efficiency, the output current waveform of the AC power supplies must be great. Therefore, to ensure smooth and efficient injection of the booster ring, the phase jitter of the AC power supplies current must be less than ±4ns. A new AC power supply is constructed and employ IGBT modules operating at higher switching frequency than the old GTO-based system for the dipole magnet. This new power supply will not only improve the phase jitter but also increase the operating efficiency than the old power supply. The measured dynamic range of the of the 10 Hz sine wave current output is better than 75dB and phase jitter is less than ±4ns. The improved performance evaluation is illustrated in the paper.  
 
THPP126 Four Quadrant 60 A, 8 V Power Converters for LHC radiation, controls, feedback, hadron 3655
 
  • L. Ceccone, V. Montabonnet
    CERN, Geneva
  The LHC (Large Hadron Collider) particle accelerator requires many true bipolar power converters (752), located under the accelerator dipole magnets in a radioactive environment. A special design and topology is required to obtain the necessary performance while meeting the criteria of radiation tolerance and compact size. This paper describes the ±60A ±8V power converter, designed by CERN to meet these requirements. Design aspects, performances and test results of this converter are presented.  
 
THPP130 SSRF Magnet Power Supply System power-supply, storage-ring, booster, controls 3667
 
  • T. J. Shen, H. G. Chen, C. L. Guo, Z. M. Hu, M. M. Huang, D. M. Li, R. Li, H. Liu, S. L. Lu, D. X. Wang, W. F. Wu, R. N. Xu, S. M. Zhu, Y. Y. Zhu
    SINAP, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF) is a third-generation synchrotron radiation light source. In SSRF, there are 520 sets of magnet power supplies for the storage ring and 163 sets for injector. All of the power supplies are in PWM switched mode with IGBT. A high precision stable output power supply for 40 dipoles rated at 840A/800V with the stability of ±2·10-5/8hrs is used for the storage ring. 200 sets of chopper type power supplies are used for exciting main winding of quadrupoles independently. In the booster, two sets of dynamic power supplies for dipoles and two sets for quadrupoles run at the biased 2Hz quasi-sinusoidal wave. All above power supplies work with digital power supply controllers designed by either PSI or SINAP. All power supplies are manufactured at professional power supply companies in China.  
 
THPP133 Magnet Power Converters for the New Elettra Full Energy Injector booster, quadrupole, controls, storage-ring 3673
 
  • R. Visintini, G. Cautero, M. Cautero, D. M. Molaro, M. Svandrlik, M. Zaccaria
    ELETTRA, Basovizza, Trieste
  A large number of power converters has been required to supply the coils and the magnets of the four sub-structures of the new Elettra full energy injector. The Linac, and the two transfer lines require highly stabilized DC power converters while the Booster has to be operated at 3 Hz supplying the magnets with sinusoidal current waveforms. The extraction Bumpers require slow pulse supplies. In order to keep all output voltages below 1 kV, a special connection has been adopted for the Booster dipoles. A particular type of low power four-quadrant converters with embedded Ethernet connection has been designed at Elettra for this specific project. The article will present the relevant facts about the different power converters and their performances.  
 
THPP141 Test of a NEG Coated Copper Dipole Vacuum Chamber vacuum, storage-ring, synchrotron, photon 3693
 
  • E. J. Wallén, M. Berglund, A. Hansson
    MAX-lab, Lund
  • R. Kersevan
    ESRF, Grenoble
  The paper reports about a test carried out at the 1.5 GeV storage ring MAX II where a standard dipole chamber made of stainless steel was replaced by a NEG coated chamber made of copper. The standard MAX II stainless steel dipole vacuum chamber is connected to an ion pump and a sublimation pump while the NEG-coated copper dipole vacuum chamber has no additional pumps. The NEG-coated dipole chamber made of copper has been demonstrated to work well with a stable vacuum level in the region where it is installed. The coating procedure for the bent dipole chamber copper tube is slightly more complicated than the coating procedure for a straight chamber of similar size due to its curvature and lack of line-of-sight. The procedure is also described in some detail. The main motivation for the interest in NEG-coated vacuum tubes is the reduced cost of the vacuum system and also the possibility to build more slender vacuum systems, thus simplifying and optimizing the design of accelerator magnet systems.