Keyword: quadrupole
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MOOCS3 Numerical and Analytical Studies of Matched Kinetic Quasi-Equilibrium Solutions for an Intense Charged Particle Beam Propagating Through a Periodic Focusing Quadrupole Lattice focusing, lattice, simulation, plasma 56
 
  • E. Startsev, R.C. Davidson, M. Dorf
    PPPL, Princeton, New Jersey, USA
 
  Funding: Research supported by the U. S. Department of Energy.
A recently developed novel perturbative Hamiltonian transformation method which allows the determination of approximate matched kinetic quasi-equilibrium solutions for an intense charged particle beam propagating through a periodic focusing quadrupole lattice is presented.* Using this method we have identified numerically the class of self-consistent periodic kinetic 'equilibria' for intense beam propagation in alternating-gradient focusing systems, and extended the nonlinear perturbative particle simulation method to intense beam propagation in such systems. The new method has been implemented in the nonlinear perturbative particle-in-cell code BEST which is used to study properties of the newly constructed beam 'equilibria'. The results of these studies are presented and analyzed in detail.
* E.A. Startsev, R.C. Davidson and M. Dorf, Phys. Rev. ST Accel. Beams 13, 064402 (2010).
 
slides icon Slides MOOCS3 [0.508 MB]  
 
MOODN5 Chromaticity Correction for a Muon Collider Optics sextupole, optics, collider, luminosity 79
 
  • E. Gianfelice-Wendt, Y. Alexahin, V.V. Kapin
    Fermilab, Batavia, USA
 
  Funding: Work supported by Fermi Research Alliance, LLC under DE-AC02-07CH11359 with the U.S. DOE
Muon Collider (MC) is a promising candidate for the next energy frontier machine. However, in order to obtain peak luminosity in the 1034cm-2s-1 range the collider lattice design must satisfy a number of stringent requirements. In particular the expected large momentum spread of the muon beam and the very small β* call for a careful correction of the chromatic effects. Here we present a particular solution for the interaction region (IR) optics whose distinctive feature is a three-sextupole local chromatic correction scheme. The scheme may be applied to other future machines where chromatic effects are expected to be large.
 
slides icon Slides MOODN5 [0.554 MB]  
 
MOODN6 Muon Collider Interaction Region and Machine-detector Interface Design dipole, collider, background, neutron 82
 
  • N.V. Mokhov, Y. Alexahin, V. Kashikhin, S.I. Striganov, A.V. Zlobin
    Fermilab, Batavia, USA
 
  Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
One of the key systems of a Muon Collider (MC)- seen as the most exciting options for the energy frontier machine in the post-LHC era - is its interaction region (IR). Designs of its optics, magnets and machine-detector interface are strongly interlaced and iterative. As a result of recent comprehensive studies, consistent solutions for the 1.5 TeV c.o.m. MC IR have been found and are described here. To provide the required momentum acceptance, dynamic aperture and chromaticity, innovative approach was used for the IR optics. Conceptual designs of large-aperture high-field dipole and high-gradient quadrupole magnets based on Nb3Sn superconductor were developed and analyzed in terms of the operation margin, field quality, mechanics, coil cooling and quench protection. Shadow masks in the interconnect regions and liners inside the magnets are used to mitigate unprecedented dynamic heat deposition due to muon decays (~1 kW/m). It is shown that an appropriately designed machine-detector interface with sophisticated shielding in the detector has a potential to substantially suppress the background rates in the MC detector.
 
slides icon Slides MOODN6 [1.233 MB]  
 
MOP015 An X-band Gun Test Area at SLAC gun, emittance, optics, cavity 133
 
  • C. Limborg-Deprey, C. Adolphsen, T.S. Chu, M.P. Dunning, C. Hast, R.K. Jobe, E.N. Jongewaard, A.E. Vlieks, D.R. Walz, F. Wang
    SLAC, Menlo Park, California, USA
  • S.G. Anderson, F.V. Hartemann, T.L. Houck, R.A. Marsh
    LLNL, Livermore, California, USA
 
  Funding: Work supported by the U.S. DOE Contract No. DE-AC03-76SF00515
The XTA (X-Band Test Area) is being assembled in the NLCTA tunnel of the SLAC National Laboratory to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200MV/m peak field X-band designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were discussed in collaboration with LLNL since the same gun will be used as a driver for the LLNL Gamma-ray Source. Our beamline includes an X-band accelerating section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.
 
 
MOP036 Epicyclic Twin-Helix Ionization Cooling Simulations resonance, optics, simulation, betatron 163
 
  • A. Afanasev
    Hampton University, Hampton, Virginia, USA
  • Y.S. Derbenev, V.S. Morozov
    JLAB, Newport News, Virginia, USA
  • V. Ivanov, R.P. Johnson
    Muons, Inc, Batavia, USA
 
  Funding: Supported in part by DOE SBIR grant DE-SC0005589
Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a high-luminosity muon collider. For the implementation of PIC, we earlier developed an epicyclic twin-helix channel with correlated behavior of the horizontal and vertical betatron motions and dispersion. We now insert absorber plates with short energy-recovering units located next to them at the appropriate locations in the twin-helix channel. We first demonstrate conventional ionization cooling in such a system with the optics uncorrelated. We then adjust the correlated optics state and induce a parametric resonance to study ionization cooling under the resonant condition.
 
 
MOP050 EPIC Muon Cooling Simulations using COSY INFINITY ion, resonance, dipole, emittance 190
 
  • J.A. Maloney, B. Erdelyi
    Northern Illinois University, DeKalb, Illinois, USA
  • A. Afanasev, R.P. Johnson
    Muons, Inc, Batavia, USA
  • S.A. Bogacz, Y.S. Derbenev
    JLAB, Newport News, Virginia, USA
  • V.S. Morozov
    ODU, Norfolk, Virginia, USA
 
  Next generation magnet systems needed for cooling channels in both neutrino factories and muon colliders will be innovative and complicated. Designing, simulating and optimizing these systems is a challenge. Using COSY INFINITY, a differential algebra-based code, to simulate complicated elements can allow the computation and correction of a variety of higher order effects, such as spherical and chromatic aberrations, that are difficult to address with other simulation tools. As an example, a helical dipole magnet has been implemented and simulated, and the performance of an epicyclic parametric ionization cooling system for muons is studied and compared to simulations made using G4Beamline, a GEANT4 toolkit.  
 
MOP052 Matched Optics of Muon RLA and Non-Scaling FFAG ARCS linac, optics, lattice, dynamic-aperture 196
 
  • V.S. Morozov, S.A. Bogacz, Y. Roblin
    JLAB, Newport News, Virginia, USA
  • K.B. Beard
    Muons, Inc, Batavia, USA
  • D. Trbojevic
    BNL, Upton, Long Island, New York, USA
 
  Funding: Supported in part by US DOE STTR Grant DE-FG02-08ER86351
Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. To reduce the number of required return arcs, we employ a Non-Scaling Fixed-Field Alternating-Gradient (NS-FFAG) arc lattice design. We present a complete linear optics design of a muon RLA with two-pass linear NS-FFAG droplet return arcs. The arcs are composed of symmetric cells with each cell designed using combined function magnets with dipole and quadrupole magnetic field components so that the cell is achromatic and has zero initial and final periodic orbit offsets for both passes’ energies. Matching to the linac is accomplished by adjusting linac quadrupole strengths so that the linac optics on each pass is matched to the arc optics. We adjust the difference of the path lengths and therefore of the times of flight of the two momenta in each arc to ensure proper synchronization with the linac. We investigate the dynamic aperture and momentum acceptance of the arcs.
 
 
MOP058 Particle Production in the MICE Beamline target, emittance, collider, electron 214
 
  • L. Coney
    UCR, Riverside, California, USA
  • A.J. Dobbs
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Funding: NSF
The Muon Ionization Cooling Experiment (MICE) will test transverse cooling of a muon beam, satisfying a crucial demonstration step along the path toward creating high intensity muon beams in a Neutrino Factory or Muon Collider. In the last year, MICE has taken a record amount of data to commission the beamline and calibrate the particle identification (PID) detectors. Studies of the MICE beamline and target timing will be discussed, including the use of Time-of-Flight (TOF) detectors to understand the MICE beam content.
 
 
MOP061 Stability of the MICE Muon Beam Line proton, emittance, target, radio-frequency 223
 
  • S.D. Blot
    University of Chicago, Chicago, Illinois, USA
 
  Funding: University of Chicago
The international Muon Ionization and Cooling Exper- iment (MICE) aims to demonstrate transverse beam emit- tance reduction for a muon beam. During the summer of 2010, data was taken using different configurations of the upstream beam line magnets to measure the optical pa- rameters of the muon beam and study the functionality of the beam line itself. Throughout this period of data taking, reference runs were taken with a fixed target configuration, and magnet settings which provide a muon beam with 200 MeV/c momentum and 6π 4D transverse emittance. Time of flight (TOF) detectors were used to measure many of the beam properties including emittance, particle identifi- cation, and profile. Analysis of these reference runs was carried out in order to determine the stability and repro- ducibility of the beam line data. This overall data quality check is essential to ensure the validity of measurements made so that further analysis can be carried out and that the muon beam is suitable for the MICE cooling channel.
 
 
MOP090 Optics Tuning Knobs for FACET plasma, optics, wakefield, focusing 268
 
  • Y. Nosochkov, M.J. Hogan, W. Wittmer
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515.
FACET is a new facility under construction at the SLAC National Accelerator Laboratory. The FACET beam line is designed to provide 23 GeV tightly focused and compressed electron and positron bunches for beam driven plasma wakefield acceleration research and other experiments. Achieving optimal beam parameters for various experimental conditions requires the optics capability for tuning in a sufficiently wide range. This will be achieved by using optics tuning systems (knobs). Design of such systems for FACET is discussed.
 
 
MOP161 Undulator-based Laser Wakefield Accelerator Electron Beam Diagnostic undulator, electron, emittance, laser 397
 
  • M.S. Bakeman, E. Esarey, W. Leemans, K. Nakamura, J. Osterhoff, K.E. Robinson, C.B. Schroeder, C. Tóth, J. van Tilborg
    LBNL, Berkeley, California, USA
  • F.J. Grüner, R. Weingartner
    LMU, Garching, Germany
 
  Funding: This work is supported by DTRA and DOE-HEP.
The design and current status of experiments to cou- ple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.
* W.P. Leemans et al., Nature Physics, Volume 2, Issue 10, pp. 696-699 (2006).
** C.B. Schroeder et al., Proceedings AAC08 Conference (2008).
*** F. Grüner et al., Appl. Phys. B, 86(3):431–435 (2007).
 
 
MOP169 Optical Beam Diagnostics at ELSA emittance, synchrotron, diagnostics, sextupole 408
 
  • S. Zander, F. Frommberger, P. Haenisch, W. Hillert, S. Patzelt
    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 storage ring providing a beam of polarized electrons of up to 3.5 GeV. At ELSA various diagnostic devices based on synchrotron radiation are installed or planned. A new beamline at the storage ring designed for high resolution diagnostics in the transversal plane will be presented. The measurement setup is sensitive at the UV range of the synchrotron light spectrum. Upgrade measures aiming to extend the diagnostic possibilities to the longitudinal direction will be detailed. In the external beamlines beam currents below 1 nA are delivered to photo production experiments. Beam profiles are detected using dedicated synchrotron light monitors optimized for low intensities. The characteristics of the monitors will be described. In addition, beam parameters derived from the measured profiles at different resonance extraction setups will be shown.
 
 
MOP176 Design of Cavity Beam Quadrupole Moment Monitor at HLS cavity, emittance, diagnostics, electron 417
 
  • Q. Luo, Q.K. Jia, B.G. Sun, Z.R. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Work supported by the Natural Science Foundation of China, National “985 Project”, China Postdoctoral Science Foundation and “the Fundamental Research Funds for the Central Universities”
Traditional ways to get beam emittance of linacs, such as multi-slits method, are destructive and then not able to be used in on-line beam diagnostics. To meet the requirements of XFEL equipments and improve the quality of electron beam, non-destructive on-line beam emittance measurement methods basing on getting the quadrupole moment of a beam non-destructively are then required. An advanced way to pick up beam information non-destructively with great precision is making use of eigenmodes of resonant cavities. High brightness injector at Hefei light source is used to study FEL based on photocathode RF electron gun. Cavity beam quadrupole moment monitor system designed for the high brightness injector consists of a square pill-box cavity used to pick up quadrupole signal, a cylindrical pill-box reference cavity, a waveguide coupling network that can suppress monopole and dipole signal, and a superheterodyne receiver used as front-end signal processing system. The whole system works at 5.712 GHz. Strength of quadupole magnets is adjust to construct a matrix which can be used to work out beam parameters.
 
 
MOP212 Quadrupole Beam-Based Alignment in the RHIC Interaction Regions controls, proton, alignment, focusing 498
 
  • J.M. Ziegler
    BNL, Upton, Long Island, New York, USA
  • T. Satogata
    JLAB, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements.
 
 
MOP250 NSLS-II High Level Application Infrastructure and Client API Design EPICS, controls, emittance, monitoring 582
 
  • G. Shen, K. Shroff, L. Yang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work performed under auspices of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.
The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes a detailed client API design, and latest progress.
 
 
TUOAN1 SuperB: Next-Generation e+e B-factory Collider solenoid, emittance, luminosity, collider 690
 
  • A. Novokhatski, K.J. Bertsche, A. Chao, Y. Nosochkov, J.T. Seeman, M.K. Sullivan, U. Wienands, W. Wittmer
    SLAC, Menlo Park, California, USA
  • M.A. Baylac, O. Bourrion, N. Monseu, C. Vescovi
    LPSC, Grenoble, France
  • S. Bettoni
    CERN, Geneva, Switzerland
  • M.E. Biagini, R. Boni, M. Boscolo, T. Demma, A. Drago, M. Esposito, S. Guiducci, M.A. Preger, P. Raimondi, S. Tomassini, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  • A.V. Bogomyagkov, E.B. Levichev, S.A. Nikitin, P.A. Piminov, D.N. Shatilov, S.V. Sinyatkin, P. Vobly
    BINP SB RAS, Novosibirsk, Russia
  • B. Bolzon, L. Brunetti, A. Jeremie
    IN2P3-LAPP, Annecy-le-Vieux, France
  • A. Chancé
    CEA, Gif-sur-Yvette, France
  • P. Fabbricatore, S. Farinon, R. Musenich
    INFN Genova, Genova, Italy
  • S.M. Liuzzo, E. Paoloni
    University of Pisa and INFN, Pisa, Italy
  • I.N. Okunev
    BINP, Novosibirsk, Russia
  • F. Poirier, C. Rimbault, A. Variola
    LAL, Orsay, France
 
  Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515.
The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 1036 cm-2 s-1. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the Y(4S) resonance. The present design is based on extremely low emittance beams colliding at a large Piwinski angle to allow very low ßy* without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal polarization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron-radiation applications.
 
slides icon Slides TUOAN1 [9.378 MB]  
 
TUOCN4 Subpicosecond Electron Bunch Train Production Using a Phase-Space Exchange Technique dipole, electron, cavity, emittance 755
 
  • Y.-E. Sun, A.S. Johnson, A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup
    Fermilab, Batavia, USA
  • T.J. Maxwell, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: The work was supported by the Fermi Research Alliance, LLC under the DOE Contract No. DE-AC02-07CH11359, and by Northern Illinois University under the DOE Contract No. DE-FG02-08ER41532.
Our recent experimental demonstration of a photoinjector electron bunch train with sub-picosecond structures is reported in this paper. The experiment is accomplished by converting an initially horizontal beam intensity modulation into a longitudinal phase space modulation, via a beamline capable of exchanging phase-space coordinates between the horizontal and longitudinal degrees of freedom. The initial transverse modulation is produced by intercepting the beam with a multislit mask prior to the exchange. We also compare our experimental results with numerical simulations.
 
slides icon Slides TUOCN4 [1.761 MB]  
 
TUODN2 Exploration of Parallel Optimization Techniques for Accelerator Design target, coupling, controls, simulation 787
 
  • Y. Wang, M. Borland, V. Sajaev
    ANL, Argonne, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Optimization through simulation is a time-consuming task in accelerator design, especially for high dimensional problems. We explored several parallel optimization techniques, including Parallel Genetic Algorithm (PGA), Hybrid Parallel Simplex (HPS), and Parallel Particle Swarm Optimization (PPSO), to solve some real world problems. The serial simplex method in elegant was used as a benchmark for newly-developed parallel optimization algorithms in Pelegant. PGA and HPS are not faster than the serial simplex method, but they more reliably find the global optimum. PPSO is well suited for parallel computing, allowing significantly faster turn-around given sufficient computing resources. Parallel optimization implementations in Pelegant thus promise to not only make optimization results more reliable, but also open the possibility of fast, "real time" optimization of complex problems for accelerator operation.
 
slides icon Slides TUODN2 [0.218 MB]  
 
TUODN6 Action and Phase Jump Analysis for LHC Orbits lattice, simulation, interaction-region, dipole 796
 
  • O.R. Blanco, J.F. Cardona
    UNAL, Bogota D.C, Colombia
 
  Funding: COLCIENCIAS, Programa Jovenes Investigadores e Innovadores "Virginia Gutierrez de Pineda" 2009 Direccion de Investigacion Sede Bogota, Universidad Nacional de Colombia (DIB, UNAL)
Action and phase orbit correction method is implemented to detect magnetic errors in LHC orbits of late 2009 run. The last achievements in the theory of action and phase jump analysis have been included to reduce action and phase plots noise and to increase precision on the calculation of linear errors. The validation of the implementation is performed by MAD-X simulations of the LHC lattice V6.5, where dipole and quadrupole errors are included and recovered within 0.02%. Then, the implementation is applied to experimental orbits, taken from the 2009 run during November and December, where several interaction regions are analyzed.
orblancog@bt.unal.edu.co, Universidad Nacional de Colombia
jfcardona@unal.edu.co, Professor, Universidad Nacional de Colombia
 
slides icon Slides TUODN6 [1.867 MB]  
 
TUP002 Study of Robinson Instabilities with a Higher-Harmonic Cavity for HLS Phase II Project cavity, simulation, dipole, coupling 808
 
  • Y. Zhao, W. Li, L. Wang, C.-F. Wu
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  In the phase II project of Hefei Light Source, a fourth-harmonic “Landau” cavity will be operated in order to suppress coupled-bunch instabilities and increase the beam lifetime of Hefei Storage Ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.  
 
TUP077 Vibrational Measurements for Commissioning SRF Accelerator Test Facility at Fermilab cryomodule, cavity, cryogenics, vacuum 967
 
  • M.W. McGee, J.R. Leibfritz, A. Martinez, Y.M. Pischalnikov, W. Schappert
    Fermilab, Batavia, USA
 
  Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.
The commissioning of two cryomodule components is underway at Fermilab’s Superconducting Radio Frequency (SRF) Accelerator Test Facility. The research at this facility supports the next generation high intensity linear accelerators such as the International Linear Collider (ILC), a new high intensity injector (Project X) and other future machines. These components, Cryomodule #1 (CM1) and Capture Cavity II (CC2) which contain 1.3 GHz cavities are connected in series in the beamline and through cryogenic plumbing. Studies regarding characterization of ground motion, technical and cultural noise continue. Mechanical transfer functions between the foundation and critical beamline components have been measured and overall system displacement characterized. Baseline motion measurements given initial operation of cryogenic, vacuum systems and other utilities are considered.

 
 
TUP145 Introduction to HLSII Storage Ring Conventional Magnets dipole, sextupole, storage-ring, synchrotron 1100
 
  • H. Zhang, G. Feng, W.W. Li, W. Li, J.J. Liang, L. Wang, S.C. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  HLS (Hefei Light Source) is a dedicated synchrotron radiation research facility, whose emittance is relatively large. In order to improve the performance of HLS, especially getting higher brilliance synchrotron radiation and increasing the number of straight section for insertion devices, an upgrade project named HLSII will be proceeded soon. The storage ring lattice comprises 8 dipoles, 32 quadrupoles and 32 combined function sextupoles. Design and analysis of the magnets are showed in the paper. the multipurpose combined function magnet is the first one designed and used in China. Mechanical design and fabrication procedures for the magnets are presented also.  
 
TUP146 Large Aperture Quadrupole Magnets for ISIS TS-1 and TS-2 dipole, target, proton, neutron 1103
 
  • S.M. Gurov, A.M. Batrakov, M.F. Blinov, F.A. Emanov, V.V. Kobets, V.A. Polukhin, A.S. Tsyganov, P. Vobly, T.A. Yaskina
    BINP SB RAS, Novosibirsk, Russia
  • S.J.S. Jago, J. Shih, S.F.S. Tomlinson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory has two target stations TS-1 and TS-2. Budker Institute of Nuclear Physics developed, produced and delivered seven type Q13 quadrupole magnets with an aperture diameter of 310 mm for TS-2 beam transfer line. Later an additional three quadrupoles with integrated dipole coils were developed and delivered to ISIS TS1. To improve the field quality across the full current range a special pole profile and end chamfer were designed using the MERMAID code. The magnetic field map was measured by a set of Hall probes. Moreover, BINP produced a rotating coil with radius 120 mm for field quality measurements.  
 
TUP147 Rotating Dipole and Quadrupole Field for a Multiple Cathode System dipole, cathode, electron, gun 1106
 
  • X. Chang, I. Ben-Zvi, J. Kewisch, V. Litvinenko, W. Meng, A.I. Pikin, V. Ptitsyn, T. Rao, B. Sheehy, J. Skaritka, Q. Wu
    BNL, Upton, Long Island, New York, USA
  • E. Wang
    PKU/IHIP, Beijing, People's Republic of China
  • T. Xin
    Stony Brook University, Stony Brook, USA
 
  A multiple cathode system has been designed to provide the high average current polarized electron bunches for the future electron-ion collider eRHIC. One of the key research topics in this design is the technique to generate a combined dipole and quadrupole rotating field at high frequency (700 kHz). This type of field is necessary for combining bunches from different cathodes to the same axis with minimum emittance growth. Our simulations and the prototype test results to achieve this will be presented.  
 
TUP149 Magnetic Field Mapping and Integral Transfer Function Matching of the Prototype Dipoles for the NSLS-II at BNL dipole, electron, storage-ring, synchrotron 1112
 
  • P. He, M. Anerella, G. Ganetis, R.C. Gupta, A.K. Jain, P.N. Joshi, J. Skaritka, C.J. Spataro, P. Wanderer
    BNL, Upton, Long Island, New York, USA
 
  The National Synchrotron Light Source-II (NSLS-II) storage ring at Brookhaven National Laboratory (BNL) will be equipped with 54 dipole magnets having a gap of 35 mm, and 6 dipoles having a gap of 90 mm. The large aperture magnets are necessary to allow the extraction of long-wavelength light from the dipole magnet to serve a growing number of users of low energy radiation. The dipoles must not only have good field homogeneity (0.015% over a 40 mm x 20 mm region), but the integral transfer functions and integral end harmonics of the two types of magnets must also be matched. The 35 mm aperture dipole has a novel design where the yoke ends are extended up to the outside dimension of the coil using magnetic steel nose pieces. A Hall probe mapping system has been built with three Group 3 Hall probes mounted on a 2-D translation stage. The probes are arranged with one probe in the midplane of the magnet and the others vertically offset by ±10 mm. The field is mapped along a nominal 25 m radius beam trajectory. The results of measurements in the as-received magnets, and with modifications made to the nose pieces will be presented.  
 
TUP152 Dipole Corrector Magnets for the LBNE Beam Line dipole, simulation, target, synchrotron 1115
 
  • M. Yu, D.J. Harding, G. Velev
    Fermilab, Batavia, USA
 
  The conceptual design of a new dipole corrector magnet has been thoroughly studied. The planned Long-Baseline Neutrino Experiment (LBNE) beam line will require correctors capable of greater range and linearity than existing correctors, so a new design is proposed based on the horizontal trim dipole correctors built for the Main Injector synchrotron at Fermilab. The gap, pole shape, length, and number of conductor turns remain the same. To allow operation over a wider range of excitations without overheating, the conductor size is increased, and to maintain better linearity, the back leg thickness is increased. The magnetic simulation was done using ANSYS to optimize the shape and the size of the yoke. The thermal performance was also modeled and analyzed.  
 
TUP162 Engineering Design of HTS Quadrupole for FRIB radiation, pick-up, vacuum, factory 1124
 
  • J.P. Cozzolino, M. Anerella, A.K. Ghosh, R.C. Gupta, W. Sampson, Y. Shiroyanagi, P. Wanderer
    BNL, Upton, Long Island, New York, USA
  • A. Zeller
    FRIB, East Lansing, Michigan, USA
 
  Funding: Supported by the U.S. Department of Energy under Contract DE-AC02-98CH10886 and under Cooperative Agreement DE-SC0000661 from DOE-SC that provides financial assistance to MSU for FRIB.
The coils of the first quadrupole in the fragment separator region of the Facility for Rare Isotope Beams (FRIB) must withstand an intense level of radiation and accommodate a very high heat load. Magnets produced with High Temperature Superconductors (HTS) are especially suitable in such an environment. The proposed design employs second generation (2G) HTS, permitting operation at ~50K. The engineering considerations this design are summarized. The goal has been to engineer a compact, readily producible magnet with a warm bore and yoke, made from radiation-resistant materials, capable of operating within the heat load limit, whose four double-layered coils will be adequately restrained under high radial Lorentz forces. Results of ANSYS finite element thermal and structural analyses of the coil clamping system are presented. Coil winding, lead routing and splicing, magnet assembly as well as remote tunnel installation/removal considerations are factored into this design and will also be discussed.
 
 
TUP165 Design, Construction and Test of Cryogen-Free HTS Coil Structure vacuum, instrumentation, superconducting-magnet, radiation 1133
 
  • H.M. Hocker, M. Anerella, R.C. Gupta, S.R. Plate, W. Sampson, J. Schmalzle, Y. Shiroyanagi
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by the U.S. Dept. of Energy under Contract No. DE-AC02-98CH10886 & under Coop. Agreement DE-SC0000661 from DOE-SC that provides financial assistance to MSU to design and establish FRIB
This paper will describe design, construction and test results of a cryo-mechanical structure to study coils made with the second generation High Temperature Superconductor (HTS) for the Facility for Rare Isotope Beams (FRIB). A magnet comprised of HTS coils mounted in a vacuum vessel and conduction-cooled with Gifford-McMahon cycle cryocoolers is used to develop and refine design and construction techniques. The study of these techniques and their effect on operations provides a better understanding of the use of cryogen free magnets in future accelerator projects. A cryogen-free, superconducting HTS magnet possesses certain operational advantages over cryogenically cooled, low temperature superconducting magnets.
 
 
TUP170 Mechanical Design of an Alternate Structure for LARP Nb3Sn Quadrupole Magnets for LHC alignment, luminosity, insertion, status 1142
 
  • J. Schmalzle, M. Anerella, J.P. Cozzolino, P. Kovach, P. Wanderer
    BNL, Upton, Long Island, New York, USA
  • G. Ambrosio, M.J. Lamm
    Fermilab, Batavia, USA
  • S. Caspi, H. Felice, P. Ferracin, G.L. Sabbi
    LBNL, Berkeley, California, USA
 
  Funding: This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.
An alternate structure for the 120mm Nb3Sn quadrupole magnet is presently under development for use in the upgrade for LHC at CERN. The design aims to build on existing technology developed in LARP with the LQ and HQ magnets and to further optimize the features required for operation in the accelerator. The structure includes features for maintaining mechanical alignment of the coils to achieve the required field quality. It also includes a helium containment vessel and provisions for cooling with 1.9k helium. The development effort includes the assembly of a six inch model to verify required coil load is achieved. Status of the R&D effort and an update on the magnet design, including its incorporation into the design of a complete one meter long cold mass is presented.
 
 
TUP171 Influence of Proton Irradiation on Angular Dependence of Second Generation (2G) HTS radiation, proton, target, superconductivity 1145
 
  • Y. Shiroyanagi, G.A. Greene, R.C. Gupta, W. Sampson
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by the U.S. DOE under Contract No. DE-AC02-98CH10886 and under Cooperative Agreement DE-SC0000661 from DOE-SC that provides financial assistance to MSU to design and establish FRIB.
In the Facility for Rare Isotope Beams (FRIB), superconducting magnets will be exposed to high levels of ionizing radiation. Quadruples in the fragment separator will be exposed to radiation doses as high as ~20 MGy/yr and heat loads as high as ~10 kW/m. High temperature superconducting (HTS) tapes are good candidates for this magnet because they can be operated in the temperature range ~30-50 K to tolerate higher temperatures than low temperature superconductors. Thus, radiation damage studies of HTS tapes are crucial to ensure that they will perform satisfactorily in such a high radiation environment. Therefore, the effects of proton irradiation on second generation HTS tapes from two vendors were studied. Each sample of HTS tape from SuperPower and American Superconductor was irradiated by a 42μA, 142 MeV proton beam at the Brookhaven Linac Isotope Producer. Two of each were irradiated at 5 dose levels: 2.5, 25, 50, 75 and 100μA•hr. The angular dependence of the critical current was measured in a magnetic field at 77K. Based on these measurements, conductors from both vendors appear to satisfy the FRIB radiation-tolerance requirement of 10 years of operation.
 
 
TUP174 Warm Magnetic Field Measurements of LARP HQ Magnet dipole, luminosity, alignment, multipole 1154
 
  • X. Wang, S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, J. Lizarazo, M. Martchevskii, C. Nash, G.L. Sabbi, C. Vu
    LBNL, Berkeley, California, USA
  • G. Ambrosio, R. Bossert, G. Chlachidze, J. DiMarco, V. Kashikhin
    Fermilab, Batavia, USA
  • J. Schmalzle, P. Wanderer
    BNL, Upton, Long Island, New York, USA
 
  The US-LHC Accelerator Research Program is develop- ing and testing a high-gradient quadrupole (HQ) magnet, aiming at demonstrating the feasibility of Nb3Sn technologies for the LHC luminosity upgrade. The 1 m long HQ magnet has a 120 mm bore with a conductor-limited gradient of 219 T/m at 1.9 K and a peak field of 15 T. HQ includes accelerator features such as alignment and field quality. Here we present the magnetic measurement results obtained at LBNL with a constant current of 30 A. A 100 mm long circuit-board rotating coil developed by FNAL was used and the induced voltage and flux increment were acquired. The measured b6 ranges from 0.3 to 0.5 units in the magnet straight section at a reference radius of 21.55 mm. The data reduced from the numerical integration of the raw voltage agree with those from the fast digital integrators.  
 
TUP195 Commissioning the ALS Digital Power Supply Controller in the Booster Dipole and Quadrupole Magnet Power Supplies booster, controls, injection, power-supply 1190
 
  • J.M. Weber, T. Scarvie, C. Steier, CA. Timossi
    LBNL, Berkeley, California, USA
 
  Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) is a third generation synchrotron light source that has been operating since 1993 at Berkeley Lab. A few years ago, the ALS was upgraded to achieve Top-Off Mode, which required replacing the booster dipole and quadrupole magnet power supplies to increase the peak booster beam energy from 1.5GeV to 1.9GeV. The original analog controller for each power supply has been replaced by a digital power supply controller (DPSC) to improve stability and resolution and provide a remote interface. The DPSC capabilities include 24-bit 100k-point digital reference waveform download and voltage reference generation, and complete digital current loop implementation. The hardware includes an FPGA with an embedded processor running a full EPICS IOC on VxWorks. This paper will present the current functionality of the DPSC as well as performance results from recent commissioning.

 
 
TUP211 Compensation of Fast Kicker Rolls with Skew Quadrupoles kicker, injection, photon, coupling 1208
 
  • I. Pinayev
    BNL, Upton, Long Island, New York, USA
 
  The development of the third generation light sources lead to the implementation of the top-up operation, when injection occurs while users collect data. The beam excursions due to the non-closure of the injection bump can spoil the data and need to be suppressed. In the horizontal plane compensation can be achieved by adjusting timing and kick amplitudes. The rolls of the kicker magnets create non-closure in the vertical plane and usually there is no means for correction. In the paper we describe proposed compensation scheme utilizing two skew quadrupoles placed inside the injection bump.  
 
TUP221 Helium Pressures in RHIC Vacuum Cryostats and Relief Valve Requirements from Magnet Cooling Line Failure vacuum, simulation, dipole, injection 1229
 
  • C.J. Liaw, R. Than, J.E. Tuozzolo
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A catastrophic failure of the RHIC magnet cooling lines, similar to the LHC superconducting bus failure incident, would pressurize the insulating vacuum in the magnet and transfer line cryostats. Insufficient relief valves on the cryostats could cause a structural failure. A SINDA/FLUINT® model, which simulated the 4.5K/ 4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the vacuum cryostat and discharging via the reliefs into the RHIC tunnel, had been developed to calculate the helium pressure inside the cryostat. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces were included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Existing relief valve sizes were reviewed to make sure that the maximum stresses, caused by the calculated maximum pressures inside the cryostats, did not exceed the allowable stresses, based on the ASME Code B31.3 and ANSYS results.
 
 
TUP229 Implementation and Operation of Electron Cloud Diagnostics for CesrTA vacuum, electron, diagnostics, pick-up 1250
 
  • Y. Li, J.V. Conway, X. Liu, V. Medjidzade, M.A. Palmer
    CLASSE, Ithaca, New York, USA
 
  Funding: Work Supported by NSF Grant #PHY-0734867 & DOE Grant #DE-FC02-08ER41538
The vacuum system of Cornell Electron Storage Ring (CESR) was successfully reconfigured to support CesrTA physics programs, including electron cloud (EC) build-up and suppression studies. One of key features of the reconfigured CESR vacuum system is the flexibility for exchange of various vacuum chambers with minimized impact to the accelerator operations. This is achieved by creation of three short gate-valve isolated vacuum sections. Over the last three years, many vacuum chambers with various EC diagnostics (such as RFAs, shielded pickups, etc) were rotated through these short experimental sections. With these instrumented test chambers, EC build-up was studied in many magnetic field types, including dipoles, quadrupoles, wigglers and field-free drifts. EC suppression techniques by coating (TiN, NEG and amorphous-C), surface textures (grooves) and clearing electrode are incorporated in these test chambers to evaluate their vacuum performance and EC suppression effectiveness. We present the implementation and operations of EC diagnostics.
 
 
WEOCN2 A Non-Destructive Profile Monitor for High Intensity Beams electron, proton, gun, controls 1438
 
  • W. Blokland, S.M. Cousineau
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
A non-destructive profile monitor has been installed and commissioned in the accumulator ring of the Spallation Neutron Source (SNS). The SNS Ring accumulates high intensity proton bunches of up to 1.5·1014 protons with a typical peak current of over 50 A and a bunch length of about 0.7 us during a 1 ms cycle. The profile monitor consists of two systems, one for each plane, with electron guns, correctors, defectors, and quadrupoles to produce pulsed electron beams that scan through the proton bunch. The proton bunch EM fields alter the trajectory of the electrons and their projection on a fluorescent screen. The projection is analyzed to determine the transverse profile of the proton bunch. The speaker will describe the theory, hardware, software, analysis, results, and improvements to these electron scanners. The results include a comparison to wire scanner profiles of extracted ring beam.
 
slides icon Slides WEOCN2 [9.476 MB]  
 
WEOCN5 Beam Halo Measurements at UMER and the JLAB FEL Using an Adaptive Masking Method FEL, electron, radiation, synchrotron 1449
 
  • H.D. Zhang, S. Bernal, R.B. Fiorito, R.A. Kishek, P.G. O'Shea, A.G. Shkvarunets
    UMD, College Park, Maryland, USA
  • S.V. Benson, D. Douglas, F.G. Wilson, S. Zhang
    JLAB, Newport News, Virginia, USA
 
  Funding: US Dept. of Energy Offices of High Energy Physics and Fusion Energy Sciences and by the Dept. of Defense Office of Naval Research and Joint Technology Office.
Beam halo is a challenging issue for intense beams since it can cause beam loss, emittance growth, nuclear activation and secondary electron emission. Because of the potentially low number of particles in the halo compared with beam core, traditional imaging methods may not have sufficient contrast to detect faint halos. We have developed a high dynamic range, adaptive masking method to measure halo using a digital micro-mirror array device and demonstrated its effectiveness experimentally on the University of Maryland Electron Ring (UMER). We also report on similar experiments currently in progress at the Jefferson Lab Free Electron Laser (FEL) using this method.
 
slides icon Slides WEOCN5 [1.287 MB]  
 
WEOCS1 Development of Long Nb3Sn Quadrupoles by the US LHC Accelerator Research Program luminosity, collider, alignment, radiation 1455
 
  • G.L. Sabbi
    LBNL, Berkeley, California, USA
 
  Insertion quadrupoles with large aperture and high gradient are required to upgrade the luminosity of the Large Hadron Collider (HL-LHC). The US LHC Accelerator Research Program (LARP) is a collaboration of DOE National Laboratories aiming at demonstrating the feasibility of Nb3Sn magnet technology for this application. Several series of magnets with increasing performance and complexity have been fabricated, with particular emphasis on addressing length scale-up issues. Program results and future directions are discussed.  
slides icon Slides WEOCS1 [4.433 MB]  
 
WEODS4 High Gradient Normal Conducting Radio-Frequency Photoinjector System for Sincrotrone Trieste gun, cathode, coupling, dipole 1504
 
  • L. Faillace, R.B. Agustsson, P. Frigola
    RadiaBeam, Santa Monica, USA
  • H. Badakov, A. Fukasawa, J.B. Rosenzweig, A. Yakub
    UCLA, Los Angeles, California, USA
  • F. Cianciosi, P. Craievich, M. Trovò
    ELETTRA, Basovizza, Italy
  • L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • B. Spataro
    INFN/LNF, Frascati (Roma), Italy
 
  Radiabeam Technologies is leading a multi-organizational collaboration by UCLA, INFN and MATS to deliver a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system to the Sincrotrone Trieste facility. Designed to operate with a 120MV/m accelerating gradient, this dual feed, fat lipped racetrack coupler design is modeled after the LCLS photoinjector with a novel demountable cathode which permits cost effective cathode exchange. Full overview of the project to date will be discussed along with basic, design, engineering, manufacturing and RF test results.  
slides icon Slides WEODS4 [3.186 MB]  
 
WEP003 A New Correction Scheme to Compensate Depolarizing Integer Resonances at ELSA resonance, polarization, dipole, electron 1507
 
  • O. Boldt, A. Dieckmann, F. Frommberger, W. Hillert
    ELSA, Bonn, Germany
 
  Funding: BMBF
Since more than four decades, the University of Bonn supports research at the in-house electron accelerator ELSA. Presently, the polarized electrons gained from an inverted source are accumulated in a stretcher ring and accelerated within a fraction of a second up to 3.2 GeV. During the fast ramping various depolarizing resonances are crossed. By taking several expedient measures (closed orbit correction, tune jumping, etc.) a high polarization degree of up to 65% is reached. One important part of these measures is the harmonic correction of integer resonances. Those resonances are compensated by applying additional horizontal fields, distributed sinusoidally along an one-turn orbit length. In case of an appropriate setting of amplitude and phase, all resonance driving effects should be neutralized completely. First studies have shown that vertical displacements and resulting horizontal fields in the quadrupole magnets, caused by the resonance correction, have to be taken into account as well. With regard to a new correction scheme, the first experimental results confirmed by simulative and theoretical studies will be presented.
 
 
WEP005 Modeling the Low-Alpha-Mode at ANKA with the Accelerator Toolbox optics, synchrotron, sextupole, dipole 1510
 
  • M. Klein, N. Hiller, A. Hofmann, E. Huttel, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller
    KIT, Karlsruhe, Germany
  • K.G. Sonnad
    CLASSE, Ithaca, New York, USA
 
  The ANKA storage ring is operated frequently with low momentum compaction lattices to produce short bunches for the generation of coherent synchrotron radiation in the THz range. The bunch length can be varied in steps from one centimeter down to the sub millimeter level. These low alpha optics are modeled by using the Matlab based tools, Accelerator Toolbox (AT) and LOCO. The results are compared with measurements such as orbit response matrices, dispersion and chromaticity. This paper provides results of a study on the feasibilities as well as limitations of the measurements and calculations.  
 
WEP010 Design of the Bilbao Accelerator Low Energy Extraction Lines linac, dipole, DTL, neutron 1519
 
  • Z. Izaola, I. Rodríguez
    ESS-Bilbao, Zamudio, Spain
  • E. Abad, I. Bustinduy, R. Martinez, F. Sordo Balbin, D. de Cos
    ESS Bilbao, Bilbao, Spain
  • D.J. Adams, S.J.S. Jago
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • F.J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao, Spain
  • V. Etxebarria, J. Portilla
    University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
 
  Funding: European Spallation Source - Bilbao
The ESS-Bilbao linac will accelerate H+ and H− beams up to 50 MeV, which need to be transported to three laboratories, where different types of experiments will be conducted. This paper reports on the preliminary design of the transfer line, which is mainly performed based on beam dynamics simulations.
 
 
WEP017 Re-Examination of the NSLS-II Magnet Multipole Specifications multipole, sextupole, magnet-design, lattice 1531
 
  • W. Guo, A.K. Jain, S. Krinsky, S. Seiler, J. Skaritka, C.J. Spataro
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The NSLS-II magnet multipole specifications were determined based on analysis of nonlinear beam dynamics. The required field quality does not exceed what was specified for the existing third-generation light sources. While the prototype magnets have met these specifications, the magnets from mass production could potentially have bigger errors which exceed certain tolerances. In this paper we discuss the results of recent calculations to provide further insight into the acceptable range of the magnet multipoles based on the physics requirements.
 
 
WEP018 Optics Error Measurements in the AGS for Polarized Proton Operation survey, sextupole, betatron, closed-orbit 1534
 
  • V. Schoefer, L. A. Ahrens, K.A. Brown, J.W. Glenn, H. Huang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A large distortion of the vertical beta function became evident in the Brookhaven AGS during the 2010 polarized proton run. This paper describes the beam measurements and model calculations made to verify the distortion of the optics, to infer possible sources and to explore correcting strategies. The optics distortion is only apparent when operating with a betatron tune very near the integer (as required for polarization preservation during acceleration in the AGS) and with the lattice chromaticity sextupoles powered. The measurements indicate a small (on the order of millimeters) unexpected systematic horizontal closed orbit displacement in the sextupoles that is not evident in beam position monitor measurements. Motivated especially by these observations a complete survey of the AGS was performed during the 2010 shutdown period.&nb sp; The results of that survey and their impact on the observed optical errors in the AGS are included.
 
 
WEP022 Status of Low Emittance Tuning at CesrTA emittance, coupling, simulation, betatron 1540
 
  • J.P. Shanks, M.G. Billing, R.E. Meller, M.A. Palmer, M.C. Rendina, N.T. Rider, D. L. Rubin, D. Sagan, C.R. Strohman, Y. Yanay
    CLASSE, Ithaca, New York, USA
 
  Funding: Work supported by the National Science Foundation and by the US Department of Energy under contract numbers PHY-0734867 and DE-FC02-08ER41538.
We report on the status of emittance tuning techniques at the CESR Test Accelerator CesrTA. The CesrTA experimental program requires the capability to operate in a variety of machine lattices with the smallest possible emittance. We have attempted to minimize the turn-around time of our low emittance tuning procedure. We utilize high bandwidth BPM electronics for fast, precision measurements of orbit, betatron phase, transverse coupling, and dispersion. Turn by turn data is used to measure BPM button electrode gains to a under a percent. Gain-corrected coupling data is utilized to determine BPM tilts to 10mrad, allowing for measurement of vertical dispersion at the level of 10mm. Measurement and analysis of the data for characterizing BPM response takes 5 minutes. Beam based measurement of machine functions, data analysis, and implementing corrections in the machine takes another 5 minutes. An x-ray beam size monitor provides a real time check on the effectiveness of the procedure. A typical correction results in an emittance less than 20pm at 2.1GeV in 1-2 iterations. Sub 15pm has been achieved with adjustment of closed coupling/vertical dispersion bumps and betatron tunes.
 
 
WEP030 Direct Focusing Error Correction with Ring-wide TBT Beam Position Data lattice, sextupole, focusing, simulation 1546
 
  • M.-J. Yang
    Fermilab, Batavia, USA
 
  Turn-By-Turn (TBT) betatron oscillation data is a very powerful tool in studying machine optics. Hundreds and thousands of turns of data are taken in just few tens of milliseconds. With beam in free oscillation and covering all positions and angles at every location focusing error diagnosis can be made almost instantly. This paper describes a new approach that observes focusing error collectively over all available TBT data to find the optimized quadrupole strength, one location at a time. Example will be shown and other issues will be discussed.  
 
WEP031 Low-Emittance Lattice Designs for ALS Ultimate Upgrade emittance, dipole, lattice, storage-ring 1549
 
  • C. Sun, H. Nishimura, D. Robin, C. Steier, W. Wan
    LBNL, Berkeley, California, USA
 
  Based upon the Theoretical Minimum Emittance (TME) technique, a new method has been developed to optimize low-emittance and low-beta lattices for further brightness upgrades at the Advanced Light Source (ALS). The study provides us a different perspective on the lattice design, and confirms results earlier found using both Global Scan of All Stable Settings (GLASS) and Genetic Algorithms (GA) techniques. Since the optimal low-beta lattice may have a dynamic aperture too small to allow off-axis injection, to overcome this problem, an alternating high-low beta lattice could be used for the upgrade. Several options of these high-low beta lattices are investigated using Genetic Algorithms.  
 
WEP036 Start-to-End Beam Dynamics Simulations for the SRF Accelerator Test Facility at Fermilab simulation, cavity, emittance, focusing 1561
 
  • C.R. Prokop, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • M.D. Church, Y.-E. Sun
    Fermilab, Batavia, USA
 
  Funding: LANL Laboratory Directed Research and Development program 20110067DR. U.S. DoE contract No. DE-FG02-08ER41532 Northern Illinois University. Fermi Research Alliance, LLC Contract No. DE-AC02-07CH11359.
Fermilab is currently building a superconducting RF (SCRF) linear-accelerator test facility. In addition to testing ILC-spec SCRF accelerating modules for ILC and Project-X, the facility will be capable of supporting a variety of advanced accelerator R&D experiments. The accelerator facility includes a 40-MeV photoinjector capable of producing bunches with variable parameters. In this paper, we present start-to-end simulations of the accelerator beamline.
 
 
WEP041 Weak Resonances Induced by Nonlinear Multipoles in a Quadrupole Doublet Lattice linac, octupole, lattice, simulation 1570
 
  • Y. Zhang, J. G. Wang
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This submission was sponsored by a contractor of the United States Government under contract DE-AC05-00OR22725 with the United States Department of Energy.
In this paper we report the effects on beam dynamics from two intrinsic multipole components of a quadrupole magnet – dodecapole and psedu-octupole, in a quadrupole doublet lattice. Weak resonances at transverse phase advances 60°; and 90°; per cell, which may contribute to halo formation and beam loss in a linac, are shown from multi-particle tracking simulations. Although the net effect of the psedu-octupole component alone is very small due to substantial cancellations within the same magnet, its existence may significantly enhance the weak resonances which are induced by the dodecapole component of quadrupole magnets. The combined contributions of these two magnetic field components may not be simply linear-scaled because of the extreme nonlinear nature.
 
 
WEP044 Emittance and Phase Space Exchange cavity, emittance, lattice, optics 1576
 
  • D. Xiang, A. Chao
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the US DOE under Contract No. DE-AC02-76SF00515.
Alternative chicane-type beamlines are proposed for exact emittance exchange between horizontal phase space (x,x') and longitudinal phase space (z, delta). Methods to achieve exact phase space exchanges, i.e. mapping x to z, x' to delta, z to x and delta to x' are suggested. Some applications of the phase space exchanger and the feasibility of an emittance exchange experiment with the proposed beamline at SLAC are discussed.
 
 
WEP045 Measurement and Manipulation of Beta Functions in the Fermilab Booster booster, coupling, acceleration, proton 1579
 
  • M.J. McAteer, S.E. Kopp
    The University of Texas at Austin, Austin, Texas, USA
  • E. Prebys
    Fermilab, Batavia, USA
 
  In order to meet the needs of Fermilab’s planned post- collider experimental program, the total proton throughput of the 8 GeV Booster accelerator must be nearly doubled within the next two years. A system of 48 ramped corrector magnets has recently been installed in the Booster to help improve efficiency and allow for higher beam intensity without exceeding safe radiation levels. We present the preliminary results of beta function measurements made using these corrector magnets. Our goal is to use the correctors to reduce irregularities in the beta function, and ultimately to introduce localized beta bumps to reduce beam loss or direct losses towards collimators.  
 
WEP050 Advances in Modeling the University of Maryland Electron Ring dipole, focusing, simulation, lattice 1585
 
  • R.A. Kishek, B.L. Beaudoin, S. Bernal, M. Cornacchia, K. Fiuza, I. Haber, T.W. Koeth, P.G. O'Shea, D.F. Sutter, H.D. Zhang
    UMD, College Park, Maryland, USA
 
  Funding: Work funded by the US Dept. of Energy Offices of Fusion Energy Sciences and High Energy Physics, and by the Dept. of Defense Office of Naval Research and the Joint Technology Office.
The University of Maryland Electron Ring (UMER) is a research accelerator designed to operate with extreme space charge. The existence of high-precision experimental measurements of tune, dispersion, chromaticity, response matrix elements, and other parameters*, **, *** has prompted a revision of the models used to describe the machine. Due to the low energy (10 keV) of the electrons, the dipole and quadrupole magnets used are air-core printed-circuit coils whose fields we calculate using a Biot-Savart solver. Different levels of approximations for the magnetic fields have been developed. We present simulation results from the particle-in-cell code WARP, and from the accelerator code, ELEGANT. These are compared both against simpler models as well as experimental results. The improved modeling has significantly reduced the discrepancies between simulation and experiment.
* D.F. Sutter, et al., Proc. PAC 2009
** C. Wu, et al., Proc. PAC 2009
*** S. Bernal, et al., Proc. AAC 2010
 
 
WEP065 Multiobjective Dynamic Aperture Optimization at NSLS-II lattice, sextupole, dipole, damping 1597
 
  • L. Yang, W. Guo, S. Krinsky, Y. Li
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In this paper we present a multiobjective approach to the dynamic aperture (DA) optimization. Taking the NSLS- II lattice as an example, we have used both sextupoles and quadrupoles as tuning variables to optimize both on-momentum and off-momentum DA. The geometric and chromatic sextupoles are used for nonlinear properties while the tunes are independently varied by quadrupoles. The dispersion and emittance are fixed during tunes variation. The algorithms, procedures, performances and results of our optimization of DA will be discussed and they are found to be robust, general and easy to apply to similar problems.
 
 
WEP067 Cornell ERL Tolerance Simulations lattice, undulator, emittance, simulation 1603
 
  • C.E. Mayes
    CLASSE, Ithaca, New York, USA
 
  Funding: Supported by NSF award DMR-0807731
Cornell University is planning to build an Energy Recovery Linac (ERL) hard x-ray lightsource operating at 5 GeV. Simulations of its approximately 3 km of electron beamline that incorporate a host of reasonable alignment and field errors, and their compensation by an orbit correction scheme, are presented. These simulations start with realistic particle distributions just after injection and track them through acceleration, the production of undulator radiation, deceleration (energy recovery), and finally transport to the beam stop. To this realistic model, single error sources are further added with increasing magnitudes in order to establish alignment and field tolerance estimates.
 
 
WEP070 Ring for Test of Nonlinear Integrable Optics betatron, lattice, optics, multipole 1606
 
  • A. Valishev, V.S. Kashikhin, S. Nagaitsev
    Fermilab, Batavia, USA
  • V.V. Danilov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: Work supported by UT-Battelle, LLC and by FRA, LLC for the U. S. DOE under contracts No. DE-AC05-00OR22725 and DE-AC02-07CH11359 respectively.
Nonlinear optics is a promising idea potentially opening the path towards achieving super high beam intensities in circular accelerators. Creation of a tune spread reaching 50% of the betatron tune would provide strong Landau damping and make the beam immune to instabilities. Recent theoretical work* have identified a possible way to implement stable nonlinear optics by incorporating nonlinear focusing elements into a specially designed machine lattice. In this report we propose the design of a test accelerator for a proof-of-principle experiment. We discuss possible studies at the machine, requirements on the optics stability and sensitivity to imperfections.
* V. Danilov and S. Nagaitsev, Phys. Rev. ST Accel. Beams 13, 084002 (2010)
 
 
WEP072 Control of Chaotic Particle Motion Using Adiabatic Thermal Beams focusing, resonance, plasma, emittance 1609
 
  • H. Wei, C. Chen
    MIT, Cambridge, Massachusetts, USA
 
  Funding: This work was supported by US Department of Energy, Grant No. DE-FG02-95ER40919 and Grant No. DE-FG02-05ER54835.
Charged-particle motion is studied in the self-electric and self-magnetic fields of a well-matched, intense charged-particle beam and an applied periodic solenoidal magnetic focusing field. The beam is assumed to be in a state of adiabatic thermal equilibrium. The phase space is analyzed and compared with that of the well-known Kapchinskij-Vladimirskij (KV)-type beam equilibrium. It is found that the widths of nonlinear resonances in the adiabatic thermal beam equilibrium are narrower than those in the KV-type beam equilibrium. Numerical evidence is presented, indicating almost complete elimination of chaotic particle motion in the adiabatic thermal beam equilibrium.
 
 
WEP073 Adiabatic Thermal Beam Equilibrium in Periodic Focusing Fields focusing, emittance, lattice, plasma 1612
 
  • C. Chen
    MIT, Cambridge, Massachusetts, USA
 
  Funding: This work was supported by US Department of Energy, Grant No. DE-FG02-95ER40919 and Grant No. DE-FG02-05ER54835.
Adiabatic thermal equilibrium is an important state of a charged-particle beam. The rigid-rotor thermal beam equilibrium in a uniform magnetic focusing field is established. The equivalent kinetic and warm-fluid theories of adiabatic thermal beam equilibrium in a periodic solenoidal magnetic focusing field are discussed. Good agreement between theories and experiment is found. The warm-fluid theory of adiabatic thermal beam equilibrium in an alternating-gradient quadrupole magnetic focusing field is discussed. For the periodic solenoidal magnetic focusing field, charged-particle dynamics in the adiabatic thermal beam equilibrium are studied numerically and compared with those in the Kapchinskij-Vladimirskij (KV) type beam equilibrium. Numerical evidence is presented, indicating almost complete elimination of chaotic particle motion in the adiabatic thermal beam equilibrium.
 
 
WEP074 Correcting Aberrations in Complex Magnet Systems for Muon Cooling Channels simulation, collider, dipole, resonance 1615
 
  • J.A. Maloney, B. Erdelyi
    Northern Illinois University, DeKalb, Illinois, USA
  • A. Afanasev, R.P. Johnson
    Muons, Inc, Batavia, USA
  • Y.S. Derbenev
    JLAB, Newport News, Virginia, USA
  • V.S. Morozov
    ODU, Norfolk, Virginia, USA
 
  Funding: Supported in part by DOE SBIR grant DE-SC0005589
Designing and simulating complex magnet systems needed for cooling channels in both neutrino factories and muon colliders requires innovative techniques to correct for both chromatic and spherical aberrations. Optimizing complex systems, such as helical magnets for example, is also difficult but essential. By using COSY INFINITY, a differential algebra based code, the transfer and aberration maps can be examined to discover what critical terms have the greatest influence on these aberrations.
 
 
WEP080 Spin Tracking with GPUs to 250 GeV in RHIC Lattice resonance, acceleration, lattice, longitudinal-dynamics 1624
 
  • V.H. Ranjbar
    Tech-X, Boulder, Colorado, USA
  • M. Bai, F. Méot
    BNL, Upton, Long Island, New York, USA
 
  Funding: Supported by DOE NP grant DE-SC0004432
We have benchmarked UAL-SPINK against Zgoubi and a list of well understood spin physics results. Along the way we addressed issues relating to longitudinal dynamics and orbit bump and distortion handling as well as appropriate slicing necessary for the TEAPOT-SPINK spin orbit integrator. We have also ported this TEAPOT-SPINK algorithm to the GPU’s. We present the challenges associated with this work.
 
 
WEP095 Analysis of the Beam Loss Mechanism in the Project-X Linac linac, solenoid, beam-losses, simulation 1651
 
  • N. Solyak, J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy
    Fermilab, Batavia, USA
 
  Minimization of the beam losses in a multi-MW H-minus linac of the Project X to the level below 1W/m is a challenging task. Analysis of different mechanisms of beam stripping, including stripping in electric and magnetic fields, residual gas, black-body radiation and intra-beam stripping, is analyzed. Other sources of beam losses are misalignment of beamline elements and errors in RF fields and phase. We presented the requirements for dynamics errors and correction schemes to keep beam losses under control  
 
WEP112 Accurate Simulation of the Electron Cloud in the Fermilab Main Injector with VORPAL electron, simulation, dipole, proton 1692
 
  • P. Lebrun, P. Spentzouris
    Fermilab, Batavia, USA
  • J.R. Cary, P. Stolz, S.A. Veitzer
    Tech-X, Boulder, Colorado, USA
 
  Precision simulations of the electron cloud at the Fermilab Main Injector (MI) have been studied using the plasma simulation code VORPAL. Fully 3D and self consistent solutions that includes Yee-type E.M. field maps, electron spatial distributions and the time evolution of the cloud with respect to the bunch structure in the MI. The microwave absorption experiment has been simulated in detail and the response of the antennas has been derived from the VORPAL's pseudo-potential data. Based on the results of these simulations and the ongoing experimental program, two distinct new experimental techniques are proposed. The first one is based on the use BPM plates placed in dipole fields and that are made of material(s) for which the secondary emission is well characterized. The second technique would be based on the optical, or ultra-violet, detection of the radiation emitted (inverse photo-electric effect) when the cloud interacts with the inner surface of the beam pipe. As the microwave absorption experiment, this techique is non-invasise and has the advantage of providing spatial images of the cloud as well as accurate timing (ns) information.  
 
WEP115 The FNAL Injector Upgrade rfq, extraction, linac, DTL 1701
 
  • C.-Y. Tan, D.S. Bollinger, K.L. Duel, J.R. Lackey, W. Pellico
    Fermilab, Batavia, USA
 
  The present FNAL linac H injector has been operational since the 1970s and consists of two magnetron H sources and a 750keV Cockcroft-Walton Accelerator. In the upgrade, both slit-type magnetron sources will be replaced with circular aperture sources, and the Cockcroft-Walton with a 200MHz RFQ. Operational experience at BNL (Brookhaven National Laboratory) has shown that the upgraded source and RFQ will be more reliable and require less manpower than the present system.  
 
WEP136 Modelling of the EMMA ns-FFAG Ring Using GPT space-charge, injection, emittance, electron 1734
 
  • R.T.P. D'Arcy
    UCL, London, United Kingdom
  • J.K. Jones, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in Aug 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10-20 MeV. The injection line consists of a dogleg to extract the beam from ALICE, a matching section, and tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. The ring is composed of forty two cells, each containing one focusing and one defocusing quadrupole. Commissioning of the EMMA ring started in late 2010. A number of different injection energy and bunch charge regimes are planned; for some of the regimes the effects of space charge may be significant. It is therefore necessary to model the electron beam transport in the injection line and the ring using a code capable of both calculating the effect of and compensating for space charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modelled for comparison with experimental results.  
 
WEP141 Development of a Stepwise Ray-Tracing Based on-Line Model at AGS dipole, lattice, multipole, closed-orbit 1749
 
  • F. Méot, L. A. Ahrens, K.A. Brown, J.W. Glenn, H. Huang, T. Roser, V. Schoefer, N. Tsoupas
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A model of the Alternating Gradient Synchrotron is being developed based on stepwise ray-tracing numerical tools. It provides a realistic representation of the lattice, and accounts for the two helical partial Siberian snake insertions. The aim is to make this stepwise ray-tracing based model an aid for the understanding of the AGS, in matter of both beam dynamics and polarization transmission.
 
 
WEP151 HPC Cloud Applied to Lattice Optimization lattice, storage-ring, synchrotron, synchrotron-radiation 1767
 
  • C. Sun, S. James, K. Muriki, H. Nishimura, Y. Qin, K. Song
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
As Cloud services gain in popularity for enterprise use, vendors are now turning their focus towards providing cloud services suitable for scientific computing. Recently, Amazon Elastic Compute Cloud (EC2) introduced the new Cluster Compute Instances (CCI), a new instance type specifically designed for High Performance Computing (HPC) applications. At Berkeley Lab, the physicists at the Advanced Light Source (ALS) have been running Lattice Optimization on a local cluster, but the queue wait time and the flexibility to request compute resources when needed are not ideal for rapid development work. To explore alternatives, for the first time we investigate running the Lattice Optimization application on Amazon’s new CCI to demonstrate the feasibility and trade-offs of using public cloud services for science.

 
 
WEP164 Accelerating Beam Dynamics Simulations with GPUs simulation, collective-effects, acceleration, space-charge 1800
 
  • I.V. Pogorelov, K. Amyx, P. Messmer
    Tech-X, Boulder, Colorado, USA
 
  Funding: This work is funded by the DOE/BES Grant No. DE-SC0004585, and by Tech-X Corp.
We present recent results of prototyping general-purpose particle tracking on GPUs, discussing our CUDA implementation of transfer maps for single-particle dynamics and collective effects. Our goal being incorporation of the GPU-accelerated tracking into ANL's accelerator code ELEGANT, we used the code's quadrupole and drift-with-LSC elements as test cases. We discuss the use of data-parallel and hardware-assisted approaches (segmented scan and atomic updates) for resolving memory contention issues at the charge deposition stage of algorithms for modeling collective effects.
 
 
WEP196 Single-Shot Longitudinal Phase Space Measurement Diagnostics Beamline Status at the Argonne Wakefield Accelerator diagnostics, cavity, simulation, dipole 1858
 
  • M.M. Rihaoui, D. Mihalcea, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • W. Gai, J.G. Power
    ANL, Argonne, USA
 
  A single-shot longitudinal phase space diagnostics experiment is currently being commissioned at Argonne Wakefield Accelerator. The diagnostic beamline consists of two magnetic dipoles that bend the beam horizontally followed by an rf deflecting cavity that streaks the beam vertically. Using this configuration, the incoming longitudinal phase space can be mapped to a final (x,y) plane which can be directly measured, e.g., using a YAG screen. In this paper we discuss the limitations of such longitudinal phase space diagnostics and present some preliminary measurements.  
 
WEP208 Design of an Antiproton Recycler Ring antiproton, target, ion, acceleration 1879
 
  • A.I. Papash, G.A. Karamysheva, A.V. Smirnov
    MPI-K, Heidelberg, Germany
  • O. Karamyshev
    JINR/DLNP, Dubna, Moscow region, Russia
  • H. Knudsen
    Aarhus University, Aarhus, Denmark
  • A.I. Papash
    JINR, Dubna, Moscow Region, Russia
  • M.R.F. Siggel-King
    The University of Liverpool, Liverpool, United Kingdom
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: Work supported by the EU under contract PITN-GA-2008-215080, the Helmholtz Association of National Research Centers (HGF) under contract VH-NG-328, and the GSI Helmholtz Centre for Heavy Ion Research.
At present, the only place in the world where experiments utilising low-energy antiprotons can be performed is the AD at CERN. The MUSASHI trap, as part of the ASACUSA collaboration, enables access to antiproton energies in the order of a few hundreds of eV. Whilst MUSASHI produces cutting-edge research, the available beam quality and luminosity is not sufficient for collision experiments on the level of differential cross sections. A small electrostatic ring, and associated electrostatic acceleration section, is being designed and developed by the QUASAR Group. It will serve as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR). This small AD recycler ring will be unique due to its combination of size, electrostatic nature and energy of the circulating particles. In this contribution, the design of the ring is described and details about the injection section are given.
 
 
WEP214 Tuning Studies on 4-Rod RFQs rfq, simulation, linac, resonance 1894
 
  • J.S. Schmidt, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  For the optimization of Radio Frequency Quadrupole (RFQ) design parameters, a certain voltage distribution along the electrodes of an RFQ is assumed. Therefore an accurate tuning of the voltage distribution is very important for the beam dynamic properties of an RFQ. A variation can lead to particle losses and reduced beam quality. Our electrode design usually implies a constant longitudinal voltage distribution. For its adjustment tuning plates are used between the stems of the 4-Rod RFQ. Their optimal positions can be found by an iterative process. To structure this tuning process simulations with a NI LabVIEW based Tuning Software and CST Microwave ® are performed and compared to measurements of the ReA3-RFQ of the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The results of this studies are presented in this paper.  
 
WEP225 H-Mode Accelerating Structures with PMQ Focusing for Low-Beta Beams focusing, simulation, ion, linac 1909
 
  • S.S. Kurennoy, J.F. O'Hara, E.R. Olivas, L. Rybarcyk
    LANL, Los Alamos, New Mexico, USA
 
  We report results of the project developing high-efficiency normal-conducting RF accelerating structures based on inter-digital H-mode (IH) cavities and the transverse beam focusing with permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of IH-PMQ structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. The H-PMQ accelerating structures following a short RFQ can be used both in the front end of ion linacs or in stand-alone applications. Results of the combined 3-D modeling – electromagnetic computations, beam-dynamics simulations with high currents, and thermal-stress analysis – for a full IH-PMQ accelerator tank are presented. The accelerating field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Multi-particle simulations with Parmela and CST Particle Studio have been used to confirm the design. Measurement results of a cold model of the IH-PMQ tank are in a good agreement with the calculations and will also be presented.  
 
WEP241 Beam Dynamics Simulations and Measurements at the Project X Test Facility rfq, dipole, simulation, focusing 1933
 
  • E. Gianfelice-Wendt, V.E. Scarpine, R.C. Webber
    Fermilab, Batavia, USA
 
  Funding: Work supported by Fermi Research Alliance, LLC under DE-AC02-07CH11359 with the U.S. DOE
Project X, under study at Fermilab, is a multi task SRF beam facility, aiming to provide high intensity protons for rare processes experiments and nuclear physics at low energy, and simultaneously for the production of neutrinos, as well as muon beams in the long term. A beam test facility - former known as High Intensity Neutrino Source (HINS) - is under commissioning for testing critical components of the project, e.g. a beam chopper. In this paper we describe the layout of the test facility and present beam dynamics simulations and measurements.
 
 
WEP277 Operational Findings and Upgrade Plans on the Superconducting Electron Accelerator S-DALINAC recirculation, electron, controls, linac 1999
 
  • F. Hug, C. Burandt, J. Conrad, R. Eichhorn, M. Kleinmann, M. Konrad, T. Kürzeder, P.N. Nonn, N. Pietralla, S.T. Sievers
    TU Darmstadt, Darmstadt, Germany
 
  Funding: DFG through SFB 634.
The S-DALINAC is a superconducting recirculating electron accelerator with a final energy of 130 MeV. It operates in cw at 3 GHz. It accelerates beams of either unpolarized or polarized electrons and is used as a source for nuclear- and astrophysical experiments at the university of Darmstadt since 1987. We will report on the operational findings, recent modifications and on the future upgrade plans: First results from the new digital rf control system, the injector current upgrade and the improved longitudinal working point will be presented. In addition, an overview of the future plans, namely installing an additional recirculation path and two scraper systems will be given.
 
 
WEP295 Status of Laser Stripping at the SNS laser, optics, linac, injection 2035
 
  • T.V. Gorlov, A.V. Aleksandrov, V.V. Danilov
    ORNL, Oak Ridge, Tennessee, USA
  • Y. Liu
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  Funding: This work was supported by SNS through UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy.
This paper presents an overview of experimental and theoretical studies on laser stripping that have been conducted up to the present time in the SNS project. The goal of this work is to develop techniques to achieve the experimental preconditions necessary for the successful realization of a future intermediate experiment on laser stripping. The experimental work consists of the tuning and measurement of H־ beam parameters in readiness for the intermediate experiment, and also takes into account the features and possibilities of the SNS accelerator.
 
 
THOAS1 On the Importance of Symmetrizing RF Coupler Fields for Low Emittance Beams emittance, gun, dipole, coupling 2044
 
  • Z. Li, C. Adolphsen, A.E. Vlieks, F. Zhou
    SLAC, Menlo Park, California, USA
 
  Funding: Work was supported by DOE Contract No. DE-AC02-76SF00515 and used computing resources at NERSC supported by DOE Contract No. DE-AC02- 05CH11231.
The input power of accelerator structure is normally fed through a coupling slot(s) on the outer wall of the accelerator structure via magnetic coupling. While providing perfect matching, the coupling slots may produce non-axial-symmetric fields in the coupler cell that can induce emittance growth as the beam is accelerated in such a field. This effect is especially important for low emittance beams at low energies such as in the injector accelerators for light sources. In this paper, we present studies of multipole fields of different rf coupler designs and their effect on beam emittance for an X-band photocathode gun, being jointly designed with LLNL, and the X-band accelerator structures. We will present symmetrized rf coupler designs for these components to preserve the beam emittance.
 
slides icon Slides THOAS1 [1.512 MB]  
 
THP016 Design of an Achromatic and Uncoupled Medical Gantry for Radiation Therapy optics, dipole, radiation, controls 2163
 
  • N. Tsoupas, D. Kayran, V. Litvinenko, W.W. MacKay
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We are presenting the layout and the optics of a beam line to be used as a medical gantry in radiation therapy. The optical properties of the gantry’s beam line are such as to make the beam line achromatic and uncoupled. These two properties make the beam spot size, which is delivered and focused by the gantry, on the tumor of the patient, independent of the angular orientation of the gantry. In this paper we present the layout of the magnetic elements of the gantry, and also present the theoretical basis for the optics design of such a gantry.
* N. Tsoupas et. al. “Uncoupled achromatic tilted S-bend” Presented at the 11th Biennial European Particle Accelerator Conference, Genoa, Italy, June 23-27,2008
 
 
THP059 Chromatic Analysis and Possible Local Chromatic Correction in RHIC lattice, sextupole, resonance, betatron 2235
 
  • Y. Luo, W. Fischer, X. Gu, D. Trbojevic
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In this article we will answer the following questions: 1) what is the source of second order chromaticities in RHIC? 2) what is the dependence of second order chromaticity on the on-momentum β-beat? 3) what is the dependence of second order chromaticity on β* at IP6 and IP8? To answer these questions, we use the perturbation theory to numerically calculate the contributions of each quadrupole and sextupole to the first, second, and third order chromaticities. Possible methods to locally reduce chromatic effects in RHIC rings are shortly discussed.
 
 
THP063 Lattice Design for Head-on Beam-Beam Compensation at RHIC lattice, proton, power-supply, betatron 2246
 
  • C. Montag
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Electron lenses for head-on beam-beam compensation will be installed in IP 10 at RHIC. Compensation of the beam-beam effect experienced at IP 8 requires betatron phase advances of ∆ψ=k·π between the proton-proton interaction point at the IP 8, and the electron lens at IP 10. This paper describes the lattice solutions for both the BLUE and the YELLOW ring to achieve this goal.
 
 
THP064 The Dipole Corrector Magnets for the RHIC Fast Global Orbit Feedback System dipole, feedback, vacuum, interaction-region 2249
 
  • P. Thieberger, L. Arnold, C. Folz, R.L. Hulsart, A.K. Jain, R. Karl, G.J. Mahler, W. Meng, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, V. Ptitsyn, J. Ritter, L. Smart, J.E. Tuozzolo, J. White
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The recently completed RHIC fast global orbit feedback system uses 24 small “window-frame” horizontal dipole correctors. Space limitations dictated a very compact design. The magnetic design and modelling of these laminated yoke magnets is described as well as the mechanical implementation, coil winding, vacuum impregnation, etc. Test procedures to determine the field quality and frequency response are described. The results of these measurements are presented and discussed. A small fringe field from each magnet, overlapping the opposite RHIC ring, is compensated by a correction winding placed on the opposite ring’s magnet and connected in series with the main winding of the first one. Results from measurements of this compensation scheme are shown and discussed.
 
 
THP067 Ambient Beam Motion and its Excitation by "Ghost Lines" in the Tevatron betatron, proton, emittance, focusing 2255
 
  • V.D. Shiltsev
    Fermilab, Batavia, USA
 
  Transverse betatron motion of the Tevatron proton beam is measured and analyzed. It is shown that the motion is coherent and excited by external sources of unknown origins. Observations of the time-varying "ghost lines" in the betatron spectrum are reported.  
 
THP069 Vibration Budget for SuperB feedback, ground-motion, luminosity, resonance 2261
 
  • K.J. Bertsche, W. Wittmer
    SLAC, Menlo Park, California, USA
  • B. Bolzon, L. Brunetti, A. Jeremie
    IN2P3-LAPP, Annecy-le-Vieux, France
  • S. Tomassini
    INFN/LNF, Frascati (Roma), Italy
 
  Funding: Work supported by the Department of Energy under contract number DE-AC03-76SF00515.
We present a vibration budget for the SuperB accelerator. This includes ground motion data, motion sensitivity of machine components, and beam feedback system requirements.
 
 
THP071 Interaction Region Design of Super-CT-Factory in Novosibirsk sextupole, interaction-region, factory, solenoid 2264
 
  • A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov
    BINP SB RAS, Novosibirsk, Russia
 
  The interaction region of the Super-CT-factory is designed to bring stored electron-positron beams into collision with luminosity of 1035 cm-2sec-1. To achieve this a waist collision scheme is implemented, which requires cross-angle collision with high Piwinski angle. The small values of the beta functions at the interaction point and distant final focus lenses are the reasons for high nonlinear chromaticity limiting energy acceptance of the whole ring. The present design allows correction of linear and nonlinear chromaticity of beta functions and of betatron tune advances, correction of second and third order geometrical aberrations from the strong sextupoles pairs, satisfies geometrical constraints, embraces realistic design of final focus quadrupoles and as close as possible positioning of crab sextupole to interaction point.  
 
THP072 Compensation of Detector Solenoid in SUPER-B solenoid, coupling, dipole, betatron 2267
 
  • Y. Nosochkov, K.J. Bertsche, M.K. Sullivan
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515.
The SUPER-B detector solenoid has a strong 1.5 T field in the Interaction Region (IR) area, and its tails extend over the range of several meters. The main effect of the solenoid field is the coupling of the horizontal and vertical betatron motion which needs to be corrected in order to preserve the small design beam size at the Interaction Point. The additional complications are that: a) due to the crossing angle the solenoid is not parallel to either of the two beams, thus leading to orbit and dispersion perturbations; b) the solenoid overlaps the innermost IR permanent quadrupoles, which will cause additional coupling effects. The proposed correction system provides local compensation of the solenoid effects independently for each side of the IR. It includes “bucking” solenoids to remove the unwanted long solenoid field tails and a set of skew quadrupoles, dipole correctors and anti-solenoids to cancel all linear perturbations to the optics. The details of the correction system design are presented.
 
 
THP073 Simulations of Emittance Measurement at CLIC emittance, collider, laser, simulation 2270
 
  • Yu.A. Kubyshin, H. Garcia
    UPC, Barcelona, Spain
  • E. Marin, D. Schulte, F. Stulle
    CERN, Geneva, Switzerland
 
  A proposal for a CLIC emittance measurement line using laser-wire beam profile monitors is presented. Results of simulations and optimizations are given. Estimates of the impact of beam size as well as statistical and machine-related errors on the measurement accuracy are discussed.  
 
THP077 SC Quadrupole for Cryomodule for ERL/ILC dipole, cryomodule, focusing, linac 2276
 
  • A.A. Mikhailichenko
    CLASSE, Ithaca, New York, USA
 
  Funding: NSF
We are considering the SC quadrupole where the field formed not only by the current distributions, but with the poles also. This delivers a good quality field in all aperture allowing compact and inexpensive design. This type of quadrupole designed for Cornell ERL could be recommended for ILC also.
 
 
THP079 Recent RHIC-motivated Polarized Proton Developments in the Brookhaven AGS resonance, polarization, emittance, proton 2282
 
  • V. Schoefer, L. A. Ahrens, M. Bai, S. Binello, M. Blaskiewicz, K.A. Brown, C.J. Gardner, J.W. Glenn, H. Huang, F. Lin, W.W. MacKay, J. Morris, S. Nemesure, T. Roser, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The RHIC polarized proton physics program requires high luminosity and high polarization which depends directly on the intensity, emittances and polarization delivered to RHIC by the injector chain. In the AGS, two partial snakes create gaps in the realized spin-tune around the integers which allows an accelerating beam with sufficiently small vertical emittance and near-integer vertical tune to avoid the imperfection and vertical intrinsic resonances. The same strategy strengthens the many (82) weak horizontal intrinsic resonances crossed during AGS acceleration. A system speeding up these resonance crossings – the AGS JumpQuad system: 82 tiny (0.04) fast (100usec) betatron tune shifts – has been commissioned and evolved during RHIC Runs 09, 10, and 11. Subtle properties of the AGS geometry and lattice, magnified into relevance by the high vertical tune can result in polarization-damaging emittance growth when combined with the Jump Quad gymnastics. Orbit stability is critical. Some aspects of the JumpQuad system, of this commissioning effort and related developments will be described.
 
 
THP085 Radiation Effects in a Muon Collider Ring and Dipole Magnet Protection dipole, collider, radiation, lattice 2294
 
  • N.V. Mokhov, V. Kashikhin, I. Novitski, A.V. Zlobin
    Fermilab, Batavia, USA
 
  Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Requirements and operating conditions for a Muon Collider Ring (MCR) pose significant challenges to superconducting magnets. The dipole magnets should provide a high magnetic field to reduce the ring circumference and thus maximize the number of muon collisions during their lifetime. One third of the beam energy is continuously deposited along the lattice by the decay electrons at the rate of 0.5 kW/m for a 1.5-TeV c.o.m. MCR. Unlike dipoles in proton machines, the MCR dipoles should allow this dynamic heat load to escape the magnet helium volume in horizontal plane predominantly towards the ring center. Two alternative designs, one based on the open mid-plane approach with block type coils and absorber outside the coils, and another based on the traditional large-aperture cos-theta approach with a shifted beam pipe and absorber inside the coil aperture were developed for the MCR designed for a luminosity of 1034 cm-2s−1. This paper presents the analysis and comparison of radiation effects in MCR based on the two dipole magnets. Tungsten masks in the interconnect regions are used in both cases to mitigate the unprecedented dynamic heat deposition and radiation in the magnet coils.
 
 
THP119 Potential Two-fold Reduction of Advanced Photon Source Emittance using Orbit Displacement lattice, emittance, sextupole, damping 2339
 
  • M. Borland
    ANL, Argonne, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is a 7-GeV electron storage ring light source that operates with an effective emittance of 3.1 nm using optics with distributed dispersion. Lower emittance is desirable for some x-ray experiments, but is difficult using conventional optics adjustments because of the required strength of quadrupoles and sextupoles. Changing the damping partition number by changing the rf frequency is another approach, but is incompatible with distributed dispersion because it would require simultaneous realignment of all APS beamlines. In this paper, we evaluate a new approach to changing the damping partition number using a systematic orbit bump in all sectors.
 
 
THP125 Multi-objective Optimization of a Lattice for Potential Upgrade of the Advanced Photon Source* lattice, sextupole, optics, dynamic-aperture 2354
 
  • V. Sajaev, M. Borland, L. Emery, A. Xiao
    ANL, Argonne, USA
 
  Funding: *Work supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is a 7-GeV storage ring light source that has been in operation for over a decade. In the near future, the ring may be upgraded, including changes to the lattice such as provision of several long straight sections (LSSs). Use of deflecting cavities for generation of short x-ray pulses is also considered. Because APS beamlines are nearly fully built out, we have limited freedom to place LSSs in a symmetric fashion. Arbitrarily placed LSSs will drastically reduce the symmetry of the optics and would typically be considered unworkable. We apply a recently developed multi-objective direct optimization technique that relies on particle tracking to compute the dynamic aperture and Touschek lifetime. We show that this technique is able to tune sextupole strengths and select the working point in such a way as to recover the dynamic and momentum acceptances. We also show the results of experimental tests of lattices developed using these techniques.
 
 
THP173 Design of the SRF Driver ERL for the Jefferson Lab UV FEL FEL, wiggler, linac, controls 2435
 
  • C. Tennant, S.V. Benson, G.H. Biallas, K. Blackburn, J.R. Boyce, D.B. Bullard, J.L. Coleman, C. Dickover, D. Douglas, F.K. Ellingsworth, P. Evtushenko, C.W. Gould, J.G. Gubeli, F.E. Hannon, D. Hardy, C. Hernandez-Garcia, K. Jordan, J.M. Klopf, J. Kortze, M. Marchlik, S.W. Moore, G. Neil, T. Powers, D.W. Sexton, M.D. Shinn, R.L. Walker, F.G. Wilson, S. Zhang
    JLAB, Newport News, Virginia, USA
 
  Funding: Support by DoE Contract DE-AC05-060R23177.
We describe the design of the SRF ERL providing the CW electron drive beam at the Jefferson Lab UV FEL. Based on the same 135 MeV linear accelerator as – and sharing portions of the recirculator with – the Jefferson Lab 10 kW IR Upgrade FEL, the UV driver ERL uses a novel bypass geometry to provide transverse phase space control, bunch length compression, and nonlinear aberration compensation (including correction of RF curvature effects) without the use of magnetic chicanes or harmonic RF. Stringent phase space requirements at the wiggler, low beam energy, high beam current, and use of a pre-existing facility and legacy hardware subject the design to numerous constraints. These are imposed not only by the need for both transverse and longitudinal phase space management, but also by the potential impact of collective phenomena (space charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation (CSR)), and by interactions between the FEL and the accelerator RF system. This report addresses these issues and presents the accelerator design solution that now successfully supports FEL lasing.
 
 
THP187 Design Concept for a Compact ERL to Drive a VUV/Soft X-Ray FEL FEL, linac, emittance, wiggler 2468
 
  • C. Tennant, D. Douglas
    JLAB, Newport News, Virginia, USA
 
  Funding: Support by US DOE contract #DE-AC05-060R23177
We explore possible upgrades of the existing Jefferson Laboratory IR/UV FEL driver to higher electron beam energy and shorter wavelength through use of multipass recirculation to drive an amplifier FEL. The system would require beam energy at the wiggler of 600 MeV with 1 mA of average current. The system must generate a high brightness beam, configure it appropriately, and preserve beam quality through the acceleration cycle - including multiple recirculations - and appropriately manage the phase space during energy recovery. The paper will discuss preliminary design analysis of the longitudinal match, space charge effects in the linac, and recirculator design issues, including the potential for the microbunching instability. A design concept for the recirculator and a lattice solution will be presented.
 
 
THP190 Additional Quadrupoles at Center of Long Straights in the NSLS-II Lattice lattice, insertion, insertion-device, injection 2474
 
  • F. Lin, J. Bengtsson, W. Guo, S. Krinsky, Y. Li, L. Yang
    BNL, Upton, New York, USA
 
  Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this note, we explore the possibility of installing additional quadrupoles at the center of selected long straight sections in order to provide two low-beta source locations for undulators. The required modification to the linear lattice is discussed as well as the preservation of adequate dynamic aperture required for good injection efficiency and adequate Touschek lifetime.
 
 
THP191 Recent Progress in Injector Improvement of SPEAR 3 booster, injection, linac, storage-ring 2477
 
  • K. Tian, W.J. Corbett, D. Dell'Orco, D. Ernst, S.M. Gierman, J.A. Safranek, J.F. Schmerge, B. Scott
    SLAC, Menlo Park, California, USA
 
  The frequent injection and high current operation of SPEAR 3 storage ring requires high stability of the injector system at the Stanford Synchrotron Radiation Laboratory (SSRL). The lattice of linac-to-booster (LTB) transport line was not well understood and controlled prior to this work. In this paper, we discuss the significant efforts that have been made to improve the performance of the LTB. A method to correct the distortion of the closed orbit in the booster by moving 2 quadrupoles is also presented.