Keyword: sextupole
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MOPO033 Design and Development of a Laser Positioning System for TPS Magnets Alignment Inspection during the Installation on a Girder laser, quadrupole, alignment, lattice 556
 
  • Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, S.Y. Perng, Y.L. Tsai, T.C. Tseng, H.S. Wang
    NSRRC, Hsinchu, Taiwan
  • J.-R. Chen
    National Tsing Hua University, Hsinchu, Taiwan
  
  A novel optical inspection architecture is designed and developed for positioning the TPS (Taiwan Photon Source) quadrupole and sextupole magnets on the girder within 30 um. This positioning system is a laser-based scheme consists of two laser position sensing devices (PSD) and two granite blocks as the standard reference of magnets. The laser position sensing device (PSD) is mounted on an adjustable circular steel module and the module is installed in a granite block. With the PSD position being adjusted and corrected, the PSD module center can be identical to the ideal pole position of magnets on the girder within 10um. The Laser ray is also adjusted and aligned according to the ideal reference line of magnets. Finally the granite blocks are replaced with the quadrupole and sextupole magnets at installation, the assembling error of magnets can be detected from the PSD module. This paper describes the detail of the system development and testing results.  
 
MOPZ039 Dispersion-free Regions and Insertions for EMMA lattice, extraction, quadrupole, injection 886
 
  • B.D. Muratori, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. A dispersion-free region may be created in two separate ways. The first is by using a layout of EMMA which is naturally dispersion-free at the start and end of each cell. This means that we can arrange for periodic dispersion-free sections in every cell or in-between cells. The second is achieved through the use of sextupoles, by going off-axis in them, one has essentially a quadrupolar force which can be used to match the dispersion to zero in a particular place and for a particular energy. The benefits and drawbacks of both methods are discussed from the point of view of practicality and space in general, and applicability to EMMA in particular.  
 
TUXB01 Methods and Tools to Simulate and Analyse Non-linear Dynamics in Electron Storage Rings storage-ring, lattice, emittance, quadrupole 937
 
  • L.S. Nadolski
    SOLEIL, Gif-sur-Yvette, France
  
  This talk will present the different approaches and tools that have been recently developed while trying to understand or predict the non-linear dynamics of electron storage rings. Different algorithms have been recently used at different places to optimize the sextupole tunings, while the refinement of the models of existing machines together with more accurate measurement techniques enable now to fully understand the limitations of such facilities specially in the presence of insertion devices.  
slides icon Slides TUXB01 [7.624 MB]  
 
TUOAB03 Enlarging Dynamic and Momentum Aperture by Particle Swarm Optimization lattice, dynamic-aperture, storage-ring, simulation 948
 
  • Z. Bai, W. Li, L. Wang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  Particle swarm optimization (PSO) is a computational intelligence algorithm for global optimization. Obtaining adequate dynamic and momentum aperture is crucial for high injection efficiency and long beam lifetime in low emittance electron storage rings. Different from nonlinear driving terms optimization, we have made direct optimization of dynamic and momentum aperture by PSO algorithm. It is critical to make a criterion for comparison of dynamic and momentum aperture tracking results in the direct optimization procedure. Thus, in this paper we first propose a quantitative criterion of dynamic aperture. Then we apply PSO to the optimization of chromatic and harmonic sextupoles to find the optimum sextupole settings for enlarging the dynamic aperture. Taking the momentum aperture into consideration, we make joint optimization of dynamic and momentum aperture. Also, the momentum aperture has its quantitative criterion. As an example of application, the dynamic and momentum aperture of an FBA lattice studied in the design of storage ring of Hefei Advanced Light Source were optimized, and the results have shown the power of PSO algorithm.  
slides icon Slides TUOAB03 [0.313 MB]  
 
TUPC016 Status of the ATF2 Lattices lattice, quadrupole, multipole, optics 1027
 
  • E. Marin, R. Tomás
    CERN, Geneva, Switzerland
  • P. Bambade
    LAL, Orsay, France
  • T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  • A. Seryi
    JAI, Oxford, United Kingdom
  • G.R. White, M. Woodley
    SLAC, Menlo Park, California, USA
  
  The latest status for the ATF2 Nominal and Ultra-low beta lattices designs obtained to minimize the detrimental effect of the measured multipoles are presented in this paper. A set of correction knobs for the most important aberrations at the IP have been obtained for both lattices in order to perform the tuning under realistic imperfections. Starting from the tuned ATF2 Nominal lattice a squeeze sequence reducing betay is performed to reach the ultra-low beta lattice. Tuning results are shown for both options.  
 
TUPC022 Design of the CLIC Drive Beam Recombination Complex emittance, linac, injection, synchrotron 1045
 
  • J. Barranco, P.K. Skowroński, F. Tecker
    CERN, Geneva, Switzerland
  • C. Biscari
    INFN/LNF, Frascati (Roma), Italy
  
  The CLIC Drive Beam Recombination Complex (DBRC) is designed to compress beam pulses from a current of 4.1 A to 100 A before using them to produce RF power in the deceleration lines. The beam is transported isochronously through a complex system consisting of a delay loop, two combiner rings and final turn around. The system is designed to preserve transverse and longitudinal emittances. During the optics design, chromaticity and non-linear dispersion were identified as the main single particle dynamics causes for transverse emittance increase. Different sextupole families are used to compensate these chromatic effects while keeping isochronicity. The bunch length is also adjusted to minimize coherent synchrotron radiation effects on bunch length, energy spread and transverse emittance. Finally, the injection scheme of the combiner rings was improved making the time variable bump created with help of the RF deflectors truly achromatic.  
 
TUPC040 Modified Lattice of the Compton X-ray Source NESTOR lattice, storage-ring, electron, focusing 1087
 
  • A.Y. Zelinsky, P. Gladkikh, A.A. Kalamayko, I.M. Karnaukhov, A. Mytsykov, A.A. Shcherbakov
    NSC/KIPT, Kharkov, Ukraine
  
  NESTOR is Compton X-ray source that is under commissioning in NSC KIPT. One of the main parts of the facility is the middle energy storage ring (40-225 MeV). The storage ring has comprehensive lattice to provide low emittance, low beam size in the interaction point and big value of the energy acceptance. One of the NESTOR storage ring lattice feature is use of bending magnets of 0.5 m radius with combined focusing function. It leads to increasing of 3D magnetic field effects on electron beam dynamics. After NESTOR magnetic element manufacturing characteristics of element magnetic fields were measured and the effect of the real magnetic field distribution on beam dynamics was calculated. As a result, to provide project X-ray source characteristics the parameters of NESTOR storage ring lattice should be modified. The second reason for the lattice modification was the desire to increase the interaction point straight section length. The results of the beam dynamics simulation after lattice modification and optimization show that the storage ring will provide all project electron beam parameters. The results of the electron beam simulations are presented in the paper.  
 
TUPC073 Emittance Variation Dependence on Resonance Extraction Parameters at ELSA emittance, extraction, resonance, septum 1168
 
  • S. Zander, O. Boldt, F. Frommberger, W. Hillert, O. Preisner
    ELSA, Bonn, Germany
  
  Funding: Funded by the DFG within the SFB / TR 16.
The Electron Stretcher Facility ELSA consists of several accelerator stages, the last one being a stretcher ring providing a beam of polarized electrons with an energy of up to 3.5~GeV. In order to guarantee a high duty cycle, a slow extraction via a third integer resonance is applied to the stretcher ring. The emittance of the extracted beam as well as the efficiency of the extraction process depend on different parameters as the sextupole strength being necessary for the excitation of the third integer resonance or the adjusted tune. In order to optimize the quality of the extracted beam, an accurate comprehension of the influence of these parameters is indispensable. Beam profiles are detected using dedicated synchrotron light monitors optimized for low intensities. The emittance was investigated by the method of quadrupole scan. The experimental studies are accompanied by numerical simulation studies. The results of the change of the emittance depending on different resonance extraction setups obtained by the experimental as well as by the theoretical studies will be presented. 		 
 
TUPS073 Top-Up Safety Simulations for the TPS Storage Ring storage-ring, quadrupole, electron, photon 1707
 
  • H.-J. Tsai, C.C. Chiang, P.J. Chou, C.-C. Kuo
    NSRRC, Hsinchu, Taiwan
  
  TPS is a 3 GeV third generation light source and operates in the top-up injection scheme. During the top-up injection, the beamline photon shutters are always open. To ensure the radiation safety of beamline experiments, we studied the possible particle leakage to ID and neighboring bending beamlines. The effects of errors on magnets and beam chamber alignments are investigated.  
 
WEZA02 Colliders for B Factories quadrupole, luminosity, emittance, factory 1931
 
  • H. Koiso
    KEK, Ibaraki, Japan
  
  Two new B factories, SuperB in Frascati and SuperKEKB in Tsukuba, aim at unprecedented luminosities close to 1036/cm2/s. The designs, status, challenges, and differences between the two machines are reported. Emphasis should be put on recent developments for the B factories. The presentation should include a realistic outlook.  
slides icon Slides WEZA02 [6.796 MB]  
 
WEPC001 Beam Based Sextupole Alignment Studies for Coupling Control at the ASLS quadrupole, coupling, storage-ring, alignment 1995
 
  • R.T. Dowd, Y.E. Tan
    ASCo, Clayton, Victoria, Australia
  
  Offsets in sextupole magnets can be a significant source of coupling in a storage ring and hinder efforts to minimize vertical emittance. Beam offsets in the sextupoles at the Australian Synchrotron Light Source were measured using a response matrix analysis in LOCO with differing magnets strengths. These results were used to obtain an estimate of offset in each sextupole as well as estimate quadrupole contributions to coupling.  
 
WEPC007 Large Energy Acceptance Dogleg for the European XFEL Injector focusing, quadrupole, linac, controls 2013
 
  • N. Golubeva, V. Balandin, W. Decking
    DESY, Hamburg, Germany
  
  The option to install two injectors is foreseen at the European XFEL Facility. The injectors will be located on top of each other in the same building, both with the offset of 2.75 m with respect to the main linac axis. The translation system (dogleg) from the injector axis to the main linac axis has to fulfill very tight requirements of the chromatic properties, because the energy chirp required for the downstream bunch length compression in magnetic chicanes will be created upstream in the injector linac. In this paper we present such an large energy acceptance dogleg and discuss the optical symmetries which form the basis of its design.  
 
WEPC016 Amplitude Dependent Orbit Shift and its Effect on Beam Injection injection, septum, betatron, synchrotron 2040
 
  • Y. Shoji
    LASTI, Hyogo, Japan
  • T. Nakamura, J. Schimizu, M. Takao
    JASRI/SPring-8, Hyogo-ken, Japan
  
  The betatron oscillation amplitude dependent orbit shift was measured at the electron storage ring, NewSUBARU. The result roughly agreed with the theoretical calculation. The effect of this shift on the beam injection is discussed using parameters of NewSUBARU and SPring-8. Generally there exists a better side for the injection, the inner side or the outer side of the ring, which depends on the sign of the orbit shift at the injection septum. In case of the NewSUBARU, the beam is injected from the outer side and the shift is positive. The effective thickness of the septum is reduced by the large oscillation amplitude of the injected beam. On the other hand at SPring-8, the beam is injected from the inner side of the ring while the orbit shift is negative. This means that the two rings are using better side for the injection.  
 
WEPC037 An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade optics, luminosity, insertion, quadrupole 2088
 
  • S.D. Fartoukh
    CERN, Geneva, Switzerland
  
  A novel optics concept has been invented and developed in the context of the LHC Upgrade studies. It offers an incredibly powerful and flexible machinery in order to squeeze beta* in a symmetric or asymmetric way (so-called “round” or “flat” optics, respectively), while perfectly controlling the chromatic aberrations induced (off-momentum beta-beating, non-linear chromaticity, spurious dispersion due to the crossing angles). The basic principles of the scheme are described and a specific path for the LHC upgrade is built accordingly, only relying on the existing and well-characterized LHC-like technology, and based on the production of flat collision optics with very small beta* (7.5 cm) in the plane perpendicular to the crossing plane.  
 
WEPC049 Operation and Storage Ring Calibration with the Transverse Bunch-by-Bunch Feedback System at the Australian Synchrotron feedback, damping, synchrotron, storage-ring 2121
 
  • M.J. Boland, Y.E. Tan
    ASCo, Clayton, Victoria, Australia
  • D.J. Peake, R.P. Rassool, K.P. Wootton
    The University of Melbourne, Melbourne, Australia
  
  The first operational experience with the transverse bunch-by-bunch feedback system for the storage ring shows a doubling of the lifetime and the ability to damp instabilities caused by IVU gap changes. The system was also used to calibrate the ring by doing simultaneous measurements on several single bunches with different bunch currents. Using the bunch-by-bunch system's capability to excite the beam to large amplitudes, the non-linear beam dynamics were also measured and compared with the model.  
 
WEPC054 Amplitude Dependent Tune Spread in the CR Operated as an Antiproton Collector quadrupole, beam-losses, antiproton, simulation 2136
 
  • A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck
    GSI, Darmstadt, Germany
  
  The Collector Ring is planned to be built for efficient cooling of antiprotons and rare isotopes beams. In order to accept hot antiproton beams coming from a separator large aperture magnets are required. This paper examines the effects which, may influence on the beam dynamic because of both large both betatron amplitude oscillations (240 mm mrad) and momentum spread (6%). Using analytic expressions the amplitude-dependent tune shifts driven by sextupole magnets, fringe field of quadrupole magnets and kinematics effects have been calculated. The results are compared with numerical simulations. Tracking studies for the CR operated as an antiproton collector have been performed considering the real shape of the magnetic field of the wide aperture quadrupole. We report on quantitative studies of the effects on the tune spread and its influence on the beam losses.  
 
WEPC056 Beam Test of Slow Extraction from the ESR extraction, resonance, septum, ion 2142
 
  • A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck
    GSI, Darmstadt, Germany
  
  In the frame of a dedicated ESR machine development the conventional third order resonant slow extraction was theoretically investigated and experimentally tested. The possibility to extract a beam from the ESR by preparing a resonant closed orbit, which has strong nonlinear characteristics, was demonstrated. A third-integer resonance slow extraction has been adopted for the 100 MeV/u Ar beam.  
 
WEPC057 Estimation of the Dynamic Aperture by Transverse Beam Excitation with Noise Close to a Resonance dynamic-aperture, lattice, resonance, beam-losses 2145
 
  • S. Sorge, G. Franchetti
    GSI, Darmstadt, Germany
  
  The present heavy ion synchrotron SIS-18 will be upgraded to be used as a booster for further synchrotrons being part of the FAIR project underway at GSI. Recently, a method was developed to measure the physical aperture of SIS-18 using transverse RF noise. This method is based on the transverse expansion of the beam with noise beyond the limiting aperture generating beam loss. The aperture was determined from the comparison of the resulting time evolution of the beam current in the machine with that obtained from a numerical simulation. In this study we attempt to apply this method to determine the dynamic aperture of SIS-18.  
 
WEPC058 Field Properties of the ESR Magnets and their Influence on Beam Optics dipole, quadrupole, betatron, simulation 2148
 
  • O.E. Gorda, C. Dimopoulou, A. Dolinskii, S.A. Litvinov, F. Nolden, M. Steck
    GSI, Darmstadt, Germany
  
  Machine experiments at the experimental storage ring (ESR) demonstrated that the ring acceptance is strongly restricted by field errors. Higher-order field harmonics of the dipole and quadrupole magnets have been calculated and then used in particle tracking simulations in order to find out the dynamic aperture of the ESR. To benchmark the results of numerical calculations, betatron tune measurements have been performed with a uranium beam at the energy of 400 MeV/u. The results of the magnetic field simulations for the ESR magnets and a comparison between the measured and calculated tune behavioгr are presented.  
 
WEPC059 Optimization of the Sextupole Scheme and Compensation of the Time-Dependent Field Errors during Slow Extraction from the Superconducting Synchrotron SIS300 extraction, lattice, dipole, resonance 2151
 
  • A. Saa Hernandez, P.J. Spiller
    GSI, Darmstadt, Germany
  • U. Ratzinger
    IAP, Frankfurt am Main, Germany
  
  The SIS300 synchrotron, planned for the new Facility for Antiproton and Ion Research (FAIR) at GSI-Darmstadt, will become the first superconducting synchrotron worldwide using cos(θ) magnets for resonant slow extraction. A multi-objective optimization algorithm has been developed for the design of the non-linear magnet scheme. The optimization algorithm makes use of the analytical model for the slow extraction from Kobayashi, the analytical description of the resonance excitation and amplitude-dependent tune-shift from Bengtsson, and corrects the chromaticity in order to fulfill the Hardt condition. As a result, the placement of the chromatic and harmonic sextupole magnets in SIS300, the number of sextupole families and the gradients of these families have been optimized for a high efficiency slow extraction. The algorithm accounts also for the sextupole errors on the dipole magnets, compensating its effects. Furthermore, optimized time-dependent settings for the sextupole magnets are generated to compensate the persistent current decay occurring at slow extraction. Tolerances for the magnets are set for the limits where the compensation is no longer valid.  
 
WEPC061 ENC Interaction Region Separation Dipoles dipole, solenoid, electron, multipole 2157
 
  • P. Schnizer, E.S. Fischer
    GSI, Darmstadt, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  
  The Electron Nucleon Collider (ENC) is proposed as an upgrade of the High Energy Storage Ringe of the FAIR. The beams are separated by two dipoles, mounted closely to the intraction point; surrounded by the detectors. Hence these magnetsmust provide sufficient field quality but be slim to be transparaent to the secondary particles. Further these must be air coil magnets due to the detector solenoid field of 2T. We present the 3D optimised magnet next to a first design of the mechanical restraint structure and a concise description for the field distortion leaking into the detector.  
 
WEPC062 Second Order Achromats with Arbitrary Linear Transfer Matrices quadrupole, focusing, beam-transport, longitudinal-dynamics 2160
 
  • V. Balandin, R. Brinkmann, W. Decking, N. Golubeva
    DESY, Hamburg, Germany
  
  The most obvious method to construct a second order achromat with an arbitrary (predefined) linear transfer matrix is to take a bend magnet system arranged in an achromat like fashion with the total transfer matrix equal to the identity matrix, attach a drift-quadrupole block with the desired linear transfer matrix and then adjust the sextupoles installed in the first part in such a way that the total system becomes a second order achromat. Unfortunately this is not always possible and, in general, the parts of such a system can not be designed independently. In this paper we give the necessary and sufficient conditions which must be satisfied for both parts of the system in order to become a second order achromat. In addition we provide some practical recommendations showing how these conditions can be fulfilled. We formulate these necessary and sufficient conditions using the group-theoretical point of view for the design of magnetic optical achromats as introduced in *.
* V. Balandin, R. Brinkmann, W. Decking, N. Golubeva, "Two Cell Repetitive Achromats and Four Cell Mirror Symmetric Achromats", Proc. IPAC'10, Kyoto, Japan (2010).
 		 
 
WEPC068 Amplitude Dependent Betatron Oscillation Center Shift by Non-linearity and Beam Instability Interlock betatron, insertion, insertion-device, simulation 2178
 
  • T. Nakamura, K. Kobayashi, J. Schimizu, T. Seike, K. Soutome, M. Takao
    JASRI/SPring-8, Hyogo-ken, Japan
  • T. Hara
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  
  The center of the betatron oscillation in storage rings shifts as the amplitude of the oscillation increases. This effect is produced by non-linear components like sextupole magnets with its first-order perturbation. This shift can be observed as the shift of the closed orbit with usual slow beam position monitor (BPM) for closed orbit measurement. At the SPring-8 storage ring, the insertion devices (IDs) have their dedicated BPMs for monitoring the beam axis in the IDs. If some amount of the shift of beam axis is observed, the beam is aborted to avoid the damage by the irradiation of the ring components by ID radiation. When a betatron oscillation is excited by a beam transverse instability, the beam axis also oscillates and might produce the damage. Though it is not easy to detect the oscillation amplitude in various bunch current and filling patterns like in SPring-8, the oscillation produces the shift of the center of the betatron oscillation and can be observed by the BPM of IDs, and the beam is aborted. Calculation, tracking simulation and observation will be reported.  
 
WEPC088 Embedding Finite Element Results for Accelerator Components in a Moment Approach Beam Dynamics Code* quadrupole, simulation, dipole, electron 2217
 
  • T. Roggen, H. De Gersem, B. Masschaele
    KU Leuven, Kortrijk, Belgium
  • W. Ackermann, S. Franke, T. Weiland
    TEMF, TU Darmstadt, Darmstadt, Germany
  
  Funding: This research is funded by grant ''KUL 3E100118'' ''Electromagnetic Field Simulation for Future Particle Accelerators''.
A moment based beam dynamics code has particular advantages, i.e. accuracy and efficiency, over macro-particle tracking and full particle-in-cell (PIC) codes respectively. Instead of embedding analytical descriptions of the accelerator components in the beam dynamics model, it is proposed to insert a surrogate model obtained from the finite element model of individual accelerator components. We apply the V-Code, which accepts moments up to the sixth order and accounts for space charge effects. We construct and calculate finite element and finite difference time domain models using the CST Studio Suite 2011 software package. An interface is implemented using VBA and MATLAB. As an example of the accuracy of this cascadic simulation approach, we compare the beam dynamics of an S-DALINAC quadrupole obtained by directly tracking particles to the calculated fields with the results for the cascadic approach with the V-Code.
This work was performed during a three month research visit at the Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt, Germany. 		 
 
WEPC104 Vicky : A Computer Code for Use in the Design and Simulation of Particle Accelerators dynamic-aperture, kicker, quadrupole, closed-orbit 2256
 
  • F. Iazzourene
    ELETTRA, Basovizza, Italy
  
  Vicky is a computer code under development for designing and simulating particle accelerators. Like other existing codes, the features include machine imperfections, closed orbit correction, Twiss functions matching, chromaticity evaluation and correction, particle tracking and so on. The goal is to give the users a friendly graphical interface with widgets to perform the wished tasks, for example to plot the orbit, the Twiss functions, the tune diagram, the dynamic aperture and so on, to select and read an input file describing the considered lattice, to perform the Twiss functions matching, a closed orbit correction and so on. The code provides a description of the particle motion by 10 parameters: four beta-functions, four alpha-functions and two phase advances, that is a 4*4 generalized transverse coupling, together with an emphasis on the treatment of the complex 3D magnetic fields of the undulators used in today’s modern synchrotron radiation facilities. The code is written in C++. It uses the free packages QT for the online plots and the graphical user interface and IT++ for the mathematics. The present status and some results of its application will be presented.  
 
WEPO020 Magnetic Field Inspection and Analysis of Multipole Lattice Magnets using a Rotating-coil Measurement System* multipole, quadrupole, storage-ring, synchrotron 2442
 
  • J.C. Jan, C.-H. Chang, Y.L. Chu, T.Y. Chung, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin
    NSRRC, Hsinchu, Taiwan
  
  A precise rotating-coil measurement system (RCS) was constructed to characterize the field quality and field center of multipole lattice magnets of Taiwan Photon Source (TPS). The mechanical center of magnets is determined by the two references of the magnet-feet and the RCS system is used to characterize the field center. The location of the magnetic field center is quantitatively accurate to better than 20 micro-meter in the horizontal direction; the granite support height of the RCS system is accurate within 5 micro-meter after artificial polishing. The measurement reproducibility of the field center was better than 10 micro-meter when the magnets were reinstalled. The relative accuracy of the multipoles components is better than 2×10-5. This paper reports the details of the bench construction and the unit composition. The field center with RCS measurement will be compared and discussed with the 3D-coordinate-measuring machine. The multipole errors obtained from RCS will be compared with a Hall-probe measurement system.  
 
WEPO022 Tightening the Tolerance Budget of Core Fabrication to Achieve Higher Magnet Performance vacuum, dipole, quadrupole, scattering 2448
 
  • N. Li, A. Madur
    LBNL, Berkeley, California, USA
  • J. Jin
    SINAP, Shanghai, People's Republic of China
  
  Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231.
Traditionally, laminated cores of AC magnets have been always built by the laminations that are produced by a punching die. There are 5 links in the tolerance chain when a magnet core is built by this procedure: 1. Error of punching die; 2. Error of lamination punching; 3. Error of half core stacking; 4. Error of core assembly; and 5. Error of magnet re-assembling during the installation in the accelerator. As time goes on, the Lattice physicists call for more and more ever higher magnet performance, which makes the required magnet field quality almost impossible achieve by traditional core fabrication procedures. It is the goal of this paper to describe a relatively new procedure that was first used by Buckley System Ltd, NZ and is being used at SINAP, China for ALS combined function sextupole core fabrication. The advantage of this new procedure and the fabrication issues related to this procedure will be described in this paper. 		 
 
WEPO024 Design and Operation Parameters of the Superconducting Main Magnets for the SIS100 Accelerator of FAIR dipole, quadrupole, multipole, ion 2451
 
  • E.S. Fischer, E. Floch, J. Macavei, P. Schnizer
    GSI, Darmstadt, Germany
  • P.G. Akishin
    JINR, Dubna, Moscow Region, Russia
  • A. Mierau
    TEMF, TU Darmstadt, Darmstadt, Germany
  
  SIS100, the worlds second large scale synchrotron for ion research, will use superferric magnets. The dipoles are of the window frame type, whose aperture was chosen as an optimum balance between the achievable field quality and AC losses at cryogenic temperatures. Analogous design optimisation was done for the quadrupole and corrector magnets as well. We present the design of the main magnets, estimate their operation parameters and define the crucial aspects to be experimentally analysed before series production, e.g. precise magnetic end field optimisation.  
 
WEPO031 The Magnetic Model of the LHC during Commissioning to Higher Beam Intensities in 2010-2011 injection, quadrupole, dipole, optics 2466
 
  • L. Deniau, N. Aquilina, L. Fiscarelli, M. Giovannozzi, P. Hagen, M. Lamont, G. Montenero, R.J. Steinhagen, M. Strzelczyk, E. Todesco, R. Tomás, W. Venturini Delsolaro, J. Wenninger
    CERN, Geneva, Switzerland
  
  The Field Description of the Large Hadron Collider (FiDeL) model is a set of semi-empirical equations linking the magnets behaviours established from magnetic measurements to the magnetic properties of the machine observed through beam measurements. The FiDeL model includes the parameterization of static components such as magnets residual magnetization, persistent currents, hysteresis and saturation as well as the decay and snap-back dynamic components. In the present paper, we outline the relationship between the beam observables (orbit, tune, chromaticity) and the model components during the commissioning to higher beam intensities in 2010-2011, with an energy of 3.5 TeV per beam. The main relevant issues are (i) the operation at 2 A/s and 10 A/s ramp rate and their influence on chromatic correction, (ii) the beta beating and its relation to the knowledge of the resistive quadrupoles transfer functions and (iii) the observed tune decay at injection energy and its possibles origins.  
 
THOBA03 Dual AC Dipole Excitation for the Measurement of Magnetic Multipole Strength from Beam Position Monitor Data* dipole, kicker, simulation, lattice 2865
 
  • M. Spata, G.A. Krafft
    JLAB, Newport News, Virginia, USA
  
  Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a technique for characterizing the nonlinear fields of the beam transport system. Two air-core dipole magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the electron beam. Fourier decomposition of beam position monitor data was then used to measure the amplitude of these frequencies at different positions along the beamline. For a purely linear transport system one expects to find solely the frequencies that were applied to the dipoles with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. The technique was calibrated using one of the sextupole magnets in a CEBAF beamline and then applied to a dipole to measure the sextupole and octupole strength of the magnet. A comparison is made between the beam-based measurements, results from TOSCA and data from our Magnet Measurement Facility. 		 
slides icon Slides THOBA03 [6.193 MB]  
 
THPPA01 EPS-AG Sacherer Prize: Beam Optics Developments for SPS, RHIC, LHC, CLIC and ATF2 resonance, optics, dipole, extraction 2894
 
  • R. Tomás
    CERN, Geneva, Switzerland
  
  Highlights of linear and nonlinear optics studies are presented from various accelerators. At the LHC, optics correction is of critical importance to guarantee safe beam operation. Preparation for LHC optics measurements and corrections has been a major activity during the last decade. In particular, SPS and RHIC have served as excellent research and development machines to test new techniques and instrumentation, such as the measurement of resonance driving terms with and without AC dipoles. Together with a meticulous field quality specification, a careful installation strategy and an elaborate magnet model, these efforts have paid off in the LHC, where a record low beta-beating for hadron colliders below 10% has been achieved. Looking further into the future, the performance of the Final Focus System (FFS) is of critical importance for a future linear collider like CLIC, since it determines the IP beam spot sizes. The large chromatic aberrations required the development of novel non-linear optimization methods. Such techniques have successfully increased the CLIC design luminosity by 70% and an experimental test has been proposed for ATF2 to halve the design IP beam spot sizes.  
slides icon Slides THPPA01 [1.514 MB]  
 
THPC020 PETRA III Upgrade undulator, optics, focusing, single-bunch 2948
 
  • K. Balewski, M. Bieler, J. Keil, A. Kling, G.K. Sahoo, R. Wanzenberg
    DESY, Hamburg, Germany
  
  PETRA III, the new third generation light source at DESY, has been running as a user facility since middle of 2010. All 14 undulator beam lines have been commissioned and up to 12 of them are currently in operation. However, already during the planning phase of PETRA III it turned out that the number of beamlines will not be sufficient to fulfill the request for beam time. The pressure to add more beamlines to PETRA III even increased after the decision to shut down DORIS III at the end of 2012. To increase the number of experimental stations two additional halls will be built each housing 5 additional beam lines and about 100 m of the accelerator close to each of the new buildings will be completely remodeled to install additional undulators. The upgrade has been formally approved and at present should be accomplished during a 6 month shut down in 2013. In this paper the layout of the upgraded accelerator will be shown. The impact of the upgrade on machine performance has been studied both theoretically and experimentally and the results of these studies will be presented.  
 
THPC026 Low Momentum Compaction Optics for Elettra optics, emittance, lattice, quadrupole 2963
 
  • E. Karantzoulis, A. Carniel, S. Krecic
    ELETTRA, Basovizza, Italy
  
  The DBA optics lattice of Elettra, the third generation Italian light source is closer to DBA minimum emittance condition than any other similar lattice. At the same time, although the lattice is also optimized for large acceptance, it is very inflexible to any changes like the reduction of the momentum compaction (very desirable to the IR and SR-FEL beam lines). Nevertheless a solution has been found and consists in abandoning the achromat condition and reversing the polarity of some quadrupole and sextupole families. This special optics and its applications to Elettra are presented and discussed.  
 
THPC067 Tolerance Studies of the Max-IV Linac linac, quadrupole, emittance, dipole 3047
 
  • P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • D. Angal-Kalinin, J.K. Jones, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M. Eriksson, S. Thorin, S. Werin
    MAX-lab, Lund, Sweden
  
  The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF) and an FEL (in phase 2). We briefly describe the layout, optics and bunch compression / linearization scheme of the linac. We then investigate the robustness of the design to element errors.  
 
THPC073 Study of Lower Emittance Lattices for SPEAR3 lattice, emittance, dynamic-aperture, injection 3062
 
  • X. Huang, Y. Nosochkov, J.A. Safranek, L. Wang
    SLAC, Menlo Park, California, USA
  
  We study paths to significantly reduce the emittance of the SPEAR3 storage ring. Lattice possibilities are explored with the GLASS technique. New lattices are designed and optimized for practical dynamic aperture and beam lifetime. Various techniques are employed to optimize the nonlinear dynamics, including the Elegant-based genetic algorithm. Experimental studies are also carried out on the ring to validate the lattice design.  
 
THPC074 Dynamic Aperture and Tolerances for PEP-X Ultimate Storage Ring Design dynamic-aperture, resonance, quadrupole, coupling 3065
 
  • M.-H. Wang, Y. Cai, R.O. Hettel, Y. Nosochkov
    SLAC, Menlo Park, California, USA
  • M. Borland
    ANL, Argonne, USA
  
  Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515.
A lattice for the PEP-X ultimate storage ring light source[1], having 11 pm-rad natural emittance at a beam energy of 4.5 GeV at zero current, using 90 m of damping wiggler and fitting into the existing 2.2-km PEP-II tunnel, has been recently designed[2]. Such a low emittance lattice requires very strong sextupoles for chromaticity correction, which in turn introduce strong non-linear field effects that limit the beam dynamic aperture. In order to maximize the dynamic aperture we choose the cell phases to cancel the third and fourth order geometric resonances in each 8-cell arc. Four families of chromatic sextupoles and six families of geometric (or harmonic) sextupoles are added to correct the chromatic and amplitude-dependent tunes. To find the best settings of the ten sextupole families, we use a Multi-Objective Genetic Optimizer employing elegant[3] to optimize the beam lifetime and dynamic aperture simultaneously. Then we evaluate dynamic aperture reduction caused by magnetic field multipole errors, magnet fabrication errors and misalignments. A sufficient dynamic aperture is obtained for injection, as well as workable beam lifetime[2]. 		 
 
THPC125 Study of some Design Concepts and Collective Effects in the MAX IV Linac linac, emittance, simulation, wakefield 3176
 
  • F. Curbis, M. Eriksson, O.E. Karlberg, S. Thorin, S. Werin
    MAX-lab, Lund, Sweden
  • D. Angal-Kalinin, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF) and an FEL (phase 2). Compression is done in two double achromats with positive R56. The natural second order momentum compaction, T566, from the achromats is used together with weak sextupoles to linearise longitudinal phase space, leaving no need for a harmonic cavity for linearization of longitudinal phase space. In this proceeding we present the design of the achromat compressors and results from particle tracking through the MAX IV linac in high brightness mode. We also investigate emittance dilution due to CSR, in the achromat compressors, and transverse wakefields in a high beta function lattice.  
 
THPC139 Study of a Pulsed Sextupole Magnet Injection System for LNLS injection, power-supply, kicker, pulsed-power 3212
 
  • X.R. Resende, F.C. Arroyo, R.H.A. Farias, L. Liu, A.R.D. Rodrigues, P.P. Sanchez, G. Tosin
    LNLS, Campinas, Brazil
  
  An injection system consisting of a pulsed sextupole magnet (PSM) is being considered for Sirius, the project of a new 3rd generation 3 GeV synchrotron source in development in Brazil. This novel injection scheme will be implemented and tested in the existing UVX ring. This will also serve as an opportunity to get acquainted with the new technology and become ready for Sirius. On this paper we report on the ongoing PSM study at LNLS. In particular, details of injection dynamics calculations, magnet and pulsed power supply designs are described, as well as machine preparations for experimental tests in the UVX storage ring.  
 
THPC155 Modification of the BESSY II Optic for the Implementation of a Small Gap Undulator undulator, optics, cryogenics, quadrupole 3251
 
  • J. Bahrdt, K.B. Bürkmann-Gehrlein, V. Dürr, W. Frentrup, A. Gaupp, A. Jankowiak, P. Kuske, J. Rahn, M. Scheer, P.O. Schmid, G. Wüstefeld
    HZB, Berlin, Germany
  
  At BESSY there is an increasing demand for photons in the range from 60 eV to 8 keV available at the same experimental station. The photons will be produced by a combination of two adjacent undulators, one of them will be a small period cryogenic undulator. Several optics schemes for the 1.7 GeV BESSY II storage ring are discussed to install the undulators. Two types of straight sections exist. A high beta straight with betaxmin=15 m and betaymin=4.5 m and a low beta straight with betaxmin=betaymin=1 m. We discuss the present plan, which clearly favours a small detuning of an existing low beta straight to shift the low beta waist to the centre of the low gap undulator, with only minor impact to the machine.  
 
THPC170 Magnetic Characterization of FEL-2 Undulators for the FERMI@Elettra Free-electron Laser undulator, FEL, multipole, quadrupole 3296
 
  • M. Kokole
    KYTE, Sezana, Slovenia
  • B. Diviacco
    ELETTRA, Basovizza, Italy
  • T. Milharcic, M. Zambelli
    KYMA, Trieste, Italy
  • G. Soregaroli, M. Tedeschi
    Euromisure srl, Pieve S. Giacomo (Cremona), Italy
  
  Kyma Srl is the spin-off company of Sincrotrone Trieste, Elettra laboratory, set up in 2007 together with the two industrial partners Cosylab d.d. and Euromisure SpA, in order to design and manufacture the undulators for the FERMI@Elettra project in Trieste, Italy. The insertion devices, for FEL-2 line, manufactured and characterized so far are the following: Modulator, 3.2 m linearly polarized undulator, three 55.2 mm APPLE-II variable polarization undulators, each 2.4 m long and six 34.8 mm APPLE-II undulators also each 2.4 m long. All the above devices have been characterized, both from the mechanical and the magnetic point of view. The measured parameters are in good agreement with the design values. This paper presents the most relevant changes in design from FEL-1 to FEL-2 line and results of the magnetic measurements carried out on all the above undulators.  
 
THPO003 Rapid-cycling Power Supplies for the J-PARC RCS Sextupole Magnets power-supply, synchrotron, proton, linac 3338
 
  • Y. Watanabe
    JAEA, Ibaraki-ken, Japan
  • T. Adachi, S. Igarashi, H. Someya
    KEK, Ibaraki, Japan
  • N. Tani
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  The rapid-cycling synchrotron of the Japan Proton Accelerator Research Complex requires 18 sextupole magnets with three families for the chromaticity correction. One family consists of six focusing sextupole magnets, and other two families consist of six defocusing sextupole magnts. An individual power supply excited for each family and the current pattern is a DC-biased sinusoidal of a frequency of 25 Hz. This paper describes design and test results of the sextupole magnet power supplies.  
 
THPO012 Using a High Precision Programmable DC Power Supply of TPS Magnet power-supply, quadrupole, controls, storage-ring 3358
 
  • Y.S. Wong, J.C. Huang, K.-B. Liu, W.S. Wen
    NSRRC, Hsinchu, Taiwan
  
  Taiwan government had been announcement to set up a third-generation synchrotron radiation light source in February 2010. It should be installed with 1032 sets of magnet power supplies for the storage ring and 152 sets for the injector. In the storage ring, high precision DC power supply for 48 dipoles magnets , 240 quadrupole magnets and 168 sextupole magnets. The main windings of quadrupole and sextupole magnets are powered by individual power supplies. In the booster rings, one set of dynamic power supply for the dipole magnets and four sets for quadrupole magnets run at the biased 3Hz quasi sinusoidal wave. The Taiwan photon source (TPS) plan was completed indication national synchrotron radiation research central (NSRRC) technical capability to build at its present site in seven years a 3~3.3 GeV electron energy, 518 meter circumference, low-emittance synchrotron storage ring which will offer one of the world's brightest synchrotron x-ray sources, provide cutting-edge experimental facilities and novel multidisciplinary scientific research opportunities, enhance world-class academic research, as well as create Taiwan's scientific research marvels in the twenty-first century.  
 
THPO013 Development of a DSP-based Digital Control Three Phase Shunt Active Power Filter for Magnet Power Supply System controls, power-supply, simulation, storage-ring 3361
 
  • B.S. Wang, K.-B. Liu, Y.S. Wong
    NSRRC, Hsinchu, Taiwan
  
  There will be 240 quadruple and 168 sextuple magnet power supplies installed in TPS storage ring, power factor of these power supplies is an important issue to be concerned. A digital control three-phase shunt active power filter (APF) for quadruple and sextuple magnet power supplies is implemented and the power factor is better than 0.98. The APF power stage employs a three-phase switch-mode rectifier (SMR) to reduce the input current harmonics distortion and correct the power factor. The digital control circuit of the three-phase shunt active power filter is implemented by using a multi-channel 12 bits analog-to-digital converter、high resolution Pulse Width Modulated (PWM) and a TMS320F28335 digital signal processor (DSP). The system configuration is described in three function blocks include principle of compensation、design of the snubber protective circuit and control strategies. Finally, the feasibility and validity of proposed scheme is simulated with Matlab simulink and verified by the homemade digital control three-phase shunt active power filter.  
 
THPZ011 Optimization of Chromatic Sextupoles in Electron Storage Rings Using Genetic Algorithms dynamic-aperture, storage-ring, resonance, emittance 3705
 
  • Z. Duan
    IHEP Beijng, Beijing, People's Republic of China
  • Q. Qin
    IHEP Beijing, Beijing, People's Republic of China
  
  Funding: Work supported by National Science Foundation of China contract 10725525.
In order to suppress the head-tail instability, strong chromatic sextupoles are used in modern electron storage rings to correct large chromaticities due to small emittance or strong insertion quadrupoles to squeeze the bunch size at some places. However, the introduction of strong chromatic sextupoles also brings severe nonlinearity and might reduce dynamic aperture drastically. In the case of several sextupole families, the genetic algorithms are applied to find suitable configurations of sextupole strengths, directly maximizing dynamic aperture. A GeneRepair operator is introduced into the algorithm to correct chromaticities and optimize the dynamic aperture simultaneously in electron storage rings. 		 
 
THPZ017 Achromatic Low-beta Interaction Region Design for an Electron-ion Collider electron, ion, betatron, interaction-region 3723
 
  • V.S. Morozov, Y.S. Derbenev
    JLAB, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by Muons, Inc.
An achromatic Interaction Region (IR) design concept is presented with an emphasis on its application at an electron-ion collider. A specially-designed symmetric Chromaticity Compensation Block (CCB) induces an angle spread in the passing beam such that it cancels the chromatic kick of the final focusing quadrupoles. Two such CCB’s placed symmetrically around an interaction point (IP) allow simultaneous compensation of the 1st-order chromaticities and chromatic beam smear at the IP without inducing significant 2nd-order aberrations. Special attention is paid to the difference in the electron and ion IR design requirements. We discuss geometric matching of the electron and ion IR footprints. We investigate limitations on the momentum acceptance in this IR design. 		 
 
THPZ022 Operation Scheme and Statistics of KEKB luminosity, injection, cavity, factory 3735
 
  • M. Tanaka
    MELCO SC, Tsukuba, Japan
  • Y. Funakoshi
    KEK, Ibaraki, Japan
  
  The KEKB B-Factory(KEKB) started a collision experiment in 1999 and finished in June, 2010. The total operation time of KEKB from fiscal year 2000 was 55657 hours. The breakdowns of operation are physics run 73.8%, machine study 6.8%, machine tuning 4.8%, beam tuning 5.9%, trouble 5.3%, maintenance 2.1% and other 1.3%. The total integrated luminosity was 1041 fb-1 and the maximum peak luminosity was 21.083 nb-1s−1. To increase the peak and integrated luminosity, the continuous injection scheme, the crab cavities and the skew sextupole magnets were effective. We finished over ten year operation of KEKB in June, 2010.