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Paper Title Other Keywords Page
MOXKI01 LHC: Construction and Commissioning Status dipole, cryogenics, injection, insertion 1
  • L. R. Evans
    CERN, Geneva
  The LHC is now in its final phase of hardware commissioning. The whole ring is complete apart from a few elements in the matching regions yet to be installed. The first of the eight sectors has been cooled down and power tests to full energy are underway. Beam commissioning will start as soon as the last sector becomes available, hopefully before the end of 2007. The commissioning plan foresees a short "engineering" run with colliding beams at or near the injection energy of 450 GeV. This will be followed by a shutdown to finish installing the detectors and to commission the last sectors to full current. A review of the commissioning status to date will be given.  
slides icon Slides  
MOZBKI02 The BEPC II: Status and Early Commissioning injection, luminosity, linac, electron 53
  • J. Q. Wang, L. Ma, C. Zhang
    IHEP Beijing, Beijing
  BEPCII is the upgrade project of Beijing Electron Positron Collider (BEPC). The installation of its storage ring components except the superconducting (SC) insertion magnets was completed in early November, 2006. While the improvement of the cryogenic system for SC magnets is in progress, the commissioning of the synchrotron radiation (SR) mode for the so called back-up scheme with conventional magnets adopted in the interaction region (IR), started on Nov. 13, 2006. The first electron beam was stored on Nov. 18 and later beam was provided to SR users for about 1 month starting from Dec. 25, 2006. The commissioning of the collision mode including the electron and positrion rings started in Feb. 2007. The first beam collision was realized on Mar. 25. Then optimization of the beam parameters was done. On May 14, a 100mA to 100mA beam collision was achieved with 20 bunches for each beam. The luminosity estimated from the measured beam-beam parameters has reached that of BEPC. From May 25 the machine turns to the second run of the SR mode. This paper provides an overview of the construction and introduce the commissioning results of the backup scheme of BEPCII.  
slides icon Slides  
MOOBAB01 Time-Resolved Phase Space Tomography at Flash Using a Transverse Deflecting RF-Structure emittance, simulation, electron, radiation 104
  • M. Roehrs, C. Gerth, H. Schlarb
    DESY, Hamburg
  To initiate Self-Amplification of Spontaneous Emission (SASE) in single-pass Free Electron Lasers (FEL), electron bunches with high peak current and small slice emittance and energy spread are necessary. At FLASH at DESY, this is accomplished by longitudinal bunch compression in two magnetic chicanes. The compression process may be accompanied by distortions from coherent synchrotron radiation and space charge forces. Their effect on the bunch properties can be studied with a vertically deflecting rf-structure (LOLA), which allows to measure the longitudinal phase space distribution and horizontal slice emittance of single bunches. In combination with tomographic methods the horizontal phase space distribution of time slices can be reconstructed. In this paper measurement results for SASE operation are presented and compared to simulations and bunch properties infered from the radiation signal.  
slides icon Slides  
MOPAN002 Active Shunts for the LNLS Storage Ring Quadrupoles power-supply, storage-ring, controls, electron 143
  • C. Rodrigues, A. R. Silva
    LNLS, Campinas
  The quadrupoles of the LNLS storage ring are divided into families with two or six units, each one being supplied by an only current source. Some experiments performed by the accelerator physics team require different currents for quadrupoles of a same family. Moreover, there is an interest in obtaining lower steps in the control of their currents. These were the main reasons that required the development of an active shunt. A prototype was built with range of -3A to +3A, what is approximately 3% of the maximum quadrupole current (200A). It was tested with a two-quadrupole family power supply. The full bridge topology was chosen, where the pulse width for the positive and negative output voltages are not the same, which gives an average output current different from zero. Some waveforms and results are shown, such as the long-term stability and output current ripple. Some measurements made in the storage ring electron beam using the active shunt are also described.  
MOPAN011 Upgrade Plans of the Vacuum System of the ESRF dipole, vacuum, radiation, storage-ring 164
  • R. Kersevan, L. Goirand
    ESRF, Grenoble
  The ESRF has been delivering beams to users for well over 12 years. The performance of the storage ring has surpassed the original specifications with respect to many accelerator parameters, such as emittance, beam stability, beam availability and so on. Along the years, many of its sub-systems have been improved in order to cope with these more demanding conditions. Now new experimental techniques and arrangements, such as nanofocusing on the samples, call for a radical upgrade of the machine. Another reason to upgrade is the recent coming into operation of new, more modern machines, and the desire for the ESRF to stay at the forefront of synchrotron radiation research. A study group has been set up, with the aim of producing a conceptual design report for what is called a "Long Term Strategy" for the upgrade of the ESRF. This paper will detail the plans for the LTS upgrade of the storage ring vacuum system.  
MOPAN021 Magnetic Field Calculations of the Superconducting Dipole Magnets for the High- Energy Storage Ring at FAIR dipole, superconducting-magnet, storage-ring, heavy-ion 194
  • H. Soltner, M. Pabst, R. Tolle
    FZJ, Julich
  For the High-Energy Storage Ring (HESR) to be established for the FAIR facility, magnetic field calculations have been carried out for the layout of the superconducting dipole magnets. Four configurations have been considered for the 2.72 m long magnets, straight ones and bent ones with a bending radius of 13,889 m, respectively, both for the cos(Θ) layout and for the double helix dipole layout. This contribution will focus particularly on the advantages and disadvantages of the individual configurations in terms of field quality in the diopole regions.  
MOPAN025 The Elettra Booster Magnets dipole, sextupole, booster, multipole 206
  • D. Zangrando, D. Castronovo, M. Svandrlik, R. Visintini
    ELETTRA, Basovizza, Trieste
  The third generation light source ELETTRA has been in operation since 1993. A new 2.5 GeV full energy booster injector, that will replace the existing linear injector limited to a maximum energy of 1.2 GeV is now under construction and the commissioning will start this August. The paper reports on the construction of dipole, quadrupole, sextupole and steerer magnets and on the magnetic measurement results with a comparison with the requested specifications.  
MOPAN038 Electric Power Compensation of the Large Scale Accelerator using SMES power-supply, linac, synchrotron, proton 239
  • H. Sato, t.s. Shintomi, M. J. Shirakata
    KEK, Ibaraki
  • T. Ise, Y. Miura
    Osaka University, Suita
  • S. Nomura
    RLNR, Tokyo
  Power supply for the large scale accelerator magnets draws a large amount of power from the utility network. For example, the peak active power and the dissipation power of J-PARC 50GeV synchrotron magnet power are estimated to be about 135MW and 37MW, respectively. Super Conducting Magnetic Energy Storage (SMES) is one of candidates to compensate these large load and line voltage fluctuation. Study on circuit configuration of the power supply with SMES has been continued. Present status of the R & D for the SMES system and small case experiment result will be discussed.  
MOPAN044 Development of Commissioning Software System for J-PARC LINAC linac, controls, lattice, alignment 257
  • H. Sako, G. B. Shen
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • C. K. Allen
    KEK, Ibaraki
  • H. Ikeda
    Visual Information Center, Inc., Ibaraki-ken
  Beam commissioning of J-PARC LINAC has been performed since November 2006. A commissioning software framework and a database system have been developed for the commissioning. We first discuss the LINAC control system, and then our commissioning software framework. Then, we discuss our strategy of comparing online/offline data and models in our system with monitors, magnets, and the RF system. Commissioning tools developed during the commissioning will be presented in detail.  
MOPAN047 Mechanical Design Considerations for Sesame Main Subsystems dipole, vacuum, sextupole, storage-ring 263
  • M. M. Shehab, G. Vignola
    SESAME, Amman
  Recent advances in the design and analysis of SESAME vacuum system engineering as well as magnets and girder system mechanical designs are described. Multi objective optimization techniques for the storage ring vacuum chambers design from mechanical design point view and the vibration and stability issues for the magnets will be presented.  
MOPAN069 Ultrasound Diagnostics of the Superconducting Cable Connections Between the Main Ring Magnets of LHC diagnostics, controls, superconducting-magnet, scattering 311
  • F. Caspers, T. Kroyer, J.-P. G. Tock, L. R. Williams
    CERN, Geneva
  • J. Kulka
    AGH, Cracow
  As part of the LHC assembly program, the super-conducting magnets are interconnected after installation. Electrical continuity between the magnets is ensured via a specifically designed cable splice box which allows the cables to be electrically joined by an automated low temperature brazing technique. The electrical resistance and mechanical strength of the cable junctions depend on the quality of the brazed joint. An ultrasound diagnostic of the brazed joint has been developed to accompany the visual inspection and reinforce the quality control process. Non-standard ultrasound diagnostic techniques, without using matching liquids or gel in the harsh and congested working environment, applied to the sandwich structure of the cable splice box, which presents high ultra-sonic losses due to multiple scattering, have been developed. The equipment and methods implemented are described in detail, together with results of quality control tests made in the production environment.  
MOPAN073 Parametric Study of Heat Deposition from Collision Debris into the Insertion Superconducting Magnets for the LHC Luminosity Upgrade insertion, luminosity, target, superconducting-magnet 323
  • C. Hoa, F. Cerutti, J.-P. Koutchouk, G. Sterbini, E. Y. Wildner
    CERN, Geneva
  • F. Broggi
    INFN/LASA, Segrate (MI)
  With a new geometry in a higher luminosity environment, the power deposition in the superconducting magnets becomes a critical aspect to analyze and to integrate in the insertion design. In this paper, we quantify the power deposited in magnets insertion at variable positions from the interaction point (IP). A fine characterization of the debris due to the proton-proton collisions at 7 TeV, shows that the energetic particles in the very forward direction give rise to non intuitive dependences of the impacting energy on the magnet front face and inner surface. The power deposition does not vary significantly with the distance to the interaction point, because of counterbalancing effects of different contributions to power deposition. We have found out that peak power density in the magnet insertion does not vary significantly with or without the Target Absorber Secondaries (TAS) protection.  
MOPAN077 Geometry of the LHC Short Straight Sections Before Installation in the Tunnel: Resulting Aperture, Axis and BPM Positioning insertion, laser, alignment, controls 335
  • D. P. Missiaen, P. Bestmann, M. C.L. Buzio, S. D. Fartoukh, M. Giovannozzi, J. B. Jeanneret, A. M. Lombardi, Y. Papaphilippou, S. Pauletta, J. C. Perez, H. Prin, E. Y. Wildner
    CERN, Geneva
  The Large Hadron Collider Short Straight Sections (SSS) are currently being installed in their final position in the accelerator tunnel. For all the SSSs, both those in the regular arcs as well as those in the insertion regions, magnetic and geometric measurements are made at different steps of their assembly. These stages range from production in the industry to the cryostating at CERN, as well as during and after cold tests or during installation of the BPM and the cold warm transition for the stand alone magnets. The results of the geometry at the various production stages by means of different procedures and analysis tools are reported and discussed in details in this paper.  
MOPAN079 Assembly and Quality Control of the LHC Cryostats at CERN. Motivations, Means, Results and Lessons Learned controls, dipole, superconducting-magnet, lattice 338
  • A. Poncet, P. Cruikshank, V. Parma, P. M. Strubin, J.-P. G. Tock, D. Tommasini
    CERN, Geneva
  In 2001 the project management decided to perform at CERN the final assembly of the LHC superconducting magnets,with cryostat parts and cold masses produced by European Industry in large series. This industrial-like production has required a very significant investment in tooling,production facilities,engineering and quality control efforts, in contractual partnership with a consortium of firms. This unusual endeavour of a limited lifetime represented more than 800'000 working hours spanning over four years,the work being done on a result oriented basis by the contractor. This paper presents the reasons for having insourced this project at CERN,describes the work breakdown structure,the production means and methods,the infrastructure specially developed,the tooling,logistics and quality control aspects of the work performed,and the results achieved, in analytical form. Finally the lessons learned are outlined.  
MOPAN083 130 mm Aperture Quadrupoles for the LHC Luminosity Upgrade dipole, optics, luminosity, magnet-design 350
  • E. Todesco, F. Borgnolutti
    CERN, Geneva
  • A. Mailfert
    ENSEM, Vandoeuvre les Nancy
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395)

Studies for the LHC luminosity upgrade showed the need for quadrupoles with apertures much larger than the present baseline (70 mm). In this paper we focus on the design issues of a 130 mm aperture quadrupole. We first consider the Nb-Ti option, presenting the magnetic design with the LHC dipole cable. We study the Lorentz forces and we discuss the field quality constraints. For the Nb3Sn option we sketch two designs, the first based on the LARP 10 mm cable, and the second one on a 15 mm cable. The issue of the stress induced by the Lorentz forces, which is critical for the Nb3Sn, is discussed using both scaling laws and finite element models.

MOPAN084 Estimating Field Quality in Low-beta Superconducting Quadrupoles and its Impact on Beam Stability multipole, luminosity, collider, superconducting-magnet 353
  • E. Todesco, B. Bellesia, J.-P. Koutchouk
    CERN, Geneva
  • C. Santoni
    Universite Blaise Pascal, Clermont-Ferrand
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395)

The aim of this analysis is to study if the field quality in a large aperture low-beta superconducting quadrupole for the LHC upgrade limits the beam performances due to increased geometric aberrations. Random field errors in superconducting quadrupoles are usually estimated by computing the effect of a random positioning of the coil blocks around the nominal position with an r.m.s. of 0.05 mm. Here, we review the experience acquired in the construction of 7 superconducting quadrupoles in the RHIC and in the LHC projects to estimate the precision in the block positioning, showing that there is no visible dependence on the magnet aperture. Different magnet models are then used to estimate the expected field quality in quadrupoles with apertures ranging from 50 to 200 mm. The impact on geometrical aberrations and scaling laws for their dependence on the aperture are finally evaluated.

MOPAN085 Completion of the Series Fabrication of the Main Superconducting Quadrupole Magnets of LHC factory, dipole, cryogenics, insertion 356
  • T. Tortschanoff, M. Modena, Y. Papaphilippou, L. Rossi, K. M. Schirm
    CERN, Geneva
  • R. Burgmer, H.-U. Klein, D. Krischel, B. Schellong, P. Schmidt
    ACCEL, Bergisch Gladbach
  • M. Durante, A. Payn, J.-M. Rifflet, F. Simon
    CEA, Gif-sur-Yvette
  By end of November 2006, the last cold mass of the main superconducting quadrupole cold masses were delivered by ACCEL Instruments to CERN. This comprised 360 cold masses for the arc regions of the machine and 32 special units dedicated to the dispersion suppressor regions. The latter ones contain the same main magnet but different types of correctors and are of increased length with respect to the regular arc ones. The end of the fabrication of these magnets coincided with the end of the main dipole deliveries allowing a parallel assembly into their cryostats and installation into the LHC tunnel. The positioning into the tunnel was optimized using the warm field measurements performed in the factory. On the other hand the correct slotting of the quadrupoles was complicated due to the multitude of variants and by the fact that a number of units needed to be replaced by spares which in some cases required a reshuffling of the positioning. The paper gives some final data about the successful fabrication at ACCEL Instruments and explains the issue of their best positions in the machine.  
MOPAN095 Design of the Precise Unit for the Rotating Coil Measurement System multipole, synchrotron, synchrotron-radiation, coupling 386
  • J. C. Jan, C.-H. Chang, J. W. Chen, T.-C. Fan, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  A precise rotating coil measurement system (RCS) is developed to characterize the magnetic field quality of the quadrupole (QM) and sextupole (SM) magnets in the Taiwan Photon Source (TPS). A measurement bench is designed to install the magnets easily and mount the rotating coil unit with high reproducibility. The Fiberglass Reinforced Epoxy (FRP) measurement unit (F-unit) exhibits a large sag and mechanical error while it is 880mm long. Therefore, a new graphite measurement unit (G-unit) with a printed circuit coil is adopted to reduce these errors. The rotating coil design and testing using a QM are also described.  
MOPAN100 Multiple Quadrupole Magnetic Center Alignment on the Girder alignment, sextupole, laser, storage-ring 395
  • L. Tsai, T.-C. Fan, C.-S. Hwang, C. J. Lin, S. Y. Perng, D.-J. Wang
    NSRRC, Hsinchu
  Conventional alignments of quadrupole magnets on the girder based on the theodolite and fiducial was limited by human-eye resolution and fiducial precision. The accumulative error of group of magnetic centers may be more than 100 μm. In this paper, an automatic quadrupole magnetic center aligning method was proposed using pulsed wire method to align group of quadrupole magnets concentrically on one girder to higher precision. In order to increase the alignment precision, a short wire reduced sag problem in long wire, laser and position sensitive detector (PSD) system was to trace the wire position to level of micron. The precision of the alignment of quadrupole magnetic centers could be within 30μm. Descriptions of the setup and test results are presented.  
MOPAN107 Quadrupole Magnets for the 20 MeV FFAG, 'EMMA' vacuum, injection, lattice, extraction 413
  • N. Marks, B. J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  EMMA is a 20 MeV non-scaling Fixed Field Alternating Gradient accelerator (nsFFAG) proof-of-principle prototype, to be built at the Daresbury Laboratory as an accelerator physics experiment to explore the behaviour of such machines. Non-scaling FFAGs have potential applications in charged particle cancer therapy and also for particle physics; however, to date, no such accelerator has been constructed. The magnet designs present major challenges - the lattice is made up of 84 quadrupoles, with different horizontal offsets from the magnet centres in the focusing and defocusing quads. These offsets alone provide the necessary bending fields in the ring. The magnets are also very thin (55mm and 65mm yoke lengths) and end field effects therefore dominate. Careful design, followed by prototype construction and measurement, is essential. The magnets have been designed in 3D from the outset, using the CST EM Studio software. The paper will present the results of the design, showing how the magnets have been optimised to improve the integrated good gradient region, and will report on the progress of the prototyping work.  
MOPAN110 A Technique for High-frequency Scanning of High Power Laser Light for Laser-wire Scanners at Electrons Accelerators laser, electron, controls, multipole 422
  • A. Bosco, G. A. Blair, S. T. Boogert, G. E. Boorman
    Royal Holloway, University of London, Surrey
  Funding: Work supported in part by PPARC LC-ABD Collaboration and the Commission of European Communities under the 6th Framework Programme Structuring the European Research Area, contract number RIDS-011899.

Electro-optic techniques might allow implementing a laserwire scanner for intra-train scanning at the ILC with scanning speed in excess of 100 kHz. A scanner capable of running at such a rate would in fact provide information about the particle beam size in about one hundred different positions along the bunch train (approximately 1ms long for the ILC*). The design of an electro-optic deflector capable to scan within 10-100 microsecond is presented, discussed and analytically treated.

* ILC Baseline Conceptual Design (2006).: http://www.linearcollider.org/.

MOPAN117 Magnet System for Helical Muon Cooling Channels emittance, dipole, simulation, lattice 443
  • S. A. Kahn, M. Alsharo'a, R. P. Johnson
    Muons, Inc, Batavia
  • V. Kashikhin, V. S. Kashikhin, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  Funding: Supported in part by STTR Grant DE-FG02-04ER86191.

A helical cooling channel consisting of a pressurized gas absorber imbedded in a magnetic channel that provides superimposed solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling of muon beams. The analysis of this muon cooling technique with both analytic and simulation studies has shown significant reduction of muon phase space. A particular channel that has been simulated is divided into four segments each with progressively stronger fields and smaller apertures to reduce the equilibrium emittance so that more cooling can occur. The fields in the helical channel are sufficiently large that the conductor for segments 1 and 2 can be Nb3Sn and the conductor for segments 3 and 4 may need to be high temperature superconductor. This paper will describe the magnetic specifications for the channel and two conceptual designs on how to implement the magnetic channel.

MOPAS006 Design and Fabrication of a Multi-element Corrector Magnet for the Fermilab Booster Synchrotron sextupole, dipole, booster, synchrotron 452
  • D. J. Harding, J. DiMarco, C. C. Drennan, V. S. Kashikhin, S. Kotelnikov, J. R. Lackey, A. V. Makarov, A. Makulski, R. Nehring, D. F. Orris, E. Prebys, P. Schlabach, G. Velev, D. G.C. Walbridge
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000.

To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and installation at 48 locations is planned. The density of elements and the rapid slew rate have posed special challenges. The magnet construction is presented along with DC measurements of the magnetic field.

MOPAS008 A Wide Aperture Quadrupole for the Fermilab Main Injector Synchrotron extraction, synchrotron, injection, proton 455
  • D. J. Harding, C. L. Bartelson, B. C. Brown, J. A. Carson, W. Chou, J. DiMarco, H. D. Glass, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, M. Tartaglia
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC02-76CH03000.

During the design of the Fermilab Main Injector synchrotron it was recognized that the aperture was limited at the beam transfer and extraction points by the combination of the Lambertson magnets and the reused Main Ring quadrupoles located between the Lambertsons. Increased intensity demands on the Main Injector from antiproton production for the collider program, slow spill to the meson fixed target program, and high intensity beam to the high energy neutrino program have led us to replace the aperture-limiting quadrupoles with newly built magnets that have the same physical length but a larger aperture. The magnets run on the main quadrupole bus, and must therefore have the same excitation profile as the magnets they replaced. We present here the design of the magnets, their magnetic performance, and the accelerator performance.

MOPAS012 Magnets for the MANX 6-D Muon Cooling Demonstration Experiment emittance, dipole, beam-cooling, simulation 461
  • V. S. Kashikhin, V. Kashikhin, M. J. Lamm, G. Romanov, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
  Funding: Supported in part by DOE STTR grant DE-FG02-04ER86191

MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a Helical Cooling Channel (HCC) for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components which diminish as the beam loses energy as it slows down in a liquid helium absorber inside the magnets. Two superconducting magnet system designs are described which use quite different approaches to providing the needed fields. Additional magnets that provide emittance matching between the HCC and upstream and downstream spectrometers are also described as are the results of G4Beamline simulations of the beam cooling behaviour of the complete magnet and absorber system.

MOPAS013 Design Study of a 2-in-1 Large-aperture IR Dipole (D2) for the LHC Luminosity Upgrade dynamic-aperture, magnet-design, luminosity, dipole 464
  • V. Kashikhin, A. V. Zlobin
    Fermilab, Batavia, Illinois
  Funding: This work was supported by the U. S. Department of Energy.

After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil.

MOPAS016 New Corrector System for the Fermilab Booster controls, booster, sextupole, dipole 467
  • E. Prebys, C. C. Drennan, D. J. Harding, V. S. Kashikhin, J. R. Lackey, A. V. Makarov, W. Pellico
    Fermilab, Batavia, Illinois
  Funding: Work supported under DOE contract DE-AC02-76CH03000.

The Fermilab neutrino program places unprecedented demands on the lab's 8 GeV Booster synchrotron, which has not changed significantly since it was built almost 35 years ago. In particular, the existing corrector system is not adequate to control beam position and tune throughout the acceleration system, and provides limited compensation for higher order resonances. We present an ambitious ongoing project to build and install a set of 48 corrector packages, each containing horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles. Space limitations in the machine have motivated a unique design, which utilizes custom wound coils around a 12 pole laminated core. Each of the 288 discrete multipole elements in the system will have a dedicated power supply, the output current of which is controlled by an individual programmable ramp. This provides for great flexibility in the system, but also presents a challenge in terms of designing the control hardware and software in such a way that the system can be operated in the most efficacious way.

MOPAS019 Focusing Solenoid for the Front End of a Linear RF Accelerator focusing, linac, dipole, proton 473
  • I. Terechkine, V. Kashikhin, T. M. Page, M. Tartaglia, J. C. Tompkins
    Fermilab, Batavia, Illinois
  Following a design study, a prototype of a focusing solenoid for use in a superconducting RF linac has been built and is being tested at FNAL. The solenoid cold mass is comprised of the main coil, two bucking coils, and a soft steel flux return. It is mounted inside a dedicated cryostat with a 20 mm diameter warm bore. At the maximum current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 0.01 T at a distance of 200 mm from the center. The flange-to-flange length of the system is 270 mm. This report discusses the main design features of the solenoid and first test results.  
MOPAS021 Slowly Rotating Coil System for AC Field Measurements of Fermilab Booster Correctors dipole, sextupole, booster, synchrotron 476
  • G. Velev, J. DiMarco, D. J. Harding, V. S. Kashikhin, M. J. Lamm, P. Schlabach, M. Tartaglia, J. C. Tompkins
    Fermilab, Batavia, Illinois
  Funding: Work supported by the U. S. Department of Energy

A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for normal and skew dipole, quadrupole, and sextupole magnets in several of these corrector packages.

MOPAS025 Conceptual Design of ILC Damping Ring Wiggler Straight Vacuum System wiggler, photon, vacuum, damping 488
  • S. Marks, K. Kennedy, D. W. Plate, D. Schlueter, M. S. Zisman
    LBNL, Berkeley, California
  Funding: U. S. Department of Energy, Contract No. DE-AC02-05CH11231.

The positron and electron damping rings for the ILC (International Linear Collider) will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR-C superconducting design* . There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC RDR. Particular emphasis will be placed on photon power load calculations and the absorber design.

* A. Mihailichenko, Optimized Wiggler Magnet for CESR, Proceedings of PAC2001, Chicago, Il, June 18-22, 2001

MOPAS027 Energy Deposition Studies of Block-Coil Quadrupoles for the LHC Luminosity Upgrade luminosity, radiation, interaction-region, cryogenics 491
  • N. V. Mokhov, V. Kashikhin, M. Monville
    Fermilab, Batavia, Illinois
  • P. Ferracin, G. L. Sabbi
    LBNL, Berkeley, California
  Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract DE-AC02-05CH11231.

At the LHC upgrade luminosity of 1035 cm-2 s-1, collision product power in excess of a kW is deposited in the inner triplet quadrupoles. The quadrupole field sweeps secondary particles from pp-collisions into the superconducting coils, concentrating the power deposition at the magnetic mid-planes. The local peak power density can substantially exceed the conductor quench limits and reduce component lifetime. Under these conditions, block-coil geometries may result in overall improved performance by removing the superconductor from the magnetic mid-planes and/or allowing increased shielding at such locations. First realistic energy deposition simulations are performed for an interaction region based on block-coil quadrupoles with parameters suitable for the LHC upgrade. Results are presented on 3-D distributions of power density and accumulated dose in the inner triplet components as well as on dynamic heat loads on the cryogenic system. Optimization studies are performed on configuration and parameters of the beam pipe, cold bore and cooling channels. The feasibility of the proposed design is discussed.

MOPAS033 A Robust Orbit-Steering and Control Algorithm Using Quadrupole-scans as a Diagnostic controls, dipole, electron, alignment 509
  • C. Wu, E. Abed, G. Bai, B. L. Beaudoin, S. Bernal, I. Haber, R. A. Kishek, P. G. O'Shea, M. Reiser, D. Stratakis, D. F. Sutter, K. Tian, M. Walter
    UMD, College Park, Maryland
  Funding: This work is funded by US Dept. of Energy.

Beam based alignment and control has been a critical issue for many accelerators. In this paper, we've developed a new approach that can correct the beam orbit using a systematic quad-scan method, where there is an insufficient number of beam position monitors. In this approach, we've proposed a calibrated response matrix. This matrix takes consideration of the different sensitivities of different quadrupoles in the lattice. With the calibrated response matrix, we can greatly enhance our ability to control the beam centroid motion and reduce the control effort.

MOPAS048 Quantitative Evaluation of Magnet Hysteresis Effects at LANSCE with Respect to Magnet Power Supply Specifications power-supply, controls, feedback, linac 542
  • J. T. Bradley III, C. J. Andrews, L. F. Fernandez, M. F. Fresquez, W. Reass, W. Roybal, J. B. Sandoval
    LANL, Los Alamos, New Mexico
  Funding: Work supported by US Department of Energy.

The proton beam in the LANSCE accelerator is guided and focused almost exclusively by electromagnets. Magnet hysteresis has had significant impacts on the tuning of the LANSCE accelerator.* Magnet hysteresis can also have an impact on Magnet Power Supply (MPS) control, regulation and repeatability requirements. To date, MPS performance requirements have been driven by the requirements on the magnetic fields as determined by the accelerator physicists. Taking hysteresis effects into account can significantly change MPS requirements, as some requirements become more stringent and some are found to be overspecified. Overspecification of MPS requirements can result in significant increases in MPS cost. Conversely, the use of appropriate MPS requirements can result in significant cost savings. The LANSCE accelerator's more than three decades of operation provide a wide variety of magnet power supply technologies and operational experience. We will survey the LANSCE magnet power supply history and determine how performance specifications can be refined to both reduce costs and improve the operators abilities to control the magnetic fields.

*R. McCrady, "Mitigation Of Magnet Hysteresis Effects at LANSCE", LINAC 2006, August, 2006.

MOPAS055 Combined Function Magnets Using Double-Helix Coils dipole, multipole, sextupole, focusing 560
  • C. Goodzeit, M. J. Ball, R. B. Meinke
    Advanced Magnet Lab., Inc, Melbourne, Florida
  We describe a technology for creating easy-to-manufacture combined function magnets. The field is produced by double-helix coils in which the axial path of the windings is defined by a sinusoidal function containing the superposition of the desired multipoles. The magnitude of the superimposed multipoles relative to the main field can be easily controlled to any level. For example, the combined function winding can contain a quadrupole magnet along with the dipole in an easily manufactured, low cost configuration. An example of a 5 T magnet with a main dipole field and a superimposed quadrupole is shown. We discuss the amplitude of the quadruple component and how it effects the maximum dipole field that can be obtained in the coil. We also show how low level (i.e. 0.1% - 1%) modulation amplitudes of superimposed multipoles can be used as built-in or "free" correction coils to compensate for iron saturation effects or geometrically-induced multipoles. An example is shown for a small bend radius (i.e. 718 mm), 100 mm aperture bent dipole in which the bent-yoke-induced quadrupole harmonic is completely corrected by the modulation function of the double helix turns.

This work is partially supported under U. S. Department of Energy grant : DoE SBIR DE-FG02-06ER 84492

MOPAS059 ILC - ATF2 DC-Magnet Power Supplies power-supply, controls, feedback, extraction 569
  • B. Lam, P. Bellomo, D. Macnair, A. C. de Lira
    SLAC, Menlo Park, California
  Funding: The development and commissioning of DC magnet power supplies for ATF2 is supported by KEK and SLAC.

In 2008 KEK is commissioning ATF2 - an extension to the existing ATF. ATF2 is a mockup of the final focus test beam accelerator envisioned in the ILC. SLAC is designing the power supply systems for the dc magnets in the ATF2, which will require 38 power supplies ranging from 1.5 to 6 kW, currents from 50 to 200 A, all rated at output voltages not higher than 30 V. Because of the extensive quantities of magnets required for the ILC, high availability is paramount to its successful operation, so the power supply topology chosen for the ATF2 uses N+1 redundancy, with 50-A power modules to construct each power supply. These power modules are current-mode buck regulators, which operate in parallel with each other and one redundant module. One bulk power supply provides off-the-line regulated dc input to a number of the power supplies. Current stability requirements for the magnets range from 10 to 1000 ppm. A precision current transductor and a recently developed SLAC-built 20-bit Ethernet Power Supply Controller will provide the current regulation required. In this paper we present the conceptual design, prototype results, and the status of the power supply systems for the ATF2.

MOPAS070 The DC-Magnet Power Supplies for the LCLS Injector power-supply, controls, dipole, diagnostics 590
  • A. C. de Lira, P. Bellomo, K. Luchini, D. Macnair
    SLAC, Menlo Park, California
  Funding: This work was performed in support of the LCLS project at SLAC and funded by Department of Energy contract DE-AC02-76SF00515

The LCLS injector at SLAC requires 100+ dc-magnet power supply systems for its operation. Power supplies are divided into two main groups: intermediate rack-mounted type for output powers up to 20 kW at 375 A, and bipolar units rated 6 A, 12 A, and 30 A for corrector magnets and small quadrupoles. The intermediate power supplies are controlled by a 20-bit Ethernet power supply controller, specially developed at SLAC to be used in this project. The bipolar units are controlled via 12-bit DACs and ADCs housed in a VME crate. EPICS is the controls interface to all systems. For all systems, stability requirements are better than 1000 ppm. The Power Conversion Department at SLAC, in close cooperation with the LCLS Controls group, was responsible for defining the major characteristics of the power supply systems, their specification, procurement, installation, and commissioning. In this paper we describe the main characteristics of the power supply systems for the LCLS injector, including results from their successful commissioning early this year.

MOPAS074 Combined Panofsky Quadrupole & Corrector Dipole dipole, power-supply, controls, electron 602
  • G. H. Biallas, D. Douglas, T. Hiatt, K. Jordan
    Jefferson Lab, Newport News, Virginia
  • N. T. Belcher
    The College of William and Mary, Williamsburg
  Funding: Work supported by the US DOE Contract #DE-AC05-84ER40150, the Office of Naval Research, The Air Force Research Laboratory, the US Army Night Vision Laboratory and the Commonwealth of Virginia,

Two styles of Panofsky Quadrupoles with integral corrector dipole windings are in use in the electron beam line of the Free Electron Laser at Jefferson Lab. We combined the functions into single magnets, adding hundreds of Gauss-cm dipole corrector capability to existing quadrupoles because space is at a premium along the beam line. Superposing high quality dipole corrector field on a high quality, weak (600 to 1'000 Gauss) quadrupole is possible because the parallel slab iron yoke of the Panofsky Quadrupole acts as a window frame style dipole yoke. The dipole field is formed when two current sources, designed and made at Jlab, add and subtract current from the two opposite quadrupole current sheet windings parallel to the dipole field direction. The current sources also drive auxiliary coils at the yoke's inner corners that improve the dipole field. Magnet measurements yielded the control system field maps that characterize the two types of fields. Details of field analysis using OPERA, construction methods, wiring details, magnet measurements and the current sources are presented.

MOPAS084 SNS Ring Extraction Septum Magnet and its Interference with Adjacent Quadrupole simulation, extraction, shielding, septum 626
  • J.-G. Wang
    ORNL, Oak Ridge, Tennessee
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract DE-AC05-00OR22725.

3D computing simulations have been performed to study the magnetic field distribution of the SNS ring extraction Lambertson septum magnet. The magnetic field for extracted beams is fully characterized in all the aspects. The stray field on the circulating beam line and the effect of a shielding box up-stream and a shielding cap down-stream is investigated. In addition, the magnetic interference between the Lambertson and an adjacent quadrupole has been studied. The simulations have provided valuable information for the SNS ring commissioning and operation. This paper reports our simulation techniques and the major results.

MOPAS093 Vibration Measurements to Study the Effect of Cryogen Flow in a Superconducting Quadrupole laser, cryogenics, superconducting-magnet, resonance 643
  • P. He, M. Anerella, S. Aydin, G. Ganetis, M. Harrison, A. K. Jain, B. Parker
    BNL, Upton, Long Island, New York
  Funding: Work supported by the US Department of Energy under contract DE-AC02-98CH10886.

The conceptual design of compact superconducting magnets for the International Linear Collider final focus is presently under development at BNL. A primary concern in using superconducting quadrupoles is the potential for inducing additional vibrations from cryogenic operation. We have employed a Laser Doppler Vibrometer system to measure the vibrations at resolutions ~1 nm (at frequencies above ~8 Hz) in a spare RHIC quadrupole coldmass under cryogenic conditions. Some preliminary results of these studies were presented at the Nanobeam 2005 workshop*. These results were limited in resolution due to a rather large motion of the laser head itself. As a first step towards improving the measurement quality, an actively stabilized isolation table was used to reduce the motion of the laser holder. The improved set-up will be described, and vibration spectra measured at cryogenic temperatures, both with and without helium flow, will be presented.

*A. Jain, et al., Nanobeam 2005, Kyoto, Japan, Oct.17-21, 2005; paper WG2d-05; available at http://wwwal.kuicr.kyoto-u.ac.jp/NanoBM .

MOPAS097 Unique features in magnet designs for R&D Energy Recovery Linac at BNL dipole, emittance, linac, electron 655
  • W. Meng, G. Ganetis, A. K. Jain, D. Kayran, V. Litvinenko, C. Longo, G. J. Mahler, E. Pozdeyev, J. E. Tuozzolo
    BNL, Upton, Long Island, New York
  Funding: Work supported by U. S. DOE under contract No DE-AC02-98CH1-886

In this paper we describe unique features of magnets for R&D ERL, which is under construction in Collider-Accelerator Department, BNL. The R&D ERL serves as a test-bed future BNL ERLs, such as electron-cooler-ERL for RHIC and 20 GeV ERL for future electron-hadron, eRHIC. We present selected designs of various dipole and quadrupole magnets, which are used in Z-bend merging systems and the returning loop, 3-D simulations of the fields in these magnets, particle tracking and analysis of magnet's influence on the beam parameters. We discuss an uncommon method of setting requirements on the quality of magnetic field and transferring them into measurable parameters as well as into manufacturing tolerances. We compare selected simulation with results magnetic measurements.

MOPAS102 Design of Beam Transfer Lines for the NSLS II booster, injection, storage-ring, extraction 664
  • N. Tsoupas, R. Heese, R. Meir, I. Pinayev, J. Rose, T. V. Shaftan, C. Stelmach
    BNL, Upton, Long Island, New York
  Funding: Work supported by the US Department of Energy

The proposed NSLS II light source* to be built at Brookhaven National Laboratory utilizes a LINAC and a Booster with a Storage-ring which share the same tunnel, but at different horizontal planes. The Booster which accepts beam from the LINAC, accelerates the electron beam to an energy of 3.0 GeV and the beam is extracted to the BoostertoStorageRing(BtS) transport line. The BtS line transports the beam and injects it into the Storage ring . In order to facilitate the design of the BtS transfer line, the line has been partitioned in three sections which can be considered as independent. The function of each the three sections will be discussed in details and the procedure for the design of the BtS line and other details about the optics and the magnetic elements of the line will be presented in the paper. The LINAC to Booster beam transfer line will also be discussed.


TUOBKI01 Experimental Characterization of the Spallation Neutron Source Accumulator Ring Collimation System collimation, beam-losses, simulation, emittance 703
  • S. M. Cousineau, S. Assadi, J. A. Holmes, M. A. Plum
    ORNL, Oak Ridge, Tennessee
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract DE-AC05-00OR22725.

The SNS ring and associated transport lines, commissioned in January 2006, are designed to accumulate and deliver up to 1.5·1014, 1 GeV protons at 60 Hz to a liquid mercury target for neutron production. In order to control activation and to allow for routine hands-on maintenance of accelerator components, beam loss in most of the ring must remain below 1 W/m . For the full 1.4 MW beam, this translates to a fractional beam loss limit of 0.01%. Accomplishing this loss limit at full beam power will require successful utilization of the ring's two-stage betatron collimation system. In this paper we present the results of initial collimation experiments. We characterize the collimation-induced beam-loss pattern and compare our results with simulations. In addition, we discuss other existing beam-loss-related challenges in the ring.

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TUZAKI02 LHC Upgrade Scenarios luminosity, dipole, interaction-region, hadron 714
  • F. Zimmermann
    CERN, Geneva
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395)

The EU CARE-HHH and US-LARP programmes for an LHC upgrade aim at increasing the LHC luminosity by a factor of 10 around the year 2015. The upgrade plan envisages rebuilding the interaction regions (IRs) and modifying the beam parameters. In addition to advanced low-beta quadrupoles, the future IRs may accommodate other novel elements such slim s.c. dipoles or quadrupoles embedded deep inside the detectors, global low-angle crab cavities, and wire compensators of long-range beam-beam effects. Important constraints on the upgrade path are the maximum acceptable number of detector pile-up events, favoring many closely spaced bunches, and the heat load on the cold-magnet beam screens, pointing towards fewer and more intense bunches. In addition, the upgrade of the LHC ring proper should be complemented by an upgrade of the injector complex. I will present preferred luminosity upgrade scenarios for the LHC IRs and beam parameters, sketch accompanying injector enhancements, and comment on a longer-term LHC energy upgrade.

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TUODKI02 Optics Considerations for the PS2 lattice, extraction, injection, proton 739
  • M. Benedikt, W. Bartmann, C. Carli, B. Goddard, S. Hancock, J. M. Jowett, Y. Papaphilippou
    CERN, Geneva
  CERN envisages replacing the existing Proton Synchrotron (PS) with a larger synchrotron (PS2) capable of injecting at higher energy into the SPS. Since it should increase the performance not only of the LHC but also CNGS and other users of beams from CERN's hadron injector complex, the new accelerator must retain much of the flexibility of the present complex. A number of candidate optics, with and without transition crossing, have been evaluated systematically and compared.  
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TUXAB01 Absolute Measurement of Electron Cloud Density electron, ion, background, simulation 754
  • M. Kireeff Covo, R. H. Cohen, A. Friedman, A. W. Molvik
    LLNL, Livermore, California
  • D. Baca, F. M. Bieniosek, B. G. Logan, P. A. Seidl, J.-L. Vay
    LBNL, Berkeley, California
  • J. L. Vujic
    UCB, Berkeley, California
  Funding: This work was supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U. S. Department of Energy, LLNL and LBNL, under contracts No. W-7405-Eng-48 and DE-AC02-05CH11231.

Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 us duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.*

* M. Kireeff Covo, A. W. Molvik, A. Friedman, J.-L. Vay, P. A. Seidl, G. Logan, D. Baca, and J. L. Vujic, Phys. Rev. Lett. 97, 054801 (2006).

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TUOAAB02 Measurement and Simulation of Space-Charge Dependent Tune Separation in FNAL Booster coupling, space-charge, booster, simulation 772
  • D. O. McCarron
    IIT, Chicago, Illinois
  • J. F. Amundson, W. Pellico, P. Spentzouris, R. E. Tomlin
    Fermilab, Batavia, Illinois
  • L. K. Spentzouris
    Illinois Institute of Technology, Chicago, Illinois
  In recent years, a number of space-charge studies have been performed in the FNAL Booster. The Booster is the first circular accelerator in the Fermilab chain of accelerators, with an injection energy of 400 MeV. The combination of this relatively low injection energy and improving beam intensity for Booster's high intensity applications necessitates a study of space charge dynamics. Measurement and simulation of space charge coupling in the Booster will be presented. The coupling measurement was performed using a standard technique, albeit repeated for different injected beam intensities. The initial transverse tune separation was minimized (Qx=Qy=6.7), followed by a systematic skew quadrupole strength variation. Transverse beam oscillation frequencies were recorded while exciting the beam. These frequencies were recorded for a range of 1.0·1012 to 3.5·1012 particles. A linear increase in the measured tune separation with beam intensity was observed. For comparison, beam coupling was also simulated with the space-charge code Synergia. This code has successfully modeled the space-charge tune shift in the Booster*, and compares favorably to other space charge codes and analytic results.

* Synergia: A 3D Accelerator Modelling Tool with 3D Space Charge. Journal of Computational Physics, Volume 211, Issue 1 , 1 January 2006, Pages 229-248.

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TUZAAB03 Emittance Measurement and Modeling for the Fermilab Booster emittance, injection, space-charge, dipole 799
  • X. Huang
    SLAC, Menlo Park, California
  • S.-Y. Lee
    IUCF, Bloomington, Indiana
  • K. Y. Ng
    Fermilab, Batavia, Illinois
  Funding: DOE/NSF

We systematically measured the emittance evolution of a fast cycling proton accelerator on a turn-by-turn basis under various beam intensities via an ionization profile monitor (IPM). The vertical emittance growth rate was derived and phenomenologically analyzed. The transverse and longitudinal components in the horizontal beam size were separated by making use of their different evolution behaviors. The quadrupole mode beam size oscillation after transition crossing is also studied and explained. We found a considerable space-charge-induced emittance growth rate component in the vertical plane but not as much for the horizontal plane. We carried out multiparticle simulations to understand the mechanism of space-charge-induced emittance growth. The major sources of emittance growth were found to be the random skew-quadrupole and dipole field errors in the presence of large space-charge tune spread.

PRSTAB 9, 014202 (2006)

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TUOCAB01 A New Code for Orbit Response Matrix Analysis lattice, booster, closed-orbit, simulation 804
  • L. Yang, S.-Y. Lee
    IUCF, Bloomington, Indiana
  • X. Huang
    SLAC, Menlo Park, California
  • B. Podobedov
    BNL, Upton, Long Island, New York
  Funding: NSF PHY-0552389, DOE DE-FG02-92ER40747

The Orbit Response Matrix (ORM) has been successfully used extensively in accelerator modeling. However, in many cases, the existing codes can not find a correct model. We develop a new code that solve the convergence and coupling problems. We test our code by carrying out systematic study of accelerator models. Effects measurement errors and the completeness of information will be addressed in this study. Possible inclusion of phase information will be discussed.

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TUOCAB02 Measurements of Compression and Emittance Growth after the First LCLS Bunch Compressor Chicane emittance, simulation, dipole, electron 807
  • P. Emma, K. L.F. Bane, Y. T. Ding, J. C. Frisch, Z. Huang, H. Loos, G. V. Stupakov, J. Wu
    SLAC, Menlo Park, California
  • E. Prat
    DESY, Hamburg
  • F. Sannibale, K. G. Sonnad, M. S. Zolotorev
    LBNL, Berkeley, California
  Funding: U. S. Depertment of Energy contract #DE-AC02-76SF00515.

The Linac Coherent Light Source (LCLS) is a SASE x-ray free-electron laser project presently under construction at SLAC. The injector section from RF photocathode gun through the first bunch compressor chicane was installed during the Fall of 2006. The first bunch compressor chicane is located at 250 MeV and nominally compresses a 1-nC electron bunch from an rms length of about 1 mm to 0.2 mm. The degree of compression is highly adjustable using RF phasing and also chicane magnetic field variations. Transverse phase space and bunch length diagnostics are located immediately after the chicane. We present measurements and simulations of the longitudinal and transverse phase space after the chicane in various beam conditions, including extreme compression where coherent radiation effects are expected to be striking.

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TUZBAB02 The Extreme Value Theory to Estimate Beam Losses in High Power Linacs linac, beam-losses, simulation, beam-transport 815
  • R. Duperrier, D. Uriot
    CEA, Gif-sur-Yvette
  The influence of random perturbations of high intensity accelerator elements on the beam losses is considered. This influence is analyzed with the help of the Extreme Value Theory (EVT) to allow loss estimates for a very low fraction of the beam. Many fields of modern science and engineering have to deal with events which are rare but have significant consequences. EVT is considered to provide the basis for the statistical modeling of such extremes events (extreme variations of financial market for insurance companies or extreme wind speed for electric companies). To illustrate the application of this theory to beam losses estimates, the SPIRAL2 driver is used. This 5 mA deuteron accelerator is simulated from the output of the source to the target with high resolution PIC modelisations (up to 1.3 million macro-particles) using realistic external fields.  
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TUODAB02 Electron Cloud Generation and Trapping in a Quadrupole Magnet at the LANL PSR electron, diagnostics, proton, beam-losses 828
  • R. J. Macek, J. E. Ledford, R. J. Macek
    TechSource, Santa Fe, New Mexico
  • M. J. Borden, A. A. Browman, R. C. McCrady, J. F. O'Hara, L. Rybarcyk, T. Spickermann, T. Zaugg
    LANL, Los Alamos, New Mexico
  • M. T.F. Pivi
    SLAC, Menlo Park, California
  Funding: Work supported by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

Recent beam physics studies on the two-stream e-p instability at LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Experimental results will be presented on various characteristics of electron cloud obtain from experiments using this diagnostic and compared with simulations. Results include data on flux and energy spectra of electrons striking the vacuum chamber, the line density and lifetime of electrons trapped in the quadrupole after the beam has been extracted as well as evidence regarding electrons ejected from the magnet during passage of the proton beam.

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TUOCC01 Software Tools for Commissioning of the Spallation Neutron Source Linac linac, acceleration, proton, optics 883
  • J. Galambos, A. V. Aleksandrov, C. K. Allen, S. Henderson, T. A. Pelaia, A. P. Shishlo, Y. Zhang
    ORNL, Oak Ridge, Tennessee
  • P. Chu
    SLAC, Menlo Park, California
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract DE-AC05-00OR22725.

The Accelerator Physics group at the Spallation Neutron Source (SNS) has developed numerous codes to assist in the beam commissioning, tuning, and operation of the SNS Linac. These codes have been key to meeting the beam commissioning milestones. For example, a recently developed code provides for rapid retuning of the superconducting Linac in case of RF stations going offline or coming online. Highlights of these "physics applications" will be presented.

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TUPMN007 Final Commissioning Results from the Injection System for the Australian Synchrotron Project injection, booster, synchrotron, sextupole 926
  • S. V. Weber, F. Bødker, H. Bach, N. Hauge, J. Kristensen, L. K. Kruse, S. P. M?ller, S. M. Madsen
    Danfysik A/S, Jyllinge
  • M. J. Boland, R. T. Dowd, G. LeBlanc, M. J. Spencer, Y. E. Tan
    ASP, Clayton, Victoria
  • N. H. Hertel, J. S. Nielsen
    ISA, Aarhus
  Danfysik has delivered a full-energy turn-key injection system for the Australian Synchrotron. The system consists of a 100 MeV linac, a low-energy transfer beamline, a 130 m circumference 3-GeV booster, and a high energy transfer beamline. The booster lattice was designed to have many cells with combined-function magnets (dipole, quadrupole and sextupole fields) in order to reach a very small emittance. The injection system has been commissioned and found to deliver a beam with an emittance of less than 30 nm, and currents in single- and multi-bunch mode in excess of 0.5 and 5 mA, respectively, fulfilling the contractual performance specifications. The repetition frequency is 1 Hz. Results from the commissioning of the system will be presented.  
TUPMN032 The New Elettra Booster Injector controls, booster, dipole, kicker 983
  • M. Svandrlik, S. Bassanese, A. Carniel, K. Casarin, D. Castronovo, P. Craievich, G. D'Auria, R. De Monte, P. Delgiusto, S. Di Mitri, A. Fabris, R. Fabris, M. Ferianis, F. Giacuzzo, F. Iazzourene, G. L. Loda, M. Lonza, F. M. Mazzolini, D. M. Molaro, G. Pangon, C. Pasotti, G. Penco, L. Pivetta, L. Rumiz, C. Scafuri, G. Tromba, A. Vascotto, R. Visintini, D. Zangrando
    ELETTRA, Basovizza, Trieste
  • L. Picardi, C. Ronsivalle
    ENEA C. R. Frascati, Frascati (Roma)
  The new full energy injector for Elettra is under construction. The complex is made of a 100 MeV linac and a 2.5 GeV synchrotron, at 3 Hz repetition rate. With the new injector top-up operation shall be feasible. In the first semester of 2007 the machine assembly has been performed. In Summer 2007 the commissioning is scheduled, while in Fall 2007 the connection to the Storage Ring is planned. The status of the project will be reported in this paper.  
TUPMN046 Quadrupole HOM Damping with Eccentric-fluted Beam Pipes dipole, damping, linac, ion 1022
  • M. Sawamura
    JAEA/ERL, Ibaraki
  • T. Furuya, S. Sakanaka, T. Suwada, T. Takahashi, K. Umemori
    KEK, Ibaraki
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  HOM damping is important for superconducting cavities, especially for high current CW machines such as ERLs. The lower Q-values of HOMs lead to the lower requirement of a refrigerator system and the higher beam current against HOM BBU. Enlarged beam pipes, which have lower cutoff frequencies, are effective to damp HOMs of monopole and dipole, but insufficient for HOMs of quadrupole which have high cutoff frequencies. An eccentric-flute is proposed to damp the HOMs of quadrupole. The eccentric-flute is formed by displacing the flute from the center of the beam pipe and/or by jackknifing around the midpoint of the flute to couple two degenerate modes. The eccentric-flute acts as a mode converter from quadrupole to dipole of the lower cutoff frequency so that the RF power can propagate through the beam pipe. The result of calculation with MAFIA and measurement of a cold model with the eccentric-flute are presented.  
TUPMN057 Design and Tuning of NSRL Undulator UD-1 undulator, radiation, sextupole, multipole 1055
  • Q. K. Jia
    USTC/NSRL, Hefei, Anhui
  The design, construction, and tuning of the first undulator UD-1 in NSRL are described. The magnetic field design and requirement are given. The results of the magnet blocks measurement and the magnetic field tuning by interchanging magnet blocks are presented.  
TUPMN059 The Nonlinear Effects of Fringe Fields in HLS dipole, storage-ring, damping, sextupole 1061
  • L. Wang, G. Feng, W. Li, L. Liu, H. Xu
    USTC/NSRL, Hefei, Anhui
  • S. C. Zhang
    USTC, Hefei, Anhui
  As a small low energy electron storage ring, the fringe field effects on linear and nonlinear properties maybe can not be ignored. In this paper, the fringe field of dipole magnets and quadrupole magnets on linear optics parameters and nonlinear driving terms of general purpose operation mode in HLS storage ring were analyzed and calculated. The results showed that, for GPLS mode, the fringe field of dipole and quadrupole is the main source of tune shift with amplitude. The fringe field of dipole contributes non-ignorable part to vertical chromaticity. Similar behavour is also displayed in non linear driving terms.  
TUPMN074 Improvements to the Injection Efficiency at the Taiwan Light Source injection, booster, storage-ring, septum 1091
  • Y.-C. Liu, H.-P. Chang, J. Chen, P. J. Chou, K. T. Hsu, K. H. Hu, C. H. Kuo, C.-C. Kuo, K.-K. Lin, G.-H. Luo, M.-H. Wang
    NSRRC, Hsinchu
  Taiwan light source started the 200 mA top-up operation in October 2005, and the stored beam current was subsequently ramped up to 300 mA top-up operation. In the early phase of top-up operation, the injection efficiency had large variation at different machine condition. We have developed the procedures to maintain the injection efficiency. These optimization procedures will be activated whenever the injection efficiency degrades during the top-up operation of TLS.  
TUPMN087 Electron Beam Dynamics Studies During Commissioning of the Diamond Storage Ring storage-ring, lattice, coupling, optics 1115
  • I. P.S. Martin, R. Bartolini, R. T. Fielder, E. C. Longhi, B. Singh
    Diamond, Oxfordshire
  The Diamond Light Source is the new medium energy 3rd generation light source located at the Harwell Science and Innovation Campus in the UK. The storage ring was successfully commissioned at full energy during the period Sept. to Dec. 2006, and is now delivering synchrotron light to users. During the commissioning period, operation of the storage ring at the design specifications was established in terms of closed orbit distortion, linear optics, coupling correction and emittance. In this report we provide details of these studies as well as more recent investigations of non-linear beam dynamics.  
TUPMN088 Commissioning and Investigation of Beam Dynamics of Phase I Insertion Devices at Diamond injection, optics, wiggler, undulator 1118
  • B. Singh, R. Bartolini, R. T. Fielder, E. C. Longhi, I. P.S. Martin
    Diamond, Oxfordshire
  Diamond is a 3 GeV low emittance third generation light source recently commissioned in Oxfordshire, UK. During Phase I of the project, seven insertion devices (IDs) have been installed and commissioned: these include 5 in-vacuum permanent magnet undulators, a variable polarization APPLE-II helical device and a superconducting wiggler. We present our experiences commissioning these devices and the results of the investigations of their effects on beam dynamics, including orbit distortion, linear tune shifts, beta-beating and beam lifetime. Alpha-matching with local and global tune compensations, as well as the LOCO algorithm, have been used to compensate the linear optic perturbations. The results are discussed and compared with theoretical predictions. Injection with IDs in operation has also been investigated in view of future top-up operation.  
TUPMN111 A Low Emittance Lattice for the Advanced Light Source sextupole, emittance, lattice, dynamic-aperture 1170
  • H. Nishimura, S. Marks, D. Robin, D. Schlueter, C. Steier, W. Wan
    LBNL, Berkeley, California
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC03-76SF00098

The possibility exists of achieving significantly lower emittances in an electron storage ring by increasing its horizontal betatron tune. However, existing magnet locations and strengths in a given ring may be inadequate to implement such an operational mode. For example, the ALS storage ring could lower its emittance to one third of the current value by increasing the horizontal tune from 14.25 to 16.25. However, this would come with the cost of large chromaticities that could not be corrected with our existing sextupole magnets. We discuss such operational issues and possible options in this paper.

TUPMN117 Exploring the Limits of the ALS Triple Bend Lattice lattice, emittance, storage-ring 1188
  • D. Robin, W. Wan
    LBNL, Berkeley, California
  Funding: Work supported by the U. S. Department of Energy under Contract No. DE-AC03-76SF00098

The triple bend achromat cell of the ALS has been shown to be very flexible and compact. It has been operated in a low emittance mode and a low momentum compaction mode. In fact the lattice can be operated in a large range of different stable modes. Until recently most of these recently discovered modes had not been explored or even known about. Many of these modes have potentially attractive features as compared with the present operational mode. In this paper we take a step back and look at the general stability limits of the lattice. We employ a technique we call GLASS that allows us to rapidly scan and find all possible stable modes and then characterize their associated properties. In this paper we illustrate how the GLASS technique gives a global and comprehensive vision of the capabilities of the lattice.

TUPMS022 Beam Breakup Simulations for the Cornell X-ray ERL linac, simulation, lattice, electron 1227
  • C. Song, G. Hoffstaetter
    CLASSE, Ithaca
  Funding: Supported by Cornell University and NSF grant PHY 0131508

Multi-pass, multi-bunch beam-breakup (BBU) can limit the current in linac-based recirculating accelerators. We have therefore made the computation of the transverse and longitudinal BBU-threshold current available in Cornell's main optics design and beam simulation library BMAD. The coupling of horizontal and vertical motion as well as time of flight effects are automatically contained. Subsequently we present a detailed simulation study of transverse and longitudinal BBU in the proposed 5GeV Energy Recovery Linac light source at Cornell University, including the use of frequency randomization, polarized cavities and optical manipulations to improve the threshold current.

TUPMS035 The FINDER Photoinjector gun, emittance, laser, cathode 1260
  • A. Fukasawa, H. Badakov, E. Hemsing, B. D. O'Shea, J. B. Rosenzweig
    UCLA, Los Angeles, California
  • S. G. Anderson
    LLNL, Livermore, California
  The FINDER project at LLNL is an inverse-Compton scattering demonstration, aimed at creating MeV-class, narrow band photons for interrogation of nuclear materials. The requirements experiment requires a state-of-the-art photoinjector. Such a device is under development by a UCLA/LLNL collaboration. We report on a number of design innovations, such as photocathode gun RF symmetrization and large mode separation, which sets this device apart from previous generations of the BNL/SLAC/UCLA 1.6 cell gun. Measurements characterizing the RF photocathode gun and emittance compensation solenoid are presented.  
TUPMS044 Design of a 980 MeV Energy Recovery Linac linac, recirculation, synchrotron, synchrotron-radiation 1287
  • R. A. Bosch, J. Bisognano, M. D. Medley
    UW-Madison/SRC, Madison, Wisconsin
  Funding: This research was supported by National Science Foundation grant no. DMR-0537588.

A 980-MeV energy recovery linac with radiofrequency (rf) of 1.5 GHz is designed. Electrons are accelerated by two passages through a 480-MeV superconducting linac, and decelerated by two subsequent passages. Recirculation is accomplished with six 60-degree bending magnets. The threshold current for beam breakup instability exceeds 100 mA. Gaussian bunches with normalized transverse emittances of 0.1 mm-mrad and rms length of 1.85 ps may be compressed by a factor of 180 (to a bunch length of 10 fs) with only a slight increase in transverse normalized emittance. Bunch charges up to 8 pC may be compressed at 980 MeV without excessive degradation from coherent synchrotron radiation, allowing operation with beam currents up to 12 mA.

TUPMS045 Improvements to the Aladdin Synchrotron Light Source insertion, insertion-device, synchrotron, undulator 1290
  • K. Jacobs, J. Bisognano, R. A. Bosch, D. Eisert, M. V. Fisher, M. A. Green, R. G. Keil, K. J. Kleman, R. A. Legg, G. C. Rogers, J. P. Stott
    UW-Madison/SRC, Madison, Wisconsin
  Funding: Work supported by the U. S. National Science Foundation under Award No. DMR-0537588.

Aladdin is an IR to soft x-ray synchrotron light source operated by the University of Wisconsin at Madison. As part of the ongoing program of upgrades and improvements, several changes have recently been made to the ring. It had previously been determined that physical apertures (BPMs) at the QF quadrupoles were limiting beam lifetime when the ring was operated in its low emittance configuration. Increasing the size of these apertures has resulted in a significant increase in lifetime. Also as part of the aperture opening process, a number of ring components were redesigned and replaced, lowering the ring impedance. This has led to an increase in the threshold beam current for microwave instability. Another modification was the design and installation of discrete trim coils on the quadrupole pole-tips to facilitate using the quads as steering correctors. Details of these and other improvements will be presented.

TUPMS093 Computations of Wakefields in the ILC Collimators simulation, dipole, insertion, emittance 1383
  • J. D.A. Smith
    Cockcroft Institute, Warrington, Cheshire
  • C. J. Glasman
    UMAN, Manchester
  The collimators in the ILC serve the dual purpose of reducing the beam halo and as of a form of machine protection from potentially miss-steered beams. However, there is a significant wakefield in the immediate vicinity of the beam caused by their presence. It is important to be able to predict this short-range wakefield and the extent which it dilutes the emittance of the beam. We extend the previous analysis*, ** of wake-fields in collimators to realistic short bunches applicable to the ILC. We achieve these results using the finite difference code GdfidL. The angular wake is decomposed into its constituent components for rectangular collimators and compared with their circular collimator counterparts. Comparisons are made between these simulations, existing analytical models, and experimental results.

* C. Beard and R. M. Jones, EUROTeV-Report-2006-103** C. Beard and J. Smith, EPAC06 Proc. MOPLS070

TUPAN001 Analytic Models for Quadrupole Fringe-Field Effects focusing, dipole, proton, multipole 1386
  • S. R. Koscielniak
    TRIUMF, Vancouver
  • C. Johnstone
    Fermilab, Batavia, Illinois
  Funding: TRIUMF receives federal funding via a contribution agreement through the National Research Council of Canada

The linear-field non-scaling FFAG lattices originally proposed for multi-GeV muon acceleration are now being modified for application to order 100 MeV/u proton or carbon medical applications. The momentum range is large and the chromatic tune variation is significant. In the medical case, the time of flight variation is immaterial but the issue of resonance crossing is more acute owing to the much lower rate of energy gain. Magnets with non-normal entry/exit faces are considered as means to reduce the tune variation. Thus one is motivated to study fringe fields and their effects. We make a brief study of dipole and quadrupole magnets with normal and rotated entry/exit faces. For the artificial case of a cosine-squared fall off in the quadrupole field, analytic results are obtained which though approximate are superior to numerical integration. This property is achieved by insisting that the error in the equation of motion is zero and the determinant is unity at the entry, exit and centre of the fringe field.

TUPAN002 Large Displacement and Divergence Analytic Transfer Maps Through Quadrupoles focusing, lattice, proton, beam-transport 1389
  • S. R. Koscielniak
    TRIUMF, Vancouver
  Funding: TRIUMF receives federal funding via a contribution agreement through the National Research Council of Canada.

Linear-field non-scaling FFAGs are proposed for multi-GeV muon acceleration and order hundred MeV/u proton or carbon medical applications. The periodic lattices, which have large momentum acceptance (factor >3), employ cells comprised of combined function magnets. In one implementation, rectangular-shaped quadrupoles are used, with the dipole component generated by off-setting the magnet centre. This feature, coupled with the large radial aperture, gives rise to orbits with large displacement and/or divergence from the quadrupole centre. The angles may be so large that there is a partial interchange of longitudinal and radial momenta. We examine two methods to devise maps (through the body field) that are third order in radial coordinate and higher order in momentum. The WKBJ approximation is concluded to be no better than the usual linear transfer matrix. A Green's function approach is carried through to non-linear mappings for the dynamical variables, which are coupled. The first partial derivative of this map (relates to tune variation) produces a linear transfer matrix which must have unity determinant. For the FFAG application, the map is comparable with numerical integration.

TUPAN012 High Intensity Heavy Ion Beam Emittance Measurements at the GSI UNILAC emittance, ion, simulation, heavy-ion 1413
  • W. B. Bayer, W. Barth, L. A. Dahl, P. Forck, P. Gerhard, L. Groening, I. Hofmann, S. Yaramyshev
    GSI, Darmstadt
  • D.-O. Jeon
    ORNL, Oak Ridge, Tennessee
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395).

The GSI UNILAC, a heavy ion linac originally dedicated for low current beam operation, together with the synchrotron SIS 18 will serve as an high current injector for FAIR (International Facility for Antiproton and Ion Research). The UNILAC post stripper accelerator consists of five Alvarez tanks with a final energy of 11.4 MeV/u. In order to meet the requirements of FAIR (15emA 238U28+, transverse normalised emittances of 0.8mm mrad and 2.5mm mrad) an UNILAC upgrade program is foreseen to increase the primary beam intensity as well as the beam brilliance. A detailed understanding of the beam dynamics during acceleration and transport of space charge dominated beams is necessary. For this purpose the study of the beam brilliance dependency on the phase advances in the Alvarez DTL is suited. Machine investigations were performed with various beam diagnostics devices established in the UNILAC. Measurements done in 2006 using an high intensity heavy ion beam coincide with the beam dynamics work package of the European JRA "High Intensity Pulsed Proton Injector" (HIPPI). Results of these measurements are presented as well as corresponding beam dynamics simulations.

TUPAN014 Status of the FAIR SIS100/300 Synchrotron Design dipole, extraction, lattice, ion 1419
  • P. J. Spiller, U. B. Blell, H. Eickhoff, E. Fischer, E. Floch, P. Hulsmann, J. E. Kaugerts, M. Kauschke, H. Klingbeil, H. G. Koenig, A. Kraemer, D. Kramer, U. Laier, G. Moritz, C. Omet, N. Pyka, H. Ramakers, H. Reich-sprenger, M. Schwickert, J. Stadlmann
    GSI, Darmstadt
  • A. D. Kovalenko
    JINR, Dubna, Moscow Region
  The project status of the main accelerators, the SIS100 and SIS300 synchrotrons of the FAIR project will be presented. In order to accommodate more preferable technical solutions, the structure of the magnet lattice had to be modified in both machines. After these changes, more appropriate technical solutions for the main magnets and quench protection systems could be adapted. The general machine layout and design, e.g. of the demanding extraction schemes, has been detailed and open design issues were solved. The developments and design of all major technical systems are in progress and prototyping has started or is in preparation.  
TUPAN028 A Low Beta Section for Polarization Studies of Antiprotons by Spin Filtering target, antiproton, emittance, focusing 1451
  • M. Statera, P. Lenisa, G. Stancari
    INFN-Ferrara, Ferrara
  • A. Garishvili, B. Lorentz, S. A. Martin, F. Rathmann
    FZJ, Julich
  In the framework of the FAIR* project, the PAX collaboration has suggested new experiments using polarized antiprotons**. The central physics issue is now to study the polarization build-up by spin filtering of antiprotons via multiple passages through an internal polarized gas target. The goals for spin-filtering experiments with protons at COSY are to test our understanding of the spin-filtering processes and to commission the setup for the AD experiments with antiprotons at the AD (CERN). Spin-filtering experiments with antiprotons at the AD will allow us to determine the total spin-dependent transversal and longitudinal cross sections. The low-beta section at COSY is composed of two superconducting quadrupole magnets on each side of the target, while at the AD, we will use three quadrupoles on each side. Accelerator technical problems and details for COSY and AD to carry out the planned spin-filtering studies together with the technical problems and details of the superconducting quadrupoles with their respective cryogenics will be discussed in this talk. The status of the construction of the quadrupoles will be reported as well.

* Conceptual Design Report for an International Facility for Antiprotonand Ion Research, www.gsi.de/GSI-future/cdr.** PAX Technical Proposal, www.fz-juelich.de/ikp/pax.

TUPAN035 Reduction of the Non-Linearities in the DAPHNE Main Rings Wigglers wiggler, multipole, octupole, simulation 1463
  • S. Bettoni
    CERN, Geneva
  • S. Guiducci, M. A. Preger, P. Raimondi, C. Sanelli
    INFN/LNF, Frascati (Roma)
  The wigglers of the DAPHNE main rings have been the main source of non-linearities for the beam dynamics in the collider. This paper describes a method to reduce the integrated odd multipoles (the even ones tend to vanish for the periodicity of the magnet) by alternatively displacing the magnetic axis of the poles to compensate the integrated odd multipoles in each half-period of the wiggler. In order to check the effectiveness of this approach, tracking studies have been performed. Tracking results have been used to tune the MAD model of the wiggler.  
TUPAN036 DAPHNE Upgrade: A New Magnetic and Mechanical Layout vacuum, kicker, dipole, interaction-region 1466
  • S. Tomassini, D. Alesini, A. Beatrici, A. Clozza, E. Di Pasquale, G. Fontana, F. Marcellini, G. Mazzitelli, M. Paris, P. Raimondi, C. Sanelli, G. Sensolini, F. Sgamma, M. Troiani, M. Zobov, A. Zolla
    INFN/LNF, Frascati (Roma)
  • M. E. Esposito
    Rome University La Sapienza, Roma
  The DAPHNE Phi-Factory upgrade, foreseen for the Siddharta detector run in 2007, will require a new magnetic and mechanical layout to exploit the "large crossing angle" and "crabbed waist" concepts*. New permanent quadrupole magnets and aluminium vacuum chamber with thin window have been designed for the new interaction region, with the aim to reuse at maximum the present magnetic and vacuum chamber components. A vacuum chamber of novel design will allow separating the beams at the second interaction region. Designs and results for the new layout will be presented.

* DAPHNE Upgrade Team, "DAPHNE Upgrade for Siddharta run", DAPHNE Tech. Note G-68, Dec. 2006.

TUPAN052 New Beam Optics Design of Injection/Fast Extraction/Abort Lines of J-PARC Main Ring extraction, injection, kicker, beam-losses 1508
  • M. Tomizawa, A. Y. Molodozhentsev, E. Nakamura, I. Sakai, M. Uota
    KEK, Ibaraki
  J-PARC Main Ring has three straight sections for injection, slow extraction and fast extraction. Injection line has been redesigned so as to give a higher reliability for the thin septa. The magnetic field can be reduced by adding an extra kicker. New optics for the fast extraction with a larger acceptance has been proposed. In this design, the thin septa are replaced by kickers with a large aperture. Beam with an arbitrary energy can be aborted from opposite side from the fast extraction. An external abort line has been designed to deliver the beam aborted with an arbitrary energy to a dump just by using a static quadrupole doublet for the focus.  
TUPAN072 Analysis of BEPCII Optics Using Orbit Response Matrix optics, sextupole, coupling, storage-ring 1544
  • Y. Wei
    IHEP Beijing, Beijing
  Funding: Work supported by Core University Program

Due to the errors in all kinds of components of storage ring, the real ring optics is different from the design one. A computer code LOCO is developed to calibrate the linear optics based on the closed orbit response matrix. This paper discusses mainly on the procedure and results of optics correction at BEPCII BPR. Using LOCO, we have determined the errors of quadrupole strengths, BPM gains and corrector kicks, and found the quadrupole strengths that best restore the design optics with sextupoles on. Optics measurement after correction shows the real optics agrees well with the design optics.


TUPAN076 Conceptual Design of the Beam Line for the PEFP User Facility proton, linac, target, optics 1547
  • Y.-S. Cho, B. Chung, J.-H. Jang, K. Y. Kim, Y.-H. Kim
    KAERI, Daejon
  Funding: The work was supported by the 21C Frontier R&D program in Ministry of Science and Technology of the Korean Government

The Proton Engineering Frontier Project (PEFP) will supply 20-MeV and 100-MeV proton beams from a 100 MeV proton linear accelerator for beam applications. The extracted 20 MeV or 100 MeV proton beams will be simultaneously distributed into the five targets through a dipole magnet equipped with a controllable AC power supply. The most important design criterion is the flexibility of the irradiation conditions in order to meet various user requirements in many application fields. For this purpose, we have designed the beamlines to the targets for wide or focused beams, external or in-vacuum beams, and horizontal or vertical beams. This work includes details of the conceptual design of the beamlines.

TUPAN077 Error Analysis of the PEFP 100 MeV Linac linac, controls, proton, simulation 1550
  • J.-H. Jang, Y.-S. Cho, K. Y. Kim, H.-J. Kwon
    KAERI, Daejon
  Funding: This work was supported by the 21C Frontier R&D program in Mnistry of Science and Technology of the Korean Government.

The 100 MeV Linac of the Proton Engineering Frontier Project (PEFP) consists of an ion source, a low energy beam transport (LEBT), a 3 MeV radio frequency quadrupole (RFQ), and an 100 MeV drift tube linac (DTL). The DTL is separated into two parts. The first part includes 4 tanks which accelerate 20 mA proton beams up to 20 MeV. The medium energy beam transport (MEBT) follows the 20 MeV accelerator in order to match proton beams into the next linac as well as to extract and supply 20 MeV proton beams to the user facilities. The second part of the DTL consists of 7 tanks to accelerate proton beams to 100 MeV. This work focuses on the error analysis of the designed 100 MeV linac in order to obtain the tolerance limit in the fabrication and alignment processes of the linac as well as to study the steering magnets which control the beam fluctuations and reduce the potential beam loss.

TUPAN079 Scheme for Flattening of Ion Density Distribution on a Target target, ion, octupole, simulation 1556
  • N. Yu. Kazarinov, G. Gulbekyan, V. I. Kazacha, V. N. Melnikov, V. I. Mironov
    JINR, Dubna, Moscow Region
  A scheme for flattening of the ion density distribution on a target is considered. The aim is to obtain the ion density distribution with deviation from the medium level not more than 5% on the target having rather big dimensions (up to ~60 cm in width and ~30 cm in height). Such kinds of targets are required for some technological purposes. The Xe ion beam extracted from a cyclotron has the following parameters: mass-to-charge ratio is 4.4, the kinetic energy is 4.2 MeV per nucleon, the beam current is 1 and the beam emittance is equal to 40 mm mrad. The ion beam line consists of quadrupoles doublet and oqtupole lens. After passimg through two quadrupoles the ion beam has big horizontal and small vertical dimensions. After that the oqtupole makes the horizontal ion beam density distribution on the target uniform withing the nessary demands. The geometry of the beam line, the quadrupole and oqtupole lens parameters are found during simulation. The simulated final beam density distribution on the target is also given.  
TUPAN081 Axial Injection Beam-Line of C400 Cyclotron for Hadron Therapy ion, cyclotron, injection, emittance 1562
  • N. Yu. Kazarinov, V. Aleksandrov, V. Shevtsov
    JINR, Dubna, Moscow Region
  • Y. Jongen
    IBA, Louvain-la-Neuve
  The axial injection beam-line of the C400 cyclotron for hadron therapy is presented. The influence of the strong magnetic field from the cyclotron on particles dynamics is taking into account during simulation. The effect of the beam space charge neutralization due to residual gas in the beam-line on parameters of the injected beam is evaluated.  
TUPAN089 The LHC Beampipe Waveguide Mode Reflectometer cryogenics, pick-up, controls, scattering 1583
  • F. Caspers, P. Borowiec, T. Kroyer, Z. Sulek, L. R. Williams
    CERN, Geneva
  Several specially developed waveguide-mode reflectometers for obstacle detection in the LHC magnet beampipes have been intensively used for more than 18 months. This "Assembly" version is based on the synthetic pulse method using a modern vector network analyzer. It has mode selective excitation couplers and uses a specially developed waveguide mode dispersion compensation algorithm with external software. In addition there is a similar "in situ" version of the reflectometer which uses permanently installed microwave couplers at the end of each of the nearly 3 km long LHC arcs. A considerable number of unexpected objects have been found in the beampipes and subsequently removed. Operational statistics and lessons learned are presented and the overall performance is discussed.  
TUPAN090 Parametric Field Modelling for the LHC Main Magnets in Operating Conditions dipole, injection, multipole, extraction 1586
  • M. DiCastro, L. Bottura, L. Deniau, N. J. Sammut, S. Sanfilippo, D. Sernelius, W. Venturini Delsolaro
    CERN, Geneva
  The first injections and ramps in the LHC will require a prediction of the settings of the main ring powering circuits as well as the main correctors. For this reason we are developing a parametric model of the magnetic field generated by the LHC magnets that will provide the field dependence on current, ramp-rate, time, and history. The model of the field is fitted on magnetic field measurements performed during the acceptance tests in operating conditions before their installation in the machine. In this paper we summarise the different steps necessary to select the relevant data and identify the parameters: the data extraction, the cleaning and the validation of the measurements, and the fitting procedure that is used to obtain the parameters from the experimental results. The main result reported is a summary of the value of the parameters obtained with the above procedure, and describing the behaviour of the magnetic field in the LHC main superconducting magnets (i.e. arc, dispersion suppressors and matching sections).  
TUPAN101 Tracking Studies with Variable Magnetic Field to Characterize Quadrupole Failures in LHC beam-losses, resonance, injection, simulation 1616
  • A. Gomez Alonso, R. Schmidt
    CERN, Geneva
  During LHC operation, energies up to 360 MJ will be stored in each proton beam and more than 10 GJ in the superconducting magnets. With these energies, a magnet failure can lead to important equipment damage if the beam is not extracted in time. The machine protection systems should detect such failures and trigger the beam extraction system. In order to characterize the beam response after magnet failures, tracking simulations have been performed with MAD-X. The magnetic field was set to change with time according to realistic current changes in the electrical circuits with the magnets after a powering failure. The effect on the beam of powering failures in the normal conducting quadrupoles has been studied. For fast failures (beam lost in less than 100 ms) the nonlinear effects are negligible. For slower failures, higher order resonances may lead to beam losses of up to ~8% of the beam.  
TUPAN114 RF Design Options for a 180 MeV H- Linac for Megawatt Beam Facilities linac, proton, impedance, factory 1643
  • D. C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  Future projects like a neutrino factory or an advanced spallation neutron source require high power proton accelerators capable of producing beams in the multi-MW range. The quality of the beam delivered to the target is very much dictated by the accelerator front end and by the lower energy linac. Prompted by the Front End Test Stand (FETS) under construction at RAL, a new 180 MeV H- linac is being considered as a possible replacement for the aging current 70 MeV ISIS injector, and the same linac has also been included in designs for the proton driver for a possible UK Neutrino Factory. In this paper, different RF design options are analysed and a general layout for the new linac is presented based on two accelerating structures to raise the beam energy from 3 to 180 MeV: a 324 MHz Drift Tube Linac (DTL) making use of commercial Toshiba klystrons, followed by Side Coupled Linac (SCL) with a triple frequency jump at the transition between the two structures.  
TUPAN115 Comparative Study of Beam Dynamics in LINAC4 using CERN and RAL MEBT (Medium Energy Beam Transport) Lines linac, emittance, simulation, beam-transport 1646
  • D. C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • E. Zh. Sargsyan
    CERN, Geneva
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, Contract No. RII3-CT-2003-506395).

CERN and RAL are working in parallel to develop Front Ends for future particle accelerators. At CERN the Front End will be part of LINAC4, a potential replacement for the Linac2 accelerator, whilst at RAL the Front End is intended to demonstrate that a high current, high quality chopped beam is achievable and that the design could be used as part of a Proton Driver for a future Neutrino Factory. The two Front End designs have many similarities and basically consist of four main components: an H- ion source, a Low Energy Beam Transport (LEBT) matching into a Radio-Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) line with a fast beam chopper. The beam choppers are different in the two designs and it is important to compare the effectiveness of the two methods of operation. This paper describes a simulation study of high intensity beam dynamics and beam transport when the RAL and CERN MEBT designs are each fed into the same CERN structure for LINAC4.

TUPAS002 RFQ Cold Model RF Measurements and Waveguide-to-Coaxial line Transition Design for the Front-End Test Stand at RAL rfq, simulation, klystron, factory 1655
  • Y. Cheng, A. Kurup, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  • A. P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • J. K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon
  A 324MHz four vane RFQ cold model has been built, as part of the development of a proton driver front end test stand at the Rutherford Appleton Laboratory (RAL) in the UK. This paper will present the results of RF measurements performed on the cold model, which include analysis of resonant modes, Q-value measurements and electric field profile measurements using a bead-pull perturbation method. These measurements were done before and after brazing of the four vanes and the results were compared to Microwave Studio simulations. Additionally a tuner has been designed, built and tested and the results will be presented together with the electromagnetic design of waveguide-to-coaxial line transition structures for the four vane RFQ.  
TUPAS012 Start-to-End Simulations for the Proposed Fermilab High Intensity Proton Source simulation, emittance, lattice, collimation 1676
  • J.-P. Carneiro, D. E. Johnson
    Fermilab, Batavia, Illinois
  A High Intensity Proton Source consisting in an 8 GeV superconducting H-minus linac and transfer line to the Main Injector has been proposed. The primary mission is to increase the intensity of the Fermilab Main Injector for the production of neutrino superbeams. Start-to-end simulations from the RFQ to the stripping foil using the simulation code TRACK (ANL) will be presented in this paper. In particular, we will study the impact of errors (jitters and alignments) on the H- phase space at the entrance of the stripping foil.  
TUPAS015 Operational Aspects of the Main Injector Large Aperture Quadrupole lattice, beam-losses, extraction, injection 1685
  • W. Chou, C. L. Bartelson, B. C. Brown, D. Capista, J. L. Crisp, J. DiMarco, J. Fitzgerald, H. D. Glass, D. J. Harding, B. Hendricks, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, T. Sager, M. Tartaglia, L. Valerio, R. C. Webber, M. Wendt, D. Wolff, M.-J. Yang
    Fermilab, Batavia, Illinois
  Funding: Work supported by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Dept. of Energy.

A two-year Large Aperture Quadrupole (WQB) Project was completed in the summer of 2006 at Fermilab.* Nine WQBs were designed, fabricated and bench-tested by the Technical Division. Seven of them were installed in the Main Injector and the other two for spares. They perform well. The aperture increase meets the design goal and the perturbation to the lattice is minimal. The machine acceptance in the injection and extraction regions is increased from 40π to 60π mm-mrad. This paper gives a brief report of the operation and performance of these magnets. Details can be found in Ref**.

* D. Harding et al, "A Wide Aperture Quadrupole for the Fermilab Main Injector," this conference.
** W. Chou, Fermilab Beams-doc-#2479, http://beamdocs.fnal.gov/AD-public/DocDB/DocumentDatabase

TUPAS017 Tune Drifts on the Tevatron Front Porch dipole, sextupole, coupling, multipole 1691
  • N. M. Gelfand
    Fermilab, Batavia, Illinois
  Funding: Operated by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

Measurements of the tune on the front porch of the Tevatron* showed a drift of the tune which tracked the time dependence of the sextupole moment in the dipoles. Calculations using survey data to calculate the closed orbit failed to reproduce the observed tune shifts. The feed down of these sextupole moments generates a quadrupole field at the ends of the dipoles. It is suggested, based on calculations, that the change in the sextupole moment of the dipoles also produces a change in the strength of the strength of the zero length quadrupole incorporated in the end of the dipoles and that this change can account for the observed tune drifts.

*Tevatron Chromaticity and Tune Drift and Snapshot Studies Report, G. Annala, P. Bauer, M. Martens, D. Still, G. Velev, Beams-doc-1236 (Jan. 5,2005)

TUPAS028 Upgrades to the Fermilab NuMI Beamline target, proton, antiproton, booster 1712
  • M. A. Martens, S. C. Childress, N. L. Grossman, P. Hurh, J. Hylen, A. Marchionni, E. McCluskey, C. D. Moore, R. E. Reilly, S. Tariq, A. Wehmann, K. E. Williams, R. M. Zwaska
    Fermilab, Batavia, Illinois
  Funding: Operated by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

The NuMI beamline at Fermilab has been operational since the spring of 2005 delivering high-intensity neutrino beams to the MINOS experiment. A beam power on target of 310 kW has been achieved and a total of more than 2·1020 protons have been delivered to the NuMI target. Upgrades to NuMI are planned in preparation for the future MINERvA and NOvA neutrino experiments increasing the NuMI beam power capability from 400 kW to 700 kW and then as much as 1.2 MW. An overview of the future upgrade to NuMI is presented.

TUPAS031 Analysis of Optics Designs for the LHC IR Upgrade optics, luminosity, sextupole, resonance 1718
  • T. Sen, J. A. Johnstone
    Fermilab, Batavia, Illinois
  We consider the different options proposed for the LHC IR upgrade. The two main categories: quadrupoles first (as in the baseline design) and dipoles first have complementary strengths. We analyse the potential of the proposed designs by calculating important performance parameters including luminosity reach, beam-beam resonances and chromaticity contributions. The goal is to enable a decision on the design path based on objective criteria.  
TUPAS033 Field Fluctuation and Beam Screen Vibration Measurements in the LHC Magnets dipole, betatron, emittance, resonance 1724
  • V. D. Shiltsev
    Fermilab, Batavia, Illinois
  • T. Kroyer, R. de Maria
    CERN, Geneva
  We present experimental methods and results of magnetic field fluctuation and beam screen vibration measurements in the LHC magnets. These noises can lead to an emittance grwoth in proton beams if they have spectral components at the betatron lines. A preliminary estimates of the effects are given.  
TUPAS047 Multi-turn Operation of the University of Maryland Electron Ring (UMER) injection, dipole, electron, space-charge 1751
  • M. Walter, G. Bai, B. L. Beaudoin, S. Bernal, D. W. Feldman, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, M. Reiser, D. Stratakis, D. F. Sutter, J. C.T. Thangaraj, C. Wu
    UMD, College Park, Maryland
  Funding: This work is funded by US Dept. of Energy grant numbers DE-FG02-94ER40855 and DE-FG02-92ER54178.

The University of Maryland Electron Ring (UMER) is a low energy, high current recirculator for beam physics research. The electron beam current is adjustable from 0.7 mA, an emittance dominated beam, to 100 mA, a strongly space charge dominated beam. UMER is addressing issues in beam physics relevant to many applications that require intense beams of high quality such as advanced concept accelerators, free electron lasers, spallation neutron sources, and future heavy-ion drivers for inertial fusion. The primary focus of this presentation is experimental results and improvements in multi-turn operation of the electron ring. Transport of a low current beam over 100 turns (3600 full lattice periods) has been achieved. Results of high current, space charge dominated multi-turn transport will also be presented.

TUPAS048 Beam Extraction Concepts and Design for the University of Maryland Electron Ring (UMER) extraction, dipole, injection, electron 1754
  • M. Walter, G. Bai, B. L. Beaudoin, S. Bernal, D. W. Feldman, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, M. Reiser, D. Stratakis, D. F. Sutter, J. C.T. Thangaraj, C. Wu
    UMD, College Park, Maryland
  Funding: This work is funded by US Dept. of Energy grant numbers DE-FG02-94ER40855 and DE-FG02-92ER54178.

The University of Maryland Electron Ring (UMER) is a low energy, high current recirculator for beam physics research. The electron storage ring has been closed and recent operations have been focused on achieving multi-turn transport. An entire suite of terminal diagnostics is available for time-resolved phase space measurements of the beam. These diagnostics have been mounted and tested at several points on the ring before it was closed. UMER utilizes a unique injection scheme which uses the fringe fields of an offset quadrupole to assist a pulsed dipole in bending the beam into the ring. Similar concepts, along with more traditional electrostatic methods, are being considered for beam extraction. This presentation will focus on the recent efforts to design and deploy these major subsystems required for beam extraction.

TUPAS050 Determination of Component Activation and Radiation Environment in the Second Stripping Region of a High-Power Heavy-Ion Linear Accelerator simulation, radiation, ion, radioactivity 1760
  • I. Baek, R. M. Ronningen, X. Wu, A. Zeller
    NSCL, East Lansing, Michigan
  • R. Remec
    ORNL, Oak Ridge, Tennessee
  Funding: U. S. Department of Energy under Grant No. DE-FG02-04ER41313

In supporting pre-conceptual research and development of the Rare-Isotope Accelerator facility or similar next-generation exotic beam facilities, one critical focus area is to estimate the level of activation and radiation in the linear accelerator second stripping region and to determine if remote handling is necessary in this area. A basic geometric layout of the second stripping region having beamline magnets, beam pipes and boxes, a stripper foil, beam slits, and surrounding concrete shielding was constructed for Monte Carlo simulations. Beam characteristics were provided within the stripping region based on this layout. Radiation fields, radioactive inventories, levels of activation, heat loads on surrounding components, and prompt and delayed radiation dose rates were simulated using Monte-Carlo radiation transport code PHITS. Preliminary results from simulations using a simplified geometry show that remote handling of foils and slits will be necessary. Simulations using a realistic geometry are underway and the results will be presented.

TUPAS051 Radiation Simulations for a Pre-Separator Area for Rare Isotope Production via Projectile Fragmentation target, radiation, dipole, simulation 1763
  • I. Baek, G. Bollen, M. Hausmann, D. Lawton, R. M. Ronningen, A. Zeller
    NSCL, East Lansing, Michigan
  Funding: U. S. Department of Energy under Grant No. DE-FG02-04ER41313

To support pre-conceptual research and development for rare isotope beam production via projectile fragmentation at the Rare-Isotope Accelerator facility or similar next-generation exotic beam facilities, the interactions between primary beams and beryllium and liquid-lithium production targets in the fragment pre-separator area were simulated using the Monte-Carlo radiation transport code PHITS. The purpose of this simulation is to determine the magnitude of the radiation fields in the pre-separator area so that levels of hadron flux and energy deposition can be obtained. It was of particular interest to estimate the maximum radiation doses to magnet coils and other components such as the electromagnetic pump for a liquid-lithium loop, and to estimate component lifetimes. We will show a detailed geometry of the pre-separator area developed for these simulations. We will provide verification that trajectories of beams and fragments when transported in the PHITS simulations agree with results from standard ion-optics calculations. We will present estimates of radiation doses to pre-separator components and give estimates for component lifetimes.

TUPAS054 Design Studies of the Reaccelerator RFQ at NSCL rfq, emittance, linac, focusing 1772
  • Q. Zhao, V. Andreev, F. Marti, S. O. Schriber, X. Wu, R. C. York
    NSCL, East Lansing, Michigan
  Rare Isotope Beams (RIBs) are created at the National Superconducting Cyclotron Laboratory (NSCL) by the in-flight particle fragmentation method. A novel system is proposed to stop the RIBS in a helium filled gas system followed by a reacceleration that will provide opportunities for an experimental program ranging from low-energy Coulomb excitation and to transfer reaction studies of astrophysical reactions. The beam from the gas stopper will first be brought into a Electron Beam Ion Trap (EBIT) charge breeder on a high voltage platform to increase its charge state and then accelerated initially up to about 3 MeV/u by a system consisting of an external multi-harmonic buncher and a Radio Frequency Quadrupole (RFQ) followed a superconducting linac. The planned RFQ will operate in the cw mode at a frequency of 80.5MHz to accelerate ion beams from ~12 keV/u to ≥ 300keV/u. An external multi-harmonic buncher will be used to produce a small longitudinal emittance beam out of the RFQ. In this paper, we will describe the design of the RFQ, present the beam dynamics simulation results, and also discuss the impact of the external buncher harmonics on the output beam properties.  
TUPAS070 Optimization of Chromatic Optics Near the Half Integer in PEP-II lattice, luminosity, sextupole, optics 1814
  • G. Yocky, Y. Cai, F.-J. Decker, Y. Nosochkov, U. Wienands
    SLAC, Menlo Park, California
  • P. Raimondi
    INFN/LNF, Frascati (Roma)
  Measurements of the W-function in PEP-II during Run 5 revealed that the chromatic beta functions in both the HER and LER were not optimized. Through a process of measurement, offline analysis and modelling, and high-current run implementation the PEP-II collider luminosity performance was increased by at least 10% by reconfiguring the strengths of sextupoles near the IP to take advantage of a minimized W and increased IP bandwidth.  
TUPAS074 Performance of the SNS Front End and Linac linac, beam-losses, radiation, target 1820
  • A. V. Aleksandrov, S. Assadi, W. Blokland, P. Chu, S. M. Cousineau, V. V. Danilov, C. Deibele, J. Galambos, S. Henderson, D.-O. Jeon, M. A. Plum, A. P. Shishlo, M. P. Stockli, Y. Zhang
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.

The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H- injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The 2.5 MeV beam from the Front End is accelerated to 86 MeV in the Drift Tube Linac, then to 185 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. With the completion of beam commissioning, the accelerator complex began operation in June 2006 and beam power is being gradually ramped up toward the design goal. Operational experience with the injector and linac will be presented including chopper performance, transverse emittance evolution along the linac, and the results of a beam loss study.

TUPAS075 The New LEBT for the Spallation Neutron Source Power Upgrade Project dipole, rfq, ion, ion-source 1823
  • B. Han, M. P. Stockli
    ORNL, Oak Ridge, Tennessee
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.

Beam envelope calculations show that a solenoid-drift-(singlet quad)-(sector dipole)-(singlet quad)-drift-solenoid LEBT allows for transporting 65-kV, high-current H- beams with smaller beam radii than the initially-explored (doublet quad)-drift-(double-focusing dipole)-drift-solenoid configuration. In addition, it appears that the new configuration is more robust because it allows for perfect matching of the final beam parameters for broad ranges of the parameters describing the lattice and the input beam. Such a LEBT with a dipole (switching-) magnet is required to assure meeting the 99% ion source availability requirement after upgrading the power of the Spallation Neutron Source. The SNS power upgrade will roughly double the neutron flux by increasing the proton beam energy from 1 to 1.3 GeV and by increasing the LINAC beam peak current from 38 to 59 mA. Because the RFQ losses increase with beam current and emittance, the RFQ input current needs to be increased from 41 to 67 mA if the normalized emittance can be maintained at 0.2 mm-mrad, or to 95 mA if the emittance increases to 0.35 mm-mrad.

TUPAS083 Design and Performance of the Matching Beamline between the BNL EBIS and an RFQ ion, rfq, emittance, injection 1844
  • J. G. Alessi, E. N. Beebe, J. Brodowski, A. Kponou, M. Okamura, A. I. Pikin, D. Raparia, J. Ritter, L. Snydstrup, V. Zajic
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the U. S. Department of Energy and the U. S. National Aeronautics and Space Administration.

A part of a new EBIS-based heavy ion preinjector, the low energy beam transport (LEBT) section between the high current EBIS and the RFQ is a challenging design, because it must serve many functions. In addition to the requirement to provide an efficient matching between the EBIS and the RFQ, this line must serve as a fast switchyard, allowing singly charged ions from external sources to be transported into the EBIS trap region, and extracted, highly charged ions to be deflected to off-axis diagnostics (time-of-flight, or emittance). The space charge of the 5-10 mA extracted heavy ion beam is a major consideration in the design, and the space charge force varies for different ion beams having Q/m from 1-0.16. The line includes electrostatic lenses, spherical and parallel-plate deflectors, magnetic solenoid, and diagnostics for measuring current, charge state distributions, emittance, and profile. A prototype of this beamline has been built, and results of tests will be presented.

TUPAS086 Snake Depolarizing Resonance Study in RHIC resonance, polarization, betatron, proton 1850
  • M. Bai, P. Cameron, H. Huang, A. U. Luccio, V. Ptitsyn, T. Roser, S. Tepikian
    BNL, Upton, Long Island, New York
  Funding: US Department of Energy, RIKEN(Japan), Renaissance Technologies Corp.(USA)

Snake depolarizing resonances due to the imperfect cancellation of the accumulated perturbations on the spin precession between snakes were observed at the Relativistic Heavy Ion Collider~(RHIC). During the RHIC 2005 and 2006 polarized proton runs, we mapped out the spectrum of odd order snake resonance at Qy=7/10. Here, Qy is the beam vertical betatron tune. We also studied the beam polarization after crossing the 7/10th resonance as a function of resonance crossing rate. This paper reports the measured resonance spectrum as well as the results of resonance crossing.

The work was performed under the US Department of Energy Contract No. DE-AC02-98CH1-886, and with support of RIKEN(Japan) and RenaissanceTechnologies C orp.(USA)

TUPAS098 RHIC Beam-Based Sextupole Polarity Verification sextupole, dipole, optics, injection 1868
  • Y. Luo, P. Cameron, A. Della Penna, T. Satogata, D. Trbojevic
    BNL, Upton, Long Island, New York
  Funding: Work supported by U. S. DOE under contract No DE-AC02-98CH10886.

A beam-based method was proposed and applied to check the polarities of the arc sextupoles in the Relativistic Heavy Ion Collider (RHIC) with repetitive local horizontal bumps. Wrong sextupole polarities can be easily identified from mismatched signs and amplitudes of the horizontal and vertical tune shifts from bump to bump and/or from arc to arc. This check takes less than 2 hours for both RHIC Blue and Yellow rings. Tune shifts in both planes during this study were tracked with a high-resolution baseband tunemeter (BBQ) system. This method was successfully used to the sextupole polarity check in the RHIC run06.

WEOCAB02 Automatic Luminosity Optimisation of the ILC Head-On BDS luminosity, linear-collider, collider, extraction 1988
  • J. Payet, S. Auclair, A. Chance, O. Napoly, D. Uriot
    CEA, Gif-sur-Yvette
  Funding: EUROTeV Project Contract no.011899 RIDS

With the local chromaticity correction scheme, the luminosity optimisation of the beam delivery systems of the e+ e- International Linear Collider (ILC) project is challenging. A manual optimization is a long and complex process and its automation becomes a necessity. Recent works have shown that it was possible to employ a simplex minimization method, applied to the beam size calculation at the Interaction Point (IP), to reach this objective automatically *. To achieve this goal in the ILC case, we have developed a minimization code which uses analytical computations of the IP beam sizes based on external code results, TRANSPORT** or MADX (with PTC extension)***. Two minimization algorithms can be employed. The maximum luminosity reached and the convergence time of the two codes and algorithms are compared. We also used the code TRACEWIN which tracks a particle cloud and minimise the rms beam spot sizes at IP to optimise the luminosity, and we compare with the previous results.

* Non-linear optimization of beam lines, R. Tomas, CLIC Note 659** Third-Order TRANSPORT with MAD Input, D. C. Carey, K. L. Brown and F. Rothacker, FERMILAB-Pub-98/310*** MADX User's Guide CERN

slides icon Slides  
WEZC01 Phase Space Tomography of Beams with Extreme Space Charge space-charge, simulation, emittance, electron 2025
  • D. Stratakis, S. Bernal, R. B. Fiorito, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, M. Reiser, J. C.T. Thangaraj, K. Tian, M. Walter
    UMD, College Park, Maryland
  Funding: This work is funded by US Dept. of Energy grant numbers DE-FG02-94ER40855 and DE-FG02-92ER54178, and the office of Naval Research grant N00014-02-1-0914.

A common challenge for accelerator systems is to maintain beam quality and brightness over the usually long distance from the source to the target. In order to do so, knowledge of the beam distribution in both configuration and velocity space along the beam line is needed. However, measurement of the velocity distribution can be difficult, especially for beams with strong space charge. Here we present a simple and portable tomographic method to map the beam phase space, which can be used in the majority of accelerators. The tomographic reconstruction process has first been compared with results from simulations using the particle-in-cell code WARP. Results show excellent agreement even for beams with extreme space charge and exotic distributions. Our diagnostic has also been successfully demonstrated experimentally on the University of Maryland Electron Ring, a compact ring designed to study the transverse dynamics of beams in both emittance and space charge dominated regimes. Special emphasis is given to intense beams where our phase space tomography diagnostic is used to shed light on the consequences of the space charge forces on the transport of these beams.

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WEPMN008 Vibration Stability Studies of a Superconducting Accelerating Module at Room Temperature vacuum, resonance, ground-motion, site 2062
  • R. Amirikas, A. Bertolini, W. Bialowons
    DESY, Hamburg
  Funding: Work supported by the Commission of the European Communities under the 6th Framework Program Structuring the European Research Area, contract number RIDS-011899.

In this presentation, we will report on a comprehensive vibration measurement program of a superconducting accelerating module designed for the European X-ray Free Electron Laser (XFEL), currently planned at DESY, at room temperature. This module is a type III, high gradient module which is also the basis of module design for the International Linear Collider (ILC). We will discuss stability within the vessel, for example, cold mass vs. He Gas Return Pipe (GRP), as well as stability along the length of the module. Results of this study may be used for the design of future XFEL/ILC module prototypes.

WEPMN009 Vibration Stability Studies of a Superconducting Accelerating Module Quadrupole Operating at 4.5K cryogenics, vacuum, damping, linac 2065
  • R. Amirikas, A. Bertolini, W. Bialowons
    DESY, Hamburg
  Funding: Work supported by the Commission of the European Communities under the 6th Framework Program Structuring the European Research Area, contract number RIDS-011899.

The European X-ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) superconducting accelerating modules, containing a string of Niobium (Nb) cavities and a quadrupole, will operate at 2K. In this paper, we will report on the vibration stability studies of a high gradient XFEL/ILC type III superconducting accelerating module quadrupole operating at 4.5K. Measurements are performed via geophones affixed on the cold mass in both horizontal and vertical directions. This data will be compared with piezoelectric accelerometers for the same module. The goal is to study the stability of the cold quadrupole and to compare the results with room temperature conditions.

WEPMN104 Mechanical Stability Study of Type IV Cryomodule (ILC Prototype) vacuum, linac, alignment, simulation 2277
  • M. McGee, R. Doremus, R. Wands
    Fermilab, Batavia, Illinois
  An ANSYS modal and harmonic finite element analysis (FEA) was performed in order to investigate cryomodule design mechanical stability for the proposed International Linear Collider (ILC). The current cryomodule, designated Type IV or T4CM, closely follows the Type III TESLA Test Facility (TTF) version used at DESY, with the exception of a proposed location of the superconducting (SC) quadrupole at the center. This analysis considered the stringent stability criteria established for the ILC, where vertical motion for the SC quad is limited to the micron range, at a few Hz. Model validation was achieved through Type II cryomodule vibration measurement studies performed at DESY. The effect of support location, support stiffness and other important parameters were considered in a parametric sensitivity study. FEA results, fast motion investigations and stabilization techniques are discussed.

Operated by Universities Research Association, Inc., under Contract No. DE-AC02-76CH03000 with the U. S. Department of Energy#mcgee@fnal.gov

WEPMN118 Mechanical Design and Analysis of a 200 MHz, Bolt-together RFQ for the Accelerator Driven Neutron Source rfq, vacuum, target, gun 2313
  • S. P. Virostek, M. D. Hoff, D. Li, J. W. Staples, R. P. Wells
    LBNL, Berkeley, California
  Funding: This work was supported by the U. S. Dept. of Energy under Contract No. DE-AC02-05CH11231 and by the Dept. of Homeland Security's Domestic Nuclear Detection Office under Award No. HSHQPB-05-X-00033.

A high-yield neutron source to screen sea-land cargo containers for shielded Special Nuclear Materials (SNM) has been designed at LBNL. The Accelerator-Driven Neutron Source (ADNS) utilizes the D(d,n)3He reaction to produce a forward directed neutron beam. Key components are a high-current radio-frequency quadrupole (RFQ) accelerator and a high-power neutron production target capable of delivering a neutron flux of >107 n/(cm2 s) at a distance of 2.5 m. The mechanical design and analysis of the four-module, bolt-together RFQ will be presented here. Operating at 200 MHz, the 5.1 m long RFQ will accelerate a 40 mA deuteron beam to 6 MeV. At a 5% duty factor, the time-average d+ beam current on target is 1.5 mA. Each of the 1.27 m long RFQ modules will consist of four solid OFHC copper vanes. A specially designed 3-D O-ring will be used to provide vacuum sealing between both the vanes and the modules. RF connections are made by means of canted coil spring contacts. Quadrupole mode stabilization is obtained with a series of 60 water-cooled pi-mode rods. A set of 80 evenly spaced fixed slug tuners is used for final frequency adjustment and local field perturbation correction.

THXKI02 Room Temperature Structure Development for High-Current Applications rfq, linac, proton, focusing 2564
  • R. Ferdinand
    GANIL, Caen
  A lot of new high current accelerators use both room temperature and superconducting structures. While it is clear that low beam current, low duty cycle accelerator should push for superconducting cavities, high current CW applications still prefers room temperature structure. This mainly depends on the accelerator constrains and objectives. This talk will present an overview of the worldwide activities and recent developments of room temperature structures for high-current applications.  
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THOBAB02 Commissioning the DARHT-II Scaled Accelerator Downstream Transport target, kicker, septum, dipole 2627
  • M. E. Schulze
    SAIC, Los Alamos, New Mexico
  • E. O. Abeyta, P. Aragon, R. Archuleta, J. Barraza, D. Dalmas, C. Ekdahl, K. Esquibel, S. Eversole, R. J. Gallegos, J. F. Harrison, E. Jacquez, J. Johnson, P. S. Marroquin, B. T. McCuistian, N. Montoya, S. Nath, L. J. Rowton, R. D. Scarpetti, M. Schauer
    LANL, Los Alamos, New Mexico
  • R. Anaya, G. J. Caporaso, F. W. Chambers, Y.-J. Chen, S. Falabella, G. Guethlein, J. F. McCarrick, B. A. Raymond, R. A. Richardson, J. A. Watson, J. T. Weir
    LLNL, Livermore, California
  • H. Bender, W. Broste, C. Carlson, D. Frayer, D. Johnson, A. Tipton, C.-Y. Tom
    NSTec, Los Alamos, New Mexico
  • T. C. Genoni, T. P. Hughes, C. H. Thoma
    Voss Scientific, Albuquerque, New Mexico
  The DARHT-II accelerator will produce a 2-kA, 17-MeV beam in a 1600-ns pulse when completed this summer. After exiting the accelerator, the long pulse is sliced into four short pulses by a kicker and quadrupole septum and then transported for several meters to a tantalum target for conversion to bremsstrahlung for radiography. We describe tests of the kicker, septum, transport, and multi-pulse converter target using a short accelerator assembled from the first available refurbished cells, which are now capable of operating of operating at over 200 kV. This scaled accelerator was operated at ~ 8 Mev and ~1 kA, which provides a beam with approximately the same nu/gamma as the final 17-MeV, 2-kA beam, and therefore the same beam dynamics in the downstream transport. The results of beam measurements made during the commissioning of this scaled accelerator downstream transport are described.  
slides icon Slides  
THPMN004 A Synchrotron Based Particle Therapy Accelerator synchrotron, vacuum, injection, extraction 2713
  • S. P. M?ller, T. Andersen, F. Bødker, A. Baurichter, P. A. Elkiaer, C. E. Hansen, N. Hauge, T. Holst, I. Jensen, L. K. Kruse, S. M. Madsen, M. Sager, S. V. Weber
    Danfysik A/S, Jyllinge
  • K. Blasche
    BTE Heidelberg, Ingeniurburo, Schriesheim
  • B. J. Franczak
    GSI, Darmstadt
  Danfysik and Siemens have entered a cooperation to market and build Particle Therapy* systems for cancer therapy. The accelerators will consist of an injector (7 MeV/u proton and light ions), a compact and simple synchrotron and a choice of fixed-angle horizontal and semi-vertical beamlines together with gantry systems. The optimized lattice configuration, including the design of injection and extraction systems, provides large transverse phase space acceptance with minimum magnet apertures. The resulting synchrotron will have light magnets, low values of peak power for pulsed operation and minimum dc power consumption. The beam can be accelerated to the maximum magnetic rigidity of 6.6 Tm in less than 1 s. A beam of 48-250 MeV protons and 88-430 MeV/u carbon ions can be slowly extracted during up to 10s. The intensity for protons and carbon ions will be well beyond the needs of scanning beam applications. The design and performance specs of the synchrotron will be described in detail including simulations. Design and manufacture of the subsystems are in progress. *Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.  
THPMN005 Technical Challenges for Head-On Collisions and Extraction at the ILC extraction, luminosity, optics, collimation 2716
  • O. Napoly, O. Delferriere, M. Durante, J. Payet, C. Rippon, D. Uriot
    CEA, Gif-sur-Yvette
  • M. Alabau, P. Bambade, J. Brossard, O. Dadoun, C. Rimbault
    LAL, Orsay
  • D. A.-K. Angal-Kalinin, F. Jackson, S. I. Tzenov
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Appleby
    UMAN, Manchester
  • B. Balhan, J. Borburgh, B. Goddard
    CERN, Geneva
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • L. Keller
    SLAC, Menlo Park, California
  • S. Kuroda
    KEK, Ibaraki
  • G. L. Sabbi
    LBNL, Berkeley, California
  Funding: EUROTeV Project Contract no.011899 RIDS

An interaction region with head-on collisions is considered as an alternative to the baseline ILC configuration. Progress in the final focus optics design includes engineered large bore superconducting final doublet magnets and their 3D magnetic integration in the detector solenoids. Progress on the beam separation optics is based on technical designs of electrostatic separator and special extraction quadripoles. The spent beam extraction is realized by a staged collimation scheme relying on realistic collimators. The impact on the detector background is estimated. The possibility of technical tests of the most challenging components is investigated.

THPMN006 Modification and Measurement of the Adjustable Permanent Magnet Quadrupole for the Final Focus in a Linear Collider permanent-magnet, linear-collider, collider, optics 2719
  • Y. Iwashita, H. Fujisawa, M. Ichikawa, Y. Tajima
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • S. Kuroda, T. Okugi, T. Tauchi
    KEK, Ibaraki
  • C. M. Spencer
    SLAC, Menlo Park, California
  Funding: This research was partially supported by JSPS, Grant-in-Aid for Scientific Research, 14204023-2002, 18204023-2006 and the U. S. DOE under contract DE-AC02-76SF00515.

An adjustable permanent magnet quadrupole has been developed for the final focus in an electron-positron linear collider. The design has two concentric rings of permanent magnets. Recent activities include a newly fabricated inner ring that demonstrates the strongest field gradient at a small bore diameter of 15mm and a new magnetic field measurement system based on a rotating coil. The prospects of the R&D will be discussed.

THPMN012 A 0.5 to 50 MeV Electron Linear Accelerator System electron, dipole, beam-transport, bunching 2731
  • C. Piel, K. Dunkel, C. Schulz
    ACCEL, Bergisch Gladbach
  Since 1998 ACCEL delivers turn key accelerator for scientific applications. After three injector systems for synchrotron light sources have been successfully commissioned, ACCEL is currently producing a 5 to 50 MeV system for the German Metrological Institute in Braunschweig. Beside excellent beam energy qualities the accelerator has to operate in a wide energy range, delivering 1 to 100 W average beam power to the target. The paper will give a description of the system layout and related technical parameters. The status of the project and results of the factory acceptance test of some of the major components will be presented as well.  
THPMN015 Longitudinal Electrode Voltage Distribution on a 4-rod RFQ Simulation Model simulation, rfq 2737
  • P. Fischer, N. Mueller, A. Schempp
    IAP, Frankfurt am Main
  For a proper working RFQ with minimized particle losses, a constant longitudinal voltage distribution on the electrodes is needed. This assures a sufficient compensation of the beam space change. The local electrode voltage and its change is mainly given by the varying aperture of the quadrupole and in consequence the changing local capacity. The simulation of the RFQ model with modulated electrodes is a very complex thread. An example for such a model will be given here.  
THPMN045 Design and Control of Emittance Growth of Short Bunch Compressor for International Linear Collider emittance, lattice, optics, alignment 2814
  • E.-S. Kim
    Kyungpook National University, Daegu
  We present an alternative design with the short system length in the bunch compressors for the International Linear Collider(ILC). We show the characteristics and performances of the designed system in detail. We also present orbit and dispersion correction schemes for the compensation of emittance growths, vertical dispersion and skew-component that may be generated by several machine errors in the system. In result, it is shown that the short bunch compressor system satisfies the required beam conditions for the ILC.  
THPMN057 New Concept for a CLIC Post-Collision Extraction Line photon, extraction, vacuum, dipole 2835
  • A. Ferrari
    UU/ISV, Uppsala
  Funding: This work is supported by the Commission of the European Communities under the 6th Framework Programme "Structuring the European Research Area", with contract number RIDS-011899.

Strong beam-beam effects at the interaction point of a high-energy e+e- linear collider such as CLIC lead to an emittance growth for the outgoing beams, as well as to the production of beamstrahlung photons and e+e- coherent pairs. We present a conceptual design of the post-collision line for CLIC at 3 TeV, which separates the various components of the outgoing beam in a vertical magnetic chicane and then transports them to their respective dump.

THPMN058 Beam Dynamics Studies in the CLIC Injector Linac linac, positron, emittance, electron 2838
  • A. Ferrari
    UU/ISV, Uppsala
  • A. Latina, L. Rinolfi, F. Tecker
    CERN, Geneva
  The CLIC Injector Linac has to accelerate both electron and positron main beams from 200 MeV up to 2.42 GeV prior to their injection into the pre-damping rings. Its 26 accelerating structures operate at 1.875 GHz, with a loaded gradient of 17 MV/m. A FODO lattice that wraps the accelerating structures at the beginning of the linac, followed by a succession of triplet lattices between the accelerating structures, is proposed. The large transverse emittance (9200 mm.mrad), bunch length (5 mm) and energy spread (7 MeV) of the positron beam set constraints on the linac in order to reach acceptable characteristics at 2.42 GeV for the injection into the pre-damping ring. The use of a bunch compressor at the entrance of the linac is an option in order to achieve good performance in both the longitudinal and transverse phase spaces. Tracking studies of both electron and positron beams in the linac have been performed and are presented.  
THPMN061 Bunch Compressor for Beam-Based Alignment linac, emittance, alignment, simulation 2844
  • A. Latina, D. Schulte
    CERN, Geneva
  • P. Eliasson
    Uppsala University, Uppsala
  Funding: Supported by the European Community under the 6th Framework Programme "Structuring the European Research Area".

Misalignments in the main linac of future linear colliders can lead to significant emittance growth. Beam-based alignment algorithms, such as Dispersion Free Steering (DFS), are necessary to mitigate these effects. We study how to use the Bunch Compressor to create the off-energy beams necessary for DFS and discuss the effectiveness of this method.

THPMN062 Dynamic Effects During Beam-Based Alignment emittance, alignment, linac, simulation 2847
  • D. Schulte, P. Eliasson, A. Latina
    CERN, Geneva
  Funding: Supported by the European Community under the 6th Framework Programme "Structuring the European Research Area".

Complex beam-based alignment procedures are needed in future linear colliders to reduce the negative effects of static imperfections in the main linac on the beam emittance. The efficiency of these procedures could be affected by dynamic imperfections during their application. In this paper we study the resulting emittance growth.

THPMN063 CTF3 Combiner Ring Commissioning optics, injection, linac, collider 2850
  • F. Tecker, R. Corsini, S. Doebert, P. K. Skowronski, P. Urschutz
    CERN, Geneva
  • C. Biscari, A. Ghigo
    INFN/LNF, Frascati (Roma)
  • E. Bressi
    CNAO Foundation, Milan
  • A. Ferrari
    UU/ISV, Uppsala
  CLIC Test Facility 3 (CTF3) has the objective to demonstrate the remaining feasibility issues of the CLIC two-beam technology for a future multi-TeV linear collider. One key issue is the efficient generation of a very high current 'drive beam' that serves as the power source for the acceleration of the main beam to high energy. This large current beam is produced by interleaving bunches in a combiner ring using transverse deflecting RF cavities. The 84 m long CTF3 combiner ring and the connecting transfer line have been recently installed and put into operation. The latest commissioning results will be presented.  
THPMN073 Collimation Optimisation in the Beam Delivery System of the International Linear Collider collimation, lattice, luminosity, betatron 2871
  • F. Jackson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. J. Barlow, A. M. Toader
    UMAN, Manchester
  • A. Latina, D. Schulte
    CERN, Geneva
  The collimation systems of the International Linear Collider (ILC) Beam Delivery System (BDS) must perform efficient removal of halo particles which lie outside the acceptable ranges of energy and spatial spread. An optimisation strategy based on earlier work is applied to the latest version of the BDS lattice. The resulting improvement in collimation performance is studied by halo tracking simulations, and the luminosity performance of the optimised lattice is also examined.  
THPMN075 Alignment Sensitivities in the ILC Damping Rings alignment, emittance, lattice, damping 2877
  • K. G. Panagiotidis, A. Wolski
    Liverpool University, Science Faculty, Liverpool
  For the International Linear Collider to reach its design luminosity, the damping rings must achieve a vertical emittance that is a factor of two below that achieved in any operating storage ring so far. Magnet alignment, orbit control and coupling correction are therefore critical issues for the ILC damping rings. We compare alignment sensitivities in some recent designs for the ILC damping ring lattices, and discuss the results of tuning simulations using different algorithms for correcting the vertical dispersion and the coupling.  
THPMN077 Improved 2mrad crossing angle layout for the International Linear Collider extraction, optics, beam-losses, luminosity 2883
  • R. Appleby, D. Toprek
    UMAN, Manchester
  • D. A.-K. Angal-Kalinin
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. Bambade, S. Cavalier, O. Dadoun
    LAL, Orsay
  The 2mrad interaction region and extraction line provide several machine and physics advantages, but also involves a number of technological challenges. In this paper a minimal extraction line without beam energy and polarization diagnostics is presented, which considerably simplifies the design and reduces costs. The optimization of the interaction region sextupoles, using current and proposed technologies, and an estimation of photon backscattering from spent beam particle losses are described. Overall performance is evaluated and compared with previous designs. The upgrade to 1 TeV and the possibility of including diagnostics are considered.  
THPMN103 New Nonscaling FFAG for Medical Applications focusing, acceleration, extraction, synchrotron 2951
  • C. Johnstone
    Fermilab, Batavia, Illinois
  • S. R. Koscielniak
    TRIUMF, Vancouver
  Funding: Work supported by by the Fermilab Research Association, Inc., under contract DE-AC02-76CH00300 with the U. S. Department of Energy.

Fixed Field Alternating Gradient (FFAG) machines have been the subject of recent international activity due to their potential for medical applications and accelerator-based technologies. In particular, nonscaling FFAGs (where the optics are not constant and therefore do not scale with momentum) stand to offer the high current advantage of the cyclotron combined with the smaller radial aperture of the synchrotron plus variable extraction energy. Here, a hybrid design for a nonscaling FFAG accelerator has been invented which uses both edge and alternating-gradient focusing principles applied to a combined-function magnet applied in a specific configuration to stabilize tunes through an acceleration cycle which extends over a factor of 2-6 in momentum. Using normal conducting magnets, the final, extracted energy from this machine attains 400 MeV/nucleon and a normalized emittance of ~10 - 20π, and thus supports a carbon ion beam in the energy range of interest for cancer therapy.

THPMN104 Recent Studies of Dispersion Matched Steering for the ILC Bunch Compressor and Main Linac emittance, linac, injection, alignment 2954
  • P. Lebrun, L. Michelotti, J.-F. Ostiguy
    Fermilab, Batavia, Illinois
  Beam Based Alignment techniques are expected to play a critical role to the emittance preservation for the ILC. The Dispersion Free Steering (DFS) method is studied in detail in the 2nd statge of the bunch Compressor and in the beginning of the curved Main Linac. It is shown than in absence of cavity tilts (rotations on the YZ plane), DMS provides a unique and stable solution with negligible emittance growth. If cavity tilts are about 200 to 300 micro-radiant, the DMS solution is no longer unique and significant emittance occurs as well. While within the ILC budget, other dynamical effects, such a large beam jitter or sudden ground motion will cause severe performance degradation. A Variant of the DFS algorithm can be used to re-aling cavity supports, leading to better LET performance. In presence of perturbations (klystron jitter, ground motion,.. ) such DFS solutions are easier to maintain and improved if they are stable and unique. Therefore, it is suggested to consider using movers on quadrupole/BPM and, a bit more controversial, for the support system of the r.f. cavities, especially at low energy, where spurious dispersion due to cavity tilts are large.  
THPMN107 Study of Emittance Bumps in The ILC Main Linac emittance, linac, alignment, simulation 2960
  • N. Solyak, K. Ranjan
    Fermilab, Batavia, Illinois
  Funding: U. S. Department of Energy

This paper reports the studies of using global emittance tuning bumps to limit the emittance growth to very small values in the main linac of the proposed International Linear Collider (ILC) machine. Simulation studies indicate that closed-orbit emittance bumps, when used after local or quasi-local beam based alignment techniques, can be utilized to further suppress the emittance growth in the ILC main linac. A series of simulations are performed to find the optimal number of bumps and their locations. A more general method of optimizing the emittance bumps in the ILC main linac is also discussed.

THPMN109 Status of the ILC Main Linac Lattice Design linac, lattice, synchrotron, synchrotron-radiation 2966
  • A. Valishev, N. Solyak
    Fermilab, Batavia, Illinois
  • M. Woodley
    SLAC, Menlo Park, California
  The report describes the present design of the ILC Main Linac lattice. The topics covered include basic element layout, optical functions, and issues centered around the linac following of the Earth's curvature. Also discussed are beam parameter measurements and instrumentation requirements.  
THPMN110 The MANX Muon Cooling Demonstration Experiment emittance, collider, dipole, vacuum 2969
  • K. Yonehara, D. R. Broemmelsiek, M. Hu, A. Jansson, V. D. Shiltsev
    Fermilab, Batavia, Illinois
  • R. J. Abrams, M. A.C. Cummings, R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
  Funding: Supported in part by DOE STTR grant DE-FG02-06ER86282

MANX is an experiment to prove that effective six-dimensional (6D) muon beam cooling can be achieved a Helical Cooling Channel (HCC) using ionization-cooling with helical and solenoidal magnets in a novel configuration. The aim is to demonstrate that 6D muon beam cooling is understood well enough to plan intense neutrino factories and high-luminosity muon colliders. The experiment consists of the HCC magnets that envelop a liquid helium energy absorber, upstream and downstream instrumentation to measure the particle or beam parameters before and after cooling, and emittance matching sections between the detectors and the HCC. We describe and compare the experimental configuration for both single particle and beam profile measurement techniques based on G4Beamline simulations.

THPMN115 Injection and Extraction Lines for the ILC Damping Rings damping, extraction, kicker, injection 2984
  • I. Reichel
    LBNL, Berkeley, California
  Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The current design for the injection and extraction lines into and out of the ILC Damping Rings is presented as well as the design for the abort line. Due to changes of the geometric boundary conditions by other subsystems of the ILC a modular approach has been used to be able to respond to recurring layout changes while reusing previously designed parts. Available beam dynamics studies for those lines are discussed.

THPMN116 Frequency Map Studies for the ILC Damping Rings lattice, dynamic-aperture, resonance, sextupole 2987
  • I. Reichel
    LBNL, Berkeley, California
  Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

Designing a lattice with sufficient dynamic aperture for the ILC Damping Rings is very challenging as the lattice needs to provide a small equilibrium emittance and at the same time a large aperture for the injected beam including a large momentum acceptance. In addition outside constraints have forced layout changes in the damping ring. Some of the layout changes had an impact on the dynamic aperture. In order to better understand the changes in dynamic aperture, frequency maps are studied. Those studies can help in identifying the reason for the changed dynamic aperture and in finding a good location for the betatron tunes and determining an upper limit for the chromaticities. A summary of recent studies and suggestions improving the dynamic aperture by choosing a different tune are presented.

THPMS034 Generation and Characterization of the Microbunched Beams with a Wire Mesh Target plasma, electron, radiation, emittance 3079
  • P. Muggli, E. Kallos
    USC, Los Angeles, California
  • M. Babzien, K. Kusche, V. Yakimenko
    BNL, Upton, Long Island, New York
  • W. D. Kimura
    STI, Washington
  Funding: Work supported by US Department of Energy contract DE-AC02-98CH10886

The presentation will cover experimental results on generation and measurement of the beams with theμbunches length from 1 to 50 microns at Brookhaven Accelerator Test Facility. Arbitrary number of microbunches is sliced out of 5 ps long beam using wire mesh and slits. The details of beam structure are characterized using CSR interferometer and 6 mm long plasma wakefield channel with the controllable plasma density.

THPMS052 Optical Wakefield from a Photonic Bandgap Fiber Accelerator electron, simulation, laser, vacuum 3106
  • C. M.S. Sears, E. R. Colby, B. M. Cowan, R. Ischebeck, C. Mcguinness, R. J. Noble, R. Siemann, J. E. Spencer, D. R. Walz
    SLAC, Menlo Park, California
  • R. L. Byer, T. Plettner
    Stanford University, Stanford, Califormia
  Photonic Bandgap (PBG) structures have recently been proposed as optical accelerators for there high coupling impedance and high damage threshold (>2 GV/m). As a first step in preparing a PBG accelerator, we propose to first observe the optical wakefield induced incoherently by an electron beam traversing the structure in the absence of a coupled laser pulse. The electrons are coupled into the fiber via a permanent magnet quadrupole triplet. The electrons excite fiber modes with speed-of-light phase velocities. By observing the wakefield using a spectrometer, the accelerating mode frequencies are determined.  
THPMS053 Compensation of the Effect of a Detector Solenoid on the Beam Size in the ILC simulation, multipole, electron, dipole 3109
  • S. Seletskiy
    SLAC, Menlo Park, California
  In the International Linear Collider (ILC) [1] the colliding beams must be focused to the nanometre size in order to reach the desired luminosity. The method of Weak Antisolenoid is used for the compensation of the effect of the Detector Solenoid on the beam size [2, 3]. The studies of this method require the computer simulation of the charged particle's kinematics in the arbitrarily distributed solenoidal, dipole, quadrupole and higher multipole fields. We suggest the mathematical algorithm that allows to optimize parameters of antisolenoid for different configurations of Final Focus magnets and to compensate parasitic effects of the Detector Solenoid on the beam.

[1] 'International Linear Collider Reference Design Report', April 2007
[2] Y Nosochkov, A. Seryi, Phys. Rev. ST Accel. Beams 8, 021001 (2005)
[3] B. Parker, A. Seryi, Phys. Rev. ST Accel. Beams 8, 041001 (2005)

THPMS067 A CW Positron Source for CEBAF positron, electron, target, simulation 3133
  • S. Golge, C. Hyde-Wright
    ODU, Norfolk, Virginia
  • A. Freyberger
    Jefferson Lab, Newport News, Virginia
  Funding: Authored by Jefferson Science Associates, LLC under U. S. DOE Contract No. DE-AC05-06OR23177.

A positron source for the 6 GeV (or the proposed 12 GeV upgrade) recirculating linacs at Jefferson Lab is presented. The proposed 100nA CW positron source has several unique characteristics; high incident beam power (100kW), 10 MeV incident electron beam energy, CW incident beam and CW production. Positron production with 10 MeV electrons has several advantages; the energy is below neutron threshold so the production target will not become activated during use and the absolute energy spread is bounded by the low incident energy. These advantages are offset by the large angular distribution of the outgoing positrons. Results of simulations of the positron production, capture, acceleration and injection into the recirculating linac are presented. Energy flow and thermal management of the production target present a challenge and are included in the simulations.

THPMS082 Muon Acceleration to 750 GeV in the Tevatron Tunnel for a 1.5 TeV mu+ mu- Collider dipole, acceleration, lattice, emittance 3178
  • D. J. Summers, L. M. Cremaldi, R. Godang, B. R. Kipapa, H. E. Rice
    UMiss, University, Mississippi
  • R. B. Palmer
    BNL, Upton, Long Island, New York
  Funding: Work supported by DE-FG02-91ER40622 and DE-AC02-98CH10886.

Muon acceleration from 30 to 750 GeV in 72 orbits using two rings in the 1000m radius Tevatron tunnel is explored. The first ring ramps at 400 Hz and accelerates muons from 30 to 400 GeV in 28 orbits using 14 GV of 1.3 GHz superconducting RF. The ring duplicates the Fermilab 400 GeV main ring FODO lattice, which had a 61m cell length. Muon survival is 80%. The second ring accelerates muons from 400 to 750 GeV in 44 orbits using 8 GV of 1.3 GHz superconducting RF. The 30 T/m main ring quadrupoles are lengthened 87% to 3.3m. The four main ring dipoles in each half cell are replaced by three dipoles which ramp at 550 Hz from -1.8T to +1.8T interleaved with two 8T fixed superconducting dipoles. The ramping and superconducting dipoles oppose each other at 400 GeV and act in unison at 750 GeV. Muon survival is 92%. Two mm copper wire, 0.28mm grain oriented silicon steel laminations, and a low duty cycle mitigate eddy current losses. Low emittance muon bunches allow small aperatures and permit magnets to ramp with a few thousand volts. Little civil construction is required. The tunnel exists.

THPMS083 The EMMA Lattice Design lattice, acceleration, resonance, longitudinal-dynamics 3181
  • J. S. Berg, A. G. Ruggiero
    BNL, Upton, Long Island, New York
  • S. R. Koscielniak
    TRIUMF, Vancouver
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  Funding: Work Supported by the United States Department of Energy, Contract No. DE-AC02-98CH10886.

EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). This paper describes the design of the EMMA lattice. We begin with a description of the experimental goals that impact the lattice design. We then describe what motivated the choice for the basic lattice parameters, such as the type of cells, the number of cells, and the RF frequency. We next list the different configurations that we wish to operate the machine in so as to accomplish our experimental goals. Finally, we enumerate the detailed lattice parameters, showing how these parameters result from the various lattice configurations.

THPAN001 LOCO at the Australian Synchrotron coupling, synchrotron, storage-ring, optics 3217
  • M. J. Spencer, M. J. Boland, R. T. Dowd, G. LeBlanc, Y. E. Tan
    ASP, Clayton, Victoria
  LOCO has been used during the commissioning of the Australian Synchrotron storage ring with a number of benefits. The LOCO (linear optics from close orbits) method compares a model response matrix to the real machine response matrix. Using this approach we are able to adjust the machine to match the ideal model. Results presented here show that LOCO has provided a high degree of control over a wide range of machine parameters.  
THPAN004 Runge-Kutta DA Integrator in Mathematica Language controls, simulation, optics 3226
  • A. Baartman, D. Kaltchev
    TRIUMF, Vancouver
  The method of Truncated Power Series Algebra is applied in a Mathematica code to compute the transfer map for arbitrary equations of motion (EOM) describing a charged particle optical system. The code is a non-symplectic integrator – a combination between differential algebra module and a numerical solver of EOM. Using the symbolic system offers some advantages, especially in case of non-autonomous EOM (element with fringe-fields). An example is given – a soft-fringe map of a magnetic quadrupole.  
THPAN005 Short Quadrupole Parametrization focusing, kaon, beam-transport, simulation 3229
  • A. Baartman, D. Kaltchev
    TRIUMF, Vancouver
  Funding: National Research Council (Canada)

The Enge function can be used to parametrize any element with well-defined edges. If an element is too short, however, there is no unambiguous definition of the effective edge. We first demonstrate that very little fringe field detail is needed to obtain accurate maps even up to fifth order. Then we go on to show a simple fitting algorithm that works well for short as well as long quadrupoles. The results are true whether the quads are magnetic or electrostatic.

THPAN006 Simulation of Decays and Secondary Ion Losses in a Betabeam Decay Ring ion, dipole, simulation, lattice 3232
  • F. W. Jones
    TRIUMF, Vancouver
  • E. Y. Wildner
    CERN, Geneva
  The beta decay of circulating ions in the decay ring of a Betabeam facility will give rise to secondary ions which differ in charge from the primary ions and will follow widely off-momentum orbits. A small fraction of these ions will be lost in the long straights, but the great majority of them will be lost in the arcs. Profiling of the losses requires detailed knowledge of the paths of these ions, which are distributed in phase space as well as around the ring circumference. We describe here a comprehensive model of ion decay, secondary ion tracking, and loss detection, which has been implemented in the tracking and simulation code Accsim. Methods have been developed to accurately track ions at large momentum deviations not amenable to conventional multiparticle tracking codes, as well as to detect their impact coordinates on vacuum chamber walls (possibly inside magnetic elements). In our simulation we have also included absorbers which are needed, along with appropriate lattice optimisations, to localize the majority of losses outside of the dipoles. From simulation results, some estimates of decay ring performance (in terms of loss concentration and management) will be given.  
THPAN009 Orbit Properties of Non-Scaling FFAG Accelerators Using Constant-Gradient Magnets lattice, betatron, synchrotron, vacuum 3241
  • M. K. Craddock
    UBC & TRIUMF, Vancouver, British Columbia
  • S. R. Koscielniak
    TRIUMF, Vancouver
  Very high momentum compaction can be obtained in non-scaling FFAG accelerators using constant-gradient magnets with their field strengths decreasing outwards - sufficiently high that the magnet apertures (and vacuum chamber) need be little wider than in a strong-focusing synchrotron. Such machines are of great potential interest for applications in the 0.1 - 50 GeV energy range requiring higher intensities or pulse repetition rates than synchrotrons can provide. Analytic formulae have been developed for the basic orbit properties, particularly their momentum dependence, in various lattices, and give accurate enough results to provide a useful tool for choosing the magnet parameters. In this paper the dependences of orbit offset and circumference on momentum are explored for doublet lattices, and numerical results from the formulae are compared with those from lattice codes.  
THPAN010 Local Magnetic Error Estimation using Action and Phase Jump Analysis of Orbit Data simulation, lattice, interaction-region, proton 3244
  • J. F. Cardona
    UNAL, Bogota D. C
  Funding: This work is funded by DINAIN, Division Nacional de Investigacion, Universidad Nacional de Colombia, Bogota Colombia

It's been shown in previous conferences [*,**] that action and phase jump analysis is a promising method to measure normal quadrupole components, skew quadrupole components and even normal sextupole components. In this paper, the action and phase jump analysis is evaluated using new RHIC data.

*J. Cardona,et al, Procceedings of PAC 2005, Knoxville, Tennesse.**J. Cardona,et al, Procceedings of EPAC 2004, Lucerne, Switzerland.

THPAN016 Improving the SIS18 Performance by use of the Orbit Response Method focusing, simulation, lattice, closed-orbit 3256
  • A. S. Parfenova, G. Franchetti, I. Hofmann, C. Omet
    GSI, Darmstadt
  • S.-Y. Lee
    IUCF, Bloomington, Indiana
  The SIS18 will be used as a booster for the new FAIR facility SIS100. A well-controlled linear optics of the SIS18 is necessary for further optimisation studies of nonlinear dynamics, resonance induced beam loss, dynamic aperture and nonlinear error measurements. The analysis of the orbit response matrix (ORM) is a powerful tool to calibrate the linear lattice models. We present results of several measurements on the SIS18 using the ORM and discuss the achieved improvement of the SIS18 performance.  
THPAN025 Evaluation of the Component Tolerances for the ILC Main Linac Assuming Global Linear Corrections emittance, linac, coupling, alignment 3280
  • F. Poirier, D. Kruecker, N. J. Walker
    DESY, Hamburg
  Funding: This work is supported by the Commission of the European Communities under the 6th Framework Programme 'Structuring the European Research Area', contract number RIDS-011899.

The small energy-spread, weak wakefields and relatively weak focusing in the ILC superconducting Main Linac result in little or no filamentation beam mismatch errors: linear correlations such as dispersion or cross-plane coupling from transverse misalignment or rotation errors of the quadrupoles respectively do not decohere as the beam is transported (accelerated) along the linac. Using correction available in the Beam Delivery System, the increase in projected emittance due to this linear correlations can to a large degree be corrected. In this paper we present component tolerances based on the assumption of a global correction at the end of the Main Linac. Some discussion on the impact of ground motion is also discussed.

THPAN027 The Optimum Chromaticity Correction Scheme for Monochromatic and Non-Monochromatic Beam in HESR sextupole, lattice, multipole, octupole 3286
  • A. N. Chechenin, Y. Senichev, N. E. Vasyukhin
    FZJ, Julich
  The High Energy Storage Ring (HESR) of FAIR project consists of two achromatic arcs and two dispersionless straight sections. Due to the multi-functional purpose of the straight sections their contribution into the total chromaticity of the first and second order exceeds the arc's contribution and can affect on the non-monochromatic beam dynamic aperture. We investigate the optimum sextupole and octupole correction scheme for monochromatic and non-monochromatic beam to reach the larger dynamic aperture.  
THPAN028 HESR Lattice with Non-similar Arcs for the Stochastic Cooling lattice, pick-up, kicker, dynamic-aperture 3289
  • Y. Senichev
    FZJ, Julich
  The advanced HESR lattice with two arcs having the identical layout and the different slip factors are developed. The conception of arcs with three families of quadrupole allows easy adjusting the imaginary transition energy in one arc and the real transition energy in another arc with the absolute value close to the beam energy in whole required region from 3.0 GeV to 14 GeV. The arcs have the special feature, when the high order non-linearities are fully compensated inside of each arc, and therefore the dynamic aperture of the whole machine is conserved. We consider and compare two lattices with the same absolute value of transition energy: the current lattice with the negative momentum compaction factor in both arcs and the lattice having the negative and positive momentum compaction factors in different arcs correspondingly. Simultaneously we analyzed the 4 and 6 fold symmetry arcs machine. It allows making the conclusion that the 4 fold symmetry lattice is more suitable to get the required slip factors. At the lowest energy 3 GeV, the absolute value of slip factor in the imaginary and the real arc is related as ~0.09/0.02 correspondingly. For the higher beam energy this ratio is much bigger.  
THPAN033 Design Study of the Dipole Magnet for the RHIC EBIS High Energy Transport Line dipole, multipole, sextupole, simulation 3301
  • T. Kanesue
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
  • M. Okamura, D. Raparia, J. Ritter
    BNL, Upton, Long Island, New York
  • J. Tamura
    RLNR, Tokyo
  The design studies of the dipole magnet for EBIS HEBT line is proceeding. The RHIC EBIS is a new high current highly charged heavy ion preinjector for RHIC. The dipole magnet discussed in this paper will be used to guide the beam to existing heavy ion injection line to Booster. A total of 145 degrees bend is provided by two identical dipole magnets with a slit between these magnets to pass only intended charge state ions. Also this magnet has a hole in the side wall to pass the beam from the existing Tandem Van de Graaff. The performance of this magnet calculated by TOSCA and the results of the particle tracking calculation are described.  
THPAN043 Comparison of Trajectory Between Modeling and Experiment for J-PARC Linac linac, simulation, beam-transport, betatron 3324
  • T. Ohkawa, K. Hasegawa
    JAEA, Ibaraki-ken
  • H. Ao, A. Ueno
    JAEA/LINAC, Ibaraki-ken
  • M. Ikegami
    KEK, Ibaraki
  • H. Sako
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  In the beam commissioning of J-PARC (Japan Proton Accelerator Research Complex) linac, three simulations codes are used to model the accelerator. We have compared with the experimental results obtained in the beam commissioning to date, where a basic agreement has been confirmed between the modeling and the actual beam behavior.  
THPAN044 Global COD Correction of SAGA-LS Storage Ring lattice, storage-ring, controls, closed-orbit 3327
  • H. Ohgaki
    Kyoto IAE, Kyoto
  • Y. Iwasaki, T. Tomimasu
    SAGA, Tosu
  • S. Koda, Y. Takabayashi, K. Yoshida
    Saga Synchrotron Light Source, Industry Promotion Division, Saga City
  SAGA Light Source is a medium size light source which has been operated from February, 2006. The stored beam orbit has been corrected by a closed orbit correction system consisted of 24 beam position monitors, 40 steering magnets and PC-LabView based control system. The singular value decomposition method has been applied for the global COD correction by using a measured response matrix. As a result, the standard deviation of the orbit error around the ring was reduced to 20 micro-meters both for horizontal plane and for vertical plane, respectively.  
THPAN057 Error Analyses of the PEFP 20/100-MeV Beamlines proton, linac, dipole, lattice 3357
  • K. Y. Kim, Y.-S. Cho, B. Chung, J.-H. Jang
    KAERI, Daejon
  Funding: This work was supported by the 21C Frontier R&D program sponsored by Ministry of Science and Technology, Korean Government.

The proton engineering frontier project (PEFP) 100-MeV proton linac has two main beamline systems to extract and deliver the proton beam to the user. The one is designed to extract 20-MeV proton beams at the medium energy transport system of the linac and to deliver them to five target stations through a beam switching system. The other is able to extract 100-MeV proton beams at the end of the linac and to deliver them to another five target stations trough a beam distribution system. We have completed the detailed beam optics designs of the beamline system and performed intensive error analyses to set the marginal limits of engineering errors of the beamline components by using a dedicated beam transport code. The paper presents the error analysis results of the PEFP beamline systems along with their characteristics and beam optics designs.

THPAN068 Wakefield Models for Particle Tracking Codes multipole, simulation, dipole, collective-effects 3378
  • A. Latina, G. Rumolo, D. Schulte
    CERN, Geneva
  • R. J. Barlow, A. Bungau
    UMAN, Manchester
  • G. A. Blair
    Royal Holloway, University of London, Surrey
  • J. D.A. Smith
    Lancaster University, Lancaster
  Wakefields have a considerable effect on beam dynamics and they must not be neglected for emittance growth studies, background estimates and other problems. The codes used for these problems are normally not capable of self-consistent wakefield calculations. They should thus be extended with either analytical models or export the wakefields numerically evaluated with other codes (such as Gdfidl) when analytical models are not feasible. We discuss both approaches and present their implementation in PLACET, MERLIN and BDSIM. The simulation results for the ILC and CLIC beam delivery systems are given as an example. Results produced with different codes are compared.  
THPAN072 A Concept for the LHC Luminosity Upgrade Based on Strong Beta* Reduction Combined with a Minimized Geometrical Luminosity Loss Factor luminosity, separation-scheme, collimation, dipole 3387
  • E. Todesco, R. W. Assmann, J.-P. Koutchouk, E. Metral, G. Sterbini, F. Zimmermann, R. de Maria
    CERN, Geneva
  A significant increase of the LHC beam current touches physics limits as collective effects, electron-cloud, heat load, collimation and machine protection. We propose an upgrade scheme mainly based on a stronger focusing, with a beta* of 10 cm, requiring a triplet quadrupole aperture of around 130 mm. The performance is further improved if the triplet is based on the Nb3Sn technology. In the present baseline, this beta* reduction provides a negligible luminosity increase: this approach requires a drastic action to minimize the crossing angle, while the beam separation at the long-range encounters has to be increased. This is provided by an early separation scheme made of small dipoles inside the detectors. Optionally, a small angle crab cavity scheme may totally suppress the residual crossing angle. The quadrupole aperture is calculated to allow a larger gap for the collimator, suppressing their impedance limitation. This concept offers high performance while significantly reducing the risks associated to a beam current increase; it opens as well new issues that deserve further studies, such as the dipole integration in the detector, and the correction of the triplet aberrations.  
THPAN094 Design Study of a Transverse-to-Longitudinal Emittance Exchange Proof-of-principle Experiment emittance, dipole, simulation, space-charge 3441
  • Y.-E. S. Sun, K.-J. Kim, J. G. Power
    ANL, Argonne, Illinois
  • P. Piot, M. M. Rihaoui
    Northern Illinois University, DeKalb, Illinois
  Funding: Dr. Sun's work is supported by U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

Transverse-to-longitudinal emittance exchange can be achieved through certain arrangements of dipole magnets and dipole mode rf cavity. Theory on such schemes has been developed in the past several years. In this paper we report our numerical simulations on the emittance exchange using particle tracking codes. Photoelectron beams with energy less than 20 MeV are used, as our purpose of simulations is to study the feasibility of performing such emittance exchange at existing facilities of beam energy at this level. Parametric studies of the dipole magnets and cavity strengths, as well as initial beam parameters, are presented.

THPAN101 Parametric Modeling of Transverse Phase Space of an RF Photoinjector linac, gun, emittance, controls 3462
  • B. Sayyar-Rodsari, E. Hartman, C. A. Schweiger
    Pavilion Technologies, Inc, Austin, Texas
  • M. J. Lee, P. Lui, J. M. Paterson, J. F. Schmerge
    SLAC, Menlo Park, California
  Funding: DOE PHASE II STTR - DE-FG02-04ER86225

High brightness electron beam sources such as rf photo-injectors as proposed for SASE FELs must consistently produce the desired beam quality. We report the results of a study in which a combined neural network (NN) and first-principles (FP) model is used to model the transverse phase space of the beam as a function of quadrupole magnet current, while beam charge, solenoid field, accelerator gradient, and linac voltage and phase are kept constant. The parametric transport matrix between the exit of the linac section and the spectrometer screen constitutes the FP component of the combined model. The NN block provides the parameters of the transport matrix as functions of quad current. Using real data from SLAC Gun Test Facility, we will highlight the significance of the constrained training of the NN block and show that the phase space of the beam is accurately modelled by the combined NN and FP model, while variations of beam matrix parameters with the quad current are correctly captured. We plan to extend the combined model in the future to capture the effects of variations in beam charge, solenoid field, and accelerator voltage and phase.

THPAN104 Coupled Optics Reconstruction from TBT Data using MAD-X optics, lattice, betatron, injection 3471
  • Y. Alexahin, E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois
  • V. V. Kapin
    MEPhI, Moscow
  • F. Schmidt
    CERN, Geneva
  Funding: Work supported by the Universities Research Assoc., Inc., under contract DE-AC02-76CH03000 with the U. S. Dept. of Energy

Turn-by-turn BPM data provide immediate information on the coupledoptics functions at BPM locations. In the case of small deviations from the known (design) uncoupled optics some cognizance of the sources of perturbation, BPM calibration errors and tilts can also be inferred without detailed lattice modelling. In practical situations, however, fitting the lattice model with the help of some optics code would lead to more reliable results. We present an algorithm for coupled optics reconstruction from TBT data on the basis of MAD-X and give examples of its application for the Fermilab Tevatron and Booster accelerators.

THPAN109 A New Lattice Design for a 1.5 TeV CoM Muon Collider Consistent with the Tevatron Tunnel lattice, collider, sextupole, dynamic-aperture 3483
  • P. Snopok, M. Berz
    MSU, East Lansing, Michigan
  • C. Johnstone
    Fermilab, Batavia, Illinois
  A recent effort is underway to design an efficient match of a Muon Collider to the Fermilab site, potentially using the Tevatron tunnel after decommissioning. This work represents a new design for such a collider with emphasis on shortened IR and systematic high-order correction and dynamics studies. With a 1 cm β*, simultaneous control of geometric and chromatic aberrations is critical and can only be achieved through the deliberate addition of nonlinear fields in the Interaction Region itself. This work studies both the correction schemes and the unavoidable impact of high-order correctors – sextupoles, octupoles and even duodecapoles – located in the Interaction Region close to the low-beta quadrupoles or focusing elements. This study proposes and systematically addresses the aberrations for different systems of nonlinear correctors and optimizes performance of an advanced IR.  
THPAN113 Mxyzptlk: An Efficient, Native C++ Differentiation Engine simulation, sextupole 3489
  • J.-F. Ostiguy, L. Michelotti
    Fermilab, Batavia, Illinois
  Funding: Authored by Universities Research Association, Inc. under contract No. DE-AC02-76CH03000 with the U. S. Department of Energy.

Mxyzptlk was one of the early and, to this day, limited number of differentiation engines implemented by taking full advantage of a language with operator overloading capabilities. It was created with an eye at enabling accelerator related computations, especially within the realm of perturbation theories. Such computations are supported by (1) a one-to-one correspondence between original mathematical abstractions and the data types and operations used to implement them; (2) the exact computation of high order derivatives. Significant efforts were invested recently in modernizing Mxyzptlk both architecturally and algorithmically. Among other things, these substantially improved performance and usabilty. We present a description of the current Mxyzptlk from both standpoints and describe its current capabilities and performance.

THPAN116 Lattice Measurement for Fermilab Main Injector lattice, injection, extraction, focusing 3498
  • M.-J. Yang
    Fermilab, Batavia, Illinois
  The installation of seven large aperture quadrupoles during the shut-down of 2006 necessitates new measurements to ascertain the state of machine lattice, both at injection and at extraction. These new quadrupoles replaced existing quadrupoles at each of the seven injection/extraction locations around the Fermilab Main Injector. Though extensive magnet measurement had been made the effect of trim coils used to compensate differences in magnet characteristics has to be verified. The result of lattice analysis and others will be discussed.  
THPAS003 Exact Analytic Solution of the Envelope Equations for a Matched Quadrupole-Focused Beam in the Low Space Charge Limit focusing, space-charge, emittance, lattice 3513
  • O. A. Anderson
    LBNL, Berkeley, California
  • L. L. LoDestro
    LLNL, Livermore, California
  Funding: Supported by U. S. Depatment of Energy under contract number DE-AC02-05CH11231

The Kapchinskij-Vladimirskij equations describe the evolution of the beam envelopes in a periodic system of quadrupole focusing cells and are widely used to help predict the performance of such systems. Being nonlinear, they are usually solved by numerical integration. There have been numerous papers describing approximate solutions with varying degrees of accuracy. We have found an exact solution for a matched beam in the limit of zero space charge. The model is FODO with a full occupancy, piecewise-constant focusing function. Our explicit result for the envelope a(z) is exact for phase advances up to 180 degrees and all other values except multiples of 180 degrees. The peak envelope size is minimized at 90 degrees. The higher stable bands require larger, very accurate, field strengths while producing significantly larger envelope excursions.

THPAS009 On the Stability of the Kapchinskij-Vladimirskij Equations simulation, focusing, lattice, ion 3528
  • C. Xu, E. Schuster
    Lehigh University, Bethlehem, Pennsylvania
  • C. K. Allen
    LANL, Los Alamos, New Mexico
  The stability of the linearized Kapchinskij-Vladimirskij (KV) equations around a matched solution, which constitute a linear periodic Hamiltonian system, is studied. By using Floquet theorem, symplectic algebra and the eigenvalue distribution theory, a critical stability condition for the linearized particle beam envelope equations is obtained. The stability conditions are expressed in terms of the time-averaged Hamiltonian system.  
THPAS019 A Beam Dynamics Application Based on the Common Component Architecture simulation, lattice, booster, target 3552
  • D. R. Dechow, D. T. Abell, P. Stoltz
    Tech-X, Boulder, Colorado
  • J. F. Amundson
    Fermilab, Batavia, Illinois
  • L. Curfman McInnes, B. Norris
    ANL, Argonne, Illinois
  Funding: Department of Engergy, Office of Advanced Scientific Computing Research, SBIR grant: DE-FG02-06ER84520

A component-based beam dynamics application for modeling collective effects in particle accelerators has been developed. The Common Component Architecture (CCA) software infrastructure was used to compose a new Python-steered accelerator simulation from a set of services provided by two separate beam dynamics packages (Synergia and MaryLie/Impact) and two high-performance computer science packages (PETSc and FFTW). The development of the proof-of-concept application was accomplished via the following tasks:

  1. addressing multilanguage interoperability in the MaryLie/Impact code with Babel;
  2. creating components by making the selected software objects adhere to the Common Component Architecture protocol;
  3. assemblying the components with a newly developed, Component Builder gui; and
  4. characterizing the performance of the space charge (Poisson) solver that was originally used in Synergia 1.0 versus the PETSc-based space charge solver that has been developed for Synergia2.
The resulting beam dynamics application will allow the Synergia2 framework to evolve simultaneously with the modeling and simulation requirements of the International Linear Collider.
THPAS030 Low-current, Space-Charge Dominated Beam Transport at the University of Maryland Electron Ring (UMER) lattice, space-charge, dipole, injection 3561
  • S. Bernal, B. L. Beaudoin, R. A. Kishek, P. G. O'Shea, M. Reiser, D. F. Sutter
    UMD, College Park, Maryland
  Funding: This work is funded by the US Dept. of Energy and by the Office of Naval Research.

The University of Maryland Electron Ring (UMER) is designed for the transport of low energy (10 keV), high current (100 mA) electrons in a 72-magnetic-quadrupole lattice over an 11.5 m circumference. With these parameters, and a typical single-particle phase advance per period of 76 deg., space charge is extreme. However, high current is not necessary for establishing space charge dominated transport in UMER. In fact, low current (0.6 mA) beam transport in combination with longer full-lattice periods can yield strong space charge conditions. All 72 quadrupoles are needed, though, to yield beams with relatively small cross sections, as required for emittance-dominated transport. We present results of calculations and experiments that demonstrate the low-current, high space charge regime in UMER. We also discuss the use of Collins-type insertions for matching into the ring lattice.

THPAS032 Modeling Skew Quadrupole Effects on the UMER Beam simulation, emittance, space-charge, electron 3567
  • C. Papadopoulos, G. Bai, B. L. Beaudoin, I. Haber, R. A. Kishek, P. G. O'Shea, M. Reiser, M. Walter
    UMD, College Park, Maryland
  Funding: US Department of Energy

This is a numerical study of the effects of skew quadrupoles on the beam used in University of Maryland Electron Ring (UMER). As this beam is space-charge dominated, we expect new phenomena to be present compared to the emittance-dominated case. In our studies we find that skew quadrupoles can severely affect the halo of the beam and cause emittance growth, even in the first turn of the beam. For our simulations we used the WARP particle-in-cell code and we compared the results with the experimental study of skew quadrupole effects (to be reported separately).

THPAS037 Open Architecture Software Integration System (OASIS) for the Particle Beam Optics Laboratory (PBO Lab) optics, target, linac, simulation 3579
  • G. H. Gillespie, W. Hill
    G. H. Gillespie Associates, Inc., Del Mar, California
  Funding: This work has been supported by the U. S. Department of Energy (DOE) Small Business Innovative Research (SBIR) program under grant number DE-FG02-04ER83961.

The Particle Beam Optics Laboratory, or PBO Lab, is a suite of software applications developed to support beamline design, accelerator operations, and personnel training. The software provides an intuitive and easy-to-use graphic user interface (GUI) that works with a variety of particle optics codes. The PBO Lab GUI is largely responsible for the popularity of this software suite, which is now used at more than ninety institutions throughout the world. While PBO Lab greatly improves the human-machine interface for several popular optics programs, it has historically required a significant effort to incorporate additional optics codes into the software suite. The Open Architecture Software Integration System, or OASIS, provides an innovative framework that allows users to readily integrate their own optics programs into PBO Lab. This paper provides an overview of the OASIS framework and describes some of the new PBO Lab Modules that have been created using OASIS.

THPAS058 Lowering the Vertical Emittance in the LER Ring of PEP-II emittance, coupling, luminosity, permanent-magnet 3621
  • F.-J. Decker, Y. Cai, Y. Nosochkov, Y. T. Yan, G. Yocky
    SLAC, Menlo Park, California
  Funding: *Work supported by Department of Energy contract DE-AC03-76SF00515.

The low energy ring (LER) in PEP-II has a design emittance of 0.5 nm-rad in the vertical, compared to nearly 0.1 nm-rad for the HER ring. This was thought to come from the "vertical step" of about 1 m in the interaction straight, where the LER beam after horizontal separation gets bend vertical so it sits on top of the HER in the rest of the ring. Since the program MAD does not easily reveal the location of the major emittance contribution, a program was written to calculate the coupled "curly H" parameter of mode 2 (mainly vertical) along z. Weighting it with the magnet bending revealed that the weak long bends inside the "vertical step" did less than 20% of the emittance growth. More than 80% comes from the ends of the adjacent arcs with strong bends. This is caused by the coupling cancellation of the solenoid starting already there with the skew quadrupoles SK5 and 6. By introducing additional skews in the straight instead of SK5 and 6 the emittance could be reduced by a factor of ten in simulations, but with very strong skews. Reasonable strong magnets might generate a workable compromise, since a factor of two in emittance promises 50% more luminosity in beam-beam simulations.

THPAS068 Calculating IP Tuning Knobs for the PEP II High Energy Ring using Singular Value Decomposition, Response Matrices and an Adapted Moore Penrose Method lattice, coupling, simulation, collider 3642
  • W. Wittmer
    SLAC, Menlo Park, California
  Funding: US-DOE

The PEP II lattices are unique in their detector solenoid field compensation scheme by utilizing a set of skew quadrupoles in the IR region and the adjacent arcs left and right from the IP. Additionally the design orbit through this region is nonzero. This combined with the strong local coupling wave makes it very difficult to calculate IP tuning knobs which are orthogonal and closed. The usual approach results either in non-closure, not being orthogonal or the change in magnet strength being too big. To find a solution the set of tuning quads had to be extended which resulted having more degrees of freedom than constrains. To find the optimal set of quadrupoles which creates a linear, orthogonal and closed knob and simultaneously minimizing the changes in magnet strength, the method using Singular Value Decomposition, Response Matrices and an Adapted Moore Penrose Method had to be extended. The results of these simulations are discussed below and the results of first implementation in the machine are shown.

THPAS072 Multipass Steering Protocols at Jefferson Lab linac, injection, controls, focusing 3648
  • R. M. Bodenstein, M. G. Tiefenback
    Jefferson Lab, Newport News, Virginia
  Funding: Authored by Jefferson Science Associates, LLC under U. S. DOE Contract No. DE-AC05-06OR23177

The CEBAF recirculating accelerator consists of two CW superconducting RF linacs, through which an electron beam is accelerated for up to 5 passes. Focusing and steering elements affect each pass differently, requiring a multipass steering protocol to correct the orbits. Perturbations include lens misalignments (including long-term ground motion), BPM offsets, and focusing and steering from RF fields inside the cavities. A previous treatment of this problem assumed all perturbations were localized at the quadrupoles and the absence of x-y coupling. Having analyzed the problem and characterized the solutions, we developed an empirical iterative protocol to compare against previous results in the presence of skew fields and cross-plane coupling. We plan to characterize static and acceleration-dependent components of the beam line perturbations to allow systematic and rapid configuration of the accelerator at different linac energy gains.

THPAS087 ACCELVIEW: A Graphical Means for Driving Integrated Numerical Experiments simulation, lattice, controls, linac 3687
  • N. Barov
    Far-Tech, Inc., San Diego, California
  • S. Reiche
    UCLA, Los Angeles, California
  Funding: Work supported by the US Department of Energy.

Many simulation efforts make use of integrated numerical experiments, where the inputs and outputs of several accelerator codes are tied together. This is usually accomplished by writing custom scripts that launch the underlying programs and perform data format translation. We present a way to simplify this process by using a graphical user interface that allows one to describe the data flow in the style of the LabVIEW and Simulink environments. A module to support a new accelerator code involves writing data translators to/from a common format (SDDS or HDF5), and a function to generate an input file based on a standard way of specifying an accelerator lattice (such as Accelerator Markup Language, or AML).

THPAS091 BPM Calibration Independent LHC Optics Correction simulation, optics, heavy-ion, alignment 3693
  • R. Calaga
    BNL, Upton, Long Island, New York
  • R. Tomas, F. Zimmermann
    CERN, Geneva
  Funding: This work is partially supported by the U. S. DOE

The tight mechanical aperture for the LHC imposes severe constraints on both the beta and dispersion beating. Robust techniques to compensate these errors are critical for operation of high intensity beams in the LHC. We present simulations using realistic errors from magnet measurements and alignment tolerances in the presence of BPM noise. Correction reveals that the use of BPM calibration and model independent observables are key ingredients to accomplish optics correction. Experiments at RHIC to verify the algorithms for optics correction are also presented.

THPAS094 Transverse to Longitudinal Emittance Exchange Beamline at the A0 Photoinjector emittance, dipole, simulation, radiation 3702
  • R. P. Fliller
    BNL, Upton, Long Island, New York
  • D. A. Edwards, H. Edwards
    Fermilab, Batavia, Illinois
  • K. C. Harkay, K.-J. Kim
    ANL, Argonne, Illinois
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  Funding: Work supported by Universities Research Association Inc. under contract DE-AC02-76CH00300 with the U. S. DOE.

The A0 photoinjector is being reconfigured to test the principal of transverse to longitudinal emittance exchange as proposed by Emma et. al., Kim and Sessler, and others. The ability to perform such an exchange could have major advantages to FELs by reducing the transverse emittance. Several schemes to carry out the exchange are possible and will be reported separately. At the Fermilab A0 Photoinjector we are constructing a beamline to demonstrate this transverse to longitudinal emittance exchange. This beamline will consist of a dogleg, and a TM110 5 cell copper cavity followed by another dogleg. The beamline is designed to reuse the bunch compressor dipoles of the photoinjector, along with some existing diagnostics. Beamline layout and optics discussed along with inital data. Future possibilites of performing a similar experiment at the proposed NML facility at Fermilab are also discussed.

THPAS098 A Low γt Injection Lattice for Polarized Protons in RHIC injection, lattice, optics, proton 3714
  • C. Montag
    BNL, Upton, Long Island, New York
  Funding: Work performed under the auspices of the US Department of Energy.

Polarized protons are injected into the Relativistic Heavy Ion Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by Delta gamma=0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by ∆ γt=0.8.

THPAS103 Design of a Thin Quadrupole to be Used in the AGS Synchrotron multipole, sextupole, simulation, acceleration 3723
  • N. Tsoupas, L. Ahrens, R. Alforque, M. Bai, K. A. Brown, E. D. Courant, J. W. Glenn, H. Huang, A. K. Jain, W. W. MacKay, M. Okamura, T. Roser, S. Tepikian
    BNL, Upton, Long Island, New York
  Funding: Work supported by the US Department of Energy

The AGS synchrotron employs two partial helical snakes* to preserve the polarization of the proton beam during acceleration in the AGS. The effect of the helical snakes on the beam optics is significant at injection energy, with the effect greatly diminishing early in the acceleration cycle. In order to compensate for the effect of the snakes on the beam optics, we have introduced eight compensation quadrupoles in straight sections of the AGS at the proximity of the partial snakes. At injection the strength of these eight quads is set at a high value but ramped down to zero when the effect of the snakes diminishes. Four of the compensation quadrupoles had to be placed in very short straight sections therefore had to be 'thin' with a length of ~30 cm. The 'thin' quadrupoles were laminated and designed to minimize the strength of the dodecoupole harmonic. The thickness of the lamination was also calculated** to keep the ohmic losses generated by the eddy currents in the laminations below an acceptable limit. Comparison of the measured and calculated harmonics will be presented and the ohmic losses due to the eddy currents, as a function of time during rumping will be discussed.

* H. Huang, et al., Proc. EPAC06, (2006), p. 273.** OPERA computer code. Vector Fields Inc.

FRXKI01 Superconducting Magnet Needs for the ILC dipole, superconducting-magnet, undulator, wiggler 3732
  • J. C. Tompkins, V. S. Kashikhin
    Fermilab, Batavia, Illinois
  • J. A. Clarke
    Cockcroft Institute, Warrington, Cheshire
  • M. A. Palmer
    CLASSE, Ithaca
  • B. Parker
    BNL, Upton, Long Island, New York
  The ILC Reference Design Report will be completed early in 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 11,000 magnetic elements of which more than 1200 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Magnet Systems Group and the leaders of the Area Systems Groups, responsible for beamline design. The superconducting magnet components include the Main Linac quadrupoles, the Positron Source undulators, the Damping Ring wigglers, and the complex array of Final Focus superconducting elements in the Beam Delivery System.  
slides icon Slides  
FRXKI02 Magnet Development for LARP 3737
  • G. L. Sabbi
    LBNL, Berkeley, California
  The talk will cover progress and prospects for developing Nb3Sn quadrupoles for the eventual upgrade of the LHC IR's. The talk should also cover developments in cabling, but not R&D on the Nb3Sn strand.  
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FRXKI03 Magnets for Upgrade of the Accelerator Complex at CERN luminosity, interaction-region, superconducting-magnet 3738
  • L. Rossi
    CERN, Geneva
  While the LHC is approaching commissioning phase, a global plan with different options for the consolidation and upgrade of the accelerator complex is under discussion at CERN. In one option the change of the interaction region (IR) magnets, in order to increase the luminosity of the LHC, is considered. This measure may be accompanied or not by an increase of the beam current. In any case the needs of new more performing Nb-Ti based magnets and/or Nb3Sn magnets is established. The choice of Nb3Sn based magnets with13-15 T peak field on the coil seems mandatory for the low-beta triplet quadrupoles in case a factor two or more in luminosity is envisaged. In another option the improvement of the injector chain is considered. For the moment the first priority is the design of a new PS of energy about 50 GeV, with duty cycle less than 1 Hz. In this paper a comparison among the option based on normal conducting magnets (today baseline) and superconducting magnets of various types will be presented. In the frame of the longer-term scenario, magnets envisaged for an upgrade of the present SPS (from 450 to 1 TeV) and for neutrino production facilities will be discussed as well.  
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FROAKI01 Magnet Acceptance and Allocation at the LHC Magnet Evaluation Board dipole, superconducting-magnet, insertion, alignment 3739
  • L. Bottura, P. Bestmann, N. Catalan-Lasheras, S. D. Fartoukh, S. S. Gilardoni, M. Giovannozzi, J. B. Jeanneret, M. Karppinen, A. M. Lombardi, K. H. Mess, D. P. Missiaen, M. Modena, R. Ostojic, Y. Papaphilippou, P. Pugnat, S. Ramberger, S. Sanfilippo, W. Scandale, F. Schmidt, N. Siegel, A. P. Siemko, D. Tommasini, T. Tortschanoff, E. Y. Wildner
    CERN, Geneva
  The normal- and superconducting magnets for the LHC ring have been carefully examined to insure that each of the more than 1800 assemblies is suitable for the operation in the accelerator. Magnet coordinators, hardware experts and accelerator physicists, joined in the LHC Magnet Evaluation Board, have contributed to this work that consists in the magnet acceptance, and the optimisation achieved by sorting magnets according to their geometry, field quality and quench level. This paper gives a description of the magnet approval mechanism that has been running since four years, reporting in a concise summary on the main results achieved. We take as specific indicators the computed mechanical aperture, the sorting efficiency with respect to systematic and random field errors in the magnets, and the case-by-case analysis necessary to accommodate hardware limitations such as quench limits and training.  
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FROAKI02 LHC Magnet Tests: Operational Techniques and Empowerment for Successful Completion cryogenics, dipole, feedback, superconducting-magnet 3742
  • V. Chohan, G. H. Hemelsoet, F. Pirotte, K. Priestnall, E. Veyrunes
    CERN, Geneva
  • N. Ali, P. Awale, S. Bahuguna, V. Chauhan, M. Y. Dixit, J. A. Gore, J. John, E. Kandaswamy, A. Kasbekar, P. Kashyap, C. P. Kulkarni, A. Laddha, S. Malhotra, M. Mascarenhas, J. K. Mishra, P. Motiwala, K. Nair, R. Narayanan, S. Padmakumar, A. Pagare, D. Peruppayikkad, S. Raghunathan, S. Rao, D. Roy, S. Sethumadhavan, S. Sharma, S. Shimjith, S. Singh, S. T. Sonnis, P. Surendran, A. Tikaria
    BARC, Mumbai
  • U. Bhunia
    DAE/VECC, Calcutta
  • A. Kasliwal
    RRCAT, Indore (M. P.)
  The LHC magnet tests operation team* developed various innovative techniques, particularly since early 2004, to complete the superconductor magnet testing by end 2006. Overall and cryogenic priority handling, rapid on-bench thermal cycling, rule-based goodness evaluation on round-the-clock basis, multiple, mashed web systems are some of these techniques applied with rigour for successful tests completion in time. This paper highlights these operation empowerment tools which had a pivotal role for success. A priority handling method was put in place to enable maximum throughput from twelve test benches, having many different constraints. For the cryogenics infrastructure, it implied judicious allocation of limited resources to the benches. Rapid On-Bench Thermal Cycle was a key strategy to accelerate magnets tests throughput, saving time and simplifying logistics. First level magnet appraisal was developed for 24 hr decision making so as to prepare a magnet further for LHC or keep it on standby. Web based systems (Tests Management and E-Traveller) were other essential ideas to track & coordinate various stages of tests handled by different teams.  
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FROBC02 RF Structures for Linac4 linac, coupling, klystron, alignment 3821
  • F. Gerigk, N. Alharbi, M. Pasini, S. Ramberger, M. Vretenar, R. Wegner
    CERN, Geneva
  Linac4 is proposed to replace the existing proton linac at CERN (Linac2). Using an increased injection energy of 160 MeV instead of 50 MeV Linac4 is expected to double the beam intensity in the PS Booster and will thus be the first step towards higher brightness beams in the LHC. In this paper we re-assess the choice of RF structures for Linac4. Different accelerating structures for different energy ranges are compared in terms of RF efficiency, ease of construction and alignment, necessary infrastructure, and cost. Eventually we present the final choice of structures for Linac4.  
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FROBC03 Efficient Accelerating Structures for Low-Energy Light Ions focusing, rfq, impedance, linac 3824
  • S. S. Kurennoy, L. Rybarcyk, T. P. Wangler
    LANL, Los Alamos, New Mexico
  The radio-frequency quadrupole (RFQ) accelerator is the best structure immediately after an ion source for accelerating light-ion beams with considerable currents. On the other hand, the higher-energy part of the RFQ is known to be not a very efficient accelerator. We consider alternative room-temperature RF accelerating structures for the beam velocities in the range of a few percent of the speed of light - including H-mode cavities and drift-tube linacs - and compare them with respect to their efficiency, compactness, ease of fabrication, and overall cost. Options for the beam transverse focusing in such structures are discussed. Possible applications include a compact deuteron-beam accelerator up to the energy of a few MeV for homeland defense.  
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FRPMN019 The Regular and Random Multi-Pole Errors Influence on the HESR Dynamic Aperture multipole, sextupole, lattice, octupole 3949
  • A. N. Chechenin, Y. Senichev, N. E. Vasyukhin
    FZJ, Julich
  The High Energy Storage Ring has the racetrack lattice, where each arc has the even number of super-periods S and the tune with one unit smaller ν=S-1 in both planes. Due to this fundamental feature the total n-order multi-pole is entirely cancelled and the regular errors can be fully compensated inside of one arc. In case of the random multi-pole errors the dynamic aperture is determined by the structure resonances excitation. We consider both regular and random multi-pole influence on the dynamic aperture and the possible correction scheme.  
FRPMN020 Beam Profile Measurements Based on Light Radiation of Atoms Excited by the Particle Beam synchrotron, diagnostics, proton, cyclotron 3955
  • J. Dietrich
    FZJ, Julich
  • C. Boehme
    UniDo/IBS, Dortmund
  • A. H. Botha, J. L. Conradie, P. F. Rohwer
    iThemba LABS, Somerset West
  • T. Weis
    DELTA, Dortmund
  Funding: Supported by BMBF and NRF, project-code SUA06/003

Diagnostics of intense particle beams requires development of new nondestructive beam monitoring methods. There are several kinds of diagnostic devices based on registration of products of accelerated beam particles interaction with atoms and molecules of residual gas in an accelerator vacuum chamber. Usually these devices used as beam profile monitors, which register electrons or/and ions produced in collisions of beam particles with residual gas. Some attempts were performed in application of light radiation of excited atoms. However, up to now this direction in the beam diagnostics was not developed properly. Nondestructive method of beam diagnostic system based on light radiation of atoms excited by the beam particles has the advantages - insensitivity to external magnetic and electric fields and, as a consequence, to the beam space charge fields. It allows to get higher spatial and time resolution. Measurements under different conditions at COSY-Juelich and in a cyclotron beamline at I'Themba LABS are presented and the pro and contra of the method is discussed

FRPMN023 New Beam Diagnostic Developments at the Photo-Injector Test Facility PITZ diagnostics, dipole, electron, booster 3967
  • S. Khodyachykh, G. Asova, J. W. Baehr, C. H. Boulware, H.-J. Grabosch, M. Hanel, S. A. Korepanov, M. Krasilnikov, S. Lederer, A. Oppelt, B. Petrosyan, S. Rimjaem, J. Roensch, T. A. Scholz, L. Staykov, F. Stephan
    DESY Zeuthen, Zeuthen
  • D. Alesini, L. Ficcadenti
    INFN/LNF, Frascati (Roma)
  • T. Garvey
    LAL, Orsay
  • L. H. Hakobyan
    YerPhI, Yerevan
  • D. J. Holder, B. D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Richter
    BESSY GmbH, Berlin
  • R. Spesyvtsev
    KhNU, Kharkov
  Funding: This work has partly been supported by the European Community, contracts RII3-CT-2004-506008 and 011935, and by the "Impuls- und Vernetzungsfonds" of the Helmholtz Association, contract VH-FZ-005.

The Photo-Injector Test Facility at DESY in Zeuthen (PITZ) is an electron accelerator which was built to develop and optimize high brightness electron sources suitable for SASE FEL operation. Currently, in parallel to the operation of the existing setup, a large extension of the facility and its research program is ongoing. The beam line which has a present length of about 13 meters will be extended up to about 21 meters within the next two years. Many additional diagnostics components will be added to the present layout. Two high-energy dispersive arms, an RF deflecting cavity and a phase space tomography module will extend the existing diagnostic system of the photo injector and will contribute to the full characterization of new electron sources. We will report on the latest developments of the beam diagnostics at PITZ.

FRPMN036 Resonance Correction systems for JPARC Main Ring resonance, sextupole, coupling, injection 4024
  • A. Y. Molodozhentsev, T. Koseki, M. Tomizawa
    KEK, Ibaraki
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  The injection time for the JPARC Main Ring for the basic scenario is about 120ms, which corresponds to about 20,000 turns. The particle losses at the Main Ring collimator should be less than 1% from the expected maximum beam power at the injection energy. To keep the particle losses for the Main Ring operation below the limit, the correction systems have been suggested to eliminate possible resonance excitation. The proposed correction schemes allow us to suppress linear and nonlinear resonances. The calculated and/or measured field data for main magnets of the ring has been taken into account for this study.  
FRPMN039 Measurement of Quadrupolar Tune Shifts After the Reconstruction of the Photon Factory Storage Ring storage-ring, betatron, factory, photon 4039
  • S. Sakanaka, T. Mitsuhashi, T. Obina
    KEK, Ibaraki
  The tune shift of transverse quadrupolar oscillations is a measure of a quadrupolar component of wakefields in the storage ring*. By measuring both dipolar and quadrupolar tune shifts, one can estimate the dipolar and the quadrupolar components of wakefields (exactly, kick factors) independently. We carried out such measurements before and after the upgrade of the Photon Factory storage ring. The results showed the change in the tune shifts which were caused by the replacement of many (about two-thirds of the ring) vacuum chambers.

* S. Sakanaka, T. Mitsuhashi, and T. Obina, Phys. Rev. ST Accel. Beams 8, 042801 (2005).

FRPMN045 Beam Position Monitor and its Calibration in J-PARC LINAC linac, monitoring, pick-up, background 4072
  • S. Sato, T. Tomisawa, A. Ueno
    JAEA/LINAC, Ibaraki-ken
  • H. Akikawa, Z. Igarashi, N. Kamikubota, S. Lee
    KEK, Ibaraki
  • M. Ikegami
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Sako, G. B. Shen
    JAEA, Ibaraki-ken
  The beam commissioning of J-PARC linac has been started in November 2006. Beam Position Monitors (BPMs) which have been calibrated on the bench setup with a scanning wire, utilize beam based calibration to relate the BPM center and the center of Q magnet. In this presentation, detail of installed BPM and the calibration methods are described.  
FRPMN046 Effects of Magnetic Field Tracking Errors on Beam Dynamics at J-PARC RCS resonance, space-charge, simulation, betatron 4078
  • H. Hotchi, F. Noda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  The 3-GeV Rapid-Cycling Synchrotron (RCS) of J-PARC aims at providing a 1-MW proton beam at a repetition rate of 25 Hz for an injection energy of 400 MeV. In this paper, we discuss influences of field tracking errors between dipoles and quadrupoles and between different families of quadrupoles on beam dynamics in combination with effects of the space charge and intrinsic nonlinear fields for the J-PARC RCS.  
FRPMN070 Controlled Longitudinal Emittance Blow-up in the CERN PS emittance, injection, simulation, acceleration 4186
  • H. Damerau, M. Morvillo, E. N. Shaposhnikova, J. Tuckmantel, J.-L. Vallet
    CERN, Geneva
  The longitudinal emittance of the bunches in the CERN PS must be increased before transition crossing to avoid beam loss due to a fast vertical instability. This controlled blow-up is essential for all high-intensity beams in the PS, including those for transfer to the LHC. The higher harmonic 200 MHz RF system (six cavities) used for this blow-up has to generate a total RF voltage which, for the most demanding blow-up, is comparable to the voltage of the main RF cavities. The system is presently subject to a major upgrade and a possible reduction in the number of higher harmonic RF cavities installed is under consideration. To determine the minimum required, detailed simulations and machine development studies to optimize the longitudinal blow-up have been performed. Further options to produce the required longitudinal emittance using other RF systems are also analyzed. The results obtained for the different scenarios for the longitudinal blow-up are presented and compared in this paper.  
FRPMN071 The LHC Beam Loss Measurement System beam-losses, radiation, vacuum, simulation 4192
  • B. Dehning, E. Effinger, J. E. Emery, G. Ferioli, G. Guaglio, E. B. Holzer, D. K. Kramer, L. Ponce, V. Prieto, M. Stockner, C. Zamantzas
    CERN, Geneva
  One of the most important elements for the protection of CERN's Large Hadron Collider (LHC) is its beam loss monitoring system. It aims to prevent the super conducting magnets from quenching and to protect the machine components from damages, as a result of critical beam losses. This contribution reviews the design requirements: a high reliability to insure a safe protection and a high availability, a high dynamic range required by the beam dump trigger generation and beam tuning and finally a high radiation tolerance to be able to install the front-end electronics in the LHC tunnel. Examples of the reliability studies using the reliability ISOGRAPH fault tree software package are shown to explain the particular design. Measurement results from the LHC beam loss system installed at HERA (DESY) and at the SPS (CERN) are given to demonstrate its functionality. The detector design of the ionisation chambers and the secondary emission monitors are summarized and measurements with high and low intensity beams as well as with continuous and pulsed proton, muon and neutron beams are discussed.  
FRPMN112 Far-Field OTR and ODR Images Produced by 7-GeV Electron Beams at APS radiation, polarization, optics, lattice 4372
  • A. H. Lumpkin, W. Berg, N. Sereno, B. X. Yang, C. Yao
    ANL, Argonne, Illinois
  • D. W. Rule
    NSWC, West Bethesda, Maryland
  Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357

We have investigated the angular distribution patterns (far-field focus) of optical transition radiation (OTR) and optical diffraction radiation (ODR) generated by 7-GeV electron beams passing through and near an Al metal plane, respectively. The 70-μrad opening angles of the OTR patterns provide calibration factors for the system. Effects of the upstream quadrupole focusing strength on the patterns as well as polarization effects were observed. The OTR data are compared to an existing OTR single-foil model, while ODR profile results are compared to expressions for single-edge diffraction. ODR was studied with impact parameters of about 1.25 mm, close to the gamma λ?bar value of 1.4 mm for 628-nm radiation. We expect angle-pointing information along the x axis parallel to the mirror edge is available from the single-lobe ODR data as well as divergence information at the sub-100-μrad level. Experimental and model results will be presented.

FRPMS008 IPM Measurements in the Tevatron injection, proton, emittance, single-bunch 3883
  • A. Jansson, K. Bowie, T. Fitzpatrick, R. Kwarciany, C. Lundberg, D. Slimmer, L. Valerio, J. R. Zagel
    Fermilab, Batavia, Illinois
  Funding: Work supported by the US Department of Energy

Two Ionization Profile Monitors (IPMs) were installed in the Tevatron in 2006. The detectors are capable of resolving single bunches turn-by-turn, using a combination of gas injection to boost the ionization signal and very fast and sensitive electronics to detect it. This paper presents recent improvements to the system hardware and its use for beam monitoring. In particular, the correction of beam size oscillations observed at injection is discussed.

FRPMS015 Correction of Second Order Chromaticity at Tevatron sextupole, betatron, resonance, injection 3922
  • A. Valishev, G. Annala, V. A. Lebedev, R. S. Moore
    Fermilab, Batavia, Illinois
  Correction of the second order betatron tune chromaticity is essential for operation at the working point near half integer resonance which is proposed as one of the ways to improve performance of the Tevatron. In this report the new chromaticity correction scheme with split sextupole families is described. Details of implementation and commissioning at the present working point are discussed.  
FRPMS017 Magnetic Error Analysis of Recycler Pbar Injection Transfer Line injection, proton, extraction, coupling 3934
  • M.-J. Yang
    Fermilab, Batavia, Illinois
  Detailed study of Fermilab Recycler Ring pbar injection transfer line became feasible with recent completion of BPM system upgrades, which includes its up-stream machine, the Main Injector. Data was taken both with proton during dedicated study and with pbar during regular beam transfer, in the opposite direction. The two Lambertson magnets on either end of transfer line have been identified as having substantial amount of error field. Using harmonic orbit decomposition the error fields were mapped and results are presented.  
FRPMS018 1-MeV Electrostatic Ion Energy Analyzer ion, space-charge, sextupole, diagnostics 3940
  • F. M. Bieniosek, M. Leitner
    LBNL, Berkeley, California
  Funding: Work performed under the auspices of the U. S. Department of Energy by the university of California, Lawrence Berkeley National Laboratory under Contract No. DE-AC03-76F00098.

We describe a high resolution (a few x 10-4) 90-degree cylindrical electrostatic energy analyzer for 1-MeV (singly ionized) heavy ions for experiments in the Heavy Ion Fusion Science Virtual National Laboratory. By adding a stripping cell, the energy reach of the analyzer is extended to 2 MeV. This analyzer has high dispersion in a first-order focus with bipolar deflection-plate voltages in the range of ±50 kV. We will present 2- and 3-D calculations of vacuum-field beam trajectories, space-charge effects, field errors, and a multipole corrector. The corrector consists of 12 rods arranged in a circle around the beam. Such a corrector has excellent properties as an electrostatic quadrupole, sextupole, or linear combination. The improved energy diagnostic allows measurements of beam charge state and energy spread, such as caused by charge exchange or temperature anisotropy, and better understanding of experimental results in longitudinal beam studies.

FRPMS050 LANSCE-Linac Beam-Centroid Jitter in Transverse Phase Space simulation, target, diagnostics, dipole 4093
  • B. Blind, J. D. Gilpatrick
    LANL, Los Alamos, New Mexico
  Funding: Work supported by the US Department of Energy under contract DE-AC52-06NA25396.

In order to characterize the beam-centroid jitter in transverse phase space, sets of position data of the 100-MeV H+ beam and 800-MeV H- beam were taken in the transport lines of the Los Alamos Neutron Science Center (LANSCE) accelerator complex. Subsequent data evaluation produced initially puzzling inconsistencies in the phase-space plots from different pairs of beam-position monitors. It is shown that very small random measurement errors will produce systematic differences between plots that should nominally be identical. The actual beam-centroid jitter and the amount of random error in the measurements can be extracted from the data by performing simulations and determining the parameters for which the resulting plots are consistent with the results from the data. Examples will be shown.

FRPMS052 H+ and H- Beam Position and Current Jitter at LANSCE isotope-production, linac, kicker, feedback 4105
  • J. D. Gilpatrick, B. Blind, M. S. Gulley, C. Pillai, J. F. Power
    LANL, Los Alamos, New Mexico
  Funding: *Work supported by the U. S. Department of Energy.

During the CY2005 and CY2006 Los Alamos Neutron Science Center (LANSCE) beam runs, six beam-development shifts were performed in order to acquire and analyze beam-current and beam-position jitter data for both the LANSCE H+ and H- beams. These data were acquired using three beam position monitors (BPMs) from the 100-MeV Isotope Production Facility (IPF) beam line and three BPMs from the Switchyard transport line at the end of the LANSCE 800-MeV linac. The two types of data acquired, intermacropulse and intramacropulse, were analyzed for statistical and frequency characteristics as well as various other correlations including comparing their phase-space characteristics in a coordinate system of transverse angle versus transverse position. This paper will briefly describe the measurements required to acquire these data, the analysis of these jitter data, and some interesting implications to beam operation.

FRPMS054 PSR Electron Cloud Detector and Suppressor Mechanical Design and Fabrication electron, vacuum, diagnostics, beam-transport 4117
  • J. F. O'Hara, M. J. Borden, A. A. Browman, N. A. Gillespie, D. Martinez, K. G. McKeown, F. R. Olivas
    LANL, Los Alamos, New Mexico
  • J. E. Ledford, R. J. Macek
    TechSource, Santa Fe, New Mexico
  Funding: Work supported by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

In order to better understand the two stream e-p instability issue in the LANSCE Proton Storage Ring, a new diagnostic instrument has been developed to measure the electron cloud formation and trapping in a quadrupole magnet at the LANSCE, PSR. The device called the Electron Cloud Detector (ECD) was fabricated and has successfully been installed in the PSR. Along with the Electron Cloud Detector, an additional device was developed to manipulate electrons ejected from the quadrupole and allow additional information to be obtained from ECD measurements. This paper will discuss the mechanical design and fabrication issues encountered during the course of developing both devices.

FRPMS097 Realistic Non-linear Model and Field Quality Analysis in RHIC Interaction Regions dipole, multipole, sextupole, interaction-region 4309
  • J. Beebe-Wang, A. K. Jain
    BNL, Upton, Long Island, New York
  Funding: Work performed under the United States Department of Energy Contract No. DE-AC02-98CH1-886.

The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. So, a realistic non-linear model is crucial for understanding the beam behavior and to achieve the ultimate performance in RHIC. A procedure is developed to build a non-linear model using the available multipolar component data obtained from measurements of RHIC magnets. We first discuss the measurements performed at different stages of manufacturing of the magnets in relation to their current state in RHIC. We then describe the procedure to implement these measurement data into tracking models, including the implementation of the multipole feed down effect due to the beam orbit offset from the magnet center. Finally, the field quality analysis in the RHIC interaction regions is presented.