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

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

MPPE045 Accelerator Physics Issues at the 2.5 GeV PLS Storage Ring lattice, insertion-device, emittance, undulator 2854
  • E.-S. Kim
    PAL, Pohang, Kyungbuk
  Over the past decade, PLS has served the synchrotron light source with the 2.0 GeV to 2.5 GeV electron beam. Accelerator physics issues at the present 2.5 GeV storage ring have been investigated in order to improve the performance of the light source. We present the issues of the low-beta lattice, low-emittance lattice, effects of six insertion devices on the lattice and low-alpha lattice, and show their effects on the beam dynamics in the storage ring.  
MPPE061 Measurement and Correction of Nonlinear Chromaticity in RHIC octupole, optics, luminosity, sextupole 3523
  • S. Tepikian, P. Cameron, A. Della Penna, V. Ptitsyn
    BNL, Upton, Long Island, New York
  Funding: Work performed under Contract Number DE-AC02-98CH10886 with the auspices of the U.S. Department of Energy.

To improve luminosity in RHIC by using smaller Beta,* higher order chromatic effects may need to be corrected. Measuring of higher order chromaticities is discussed and compared to a model of RHIC, showing good agreement. Assuming round beams, four families of octupoles are used to correct the second order chromaticities while keeping under control the amplitude dependent betatron tune spread in the beams. We show that the octupoles can reduce the second order chromaticity in RHIC, but they have insufficient strength for complete correction.

MPPE069 Optics for the ALBA Lattice lattice, insertion-device, vacuum, synchrotron 3777
  • M. Muñoz, D. Einfeld
    CELLS, Bellaterra (Cerdanyola del Vallès)
  ALBA will be a third generation synchrotron light source built in Spain near Barcelona. The lattice chosen for ALBA consists in an extended DBA-like structure with finite dispersion in the straight sections, providing low emittance (under 5nmrad), small beam cross sections at the source points (σ x ~ 150 micrometers and σ y ~ 10micrometers), and a large number of straight sections (4 times 8m, 12 times 4.2m and 8 times 2.6m). The small circumference (268 meters) and medium energy (3GeV) makes it challenging to provide the desired emittance while preserving a large enough dynamic aperture and energy acceptance. This paper reviews the main beam dynamics issues (dynamic aperture, energy acceptance, closed correction, lifetime, influence of insertion devices, and higher multipoles of magnets) and the solutions adopted.  
MPPP003 FALSE BPM READINGS AFFECTING ORBIT FEEDBACK feedback, vacuum, insertion-device, synchrotron 847
  • H.-S. Kang, J. Choi, M.-H. Chun, K.M. Ha, J.Y. Huang, Y.-C. Kim, E.-H. Lee, T.-Y. Lee, W.W. Lee, J.-H. Suh
    PAL, Pohang, Kyungbuk
  Funding: Ministry of Science and Technology, Korea.

A slow global orbit feedback (SOFB) is routinely operating in the usual user service operation at PLS. The orbit feedback uses 22 correctors in each plane which have 20-bit capability for the vertical plane and 16-bit capability for the horizontal plane, and the feedback speed is 4 seconds. The orbit stability in RMS was maintained below 1 mm in both planes for one hour and 3 mm for a 12-hour operation. The BPM chamber movement due to the change of synchrotron radiation heat load mainly limits the SOFB performance. The intensity dependence of BPM electronics is well compensated by a look-up table of BPM.

MPPP017 User Operation and Upgrades of the Fast Orbit Feedback at the SLS feedback, photon, beam-losses, damping 1538
  • M. Böge, B. Keil, A. Lüdeke, T. Schilcher
    PSI, Villigen
  A report on the performance of the fast orbit feedback (FOFB) in its 2nd year of user operation is given. Photon beam position monitors (XBPM) have been included by means of a slow feedback which changes the reference settings of the FOFB. Users are permitted to change the XBPM references within certain limits while the feedback is running. A fast synchronous readout of the XBPMs allows their integration into the FOFB loop. The FOFB will be extended by an additional beam position monitor (BPM) in order to satisfy the requirements of the upcoming FEMTO project.  
MPPP018 Correction of Insertion Device Induced Orbit Distortions at the SLS photon, feedback, undulator, insertion-device 1584
  • M. Böge, J.T.M. Chrin, G. Ingold, B. Keil, J. Krempasky, T. Schilcher, V. Schlott, T. Schmidt, A. Streun
    PSI, Villigen
  Corrections of insertion device (ID) induced orbit distortions at the SLS are performed by means of feed forward schemes down to the micron level at the corresponding photon beam position monitors (XBPMs). The remaining orbit fluctuations are suppressed by XBPM feedbacks which are an integral part of the fast orbit feedback system. As a result, sub-um RMS stability at the XBPMs is achieved while the ID settings are varied.  
MPPP021 Evolution of the Machine Impedance following the ESRF Upgrade to Low-Gap NEG Coated Aluminium Chambers impedance, single-bunch, vacuum, simulation 1712
  • T.F. Günzel, L. Farvacque, T. Perron, J.-L. Revol
    ESRF, Grenoble
  The installation of 5 meter-long, 8 mm vertical aperture insertion device (ID) aluminum chambers coated in house with non evaporable getter material is progressing at a rate of one chamber per shutdown. The evolution of the impedance with associated consequences on instability thresholds, following the installation of a number of low aperture insertion device chambers will be reported. In particular the impedance measurement using the local bump method allowed the identification and the replacement of the chambers of highest impedance. Correlation with the evolution of the single bunch instability thresholds and the theoretical prediction will be discussed. It could be observed that change in vertical aperture has a sensible effect on the single bunch horizontal threshold.  
MPPP022 The Impedance of Selected Components of the Synchrotron Light Source Petra III impedance, vacuum, synchrotron, dipole 1751
  • R. Wanzenberg, K. Balewski
    DESY, Hamburg
  At DESY it is planned to convert the PETRA ring into a synchrotron radiation facility, called PETRA III, in 2007. Since the impedance of the machine determines its performance with respect to coupled and single bunch instabilities it is important to know the wakefields and higher order modes (HOMs) of the different components of the vacuum system. Numerical calculations of wakefields and HOMs are presented for several components of PETRA III, including the rf-cavities, shielded bellows and tapered vacuum chamber transitions. The impedance of these components is presented in terms of the loss and kick parameters.  
MPPP026 Development of Longitudinal Coupling Impedance Measurement Platform for BEPCII impedance, coupling, storage-ring, controls 1940
  • G. Huang, W.-H. Huang, S. Zheng
    Tsinghua University, Beijing
  • J.Q. Wang, D.M. Zhou
    IHEP Beijing, Beijing
  Funding: Supported by NSFC 10375035.

A coaxial line impedance measurement platform is developed for BEPCII. A pair of gradual change impedance matching section is designed and fabricated by numerical control milling machine. The special designed RF connector is applied to strengthen the inner conductor. The algorithm of TRL calibration is applied in the system to avoid the usage of a reference pipe for each device under test. The measurement is accomplished by a VNA under the control of the software written in LabView.

MPPP045 Two Dimensional Aspects of the Regenerative BBU in Two-Pass Recirculating Accelerators recirculation, dipole, polarization, higher-order-mode 2872
  • E.P. Pozdeyev
    Jefferson Lab, Newport News, Virginia
  Funding: Work supported by DOE Contract DE-AC05-84ER40150.

In this paper, I present the formula, describing a threshold of the regenerative multi-pass Beam Breakup (BBU) for a single dipole higher order mode with arbitrary polarization in a two-pass accelerator with a general-form, 4x4 recirculation matrix. To illustrate specifics of the BBU in two dimensions, the formula is used to calculate the threshold for the reflecting and rotating optics of the recirculator that can lead to higher threshold currents. Then, I present a mathematical relation between transfer matrices between cavities of the accelerating structure and recirculation matrices for each cavity, which must be satisfied in order to successfully suppress the BBU by reflection or rotation in several cavities. At the end of the paper, a fast, two-dimensional BBU code developed at the Jefferson Lab is described.

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

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

MPPT026 Insertion Device Upgrade Plans at the NSLS undulator, impedance, insertion-device, vacuum 1949
  • T. Tanabe, A. Blednykh, D.A. Harder, M. Lehecka, G. Rakowsky, J. Skaritka
    BNL, Upton, Long Island, New York
  This paper describes plans to upgrade insertion devices at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, U.S.A. The aging wiggler (W80) at X25 is being replaced by a 1 m long in-vacuum mini-gap undulator (MGU-18) optimized for a dedicated macromolecular crystallography program. A new, 1/3 m long, in-vacuum undulator (MGU-13.5), will be installed between a pair of RF cavities at X9, and will serve a new beamline dedicated for small angle x-ray scattering (SAXS). Both MGU’s will have provision for cryocooling the NdFeB hybrid arrays to 150K to raise the field and K-value and to obtain better spectral coverage. Design issues of the devices and other considerations, especially magnetic measurement methods in low temperature will be discussed.  
MPPT042 Field Quality and Alignment of the Series Produced Superconducting Matching Quadrupoles for the LHC Insertions quadrupole, multipole, alignment, dipole 2738
  • N. Catalan-Lasheras, G. Kirby, R. Ostojic, J.C. Perez, H. Prin, W.  Venturini Delsolaro
    CERN, Geneva
  The production of the superconducting quadrupoles for the LHC insertions is advancing well and about half of the magnets have been produced. The coil size and field measurements performed on individual magnets both in warm and cold conditions are yielding significant results. In this paper we present the procedures and results of steering the series production at the magnet manufacturers and the assembly of cold masses at CERN. In particular, we present the analysis of warm-cold correlations and hysteresis of the main field multipoles, the correlation between coil sizes and geometrical field errors and the effect of permeability of magnet collars. The results are compared with the target errors for field multipoles and alignment.  
MPPT043 Low-Beta Quadrupole Designs for the LHC Luminosity Upgrade quadrupole, luminosity, dipole, multipole 2795
  • R. Ostojic, N. Catalan-Lasheras, G. Kirby
    CERN, Geneva
  Several candidate scenarios are considered for the upgrade of the LHC insertions in view of increasing the luminosity in excess of 1034 cm-2s-1. In all cases, superconducting low-beta quadrupoles with apertures in the range of 90-110 mm are required in view of increased heat loads and beam crossing angles. We present possible low-beta quadrupole designs based on Nb3Sn and NbTi superconducting cables, including existing LHC-class superconductors, present scaling laws for the magnet parameters and discuss relative advantages of the underlying triplet layouts.  
MPPT044 The Construction of the Low-Beta Triplets for the LHC quadrupole, multipole, vacuum, dipole 2798
  • R. Ostojic, M. Karppinen, T.M. Taylor, W.  Venturini Delsolaro
    CERN, Geneva
  • R. Bossert, J. DiMarco, SF. Feher, J.S. Kerby, M.J. Lamm, T.H. Nicol, A. Nobrega, T.M. Page, T. Peterson, R. Rabehl, P. Schlabach, J. Strait, C. Sylvester, M. Tartaglia, G. Velev
    Fermilab, Batavia, Illinois
  • N. Kimura, T. Nakamoto, T. Ogitsu, N. Ohuchi, t.s. Shintomi, K. Tsuchiya, A. Yamamoto
    KEK, Ibaraki
  The performance of the LHC depends critically on the low-beta triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was set up in 1996 to design and build the triplet systems, and after nine years of joint effort the production will be completed in 2005. We retrace the main events of the project and present the design features and performance of the low-beta quadrupoles, built by KEK and Fermilab, as well as of other vital elements of the triplet. The experience in assembly of the first triplet at CERN and plans for tunnel installation and commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-beta triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of physics experiment collaborations, and rarely before achieved in accelerator building.  
MPPT050 Test Results for LHC Insertion Region Dipole Magnets dipole, quadrupole, sextupole, octupole 3106
  • J.F. Muratore, M. Anerella, J.P. Cozzolino, G. Ganetis, A. Ghosh, R.C. Gupta, M. Harrison, A.K. Jain, A. Marone, S.R. Plate, J. Schmalzle, R.A. Thomas, P. Wanderer, E. Willen, K.-C. Wu
    BNL, Upton, Long Island, New York
  Funding: U.S. Department of Energy.

The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has made 20 insertion region dipoles for the Large Hadron Collider (LHC) at CERN. These 9.45 m-long, 8 cm aperture magnets have the same coil design as the arc dipoles now operating in the Relativistic Heavy Ion Collider (RHIC) at BNL and are of single aperture, twin aperture, and double cold mass configurations. They produce fields up to 3.8 T for operation at 7.56 TeV. Eighteen of these magnets have been tested at 4.5 K using either forced flow supercritical helium or liquid helium. The testing was especially important for the twin aperture models, which have the most challenging design. In these, the dipole fields in both apertures point in the same direction, unlike LHC arc dipoles. This paper reports on the results of these tests, including spontaneous quench performance, verification of quench protection heater operation, and magnetic field quality. Magnetic field measurements were done at 4.5K and at room temperature, and warm-cold correlations have been determined. Some dynamic measurements to study the effect of time decay and snapback at injection were also done, using a fast rotating coil.

MPPT079 Commissioning of an APPLE-II Undulator at Daresbury Laboratory for the SRS undulator, electron, insertion-device, photon 4051
  • J.A. Clarke, F.E. Hannon, D.J. Scott, B.J.A. Shepherd, N.G. Wyles
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A new variable polarisation undulator of the APPLE-II type has been designed and constructed at Daresbury Laboratory. Initial magnet testing of the 56mm period device was followed by an intensive period of shimming to improve the field quality. After this was successfully completed the undulator was installed into the SRS and tests made of the effect of the device upon the electron beam. This beam commissioning was completed in a very short space of time with the beamline being given full control of the gap and phase of the magnet within a few weeks of installation. This paper summarises the measurement of the magnet and the shimming techniques employed to improve the field quality. It also describes the effect of the device upon the stored 2 GeV electron beam and the measures taken to minimise these effects during user operations.  
MPPT091 Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies vacuum, monitoring, radiation, induction 4260
  • J.G. Hubrig
    Innovation Services, Inc, Knoxville, Tennessee
  • G.H. Biallas
    Jefferson Lab, Newport News, Virginia
  Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.  
TPAP003 Exploring a Nonlinear Collimation System for the LHC sextupole, collimation, optics, betatron 877
  • J. Resta, A. Faus-Golfe
    IFIC, Valencia
  • R.W. Assmann, S. Redaelli, G. Robert-Demolaize, D. Schulte, F. Zimmermann
    CERN, Geneva
  We explore the adaptation of a nonlinear collimation system, as previously considered for linear colliders, to LHC betatron cleaning. A possible nonlinear system for LHC consists of a horizontal and vertical primary collimator located in between a pair of skew sextupoles. We discuss the modified LHC optics, the need for and optimum placement of secondary absorbers, and the simulated cleaning efficiency.  
TPAP005 Calculation of Residual Dose Rates and Intervention Scenarios for the LHC Beam Cleaning Insertions–Constraints and Optimization simulation, radiation, radioactivity, quadrupole 940
  • M. Brugger, O. Aberle, R.W. Assmann, D. Forkel-Wirth, H.G. Menzel, S. Roesler, H. Vincke
    CERN, Geneva
  Radiation protection of the personnel who will perform interventions in the LHC Beam Cleaning Insertions is mandatory and includes the design of equipment and the establishment of work procedures. Residual dose rates due to activated equipment are expected to reach significant values such that any maintenance has to be planned and optimized in advance. Three-dimensional maps of dose equivalent rates at different cooling times after operation of the LHC have been calculated with FLUKA. The simulations are based on an explicit calculation of induced radioactivity and of the transport of the radiation from the radioactive decay. The paper summarizes the results for the Beam Cleaning Insertions and discusses the estimation of individual and collective doses received by personnel during critical interventions, such as the exchange of a collimator or the installation of Phase 2. The given examples outline the potential and the need to optimize, in an iterative way, the design of components as well as the layout of the beam cleaning insertions. Furthermore, results of measurements and simulations of residual dose rates for a collimator test recently performed at the SPS are presented.  
TPAP007 LHC Collimation: Design and Results from Prototyping and Beam Tests collimation, impedance, proton, beam-losses 1078
  • R.W. Assmann, O. Aberle, G. Arduini, A. Bertarelli, H.-H. Braun, M. Brugger, H. Burkhardt, S. Calatroni, F. Caspers, E. Chiaveri, A. Dallocchio, B. Dehning, A. Ferrari, M. Gasior, A. Grudiev, E.B. Holzer, J.-B. Jeanneret, J.M. Jimenez, Y. Kadi, R. Losito, M. Magistris, A.M. Masi, M. Mayer, E. Métral, R. Perret, C. Rathjen, S. Redaelli, G. Robert-Demolaize, S. Roesler, M. Santana-Leitner, D. Schulte, P. Sievers, E. Tsoulou, H. Vincke, V. Vlachoudis, J. Wenninger
    CERN, Geneva
  • I. Baishev, I.L. Kurochkin
    IHEP Protvino, Protvino, Moscow Region
  • G. Spiezia
    Naples University Federico II, Science and Technology Pole, Napoli
  The problem of collimation and beam cleaning concerns one of the most challenging aspects of the LHC project. A collimation system must be designed, built, installed and commissioned with parameters that extend the present state-of-the-art by 2-3 orders of magnitude. Problems include robustness, cleaning efficiency, impedance and operational aspects. A strong design effort has been performed at CERN over the last two years. The system design has now been finalized for the two cleaning insertions. The adopted phased approach is described and the expected collimation performance is discussed. In parallel robust and precisely controllable collimators have been designed. Several LHC prototype collimators have been built and tested with the highest beam intensities that are presently available at CERN. The successful beam tests are presented, including beam-based setup procedures, a 2 MJ robustness test and measurements of the collimator-induced impedance. Finally, an outlook is presented on the challenges that are ahead in the coming years.  
TPAP014 Energy Deposition Studies for the Betatron Cleaning Insertion (IR7) of LHC simulation, proton, collimation, quadrupole 1386
  • M. Santana-Leitner, R.W. Assmann, A. Ferrari, M. Magistris, E. Tsoulou, V. Vlachoudis
    CERN, Geneva
  Two insertions (IR3, IR7) of the Large Hadron Collider (LHC) are dedicated to beam cleaning with the design goals of absorbing part of the primary beam halo and of the secondary radiation. The tertiary halo which escapes the collimation system in IR7 may heat the cold magnets at unacceptable levels, if no additional absorber is used. In order to assess the energy deposition in sensitive components, extensive simulations were run with the Monte Carlo cascade code FLUKA. The straight section and the dispersion suppressors of IR7 were fully implemented. A modular approach in the geometry definition and an extensive use of user-written programs allowed the implementation of all magnets and collimators with high precision, including flanges, steel supports and magnetic field. This paper provides the number and location of additional absorbers needed to keep the energy deposition in the coils of the magnets below the quenching limit.  
TPAP020 Tests of a Roman Pot Prototype for the TOTEM Experiment impedance, coupling, vacuum, scattering 1701
  • M. Deile, E. Alagoz, G.M. Anelli, G.A. Antchev, M. Ayache, F. Caspers, E. Dimovasili, R. Dinapoli, F.D. Drouhin, K. Eggert, L. Escourrou, O. Fochler, K. Gill, R. Grabit, F. Haug, P. Jarron, J. Kaplon, T. Kroyer, T. Luntama, D. Macina, E. Mattelon, L. Mirabito, H. Niewiadomski, E.P. Noschis, M. Oriunno, A. Park, A.-L. Perrot, O. Pirotte, J.M. Quetsch, F. Regnier, G. Ruggiero, S. Saramad, P. Siegrist, W. Snoeys, T. Souissi, R. Szczygiel, J. Troska, F. Vasey, A. Verdier
    CERN, Geneva
  • V. Avati, M. Järvinen, M. Kalliokoski, J. Kalliopuska, K. Kurvinen, R. Lauhakangas, F. Oljemark, R. Orava, V. Palmieri, H. Saarikko, A. Soininen, K. Österberg
    Helsinki University, Department of Physics, University of Helsinki
  • V. Berardi, M.G. Catanesi, E. Radicioni
    INFN-Bari, Bari
  • V. Boccone, M. Bozzo, A. Buzzo, S. Cuneo, F. Ferro, M. Macri, S. Minutoli, A. Morelli, P. Musico, M. Negri, A. Santroni, G. Sette, A. Sobol
    INFN Genova, Genova
  • C. Da Vià, J. Hasi, A. Kok, S. Watts
    Brunel University, Middlesex
  • J. Kasper, V. Kundrât, M. V. Lokajicek, J. Smotlacha
    FZU, Prague
  The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC.* TOTEM Roman Pots contain stacks of 10 silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10 σ + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place first in a fixed-target muon beam at CERN's SPS, and then in the proton beam-line of the SPS accelerator ring. We present the test beam results demonstrating the successful functionality of the system despite slight technical shortcomings to be improved in the near future.

TOTEM, Technical Design Report, CERN-LHCC-2004-002.

TPAP046 Towards an Optimization of the LHC Intersection Region using New Magnet Technology quadrupole, dipole, radiation, lattice 2920
  • P.M. McIntyre, A. Sattarov
    Texas A&M University, College Station, Texas
  • J.-P. Koutchouk
    CERN, Geneva
  An optimized design of the intersection region of LHC is presented. The starting point of the design is to move the quadrupole triplet to a minimum distance from the intersect – 12 m. The innermost quadrupole must accommodate substantial heat load from particles, and is designed using a structured cable that incorporates internal refrigeration with supercritical helium. Using the reduced aperture required by this closer spacing, Nb3Sn quadrupoles have been designed with gradients of 350-400 T/m for the triplet. The separation dipole utilizes a levitated-pole design that mitigates the extreme heat and radiation challenges for that application. The above technical elements have been incorporated into an optimized insertion design that minimizes ?* while significantly reducing sensitivities to errors in multipoles and alignment. The additional space that is opened in the lattice can be used to fully localize the optical design of the insertion so that it does not require corrections through the neighboring arcs.  
TPAT011 Impedance Analysis of Longitudinal Bunch Shape Measurements at PLS impedance, undulator, damping, single-bunch
  • I. Hwang, M. Yoon
    POSTECH, Pohang, Kyungbuk
  • Y.J. Han, E.-S. Kim
    PAL, Pohang, Kyungbuk
  We measured the longitudinal bunch shape by streak camera at 2.5 GeV Pohang Light Source. The impedances estimated by a series R+L model indicate a resistance R= 960 ohm, an inductance L= 80 nH and a longitudinal impedance Z/n= 0.53 ohm. The scaling law for the bunch lengthenig is expressed as I0.22. The effects of insertion device in the ring on the ring impedance, particularly the vertical height of in-vacuum undulator are also presented.  
TPPT004 A 175 MHz RFQ Design for IFMIF Project rfq, linac, quadrupole, simulation 904
  • S. Maebara, S. Moriyama, M.S. Sugimoto
    JAERI, Ibaraki-ken
  • M.S. Saigusa, Y. Saitou
    Ibaraki University, Electrical and Electronic Eng., Ibaraki
  International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based neutron irradiation facility employing the D-Li stripping reaction, to produce the neutron field similar to the D-T Fusion reactor (2MW/m2,20 dpa/year for Fe). The required beam current of 250 mA is realized by two beam lines of 125mA, and the output energies at injector,RFQ and DTL were designed to be 0.1, 5 and 40 MeV,respectively. The operation frequency of 175MHz was selected to accelerate the large current of 125mA. After an intensive beam simulation, the RFQ with a total length of 12m was designed to keep the minimum emittance growth with the RF injection power of 2.3MW CW. For such a 175MHz RFQ, a design for RF input coupler with loop antenna and co-axial window, supplying RF power shared by 3 x 4 ports, was conducted by using the 3-D electromagnetic code of MW-Studio. In order to withstand the voltage exceeding 200kW CW per one loop antenna, the co-axial line of 4 1/16” diameter is necessary, and it is found that the electric field distortion factor less than 1% can be achieved in beam bore only by employing the 4-loop antenna configuration providing the same power for each quadrants.  
TPPT018 Tuning of 20MeV PEFP DTL target, proton, simulation, klystron 1598
  • M.-Y. Park, Y.-S. Cho, H.-S. Kim, H.-J. Kwon, K.T. Seol, Y.G. Song
    KAERI, Daejon
  Funding: This work is supported by the 21C Frontier R&D program in the Ministry of Science and Technology of the Korean government.

The PEFP (Proton Engineering Frontier Project) 20 MeV DTL have been constructing in KAERI site. The tuning goals for PEFP DTL are achieving the tank frequency as ± 5 kHz of designed resonant frequency and 1% of field profile through a tank. To tune the tank frequency 8 low power slug tuners per tank are fabricated and the tuning range is ±125 kHz per a tuner. Post couplers with tap to stabilize the field against the perturbation also are fabricated and will be installed every 3rd (1st tank) and 2nd (2,3,4th tank) drift tubes. We set up the bead perturbation measurement equipment as measuring the phase shift of a tank using network analyzer and LabView program. We are finalizing the tuning procedures and also the data calculation program. In this presentation we will show the overall features of the PEFP DTL tuning and discuss the measurement results.

TPPT036 Higher-Order-Mode Damper Testing and Installation in the Advanced Photon Source 352-MHz Single-Cell RF Cavities storage-ring, simulation, vacuum, photon 2443
  • G.J. Waldschmidt, N.P. Di Monte, D. Horan, L.H. Morrison, G. Pile
    ANL, Argonne, Illinois
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

Higher-order-mode dampers were recently installed in the storage ring rf cavities at the Advanced Photon Source to eliminate longitudinal coupled-bunch instability. It was discovered that the 540-MHz cavity dipole mode created beam instability at beam currents in excess of 85 mA causing horizontal emittance blowup. Methods of compensating for the instability by detuning the cavities and adjusting the cavity water temperature were becoming more difficult at higher beam currents as tests were performed to prepare for eventual 300-mA beam current operation. Electric field passive dampers located on the median plane of each cavity were determined to be the most promising solution. Simulation models were created and verified with low-power testing of the dampers. High-power testing of the dampers as well as conditioning of the damper ceramic load were also performed at the APS 352-MHz rf test stand and compared with simulation results. Preliminary test results will be discussed.

TPPT051 High Power Coupler for the TESLA Superstructure Cavities vacuum, electron, coupling, SNS 3141
  • Q.S. Shu, G. Cheng, J. T. Susta
    AMAC, Newport News, Virginia
  • S.J. Einarson
    CPI/BMD, Beverley, Massachusetts
  • T. Garvey
    LAL, Orsay
  • W.-D. Müller, D. Proch
    DESY, Hamburg
  • T.A. Treado
    CPI, Beverley, Massachusetts
  Funding: U.S. Department of Energy Grant No. DE-FG02-00ER86102.

More and more accelerators are built with superconducting cavities operating at cryogenic temperatures, and the probability of a ceramic window failure presents increasing problems because of the resulting contamination of the cavities surfaces and the resulting accelerating electric field degradation. A cost effective design and fabrication method for the TESLA cavities has been developed in the framework of a DOE STTR grant. This new design replaces the present TESLA cylindrical ceramic windows with two planar disc windows separated by a vacuum space and is optimized for RF input power, vacuum characteristics, and thermal properties. This novel coupler will reduce the costs of fabrication and improve the RF performance of the coupler, the vacuum between the two windows, and the cleaning procedure. Two couplers with this design have been fabricated and are presently being conditioned for testing at DESY, Germany, and LAL, France, on the RF high power testing stand and on a test cryomodule.

TPPT079 Performance Overview of the Production Superconducting RF Cavities for the Spallation Neutron Source Linac SNS, linac, proton, controls 4048
  • J.P. Ozelis, J.R. Delayen, J. Mammosser
    Jefferson Lab, Newport News, Virginia
  Funding: Work supported by U.S. Department of Energy under contract DE-AC05-84ER40150.

As part of its efforts for the SNS construction project, Jefferson Lab has produced 23 cryomodules for the superconducting linac. These modules contained 81 industrially produced multicell Nb accelerating cavities. Each of these cavities was individually tested before assembly into a cryomodule to verify that they achieved the required performance. This ensemble of cavities represents the 3rd largest set of production superconducting cavities fabricated and tested to date. The timely qualification testing of such a collection of cavities offers both challenges and opportunities. Their performance can be characterized by achieved gradient at the required Qo, achieved peak surface field, onset of field emission, and observations of multipacting. Possible correlations between cavity performance and process parameters, only really meaningful in the framework of a large scale production effort, will also be presented. In light of the potential adoption of these cavities for projects such as the Rare Isotope Accelerator or Fermilab Proton Driver, such an analysis is crucial to their success.

WPAE017 Installation of the LHC Long Straight Sections (LSS) shielding, injection, quadrupole, vacuum 1563
  • S. Bartolome-Jimenez, G. Trinquart
    CERN, Geneva
  The LHC long straight sections (LSS) serve as experimental or utility insertions. There are two high luminosity experimental insertions located at points 1 and 5 and two more experimental insertions at points 2 and 8 which also contain the injection systems. The beams only cross at these four locations and are focused by superconducting low-beta triplets. Insertions 3 and 7 each contain two collimation systems. Insertion 4 contains two RF systems. Insertion 6 contains the beam dumping system. The installation of the LSS is a challenge due to the compact layout that characterises these areas and the difficulties related to the underground work mainly in zones of restricted access. Specific devices are required for handling and installing various heavy and voluminous elements. This paper reviews the installation scenarios, describes the sequences presently planned and highlights the potential problem areas. The particular case of sector 7-8 where the LSS elements will be installed in parallel with the cryogenic distribution line (QRL) is used as an example of a ‘rapid’ installation scheme to illustrate how resources are used. The consequences of possible shortcuts are also mentioned.  
WPAE021 Short Straight Sections in the LHC Matching Sections (MS SSS): An Extension of the Arc Cryostats To Fulfill Specific Machine Functionalities vacuum, quadrupole, collider, lattice 1724
  • V. Parma, H. Prin
    CERN, Geneva
  • fl. Lutton
    IPN, Orsay
  Funding: IPN-CNRS, 15 rue Georges Clémenceau 91406 ORSAY, France.

The LHC insertions require 50 specific superconducting quadrupoles, operating in boiling helium at 4.5 K and housed in individual cryostats to form the MS Short Straight Sections (MS SSS). The quadrupoles and corrector magnets are assembled in 8 families of cold masses, with lengths ranging from 5 to 11 m and weights ranging from 60 to 140 kN. The MS SSS need to fulfil specific requirements related to the collider topology, its cryogenic layout and the powering scheme. Most MS SSS are standalone cryogenic and super-conducting units, i.e. they are not in the continuous arc cryostat, and therefore need dedicated cryogenic and electrical feeding. Specially designed cryostat end-caps are required to close the vacuum vessels at each end, which include low heat in-leak Cold-to-Warm transitions (CWT) for the beam tubes and 6 kA local electrical feedthrough for powering the quadrupoles. This paper presents the design of the MS SSS cryostats as an extension of the arc cryostat’s design to achieve a standard and consequently cost-effective solution, and the design solutions chosen to satisfy their specific functionalities.

WPAT001 HFSS Simulation of Vacuum Tube RF Power Amplifiers cyclotron, booster, simulation, vacuum 767
  • V. Zviagintsev, I. Bylinskii
    TRIUMF, Vancouver
  Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada.

Development and upgrade of rf power amplifiers require comprehensive calculations to predict and optimize various parameters of the system before hardware modifications are applied. ANSOFT HFSS code provides a powerful tool for 3D EM simulation of the amplifier output resonator comprising a vacuum tube as a passive element. Two examples of this kind of simulation applied for upgrade of the TRIUMF Cyclotron rf system are presented in this paper.

WPAT002 High Power (35 kW and 190 kW) 352 Solid State Amplifiers for the SOLEIL Synchrotron vacuum, power-supply, booster, synchrotron 811
  • P. Marchand, M.D. Diop, R.L. Lopes, J. Polian, F. Ribeiro, T. Ruan
    SOLEIL, Gif-sur-Yvette
  In the SOLEIL Storage Ring, two cryomodules, each containing a pair of superconducting cavities will provide the maximum power of 600 kW, required at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. Each of the four cavities will be powered with a 190 kW solid state amplifier consisting in a combination of 315 W elementary modules (about 750 modules per amplifier). The amplifier modules, based on a technology developed in house, with MOSFET transistor, integrated circulator and individual power supply, are fabricated in the industry. In the booster, a 35 kW solid state amplifier (147 modules) will power a 5-cell copper cavity of the LEP type. The first operational results and the status of the RF power plants are reported in this paper. Although quite innovative for the required power range, the solid state technology proved to be very attractive with significant advantages as compared to vacuum tubes.  
WPAT011 Application of TRL Calibration in Longitudinal Coupling Impedance Measurement Platform for BEPCII impedance, coupling, vacuum, feedback 1225
  • G. Huang, W.-H. Huang, S. Zheng
    Tsinghua University, Beijing
  • D.M. Zhou
    IHEP Beijing, Beijing
  Funding: Supported by NSFC 10375035.

TRL calibration is one of the standard calibration methods for RF measurement. Applying the TRL calibration method into the longitudinal coupling impedance platform makes it possible to eliminate the error matrix of the matching section and the RF connector. By using TRL calibration in the platform, the reference pipe of each device under test no longer required. The formula of the calibration is discussed in this paper and the software based on it is introduced.

WPAT069 Development of a Solid State RF Amplifier in the kW Regime for Application with Low Beta Superconducting RF Cavities simulation, ion, booster, monitoring
  • C. Piel
    ACCEL, Bergisch Gladbach
  • B. A. Aminov, A. Borisov, S. K. Kolesov, H. Piel
    CRE, Wuppertal
  Projects based on the use of low beta superconducting cavities for ions are under operation or development at several labs worldwide. Often these cavities are individually driven by RF power sources in the kW regime. For an ongoing project a modular 2 kW, 176 MHz unconditionally stable RF amplifier for CW and pulsed operation was designed, built, and tested. Extended thermal analysis was used to develop a water cooling system in order to optimize the performance of the power transistors and other thermally loaded components. The paper will outline the design concept of the amplifier and present first results on the test of the amplifier with a superconducting cavity.  
WPAT070 500 MHz Coaxial Transition Between the ELETTRA Input Coupler and the Transmission Waveguide vacuum, injection, resonance, storage-ring 3810
  • C. Pasotti, A. Fabris, M. Svandrlik
    ELETTRA, Basovizza, Trieste
  The investigations have shown that the 500 MHz ELETTRA input power coupler can safely sustain more than 150 KW. The critical component limiting the increase of the trasmitted RF power is the connection element between the input power coupler and the transmission line. An optimized design has been studied to overcome this limit. During the optimization process, the entire RF chain (input power coupler, connection element and transition to the standard waveguide WR1800) has been verified. The analysis has been carried out to check the performances of the whole lay-out in terms of efficiency of transmitted power and sensitivity to any signal coming from the cavity ( HOMs included). A prototype with an improved cooling system has been realized and tested.  
WPAT076 Resonant High Power Combiners resonance, impedance, radio-frequency, synchrotron 3970
  • M.L. Langlois, J.P. Buge, G. Peillex-Delphe
    TED, Vélizy Cedex
  Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.  
WOAB003 The Brazilian Synchrotron Light Source synchrotron, storage-ring, injection, booster 325
  • P.F. Tavares, J.A. Brum
    LNLS, Campinas
  The Brazilian Synchrotron Radiation Laboratory has been operating the only light source in the southern hemisphere since July 1997. Over this 7 year period, approximately 22000 hours of beam time were delivered to users from all over Brazil as well as from 10 other countries. In this article, we report on the present configuration of the 1.37 GeV electron storage ring and associated instrumentation, describe recent improvements to the light source and analyze future prespectives including the installation of insertion devices and additional beamlines.  
WOAC003 Effects of Fringe Fields and Insertion Devices Revealed Through Experimental Frequency Map Analysis sextupole, storage-ring, undulator, dynamic-aperture 266
  • P. Kuske
    BESSY GmbH, Berlin
  Funding: This work was supported by the Bundesministerium für Bildung und Forschung and by the Land Berlin.

Following the pioneering work at the ALS* frequency map analysis was performed at the light source BESSY. With altogether 7 families of sextupole magnets available in the storage ring, amplitude dependent tune shifts can be made rather small. Therefore, the impact of fringe fields of dipole and quadrupole magnets as well as systematic octupole and decapole field components of the quadrupole and sextupole magnets used in addition as horizontal, vertical and skew gradient correctors are clearly visible in the measured maps. Insertion devices with their known systematic and usually unknown random non-linear field components impact the appearance of the frequency maps even more strongly. In the talk the current status of the experiments as well as the results of the theoretical modeling will be presented.

*"Global Dynamics of the Advanced Light Source Revealed through Experimental Frequency Map Analysis," D. Robin, et al., Phys. Rev. Lett. 85, 558 (2000).

ROAC010 Development of Ultra-Fast Silicon Switches for Active X-Band High Power RF Compression Systems simulation, power-supply, extraction, vacuum 701
  • J. Guo, S.G. Tantawi
    SLAC, Menlo Park, California
  Funding: DOE

In this paper, we present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity SOI (silicon on oxide) wafer. The wafer is inserted into a cylindrical waveguide under T·1001 mode, performing switching by injecting carriers into the bulk silicon. Our current design is using a CMOS compatible process and the fabrication is accomplished at SNF (Stanford Nanofabrication Facility). This design is able to achieve sub-100ns switching time, while the switching speed can be improved further with 3-D device structure and faster circuit. Power handling capacity of the switch is at the level of 10MW. The switch was designed for active X-band RF pulse compression systems - especially for NLC, but it is also possible to be modified for other applications and other frequencies such as L-band.

RPAE004 Parametric Mechanical Design of New Insertion Devices at the APS undulator, insertion-device, brilliance, radiation 889
  • J.H. Grimmer, R.T. Kmak
    ANL, Argonne, Illinois
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences under Contract No. W-31-109-ENG-38.

Three permanent-magnet, planar, hybrid ID designs have recently been completed at the APS. The periods of the devices are 2.7 cm, 3.0 cm and 3.5 cm with nominal lengths of 2.4 m. Several design studies were performed for the initial 2.7 cm period device to investigate the utility of various design features. Then a parametric solid model for the initial device was developed and value engineered to minimize manufacturing, assembly and tuning costs. The model allowed the very rapid design of subsequent devices of similar periods and allowed commonality of several components of the IDs. This design family incorporates a low-cost method of pole retention and registration. Poles are secured by screws in two holes tapped into each pole. Pole location is registered by means of two small dowel pins for each pole in mating holes reamed into each pole and a base plate common to the poles and magnets. This base plate is flexible in bending along its length so shimming behind it can be used to accurately change the height of a pair of poles for tuning. Another feature of the design is modular construction to allow each device to be used full-length or shortened to a nominal 2.1 m length for use in APS "canted undulator" sectors.

RPAE035 Orbit Stability at BESSY feedback, diagnostics, electron, dipole 2366
  • R. Müller, J. Feikes, K. Holldack, P. Kuske
    BESSY GmbH, Berlin
  Funding: Funded by the Bundesministerium für Bildung und Forschung and by the Land Berlin.

Traditionally intrinsic component stability as well as perturbation source identification and suppression (like set-up modifications or feed-forward compensations) have been the preferred methods used to guarantee beam orbit stability for user operation at BESSY. Second focus of activity is the reliability of slow drift control and the high degree of beam position reproducibility maintained under frequently changed operation conditions. Along these lines an overview of the measures taken, the available diagnostic means as well as the achievements and shortcomings of the existing slow orbit feedback is given. Diagnostic capabilities of a fast BPM read-out and data distribution system give insight into the demands on a fast orbit feedback that could provide better operation flexibility and improved performance.

RPAE040 COD Correction at the PF and PF-AR by New Orbit Feedback Scheme feedback, insertion-device, dipole, electron 2613
  • K. Harada, T. Obina
    KEK, Ibaraki
  • N. Nakamura, H. Sakai, H. Takaki
    ISSP/SRL, Chiba
  The eigen-vector method with a constraint condition is a new COD correction method that enables us to combine the local orbit correction at the insertion devices with the global COD correction by integrating the local one into the global one as the constraint condition using the Lagrange’s undetermined multiplier method. In order to achieve this method, we only use the new contrived response matrix for the global COD correction where the local correction is involved and done simultaneously. We have tested this correction scheme at the PF ring and the PF-AR. In the machine studies, the new orbit correction method is successfully demonstrated. The RMS COD of the constraint BPMs are sufficiently suppressed and, on the other hand, there is almost no large difference in the RMS COD of all the other BPMs between the new and ordinary methods.  
RPAE054 Beam Stability at the Advanced Photon Source photon, insertion-device, vacuum, instrumentation 3268
  • G. Decker, O. Singh
    ANL, Argonne, Illinois
  Funding: This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

The Advanced Photon Source has been in operation since 1996. Since that time, extensive incremental improvements to orbit stabilization systems have been made. This includes the addition of 80 channels of narrowband rf beam position monitors (bpm's), 40 channels of bending magnet photon bpm's, and most recently the inclusion of 36 insertion device photon bpm's into the orbit correction response matrix. In addition, considerable improvements have been made in the area of power supply regulation, both for the main multipole magnets and the steering corrector magnets. The present status of overall performance will be discussed, including long term pointing stability, reproducibility, and AC beam motion.

RPAE056 NSLS II: The Future of the NSLS synchrotron, brightness, insertion-device, photon 3345
  • J.B. Murphy, J. Bengtsson, R. Biscardi, A. Blednykh, G.L. Carr, W.R. Casey, S. Chouhan, S.B. Dierker, E. Haas, R. Heese, S. Hulbert, E.D. Johnson, C.C. Kao, S.L. Kramer, S. Krinsky, I.P. Pinayev, S. Pjerov, B. Podobedov, G. Rakowsky, J. Rose, T.V. Shaftan, B. Sheehy, J. Skaritka, N.A. Towne, J.-M. Wang, X.J. Wang, L.-H. Yu
    BNL, Upton, Long Island, New York
  Funding: Under Contract with the United States Department of Energy Contract Number DE-AC02-98CH10886

The National Synchrotron Light Source at BNL was the first dedicated light source facility and it has now operated for more than 20 years. During this time the user community has grown to more than 2400 users annually. To insure that this vibrant user community has access to the highest quality photon beams, the NSLS is pursuing the design of a new ultra-high brightness (~10E21) electron storage ring, tailored to the 0.3-20 KeV photon energy range. We present our preliminary design and review the critical accelerator physics design issues.

RPAE070 Recent Developments at Aladdin emittance, insertion-device, undulator, linac 3813
  • 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. NSF under Award No. DMR-0084402.

Following on the success of lower emittance operation at 800 MeV, SRC is pursuing a number of additional enhancements to the performance of the Aladdin storage ring. Work on Aladdin has included development of low emittance lattices at 1 GeV, which will maximize the capabilities of a recently installed spectromicroscopy beamline and a proposed high-resolution keV beamline. Installation of one-meter long insertion devices in the short straight sections within the quadrant arcs of the four sided storage ring is being considered to increase the number of undulator beamlines from four to possibly eight. Studies have been made to determine what is the minimum insertion device gap that does not interfere with nominal ring operation (injection, ramping, and lifetime at full energy), and indicate that smaller-gapped devices for higher photon energy are reasonable. Lifetime increases or further emittance reductions appear possible with modest aperture increases at a small number of points on the ring. Finally, planning is under way for long term projects such as a new injector or a next generation VUV/soft-xray source for the Midwest. Details will be presented.

RPAE077 A Magnetic Field Model for the Undulator in HLS undulator, wiggler, storage-ring, insertion-device 3994
  • H. Zhang, L. Wang
    USTC/NSRL, Hefei, Anhui
  • Y.L. Li
    DESY, Hamburg
  It is important to understand the influence of wigglers and undulators on the beam dynamics in design and optimization of a storage ring, especially when the storage ring runs on a low emittance mode. We present an analytic model of the undulator field in HLS, which can be used in the tracking study to evaluate the effects of it. Coefficients needed by the model are generated by fitting to the results of a numerical field caculation. Fringe fields are included in this model. Then we use three different methods to track particles through the undulator, and compare the results.  
RPAE082 The New Undulator Based fs-Slicing Beamline at the ALS undulator, insertion-device, wiggler, laser 4096
  • C. Steier, D. Robin, F. Sannibale, R.W. Schoenlein, W. Wan, W. Wittmer, A. Zholents
    LBNL, Berkeley, California
  Funding: This work was supported by the U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

The existing Femtoslicing beamline at the ALS employs a femtosecond laser beam interacting resonantly with the electron beam in a wiggler (modulator). The induced energy spread over the femtosecond duration is converted to a transverse displacement by exploiting the storage ring dispersion. The displaced femtosecond pulse radiates and produces femtosecond synchrotron radiation. Up to now a regular bending magnet was used as radiator. To improve the flux, a significant upgrade was implemented, replacing the modulator, installing an in-vacuum undulator as new radiator, and installing a higher repeptition rate laser system. The new beamline will provide 100-200 fs long pulses of soft and hard x-rays with moderate flux and with a repetion rate of 10-40 kHz for experiments concerning ultrafast dynamics in solid state physics, chemistry and biology. To achieve the necessary spatial separation of the energy modulated slice from the rest of the bunch, a sizeable local vertical dispersion bump in the radiator is required. All accelerator physics aspects of the upgrade including challenging issues like the impact on the transverse single particle dynamics will be discussed together with initial results of the commissioning.

RPAP036 A Compact 5 MeV S-Band Electron Linac Based X-Ray Source for Industrial Radiography linac, electron, target, collimation 2428
  • L. Auditore, R.C. Barnà, D. De Pasquale, U. Emanuele, A. Trifirò, M. Trimarchi
    INFN & Messina University, S. Agata, Messina
  • A. Italiano
    INFN - Gruppo Messina, S. Agata, Messina
  A compact and reliable X-ray source, based on a 5 MeV, 1 kW, S-band electron linac, has been set up at the Dipartimento di Fisica, Universit\‘a di Messina. This source, coupled with a GOS scintillator screen and a CCD camera, represents an innovative transportable system for industrial radiography and X-ray tomography. Optimization of the parameters influencing the e-gamma conversion and the X-ray beam characteristics have been studied by means of the MCNP-4C2 code. The converter choice is the result of the study of the e-gamma conversion performances for different materials and materials thicknesses. Also the converter position with respect to the linac exit window was studied. The chosen converter consists in a Ta-Cu target inserted close to the linac window. The Cu layer acts as a filter both on the electrons from the source and on the low energy X-rays. The X-ray beam angular profile was studied by means of GafChromic films with and without collimation. In the final source project, a collimation system provides a 14 cm diameter X-ray spot at the sample position and first radiographyc results were obtained by inspecting different density materials and thicknesses.  
ROAD005 Status of NEG Coating at ESRF vacuum, insertion-device, quadrupole, storage-ring 422
  • M. Hahn
    ESRF, Grenoble
  • R. Kersevan
    ORNL, Oak Ridge, Tennessee
  The ESRF non-evaporable getter (NEG) coating facility is in operation since two years now. A large part of the insertion device straight sections of the electron storage ring has been equipped with in-house coated 5m long aluminum vacuum chambers with an inner vertical aperture of 8 mm. Operational experience with different coating parameters leading to different film thicknesses will be given and compared to bremsstrahlung data. The paper deals also with improvements of the coating production and chamber preparation, and describes some aspects of NEG coating data acquisition, visualization, and remote control. The R&D program leading to a more powerful DC solenoidal coating tool to further improve the NEG coating production throughput and quality aspects is also discussed.  
RPPE040 Development of Copper Coated Chamber for Third Generation Light Sources vacuum, impedance, insertion-device, feedback 2633
  • H. Sakai, I. Ito, H. Kudo, N. Nakamura, S. Shibuya, K. Shinoe, H. Takaki
    ISSP/SRL, Chiba
  • K. Kobayashi
    KEK, Ibaraki
  For the 3rd generation light sources, it is essential to reduce the beam instability in order to produce the highly bright synchrotron light much stably. Especially, to avoid the coupled bunch instability, the resistive wall impedance must be reduced. The copper-coating inner surface of the chamber(especially in insertion device section)is much effective method for the reduction of the resistive wall impedance, whose method was already proposed by our group (N.Nakamura et.al., EPAC 1998 p984). We have already produced the copper coated chamber. In this paper, we describe the measurement of the outgassing from the copper coated chamber to evaluate if this chamber is valid on the ultra-low high vacuum condition.  
RPPE043 Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-Out radiation, vacuum, synchrotron, simulation 2744
  • C. Rathjen, S. Blanchard, B. Henrist, K. Koelemeijer, B. Libera, P. Lutkiewicz
    CERN, Geneva
  Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.  
RPPE058 Successful RF and Cryogenic Tests of the SOLEIL Cryomodule electron, coupling, insertion-device, synchrotron 3438
  • P. Marchand, M. Louvet, M. Louvet-Monsanglant, K. Tavakoli, C. Thomas-Madec
    SOLEIL, Gif-sur-Yvette
  • L. Arnaudon, O. Brunner, R. Losito, P. Maesen, E. Montesinos, G. Pechaud, M.P. Prax
    CERN, Geneva
  • P. Bosland, P. Bredy, S. Chel, G. Devanz
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In the Storage Ring (SR) of the Synchrotron SOLEIL light source, two cryomodules will provide the maximum power of 600 kW required at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. A cryomodule prototype, housing two 352 MHz superconducting single-cell cavities with strong damping of the Higher Order Modes has been built and successfully tested in the ESRF. Even though the achieved performance (3 MV and 380 kW) does meet the SOLEIL requirement for the first year of operation, it was decided to upgrade the cryomodule prototype before its implementation in the SR. Modifications of the internal cryogenic system as well as the input power and dipolar HOM couplers required complete disassembling, reassembling and testing of the cryomodule, which were carried out at CERN. This refurbishment program, which was achieved in the framework of a collaboration between SOLEIL, CEA and CERN, is reported in this paper. A second cryomodule, similar to the modified prototype, is under manufacturing and will be implemented in the SR by the end of 2006.  
RPPE059 Measurements of Epsilon and Mu of Lossy Materials for the Cryogenic HOM Load damping, resonance, coupling, superconductivity 3462
  • V.D. Shemelin, H. Padamsee
    Cornell University, Ithaca, New York
  • M. Liepe
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: Supported by Cornell University

In high current storage rings with superconducting cavities strong broadband HOM damping has been achieved by using beam-pipe ferrite loads, located at room temperature. Adopting the same damping concept for the ERL with RF absorbers between the cavities in a cavity string will require operating the absorbers at a temperature of about 80 K. This temperature is high enough to intercept HOM power with good cryogenic efficiency, and is low enough to simplify the thermal transition to the cavities at 2 K. However the electromagetic properties of possible absorber materials were not well known at cryogenic temperatures. We performed a measurement program at Cornell to find possible absorbers for HOMs in the ERL. Measurements were done for 10 different materials in the range from 1 to 40 GHz.

RPPP036 A Test Facility for the International Linear Collider at SLAC End Station A for Prototypes of Beam Delivery and IR Components synchrotron, linear-collider, collider, wiggler 2461
  • M. Woods, R.A. Erickson, J.C. Frisch, C. Hast, R.K. Jobe, L. Keller, T.W. Markiewicz, T.V.M. Maruyama, D.J. McCormick, J. Nelson, N. Phinney, T.O. Raubenheimer, M.C. Ross, A. Seryi, S. Smith, Z. Szalata, P. Tenenbaum, M. Woodley
    SLAC, Menlo Park, California
  • D.A.-K. Angal-Kalinin, C.D. Beard, F.J. Jackson, A. Kalinin
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Arnold
    University of Massachusetts, Amherst
  • D. Bailey
  • R.J. Barlow, G.Yu. Kourevlev, A. Mercer
    UMAN, Manchester
  • S.T. Boogert, A. Liapine, S. Malton, D.J. Miller, M.W. Wing
    UCL, London
  • P. Burrows, G.B. Christian, C.C. Clarke, A.F. Hartin, S. Molloy, G.R. White
    Queen Mary University of London, London
  • D. Burton, N. Shales, J. Smith, A. Sopczak, R. Tucker
    Microwave Research Group, Lancaster University, Lancaster
  • D. Cussans
    University of Bristol, Bristol
  • C. Densham, J. Greenhalgh
    CCLRC/DL, Daresbury, Warrington, Cheshire
  • M.H. Hildreth
    Notre Dame University, Notre Dame, Iowa
  • Y.K. Kolomensky
    UCB, Berkeley, California
  • W.F.O. Müller, T. Weiland
    TEMF, Darmstadt
  • N. Sinev, E.T. Torrence
    University of Oregon, Eugene, Oregon
  • M.S. Slater, M.T. Thomson, D.R. Ward
    University of Cambridge, Cambridge
  • Y. Sugimoto
    KEK, Ibaraki
  • S.W. Walston
    LLNL, Livermore, California
  • N.K. Watson
    Birmingham University, Birmingham
  • I. Zagorodnov
    DESY, Hamburg
  • F. Zimmermann
    CERN, Geneva
  Funding: U.S. Department of Energy.

The SLAC Linac can deliver damped bunches with ILC parameters for bunch charge and bunch length to End Station A (ESA). A 10Hz beam at 28.5 GeV energy can be delivered to ESA, parasitic with PEP-II operation. During the engineering design phase for the ILC over the next 5 years, we plan to use this facility to prototype and test key components of the Beam Delivery System (BDS) and Interaction Region (IR). We discuss our plans for this ILC Test Facility and preparations for carrying out experiments related to Collimator Wakefields, Materials Damage Tests and Energy Spectrometers. We also plan an IR Mockup of the region within 5 meters of the ILC Interaction Point to investigate effects from backgrounds and beam rf higher-order modes (HOMs).

RPPT044 Design, Construction and Commissioning of a NEG Coated Wiggler Vacuum Chamber for the LNLS Storage Ring vacuum, wiggler, photon, insertion-device 2807
  • M.J. Ferreira, R.O. Ferraz, H.G. Filho, M.B. Silva
    LNLS, Campinas
  Funding: MCT - CNPQ - FAPESP

We present the design of the vacuum chamber for the LNLS 2 T Hybrid Wiggler. The chamber is a 3 m long, 1.2 mm thick 316 SS tube, which was mechanically pressed into an elliptical shape from an originally round tube. In order to provide the necessary mechanical tolerances, the rather flexible tube is welded to lateral supports that run the complete length of the chamber. Special care has been given to the mechanical and magnetic characterization of the chamber and the inner surface of the chamber was NEG-coated at the ESRF. We present the installation procedure as well the vacuum conditioning charge evolution.

FPAE050 Injector Linac for the BNL Super Neutrino Beam Project linac, quadrupole, SNS, proton 3129
  • D. Raparia, J.G. Alessi, A. Ruggiero, W.-T. Weng
    BNL, Upton, Long Island, New York
  Funding: This work was performed under the auspices of the U.S. DOE, Contract No. DE-AC02-98H10886.

BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility. We have examined possible upgrades to the AGS complex that would meet the requirements of the proton beam for a 1.0 MW neutrino superbeam facility. We are proposing to replace part of the existing 200 MeV linac with coupled cavity structure from 116 MeV to 400 MeV and then add additional 1.1 GeV superconducting linac to reach a final energy of 1.5 GeV for direct H- injection into the AGS. We will present possible choices for the upgrade and our choice and its design.

FPAT003 Joining the RHIC Online and Offline Models simulation, lattice, optics, luminosity 880
  • N. Malitsky, K.A. Brown, N. D'Imperio, A.V. Fedotov, J. Kewisch, A.U. Luccio, F.C. Pilat, V. Ptitsyn, T. Satogata, S. Tepikian, J. Wei
    BNL, Upton, Long Island, New York
  • R.M. Talman
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: Work performed under the auspices of the U.S. Department of Energy.

The paper presents an interface encompassing the RHIC online ramp model and the UAL offline simulation framework. The resulting consolidated facility aims to minimize the gap between design and operational data, and to facilitate analysis of RHIC performance and future upgrades in an operational context. The interface is based on the Accelerator Description Exchange Format (ADXF), and represents a snapshot of the RHIC online model which is in turn driven by machine setpoints. This approach is also considered as an intermediate step towards integrating the AGS and RHIC modeling environments to produce a unified online and offline AGS model for operations.