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MOZAG02 Short Bunches in Electron Storage Rings and Coherent Synchrotron Radiation radiation, storage-ring, optics, electron 26
 
  • G. Wuestefeld
    BESSY GmbH, Berlin
  Significant progress has been made in recent years in achieving short bunches in third generation synchrotron light sources and the generation of coherent radiation. This talk will review the properties of the radiation and the associated beam dynamics, and will discuss optics issues and the limits of the available techniques.  
slides icon Slides  
 
MOZBG01 Vacuum Performances in the Most Recent Third Generation Synchrotron Light Sources vacuum, storage-ring, impedance, radiation 31
 
  • E. Al-Dmour
    ALBA, Bellaterra
  Several 3rd generation synchrotron light sources were built and commissioned during the last ten years. The vacuum system of these light sources was designed using different approaches, but with the same objectives which guarantee the lowest outgassing rate and the highest pumping speed that by the end will achieve the lowest influence in the circulated beam (longest life time, the lowest impedance and instabilities, etc). The performance of recently commissioned rings (DIAMOND, SOLEIL and the Australian Light Source) are presented, together with a comparison of the different approaches which have been used in the design of the vacuum system and the lessons for the design of new vacuum systems.  
slides icon Slides  
 
MOPC008 The Impact of PSK Timing on Energy Stability of e-Beam at FERMI@ELETTRA linac, klystron, simulation, injection 82
 
  • G. D'Auria, P. Delgiusto, M. M. Milloch, C. Serpico, D. Wang
    ELETTRA, Basovizza, Trieste
  The existing linac sections S1-S7 at ELETTRA will be upgraded for the FERMI@ELETTRA FEL project. These seven sections are 3/4 π-mode backward traveling wave (BTW) constant-impedance structures, powered by 45-MW klystrons (Thales TH 2132A) and with a SLED system to increase the RF peak power. Because of the strict requirement on the pulse-to-pulse beam energy stability (<0.1%) of the FERMI@ELETTRA project, the impact of phase shift keying (PSK), the timing of phase flipping, on beam energy needs to be revisited and evaluated. Here the results obtained with a simulation model built up by use of MATLAB simulink are present and discussed.  
 
MOPC024 Calculation of Coherent Synchrotron Radiation in General Particle Tracer space-charge, shielding, electron, emittance 118
 
  • I. V. Bazarov
    Cornell University, Department of Physics, Ithaca, New York
  • T. Miyajima
    KEK, Ibaraki
  General Particle Tracer (GPT) is a particle tracking code, which includes 3D space charge effect based on nonequidistant multigrid Poisson solver or point-to-point method. It is used to investigate beam dynamics in ERL and FEL injectors. We have developed a new routine to simulate coherent synchrotron radiation (CSR) in GPT based on the formalism of Sagan*. The routine can calculate 1D-wake functions for arbitrary beam trajectories as well as CSR shielding effect. In particular, the CSR routine does not assume ultrarelativistic electron beam and is therefore applicable at low beam energies in the injector. Energy loss and energy spread caused by CSR effect were checked for a simple circular orbit, and compared with analytic formulas. In addition, we enhanced the 3D space charge routine in GPT to obtain more accurate results in bending magnets.

*D. Sagan, EPAC06, pp. 2829-2831.

 
 
MOPC041 Microfabrication of Relativistic Electron Beam by Laser and its Application to THz Coherent Synchrotron Radiation electron, laser, radiation, storage-ring 163
 
  • M. Katoh, M. Adachi, S. I. Kimura, A. Mochihashi, M. Shimada
    UVSOR, Okazaki
  • S. Bielawski, C. Evain, C. Szwaj
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex
  • T. Hara
    RIKEN Spring-8 Harima, Hyogo
  • M. Hosaka, Y. Takashima, N. Yamamoto
    Nagoya University, Nagoya
  • T. Takahashi
    KURRI, Osaka
  It is well known that broadband coherent synchrotron radiation (CSR) is emitted by an electron bunch whose length is shorter than radiation wavelength. However, even a long electron bunch can emit CSR when it has micro-density structure whose characteristic length is equal to the radiation wavelength. Recently, we have demonstrated that, by injecting amplitude modulated laser pulses into an electron storage ring, quasi-monochromatic and tunable terahertz (THz) CSR could be produced. In this method, periodic micro-density structure of THz scale was created on the electron bunch, as the result of the laser-electron interaction. The bunch emitted quasi-monochromatic THz radiation in a uniform dipole filed, not in an undulator. This new technology provides a way to imprint periodic wave patterns inside the electron bunch phase space. In adding to the light source applications, this would be a new tool to investigate electron beam dynamics.  
 
MOPC048 Coherent Synchrotron Radiation Burst from Electron Storage Ring under External RF Modulation radiation, synchrotron-radiation, electron, storage-ring 178
 
  • Y. Shoji
    NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
  • T. Takahashi
    KURRI, Osaka
  It is known that a high-peak-current beam in an electron storage ring emits a burst of coherent synchrotron radiation (CSR) in the THz region. This CSR is powerful and easily obtained with no special expense, but is not used by synchrotron radiation users. This is because the burst arises from a fine time structure in the bunch due to longitudinal beam instabilities, and is unstable. We quantitatively investigated its time structure to find out how unstable it is. The measurements of CSR from one bunch showed that with an average period of 10ms (comparable with the damping time, 12 ms) the fluctuation of averaged power was about 10%. This would be reduced to 1% with 100 bunches. The fluctuation ratio had small dependence on beam charge, rf acceleration voltage and momentum compaction factor. The successive bursts had a correlation because the beam had a memory of former bursts. This worked to reduce the fluctuation in long period. When the rf phase was modulated with 2fs (twice of the synchrotron oscillation frequency), the burst structure was modulated with 2fs and the long term fluctuation was reduced. This modulation can be used to eliminate background noise in user experiments.  
 
MOPC061 Progress in R&D Efforts on the Energy Recovery Linac in Japan linac, laser, gun, electron 205
 
  • S. Sakanaka, T. A. Agoh, A. Enomoto, S. Fukuda, K. Furukawa, T. Furuya, K. Haga, K. Harada, S. Hiramatsu, T. Honda, Y. Honda, K. Hosoyama, M. Izawa, E. Kako, T. Kasuga, H. Kawata, M. Kikuchi, H. Kobayakawa, Y. Kobayashi, T. Matsumoto, S. Michizono, T. Mitsuhashi, T. Miura, T. Miyajima, T. Muto, S. Nagahashi, T. Naito, T. Nogami, S. Noguchi, T. Obina, S. Ohsawa, T. Ozaki, H. Sasaki, S. Sasaki, K. Satoh, M. Satoh, M. Shimada, T. Shioya, T. Shishido, T. Suwada, T. Takahashi, Y. Tanimoto, M. Tawada, M. Tobiyama, K. Tsuchiya, T. Uchiyama, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  • R. Hajima, H. Iijima, N. Kikuzawa, E. J. Minehara, R. Nagai, N. Nishimori, M. Sawamura
    JAEA/ERL, Ibaraki
  • H. Hanaki
    JASRI/SPring-8, Hyogo-ken
  • A. Ishii, I. Ito, T. Kawasaki, H. Kudo, N. Nakamura, H. Sakai, S. Shibuya, K. Shinoe, T. Shiraga, H. Takaki
    ISSP/SRL, Chiba
  • M. Katoh
    UVSOR, Okazaki
  • Y. Kobayashi, K. Torizuka, D. Yoshitomi
    AIST, Tsukuba
  • M. Kuriki
    HU/AdSM, Higashi-Hiroshima
  The future synchrotron light sources, based on the energy recovery linacs (ERL), are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The ERL-based light sources are under development at such institutes as the Cornell University, the Daresbury Laboratory, the Advanced Photon Source, and KEK/JAEA. The Japanese collaboration team, including KEK, JAEA, ISSP, and UVSOR, is working to realize the key technologies for the ERLs. Our R&D program includes the developments of ultra-low-emittance photocathode DC guns and of superconducting cavities, as well as proofs of accelerator-physics issues at a small test ERL (the Compact ERL). A 250-kV, 50-mA photo-cathode DC gun is under construction at JAEA. Two single-cell niobium cavities have been tested under high electric fields at KEK. The conceptual design of the Compact ERL has been carried out. We report recent progress in our R&D efforts.  
 
MOPC100 Design Status of the FAIR Synchrotrons SIS100 and SIS300 and the High Energy Beam Transport System extraction, acceleration, beam-losses, dipole 298
 
  • P. J. Spiller, U. B. Blell, O. Boine-Frankenheim, E. S. Fischer, G. Franchetti, F. Hagenbuck, I. Hofmann, J. E. Kaugerts, M. Kauschke, M. Kirk, H. Klingbeil, A. Kraemer, D. Krämer, G. Moritz, C. Omet, N. Pyka, H. Ramakers, S. Ratschow, A. Saa-Hernandez, M. Schwickert, J. Stadlmann, H. Welker
    GSI, Darmstadt
  • A. D. Kovalenko
    JINR, Dubna, Moscow Region
  The present status of system- and technical design and R&D for the new heavy ion synchrotrons SIS100 and SIS300 and the HEBT system is summarized. The overall machine planning and the general layout has been completed and the detailed technical machine design has been started. Device and component specifications, technical parameter lists and technical design reports are in preparation with the goal to enable international partners or industry to finalize the component design to achieve production readiness. In the frame of international working groups the distribution and sharing of the work packages, especially of the cryomagnetic system is under discussion.  
 
MOPC101 Design Considerations of Fast-cycling Synchrotrons Based on Superconducting Transmission Line Magnets proton, power-supply, cryogenics, target 301
 
  • H. Piekarz, S. Hays, Y. Huang, V. D. Shiltsev
    Fermilab, Batavia, Illinois
  Fast cycling synchrotrons have become necessary components of contemporary accelerator systems for advanced nuclear and high-energy physics programs. We explore a possibility of using super-ferric dipole magnets of up to 2 Tesla B-field powered by a superconducting transmission line conductor. We present both the LTS and the HTS conductor design options for these magnets and their impact on both static and dynamic power losses with operation cycles from o.5 Hz to 5 Hz, depending on the beam energy and the size of the accelerator ring. We also discuss expected B-field quality and the corrector magnets options. We outline magnet string inter-connections and creation of space for the corrector magnets and discuss option for a superconducting dump switch of the quench protection system.  
 
MOPC104 A New Method of Beam Stacking in Storage Rings antiproton, emittance, storage-ring, simulation 307
 
  • C. M. Bhat
    Fermilab, Batavia, Illinois
  Use of barrier buckets at synchrotron storage rings has paved way for development of new techniques for beam stacking in storage rings. The Fermilab Recycler, anit-proton storage ring, has been augmented with multipurpose broad-band barrier rf systems. Recently we have developed a new beam accumulation scheme called "longitudinal phase-space coating" that can be used for stacking beam over already e-cooled high intensity low emittance antiproton beam and demonstrated with beam experiments. Multi-particle beam dynamics simulations convincingly validate the concepts and practicality of the method. Starting with a proof-of-principle beam experiment both protons and anti-protons have been stacked a number of times using this technique in the Recycler. We present the results from both simulations and experiments. The method presented here is the first of its kind.  
 
MOPC105 Activities of Hitachi Relating to Construction of J-PARC Accelerator power-supply, linac, injection, rfq 310
 
  • Y. Chida, S. Koseki
    Hitachi Ltd., Ibaraki-ken
  • M. Abe
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • K. Nakamura, M. Watanabe, T. Watanabe, T. Watanuki
    Hitachi. Ltd., Hitachi Works, Hitachi-shi
  The Japan Proton Accelerator Research Complex (J-PARC) consists of a 330-m-long linac, a 3-GeV rapid cycle synchrotron with a circumference of 350 m, and a 50-GeV synchrotron with a circumference of 1,570 m. Owing to a collaboration between the Japan Atomic Energy Agency (JAEA) and the High Energy Accelerator Research Organization (KEK), the accelerators will be commencing operations at the site of JAEA Tokai Research and Development Center. The beam commissioning of the entire accelerator system is planned to take place before the end of 2008. Along with the JAEA and KEK, Hitachi has contributed to the construction of the system by manufacturing some major equipment with specifications that are of the highest level in the world.  
 
MOPC119 Low-Output-Impedance RF System for the ISIS Second Harmonic Cavity impedance, beam-loading, controls, acceleration 343
 
  • Y. Irie, S. Fukumoto, K. Muto, A. Takagi
    KEK, Ibaraki
  • D. Bayley, I. S.K. Gardner, A. Seville, J. W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • J. C. Dooling, D. Horan, R. Kustom, M. E. Middendorf
    ANL, Argonne, Illinois
  • T. Oki
    Tsukuba University, Ibaraki
  Low-output-impedance RF system for the second harmonic cavity in the ISIS synchrotron has been developed by the collaboration between Argonne National Laboratory, US, KEK, Japan and Rutherford Appleton Laboratory, UK. Low output impedance is realized by the feedback from plate output to grid input of the final triode amplifier, resulting in less than 30 Ω over the frequency range of interest. Precise control of the second harmonic voltage can then be realized without considering beam loading effects. Beam test scenario in the ISIS synchrotron is discussed.  
 
MOPC121 Progress on Dual Harmonic Acceleration on the ISIS Synchrotron acceleration, power-supply, proton, beam-losses 349
 
  • A. Seville, D. Bayley, I. S.K. Gardner, J. W.G. Thomason, C. M. Warsop
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • D. J. Adams
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK is currently undergoing an RF upgrade. Four, h=4 cavities have been installed in addition to the existing 6, h=2, cavities and should be capable of increasing the operating current from 200 to 300 μA. Two of the four cavities have been in operation for the last 2 user cycles improving trapping lossess and increasing operating currents beyond 200 μA. The remaining two cavities were commissioned in the spring of 2008. This paper reports on hardware commissioning, beam tests and beam simulation results.  
 
MOPC123 Lattice Study for the Carbon Ion Synchrotron forTherapy with Electron Cooling ion, extraction, electron, septum 355
 
  • S. V. Sinyatkin, V. A. Kiselev, E. B. Levichev, V. V. Parkhomchuk, V. B. Reva, V. A. Vostrikov
    BINP SB RAS, Novosibirsk
  In this paper the preliminary design of magnet lattice of the Carbon Ion Therapy Facility with electron cooling is described. The influence of misalignments of magnetic elements on ring parameters and the layout of orbit correction are estimated. The different methods of ion extractions from the synchrotron are considered, i.e., the pellet extraction, recombination extraction and the extraction on the sextupole resonance.  
 
MOPC125 The HESR RF-system and Tests in COSY target, acceleration, antiproton, injection 361
 
  • R. Stassen, K. Bongardt, F. J. Etzkorn, H. Stockhorst
    FZJ, Jülich
  • A. Schnase
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  Two RF cavities will be installed in the High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt, one “small” cavity for barrier-bucket operation and one “large” cavity to accelerate and decelerate the beam and for bunch rotation. Additionally a barrier bucket with h=1..5 will be formed by this cavity to separate the decelerated beam from the refilled beam in the high luminosity mode (HL). Both prototype cavities have been built and first RF measurements were carried out. The recent results will be presented.  
 
MOPC126 Beam Acceleration with Full-digital LLRF Control System in the J-PARC RCS injection, controls, acceleration, feedback 364
 
  • F. Tamura, K. Haga, K. Hasegawa, M. Nomura, A. Schnase, M. Yamamoto
    JAEA/J-PARC, Tokai-mura
  • S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii
    KEK, Ibaraki
  In the J-PARC RCS (Rapid Cycling Synchrotron) we employ a full-digital LLRF control system to accelerate an ultra-high intensity proton beam. The key feature is the multi-harmonic RF signal generation by using direct digital synthesis (DDS) technology. By employing a full-digital system, highly accurate, stable and reproductive RF voltages are generated in the wide-band RF cavities loaded by magnetic alloy (MA) cores. The beam commissioning of the J-PARC RCS has been started in October 2007. The accelerators, the linac and the RCS, show good stability. The beam orbit and the longitudinal beam shape and phase are reproductive from cycle to cycle especially thanks to the stability of the linac energy, the RCS bending field and the frequency and voltage of the RCS RF. This reproductivity makes the beam commissioning efficient. We present the examples of the orbit signals and the longitudinal current signals. Also, we discuss the longitudinal beam control performance and future plans.  
 
MOPC130 Space Charge Loss Mechanisms Associated with Half Integer Resonance on the ISIS Synchrotron simulation, resonance, emittance, space-charge 373
 
  • C. M. Warsop, D. J. Adams, B. G. Pine
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a 50 Hz proton synchrotron, which accelerates ~3·1013 ppp from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. Beam loss limits operational intensity, and a main contributing mechanism is the action of half integer resonance under high space charge. Progress on studies using particle in cell simulations to explore the evolution of envelope motion, associated 2:1 parametric halo, growth of particles from the outer core, and effects of dispersion and longitudinal motion is presented. Comparisons are made with relevant theoretical models and progress on experimental studies summarised, presently emphasising the simplified 2D coasting beam case.  
 
MOPC132 Acceleration Voltage Pattern for J-PARC RCS acceleration, proton, emittance 379
 
  • M. Yamamoto, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii
    KEK, Ibaraki
  The beam commissioning has been started at the J-PARC RCS. Some acceleration voltage patterns are tested to prevent the beam losses. The calculation code for the acceleration voltage pattern is usually based on the differential equation of the longitudinal synchrotron motion. We have developed the code based on the forward-difference equation which satisfies the synchronization with the bending magnetic field ramping accurately. This is very useful especially at the rapid cycling synchrotron where the ramping rate is high. The results of the test are described.  
 
MOPC133 Radiation Level in the J-PARC Rapid Cycling Synchrotron after First Study beam-losses, injection, acceleration, proton 382
 
  • K. Yamamoto, N. Hayashi, S. Hiroki, R. Saeki
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • K. Satoh, M. Tejima
    KEK, Ibaraki
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  The 3GeV RCS (Rapid-Cycling Synchrotron) in J-PARC has been commissioned in October of 2007. The most important issue in the beam study is to reduce unnecessary beam loss and to keep the beam line clean for the sake of maintenance and upgrade of the machines. In order to achieve this purpose, we observed the beam loss monitors located around the RCS beam line and observed them for beam commissioning. We also investigated the residual dose of accelerator components during an interval of beam study. From these results, we found that beam loss points were the injection junction point, the branch of H0 dump and extraction line, transverse collimators, and dispersion maximum points in the arcs. Especially, the entrance of the primary collimator chamber and the current transformer of the H0 dump line were the most radio-activated points in the RCS. To make the best use of these results for beam commissioning, we managed to minimize the beam losses and succeeded in suppressing the residual dose to a level low enough to allows us to work close to those components.  
 
MOPC134 The Status of the J-PARC RF Systems acceleration, injection, linac, controls 385
 
  • M. Yoshii, S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda
    KEK, Ibaraki
  • K. Haga, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The first acceleration of a proton beam at the J-PARC Rapid Cycling Synchrotron started in October 2007. The R&D for magnetic alloy (MA) loaded rf-systems to realize a high field gradient accelerating system for a rapid cycling machine has been initiated in 1996 with the aim of surpassing standard ferrite loaded cavities. The RCS RF system is broad-band and designed to cover both the RCS accelerating frequency range and the second harmonic for bunch shape manipulation. The optimum Q value of the RCS cavities is approximately 2. This is realized by combining a high-Q parallel inductor with an un-cut core configuration. The beam commissioning of the 50GeV Main Ring synchrotron will start in May 2008. Acceleration and slow-beam extraction are planned for December 2008. In case of the MR RF system, the accelerating frequency swing is small. The Q-value in the order of 20 has been selected to reduce transient beam loading due to the multiple-batch injection scheme. The MR RF cavities realize the Q-value by a cut-core configuration. The details of the RF systems and the results of beam accelerations are summarized.  
 
MOPD019 Construction and Quality Control of Synchrotron SOLEIL Beam Position Monitors vacuum, controls, simulation, impedance 487
 
  • E. Cenni, M. Canetti, F. Gangini
    RIAL VACUUM S.p. A, Parma
  • J. L. Billaud
    Saint-Gobain C. R.E. E., Cavaillon
  • L. Cassinari, J.-C. Denard, C. Herbeaux
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a third generation synchrotron light source located near Paris. Due to the high performance required for SOLEIL’s diagnostics, a special production procedure was tailored. During the production of 131 Beam Position Monitors (BPM) more than 500 feedthroughs were inspected; all of them passed strict tests at different stages of the production: Leak test (< 10-10 mbar l/s), Dimensional control (Displacement <0.050 mm), Vacuum test (Specific Outgassing < 10-12 mbar l/s cm2, Residual Gas Analysis) and Electrical test (Capacitance measure ~8pF, Insulation >50 MΩ, Impedance <0.1 Ω). All the established procedures and tests have been performed in a tight partnership that was more than a simple contractual framework, in which an intensive collaboration led to a knowledge transfer between SOLEIL and Rial Vacuum. The result has been a high percentage of success (few feedthroughs over 500 were replaced) during preliminary tests and a deeper knowledge of “BPM problem solving”; in this article are presented different test procedures to obtain high quality and high performance BPMs.  
 
MOPD029 Commissioning of the 2,2 kW, 476 MHz Solid State RF Power Source for the LNLS Booster Synchrotron booster, injection, storage-ring, electron 511
 
  • C. Pardine, R. H.A. Farias, P. F. Tavares
    LNLS, Campinas
  A 2.2 kW, 476 MHz unconditionally stable solid state RF amplifier for CW operation has been built, tested, and is being used since july 2007 at LNLS. The amplifier, designed and developed in collaboration with Synchrotron SOLEIL, is made of 9 modules, each one containing one push-pull 290 W MOSFET equipped with an internal circulator and RF load. Low cost, reliability, linearity and high efficiency are the main features we aimed for in this device, which was developed for the LNLS Booster Injector. In this paper, we present technical characteristics as well as test results of the system.  
 
MOPD031 Automatic Implementation of Radiation Protection Algorithms in Programs Generated by GCC Compiler radiation, controls, insertion 517
 
  • A. Piotrowski, D. R. Makowski, A. Napieralski, Sz. Tarnowski
    TUL-DMCS, Łódź
  Radiation influence on microprocessor-based systems is serious problem especially in places like accelerators and synchrotrons, where sophisticated digital devices operate closely to the radiation source. Reliability of such systems is significantly decreased due to effects like SEU or SEFI. One of the possible solutions to increase radiation immunity of the microprocessor systems is a strict programming approach known as Software Implemented Hardware Fault Tolerance. SIHFT methods are based on the redundancy of variables or procedures. Sophisticated algorithms are used to check the correctness of control flow in application. Unfortunately, manual implementation of presented algorithms is difficult and can introduce additional problems with program functionality cased by human errors. Proposed solution is based on modifications of the source code of the C language compiler. Protection methods are applied at intermediate representation of the compiled source code. This approach makes it possible to use standard optimization algorithms during compilation. In addition, a responsibility for implementing fault tolerant is transferred to the compiler and is transparent for programmers.  
 
MOPD034 Status of the High Power, Solid-State RF Amplifier Development at Laboratori Nazionali di Legnaro controls, power-supply, extraction, coupling 526
 
  • F. Scarpa, A. Facco, D. Zenere
    INFN/LNL, Legnaro, Padova
  The development of high power, unconditionally stable solid-state amplifiers for superconducting low-beta cavities, performed at Laboratori Nazionali di Legnaro in the framework of the EURISOL Design Study, has led to the construction and testing of two, newly designed 10 kW units that can be used both individually or coupled together to obtain a 20 kW source. Characteristic of this family of amplifiers, based on parallel assemblies of 300W modules equipped with mosfets and individual circulators, is their possibility of operating in any matching conditions and also, at a reduced power, in case of failure of one mosfet. Characteristics of the amplifiers and of the high power combiner will be described, and their performance and test results will be reported.  
 
MOPP038 Optimizing the CLIC Beam Delivery System luminosity, radiation, synchrotron-radiation, emittance 631
 
  • R. Tomas
    BNL, Upton, Long Island, New York
  • H.-H. Braun, M. Jorgensen, D. Schulte
    CERN, Geneva
  The optimization of the new CLIC Final Focus System (FFS) with L*=3.5m is presented for a collection of CLIC beam parameters. The final performance is computed for the full Beam Delivery System including the new diagnostics section. A comparison to previous designs is also presented.  
 
MOPP085 Bench Characterization of a Prototype of a 3rd Harmonic Cavity for the LNLS Electron Storage Ring impedance, electron, storage-ring, controls 748
 
  • R. H.A. Farias, D. A. Nascimento, C. Pardine, P. F. Tavares
    LNLS, Campinas
  The UVX electron storage ring at the Brazilian Synchrotron Light Laboratory suffers from longitudinal instabilities driven by a HOM of one of the RF cavities. The operational difficulties related to these unstable modes were successfully overcome by determining the proper cavity temperature set point in combination with phase modulation of the RF fields at the second harmonic of the synchrotron frequency. However, a serious drawback of the method is to increase the energy spread of the electron beam, which is detrimental for the undulator emission spectrum. The use of higher harmonic cavities is a more appropriate technique since it provides damping of the longitudinal modes without increasing the energy spread. A full scale prototype of a 3rd harmonic cavity was manufactured at the LNLS workshops and had its main rf properties measured. Special care was taken to measure the shunt impedance of the fundamental resonant mode since it determines how many cavities will be necessary for the adequate operation of the system, which is designed to operate in passive mode. In this work we present the results of the bench characterization of the cavity.  
 
MOPP087 RF System for the SSRF Booster Synchrotron booster, injection, extraction, electron 754
 
  • Q. Gu, L. X. Chen, M. Chen, L. Feng, Z. Q. Feng, H. T. Hou, J. F. Liu, C. Luo, D. Q. Mao, F. Wang, Zh. G. Zhang, S. J. Zhao, Y. B. Zhao, Z. S. Zhou
    SINAP, Shanghai
  The booster synchrotron of the Shanghai Synchrotron Radiation Facility (SSRF) ramps the energy of electron beam from 150 MeV to 3.5 GeV with a repetition rate of 2 Hz. The guidelines of the system design are simplicity and reliability, and the ability of top-up injection for the storage ring is also taking into account. The RF system consists of a 180kW CW plant with a WR1800 waveguide line, two PETRA type 5-cell cavities and an analog low level RF electronics with vector-sum scheme. An overview, installation and commissioning of the whole booster RF system are presented in this paper. The performance of the RF system with the beam is also given.  
 
MOPP094 Reduction of Q-loss-effects in Ferrite-loaded Cavities damping, resonance, vacuum 772
 
  • H. G. Koenig, S. Schaefer
    GSI, Darmstadt
  Accelerating cavities loaded with Ni-Zn ferrites have been widely used in synchrotrons for many years. So far their performance is significantly limited by the so-called high-loss-effect (HLE) or quality-loss-effect (QLE). After some milliseconds, this effect leads to a sudden drop of the resonator's voltage namely under the following conditions: fixed frequencies with RF-power above a specific threshold level and a parallel DC-biasing. The mechanism of this unwanted loss has not been fully understood yet. Now a simple method has been found to work against this effect with the aid of mechanical damping of surface waves. For small samples of ferrites the QLE is fully suppressed by using a rubber belt around the circumference or by covering the surface with a thin layer of hot-melt adhesive. We were able to show that similar methods applied to full size rings lead to a significant increase of the onset voltage of the QLE. Most of the existing ferrite loaded accelerating cavities with QLE-limitations can be increased in their accelerating voltage by the above-mentioned modification.  
 
MOPP103 High Field Gradient RF System for Bunch Rotation in PRISM-FFAG impedance, power-supply, controls, cathode 796
 
  • C. Ohmori
    KEK, Ibaraki
  • M. Aoki, Y. Arimoto, I. Itahashi, Y. Kuno, Y. Kuriyama, A. Sato, M. Y. Yoshida
    Osaka University, Osaka
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • Y. Mori
    KURRI, Osaka
  The PRISM project aims to supply a high quality muon beam using a wide aperture FFAG for mu-e conversion experiment. The low energy muon which has a large momentum spread will be manipulated in the FFAG using a bunch rotation technique with a low frequency RF around 3.5 MHz. Because of a short lifetime of muon, the rotation should be end in 5-6 turns in the FFAG and more than 2 MV is needed. The low frequency RF system using a magnetic alloy is designed to achieve a very high field gradient of more than 200 kV/m. The whole system is designed for a very low duty pulse operation to minimize the cost. The system has been modified to operate at 2 MHz for the beam test using alpha particle. A field gradient of more than 100 kV/m has been obtained by the preliminary test.  
 
MOPP104 Possible Upgrade Scenario for J-PARC Ring RF impedance, acceleration, power-supply, linac 799
 
  • C. Ohmori, K. Hara, A. Takagi, M. Toda, M. Yoshii
    KEK, Ibaraki
  • K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The whole J-PARC RCS RF system is operational and during beam commissioning in 2007 the beam in RCS was successfully accelerated to final energy and then extracted. The Main Ring RF system has been installed in the tunnel. Both Ring RF systems are based on the new technology using magnetic alloy loaded cavities and have achieved higher field gradient than existing ferrite base RF systems in this frequency region. For the future upgrade of the J-PARC Main Ring, a short accelerating cycle is required to increase the average beam current. In this paper, a possible upgrade scenario for RF cavities based on improvements of the magnetic alloy ring cores will be described.  
 
MOPP105 Compact, Tunable RF Cavities booster, proton, vacuum, controls 802
 
  • M. Popovic, C. M. Ankenbrandt, E. Griffin, A. Moretti, R. E. Tomlin
    Fermilab, Batavia, Illinois
  • M. Alsharo'a, I. B. Enchevich, R. P. Johnson, S. Korenev
    Muons, Inc, Batavia
  New developments in the design of fixed-field alternating gradient (FFAG) synchrotrons have sparked interest in their use as rapid-cycling, high intensity accelerators of ions, protons, muons, and electrons. Potential applications include proton drivers for neutron or muon production, rapid muon accelerators, electron accelerators for synchrotron light sources, and medical accelerators of protons and light ions for cancer therapy. Compact RF cavities that tune rapidly over various frequency ranges are needed to provide the acceleration in FFAG lattices. An innovative design of a compact RF cavity that uses orthogonally biased ferrite for fast frequency tuning and liquid dielectric to adjust the frequency range is being developed using physical prototypes and computer models.  
 
TUOBG04 A Vlasov-Maxwell Solver to Study Microbunching Instability in the FERMI@ELETTRA First Bunch Compressor System dipole, quadrupole, electron, emittance 971
 
  • G. Bassi
    Liverpool University, Science Faculty, Liverpool
  • G. Bassi
    Cockcroft Institute, Warrington, Cheshire
  • J. A. Ellison, K. A. Heinemann
    UNM, Albuquerque, New Mexico
  Microbunching can cause an instability which degrades beam quality. This is a major concern for free electron lasers where very bright electron beams are required. A basic theoretical framework for understanding this instability is the 3D Vlasov-Maxwell system. However, the numerical integration of this system is computationally too intensive at the moment. As a result, investigations to date have been done using very simplified analytical models or numerical solvers based on simple 1D models. We have developed an accurate and reliable 2D Vlasov-Maxwell solver which we believe improves existing codes. Our solver has been successfully tested against the Zeuthen benchmark bunch compressors*. In the present contribution we apply our self-consistent, parallel solver to study the microbunching instability in the first bunch compressor system of FERMI@ELETTRA. This system was proposed as a benchmark for testing codes at the September'07 workshop on microbunching instability in Trieste**.

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

 
slides icon Slides  
 
TUOCG01 The Heidelberg Ion Therapy (HIT) Accelerator Coming into Operation extraction, ion, proton, linac 979
 
  • D. Ondreka, U. Weinrich
    GSI, Darmstadt
  The Heidelberg Ion Therapy Facility (HIT) is the first dedicated proton and carbon therapy facility in Europe. It uses full three dimensional intensity-controlled raster scanning as basic treatment technique. The commissioning of the accelerator with beam was successfully finished for two fixed-beam treatment places in December 2007. Therefore a library of 40000 combinations of beam properties (ion type, treatment place, energy, intensity, beam size) is now offered to the treatment technique teams preparing the treatment systems for the clinical use. The HIT facility also comprises a gantry with full scanning properties constituting the only carbon ion gantry worldwide. The gantry can be rotated by 360 degree, so that the beam may be aimed at the patient from arbitrary directions. Commissioning with beam of the gantry was started in January 2008 when the first beams were transported successfully into the treatment room. The talk will report on experiences and results of the commissioning of the accelerator sections. It puts special emphasis on the subject of preparing the enormous variety of beam properties in an efficient and reliable way.  
slides icon Slides  
 
TUOCG02 Status Report on the Centro Nazionale di Adroterapia Oncologica (CNAO) ion, injection, emittance, extraction 982
 
  • M. Pullia
    CNAO Foundation, Milan
  The Centro Nazionale di Adroterapia Oncologica (National Center for Oncological Hadrontherapy, CNAO) is the Italian center for deep hadrontherapy. It will deliver treatments with active scanning both with proton and carbon ion beams. The accelerator complex is based on a 25 m diameter synchrotron capable of accelerating carbon ions up to 400 MeV/u and protons up to 250 MeV. Four treatment lines, in three treatment rooms, are foreseen in the first stage. In one of the three rooms a vertical and a horizontal fixed beam lines are provided, while in the other two rooms the treatment will be administered with horizontal beams only. The injection chain is positioned inside the synchrotron ring itself, to save space and to better exploit the two non-dispersive regions in the synchrotron. The injection chain is made by a 8 keV/u Low Energy Beam Transfer line (LEBT), a RFQ accelerating the beam to 400 keV/u, a LINAC to reach the injection energy of 7 MeV/u and a Medium Energy Beam Transfer line (MEBT) to transport the beam to the synchrotron. This report describes the design and the performances of the CNAO complex, and reports about the status of the commissioning of the machine.  
slides icon Slides  
 
TUZM02 Overview of Fast Beam Position Feedback Systems feedback, controls, electron, collider 1021
 
  • D. Bulfone
    ELETTRA, Basovizza, Trieste
  Modern circular and linear accelerators often rely on fast beam position feedbacks for the achievement of their design parameters. Such systems have gone through a significant evolution, which has taken advantage of recent progress of the associated equipment, like beam position monitors, as well as of the hardware and software processing technologies. A review of the latest developments and foreseen designs at different accelerators is given.  
slides icon Slides  
 
TUOCM02 X-ray Monitor Based on Coded-aperture Imaging for KEKB Upgrade and ILC Damping Ring photon, optics, damping, monitoring 1029
 
  • J. W. Flanagan, H. Fukuma, S. Hiramatsu, H. Ikeda, K.-I. Kanazawa, T. Mitsuhashi, J. Urakawa
    KEK, Ibaraki
  • J. P. Alexander
    CLASSE, Ithaca
  • M. A. Palmer
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • G. S. Varner
    UH, Honolulu, HI
  We present here design considerations for an x-ray monitor for high-resolution (a few um) and fast response (sub-nanosecond) for beam profile measurements to be used at an upgraded KEKB and/or ILC damping ring. The optics for the monitor are based on a technique borrowed from x-ray astronomy, coded-aperture imaging, which should permit broad-spectrum, low-distortion measurements to maximize the observable photon flux per bunch. Coupled with a high-speed digitizer system, the goal is to make sub-bunch-length, turn-by-turn measurements of beam profile and position.  
slides icon Slides  
 
TUPC007 Numerical and Experimental Investigation of the Contamination of X-ray Beam Position Monitors by Bending Magnet Edge Radiation radiation, dipole, undulator, photon 1053
 
  • C. Bloomer, G. Rehm, C. A. Thomas
    Diamond, Oxfordshire
  The details of an investigation into bending magnet edge radiation at Diamond are discussed, reviewing the effects of this radiation on X-ray Beam Position Monitoring (XBPM) equipment. For some time it has been recognized that there are difficulties using XBPMs for determining the centre of mass position of an undulator beam due to contamination from bending magnet radiation. While the geometry of the XBPM blades is designed to help reduce background dipole interference, this radiation is known to account for approximately 1% of the signal received, skewing the calculated beam position by several micrometres. We made detailed models of the bending magnet edge radiation using the SRW program and used Matlab to analyse the data. We present this model and compare our prediction to experimental results obtained at Diamond.  
 
TUPC008 Beam Diagnostics with IR Light Emitted by Positron at DAΦNE diagnostics, positron, radiation, synchrotron-radiation 1056
 
  • A. Bocci, A. Clozza, A. Drago, A. G. Grilli, A. Marcelli, A. R. Raco, R. S. Sorchetti
    INFN/LNF, Frascati (Roma)
  • A. De Sio, L. Gambicorti, E. Pace
    Università degli Studi di Firenze, Firenze
  • E. P. Emanuele
    Università degli Studi di Firenze, Firenze
  • M. P. Piccinini
    Università Roma Tre, Roma
  • J. P. Piotrowski
    Vigo System Sa, Warsaw
  Real-time beam diagnostics is mandatory in accelerators and represents one of the most challenging issues of modern storage rings and future FEL's. Recently, compact mid-IR fast uncooled photo-detectors have been used at DAΦNE to monitor single e- bunches using the SINBAD IR beamline installed on the e- ring*. Electron bunches have a FWHM of 150-300 ps and are separated by 2.7 ns**. Detectors performances are then suitable for a compact and low cost bunch-by-bunch longitudinal diagnostic device. To improve the DAΦNE diagnostic a bending magnet SR port on the e+ ring has been set-up with a HV chamber, a gold-coated plane mirror and a ZnSe window. To collect the SR light and focus radiation on IR detectors allowing the diagnostic of e+ a compact optical system has been installed in air after the window. Here we will present the status of the apparatus, the source characteristics, the optical setup and the complete acquisition system. This IR port will allow comparison in the ns time domain between data collected on both rings, and could be also used to improve DAΦNE diagnostics, i.e., identify and characterize bunch instabilities and/or increase the current in the e+ ring.

*M. Cestelli Guidi et al. J. Opt. Soc. Amer. A 22, 2810 (2005).
**A. Bocci et al. NIM-A, 580, 190 (2007).

 
 
TUPC009 Vertical Beam Profile Measurement and Analysis with X-ray Pinhole emittance, dipole, alignment, lattice 1059
 
  • M. J. Boland, M. J. Spencer
    ASP, Clayton, Victoria
  Imaging the electron beam profile at a synchrotron light source is commonly performed in the x-ray regime using a pinhole camera system. However, with machines pushing down the vertical emittance, including errors in source point optical parameters, pinhole manufacturing limitations and error analysis difficulties associated with diffraction and image capture, the pinhole imaging system has large errors, up to 50% for an emittance of a few picometre. An analysis has been done at the Australian Synchrotron (AS) looking at the effects of errors in determining the x-ray pinhole source point parameters.  
 
TUPC010 Single Bunch Studies at the Australian Synchrotron impedance, single-bunch, storage-ring, diagnostics 1062
 
  • R. T. Dowd, M. J. Boland, G. LeBlanc, M. J. Spencer, Y. E. Tan
    ASP, Clayton, Victoria
  Studies using a single high charge electron bunch have been conducted at the Australian Synchrotron to characterise the impedance of the machine at various stages of commissioning and insertion device configuration. This paper will present the results of these studies and show the time evolution of machine impedance with increasing number of insertion devices.  
 
TUPC031 Longitudinal Beam Diagnostics Application of Synchrotron Radiation at FLASH radiation, synchrotron-radiation, electron, monitoring 1116
 
  • O. Grimm, J. Rossbach
    Uni HH, Hamburg
  • C. Behrens, B. Schmidt
    DESY, Hamburg
  For the operation of the FLASH free electron laser at DESY, Hamburg, tools to measure the longitudinal charge distribution and especially its stability over time are important for efficient machine running. Several techniques using both coherent far-infrared and incoherent visible synchrotron radiation from the two bunch compressor chicanes are summarized and compared in this paper. The experimental setups used are
  1. a Martin-Puplett interferometer with both a room-temperature pyroelectric and a liquid-Helium cooled bolometer as detector,
  2. a streak camera to directly measure the time profile,
  3. the analysis of intensity fluctuations of the optical synchrotron radiation measured (with a photomultiplier) through a narrow filter,
  4. a single shot grating spectrometer covering the spectral range from 5 μm to 150 μm.
Data from the various and complementary experimental methods will be presented and compared. 		 
 
TUPC034 Beam Instrumentations for the J-PARC RCS Commissioning injection, proton, linac, diagnostics 1125
 
  • N. Hayashi, S. Hiroki, R. Saeki, K. Satou, R. Toyokawa, K. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • D. A. Arakawa, S. Hiramatsu, M. Tejima
    KEK, Ibaraki
  • S. Lee, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  A 3-GeV Rapid-Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has been commissioned recently. During its beam commissioning, various beam diagnostic instrumentation has been used. The multi-wire profile monitor (MWPM) is used to establish injection and H0 dump line, which transports un-stripped H- or H0 beam to the dump. The electron catcher confirms that the beam hits a charge exchange carbon foil and the specified current monitor limits the beam current to the H0 dump. Single pass BPMs which detect linac frequency (324MHz) and ionization profile monitors (IPM) help to check the one pass orbit without circulation of the beam. The beam position monitor (BPM) can measure both COD and turn-by-turn position. Tune monitor system consists of exciter and its own BPM. The exciter shakes the beam and coherent oscillation is measured at BPM. Dedicated BPMs, Fast CT (FCT) and Wall Current Monitor (WCM) are used for RF feedback or feedforward control. It will describe the performance of each instruments and how they are contributed to the successful beam commissioning.  
 
TUPC038 Filling Pattern Measurement for the Taiwan Light Source photon, injection, controls, storage-ring 1137
 
  • C. Y. Wu, J. Chen, K. T. Hsu, K. H. Hu, C. H. Kuo
    NSRRC, Hsinchu
  Filling pattern will affect various operation performance of a synchrotron light source. Measurement of the filling pattern correctly is important. The dedicated filling pattern measurement system has been implemented in 2004 for multi-bunch operation in top-up operation mode. Measurement the purity of an isolated bunch by using time correlated single photon counting method is also addressed. Results are presented in this report.  
 
TUPC054 Pulse-by-pulse Photon Beam Monitor with Microstripline Structure in NSRRC photon, storage-ring, synchrotron-radiation, impedance 1176
 
  • C. K. Kuan, C. L. Chen, J.-R. Chen, G.-Y. Hsiung, I. C. Sheng, Z.-D. Tsai, D.-J. Wang
    NSRRC, Hsinchu
  • H. Aoyagi, H. Kitamura, S. Takahashi
    JASRI/SPring-8, Hyogo-ken
  In order to diagnostic pulse-by-pulse beam movement of photon beam, NSRRC(Taiwan) and SPring-8 (Japan) have worked together to develop a front end beam monitor with microstripline structure, which is designed to have specific impedance of 50 ohm. The detector head is composed of a metal line (copper), ceramic plates (aluminum nitride) and a cooling base (copper tungsten). The metal line functions as a photocathode. The metal line is directly connected to SMA feed-through connectors to have fast response time. The detector head has been fabricated in SPring-8, and mounted on the monitor chamber and installed in NSRRC Superconducting Wiggler (SW) front end. The beam monitor can be used to examine not only pulse-by-pulse photon beam, but also the storage ring intensity and the pulse timing. Unique feature of the monitor is to produce unipolar short pulses. The design, fabrication and the measurement will be presented in this paper.  
 
TUPC060 A Counting Module for an Advanced Ionization Profile Monitor photon, controls, background, extraction 1194
 
  • D. A. Liakin, S. V. Barabin, A. Y. Orlov
    ITEP, Moscow
  • P. Forck, T. Giacomini
    GSI, Darmstadt
  A new multi-channel counting module has been developed for advanced Ionization Profile Monitor applications. The module's maximal performance concerning time resolution is about 10 beam profile measurements per microsecond at the cost of a slightly reduced spatial resolution with 80% accuracy (or better). Module architecture, basic modes of operation and the user interface are discussed. The results of the first test in laboratory and first beam profile measurements are also presented.  
 
TUPC064 Design and Commissioning of a Quadrant BPM for the LNLS Beamlines vacuum, shielding, photon, instrumentation 1200
 
  • S. R. Marques, F. H. Cardoso, C. Grizolli, L. Sanfelici, M. M. Xavier
    LNLS, Campinas
  We have recently designed and installed the first quadrant beam position monitor in the MX2 beamline. The whole monitor, including its electronics, was installed in vacuum to reduce errors from current leakage and noise coupled outside the vacuum chamber. Aspects of the mechanical and electronic design of this fluorescence-based beam position monitor, as well as the commissioning results are presented.  
 
TUPC082 Research and Development Program on Beam Position Monitors for NSLS-II Project vacuum, emittance, storage-ring, diagnostics 1245
 
  • I. Pinayev, R. Alforque, A. Blednykh, P. Cameron, V. Ravindranath, S. Sharma, O. Singh
    BNL, Upton, New York
  The NSLS-II Light Source which is planned to be built at Brookhaven National Laboratory is designed for horizontal emittances below 1 nm and will provide users with ultra-bright synchrotron radiation sources. In order to utilize fully the very small emittances and electron beam sizes, submicron stability of the electron orbit in the storage ring needs to be provided. This can only be achieved with high stability beam position monitors. The research program presently carried is aimed for characterization of commercially available RF BPM receivers and on the development of high stability mechanical supports for BPM modules. The details of the program and preliminary results are presented.  
 
TUPC086 Pinhole Camera Resolution and Emittance Measurement emittance, coupling, synchrotron-radiation, radiation 1254
 
  • C. A. Thomas, G. Rehm
    Diamond, Oxfordshire
  Third generation synchrotron light source are characterised by a low emittance and a low emittance coupling. Some light sources are already proposing to operate with extremely low coupling close to 0.1% and thus vertical emittance approaching 1pm. We derive the limits for the emittance coupling measurement due to the resolution of the X-ray pinhole camera. We also show that it is possible to design a pinhole camera in order to push the limit resolution beyond 0.1% emittance coupling. We then illustrate our calculations with the example of Diamond and compare them with experimental data.  
 
TUPC091 Measurement of Quadrupolar Tune Shifts under Multibunch Operations of the Photon Factory Storage Ring storage-ring, single-bunch, quadrupole, factory 1269
 
  • S. Sakanaka, T. Mitsuhashi, T. Obina
    KEK, Ibaraki
  The quadrupolar tune shifts were observed under a single-bunch operation of the Photon Factory storage ring at KEK, which indicated that a quadrupolar component of wakefields affected the motion of an electron bunch. We recently measured the quadrupolar tune shifts under a multibunch operation of the Photon Factory storage ring. To detect the transverse quadrupole-mode oscillations of electron bunches, we used an avalanche photo diode (APD) which can detect visible synchrotron light with short rise-time of less than 1 ns. As a result, we observed that the quadrupolar tunes depended on the total beam current by 0.0082 1/A (in horizontal) and -0.0082 1/A (in vertical), respectively. These tune shifts can be caused by a quadrupolar component of long-range wakefield.  
 
TUPC092 An Application for Beam Profile Reconstruction with Multi-wire Profile Monitors at J-PARC RCS injection, linac, controls, beam-transport 1272
 
  • H. Sako, S. Hiroki, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Ikeda
    Visual Information Center, Inc., Ibaraki-ken
  • H. Takahashi
    JAEA, Ibaraki-ken
  J-PARC RCS is commissioned since October 2007. In the early stage of RCS commissioning, Multi-Wire Profile Monitors (MWPM's) are most important beam monitors to measure positions and profiles of beam orbit in the injection line from LINAC. A MWPM consists of either a horizontal or a vertical wire plane. Each wire plane consists of several wires which has a tilt angle, and a wire scatters H- or proton beams and induced current in the wire is detected. A wire plane moves at a small step in the perpendicular direction to the wires and scans a beam profile. A complex analysis procedure and geometrical description is developed to reconstruct a beam profile from a MWPM. Beam profiles have been measured at MWPM's in the injection line and the H0 beam dump line.  
 
TUPC093 Beam Profile Monitor of the J-PARC 3GeV Rapid Cycling Synchrotron electron, ion, beam-losses, linac 1275
 
  • K. Satou, N. Hayashi, R. Saeki, A. Ueno, K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Harada
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima
  • S. Lee, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken
  • M. Tejima
    KEK, Ibaraki
  To obtain high intensity (1MW) and large emittance (214 π mm mrad) beam profiles of the 3GeV Rapid Cycling Synchrotron (RCS) of the J-PARC, we have developed the ionization profile monitors (IPMs) with wide active aperture and high dynamic range. It has three Microchannel Plates (MCPs) with active area of 81*41mm for signal multiplication and read out devices, and magnet system to generate guiding fields to collect electrons. The wide active aperture of ±116mm is obtained by arranging the three MCPs perpendicular to the beam axis. Furthermore, the dynamic range of 104 level can be obtained by adjusting each bias voltage of the MCPs. The IPMs are now collecting ions without the guiding fields. The beam commissioning of the RCS has been in progress since last year. The horizontal and vertical profiles are of great help, particularly to check injection errors. At the conference, the present status of the IPM system and the latest beam profiles will be reported.  
 
TUPC103 Digital Generation of Noise-signals with Arbitrary Constant or Time-varying Spectra simulation, emittance, target, injection 1299
 
  • J. Tuckmantel
    CERN, Geneva
  Noise sources in the RF system of an accelerator produce longitudinal emittance increase or loss. This noise is inherent, from the beam-control system electronics, external sources or high power components, or can be purposely injected for a specific need such as bunch distribution modification or controlled emittance increase. Simulations to study these effects on the beam require precise reproduction either of the total noise measured on the hardware, or of the noise spectrum to be injected and optimized to produce the desired changes. In the latter case the 'optimized' noise source has also to be created in real-time to actually excite the beam via the RF system. This paper describes a new algorithm to create noise spectra of arbitrary spectral density varying with cycle time. It has very good statistical properties and effectively infinite period length, important for long simulation runs. It is spectrally clean and avoids undesired mirror spectra. Coded in C++, it is flexible and fast. Used extensively in simulations it has also successfully created controlled emittance increase in the SPS by the injection of artificial real-time RF noise.  
 
TUPC109 Analysis of Measurement Errors in Residual Gas Ionisation Profile Monitors in a High Intensity Proton Beam ion, space-charge, simulation, proton 1317
 
  • R. E. Williamson, S. J. Payne, B. G. Pine, C. M. Warsop
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  ISIS is the pulsed neutron and muon source based at the Rutherford Appleton Laboratory in the UK. Operation is centred on a loss-limited 50 Hz proton synchrotron which accelerates ~3·1013 protons per pulse from 70 MeV to 800 MeV, corresponding to a mean beam power of 0.2 MW. Beam profile measurements are a key component of both ISIS operational running and R&D beam studies. Understanding and quantifying limitations in these monitors is essential, and has become more important as work to optimise and study the beam in more detail has progressed. This paper presents 3D field and ion trajectory modelling of the ISIS residual gas ionization profile monitors, including the effects of non-uniformity in longitudinal and transverse drift fields, and beam space charge. The simulation model allows comparison between the input beam profile, and that deduced from ion currents. The resulting behaviour, corrections and errors are then compared with experimental data from the ISIS synchrotron.  
 
TUPC127 Utility Design for the 3GeV TPS Electron Storage Ring storage-ring, booster, controls, synchrotron-radiation 1365
 
  • J.-C. Chang, Y.-C. Lin, Y.-H. Liu, Z.-D. Tsai
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  Having been running the Taiwan Light Source (TLS) for fourteen years since its opening in 1993, National Synchrotron Radiation Research Center (NSRRC), Taiwan, has been approved to build a photon source (TPS) last year. TPS is preliminarily designed with 3.0 GeV in energy, 518.4m in circumference and 24 Double-Bend Achromat (DBA). The utility system, including the electrical power, cooling water and air conditioning system of the TPS were designed to meet requirements of high reliability and stability. Because the power consumption of the TPS is estimated about three times that of TLS, energy saving is another consideration. This paper therefore discusses utility design concepts and presents partial design results, including capacity requirements, equipment and piping layouts.  
 
TUPC132 The Strategy between Optimal Control and Energy Saving about Utility System Operation controls, synchrotron-radiation, radiation, simulation 1380
 
  • Z.-D. Tsai, J.-C. Chang
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  Previously, the Taiwan Light Source (TLS) at NSRRC has proven the good beam line quality depend on the utility system stability. Subsequently, several studies including the temperature control of cooling water and air conditioner was in progress for improving the system stability. Due to the importance of energy saving issue, the heavy power consumption of utility system are also discussed and intended to reduce extensively. The paper addresses some experience between optimal control and energy saving about operation of utility system in TLS. This provides a strategy between stability control and power reduction, including the flow balance, inverter usage, facility operation, control philosophy and so on.  
 
TUPC139 LLRF Electronics for the CNAO Synchrotron controls, pick-up, acceleration, proton 1392
 
  • O. Bourrion, D. Tourres, C. Vescovi
    LPSC, Grenoble
  The Italian National Centre for Oncological hAdrontherapy (CNAO) is undergoing its final construction phase in Pavia and will use proton and carbon ion beams to treat patients affected by solid tumours. At the hearth of CNAO is a 78 meters circumference synchrotron, capable of accelerating particle up to 400 MeV/u with a repetition rate of 0.4 Hz. Particle acceleration is done by a unique VITROVAC load RF cavity operating at a frequency between 0.3 and 3MHz and up to 3kV peak amplitude. In order to control this cavity a digital LLRF system has been designed at LPSC. It is based mainly upon Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGA) and Direct Digital Synthesizers (DDS). The LLRF system implement both cavity control and beam control capabilities in a compact, remotely programmable and configurable, Ethernet controlled electronic module. It also allows an easy regulation loop tuning, thanks to an embedded acquisition system that stores all input and output signals during a given acceleration cycle. This paper describes the electronics architecture, lab measurements and test results obtained with the system coupled with the CNAO cavity.  
 
TUPC144 Digital Low Level RF System for SOLEIL feedback, simulation, beam-loading, controls 1407
 
  • P. Marchand, M. D. Diop, F. Ribeiro, R. Sreedharan
    SOLEIL, Gif-sur-Yvette
  • M. Luong, O. Piquet
    CEA, Gif-sur-Yvette
  In the SOLEIL storage ring, two cryomodules, each containing a pair of 352 MHz superconducting cavities, will provide the maximum power of 560, required at the nominal energy of 2.75 GeV with the full beam current of 500 mA. Presently, an analogue Low Level RF system is successfully operating to control the amplitude and phase of the accelerating voltage. A fast digital FPGA based I-Q feedback is currently under development. The digital I-Q loop is realised with a HERON IO2 FPGA module using a Virtex II with 1M gates. The performance of the digital LLRF system has been evaluated using a Matlab-Simulink based simulation tool taking into account different features (loop delays, bandwidth limitation, extra power budget). The hardware design is described and the first experimental results are reported.  
 
TUPC147 Analogue LLRF for the ALBA Booster booster, controls, injection, resonance 1416
 
  • H. Hassanzadegan, F. Pérez
    ALBA, Bellaterra
  ALBA Booster will inject up to 2 mA of current, at 3 Hz, in the 3 GeV 3rd generation Synchrotron Light Source ALBA, that is in the construction phase in Cerdanyola, Spain. The Booster will ramp the beam energy from 100 MeV to 3 GeV, the RF voltage will be ramped as well from <100 kV to 1 MV to improve injection efficiency and maintain the beam stable. The Booster RF System will have to provide up to 1 MV of accelerating voltage and have a high dynamic range. An Analogue LLRF prototype has been developed for the Booster 5 cell RF Cavity. The prototype is based on the IQ modulation/demodulation technique and it has been designed completely in house. The prototype has been installed in the high power RF lab of CELLS and tested to control up to 80 kW on the real Booster Cavity. The test results of the control loops (amplitude, phase and tuning) will be presented, as well as the hardware structure and the system interface.  
 
TUPC154 CERN PSB Beam Tests of CNAO Synchrotron's Digital LLRF extraction, controls, proton, acceleration 1431
 
  • M.-E. Angoletta, A. Findlay
    CERN, Geneva
  • O. Bourrion, R. Foglio, D. Tourres, C. Vescovi
    LPSC, Grenoble
  • C. De Martinis
    INFN-Milano, Milano
  • L. Falbo, S. Hunt
    CNAO Foundation, Milan
  The Italian National Centre for Oncological hAdrontherapy (CNAO), in its final construction phase, uses proton and carbon ion beams to treat patients affected by solid tumours. At the heart of CNAO is a 78-meter circumference synchrotron that accelerates particles to up to 400 MeV/u. The synchrotron relies on a digital LLRF system based upon Digital Signal Processors (DSPs) and Field Programmable Gate Array (FPGA). This system implements cavity servoing and beam control capabilities, such as phase and radial loops. Beam tests of the CNAO synchrotron LLRF system were carried out at CERN’s Proton Synchrotron Booster (PSB) in autumn 2007, to verify the combined DSP/FPGA architecture and the beam control capabilities. For this, a prototype version of CNAO’s LLRF system was adapted to the PSB requirements. This paper outlines the prototype system layout and describes the tests carried out and their results. In particular, system architecture and beam control capabilities were successfully proven by comparison with the PSB operational beam control system and with the help of several existing beam diagnostic systems.  
 
TUPD016 Grounding and Induced Voltage Issues of the Injection Bump Magnet System of the 3-GeV RCS in J-PARC power-supply, controls, linac, proton 1461
 
  • T. Takayanagi, J. Kamiya, M. Kinsho, T. Ueno, M. Watanabe, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Irie
    KEK, Ibaraki
  The power supply of the injection shift bump magnets is required to rate a large current with high precision. The rating current is 20 kA and the pulse width is 1.3 ms. The power supply with the multiple connected two-quadrant IGBT choppers, which is controlled by the switching frequency over 48 kHz, realizes the tracking error less than 1.0 %. However, the switching noise due to the IGBT choppers caused damages to the control device and the measuring instrument. The ground cables were changed to copper sheets, so that the voltage due to the switching noise between the power supply board and the ground decreased from 800 V to 40 V. Furthermore, the output voltage of the RF shield was measured in connection with the several waveform patterns. These results showed the good agreement with the calculation and the experiment. The good performances of the shift bump magnet and power supply have been confirmed.  
 
TUPD028 How to Stably Store Electron Beam in a Synchrotron Radiation Facility from the Point of View of an RF System Design storage-ring, klystron, electron, synchrotron-radiation 1485
 
  • Y. Kawashima, H. Ego, Y. Ohashi
    JASRI/SPring-8, Hyogo-ken
  • M. Hara
    RIKEN Spring-8, Hyogo
  In any synchrotron radiation facilities, the users wish that electron beams are stably stored without beam abortion for as long as possible. It must be recognized that RF system is a main cause of beam abortions. In order to store beam stably, it is necessary for staffs in charge of RF system to foresee various beam instabilities and to take measures. Before discussing coupled-bunch instability problems, one should understand some trivial issues such as ion trapping and fundamental acceleration frequency modulated by high voltage ripple. The former causes transverse mode instability and the latter shakes stored electron beam longitudinally in RF cavities. In newly designed synchrotron radiation facilities, those issues mentioned above should be suppressed before beam commissioning. As for other issues relating with RF system, we would like to state the importance of a water-cooling system with stable temperature for cavities, and the electric earth problem of low level RF system and high voltage power equipment of a klystron. We describe how we have managed those issues in designing of SPring-8 RF system of the storage ring.  
 
TUPP004 Evolution and Status of the Electronic Logbooks at the ESRF controls, power-supply, storage-ring, radio-frequency 1532
 
  • L. Hardy, J. M. Chaize, O. Goudard
    ESRF, Grenoble
  • S. D. Cross, D. Fraser, N. V. Hurley
    St James Software, Cape Town
  In 2004 the ESRF moved to electronic logbooks. Such logbooks should be configurable enough to be used in several situations: document management, exchange of technical information and, in the Control Room, as a powerful tool for storing and retrieving information at a glance. The St James software company developed such a product which met our constraints and which is easy to configure. Moreover, this product can be tailored and evolved with time by its users and allows automatic access to control system parameters. After gaining experience with several logbooks using the old version 4 system, a new more user-friendly version which offers extensive customisation possibilities has been launched. This new version, J5, has already been interfaced to the ESRF control system (Tango) through a Python binding. This allows automatic triggering of records on specific events and the generation of automatic reports from the history database system. J5 can use an LDAP server for security management.  
 
TUPP006 Beam Test with a New Control System of Acceleration in HIMAC acceleration, controls, lattice, bunching 1538
 
  • M. Kanazawa
    NIRS, Chiba-shi
  • K. Maeda
    Toshiba Corporation, Tokyo
  • K. Watanabe
    Chiba University, Graduate School of Science and Technology, Chiba
  In the present acceleration system in HIMAC, acceleration frequency of a direct digital synthesizer is controlled with B-clock pulses of B+ and B- signals that correspond to 0.2 Gauss increment and decrement of dipole magnetic field. In the tested new control system, we will use only clock pulse whose clock rate is locked to the power line frequency. With this simple system, it is easy to build up the acceleration control system for multiple flat-top pattern. This pattern operation is expexted to use in the next irradiation system of spot-scanning in HIMAC. In this presentation, the used system and its beam tests will be presented.  
 
TUPP022 Measurements of Broad Band Impedance Related Longitudinal Properties of Electron Bunches at DELTA impedance, single-bunch, undulator, klystron 1577
 
  • R. Burek, H. Huck, G. Schmidt, T. Weis, K. Wille
    DELTA, Dortmund
  DELTA is a 1.5 GeV synchrotron light source which can be operated also at 550 MeV for FEL experiments. Due to interactions with the vacuum chamber, the beam induces wake fields, which act back on the beam and result in a disturbed bunch profile because of potential well distortion and turbulent bunch lengthening. These interactions limit the obtainable bunch length and achievable peak current and therefore strongly affect the FEL-operation. Recent results obtained by streak camera measurements have shown that for short bunches with maximum bunch lengths of 40 ps the longitudinal broad band impedance has to be scaled (SPEAR-scaling) to explain the measurements. The broad band impedance fits well to impedance measurements and calculations performed throughout the last years. The energy spread related to the bunch lengthening has been measured by analysing the undulator spectrum.  
 
TUPP023 Direct Detection of the Electron Cloud at ANKA electron, vacuum, simulation, storage-ring 1580
 
  • S. Casalbuoni, A. W. Grau, M. Hagelstein, A.-S. Müller
    FZK, Karlsruhe
  • U. Iriso
    ALBA, Bellaterra
  • E. M. Mashkina
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  • R. Weigel
    Max-Planck Institute for Metal Research, Stuttgart
  Low energy electrons generated by the interaction of high energy particles with the beam pipe surface can be detrimental for accelerators performances increasing the vacuum pressure, the heat load and eventually producing beam instabilities. The low energy electrons accumulating in the beam pipe are often referred to as electron cloud. In this presentation we report on the direct evidence of the electron cloud in the electron storage ring of the synchrotron light source ANKA (ANgstrom source KArlsruhe).  
 
TUPP037 Impedance and Instabilities for the ALBA Storage Ring impedance, damping, vacuum, storage-ring 1622
 
  • T. F. Günzel, F. Pérez
    ALBA, Bellaterra
  The geometrical impedance in all 3 planes for most of the vacuum chamber elements of the ALBA storage ring was computed with the 3D-solver GdfidL. Optimisation of some element geometries was carried out in order to reduce dissipative losses and in general the impedance. Resistive wall impedance was calculated analytically. The thresholds of various instabilities were determined on the basis of analytically formulated threshold criteria. The most important are a HOM-driven longitudinal multibunch instability and the transverse resistive wall instability. It is proposed to combat the first one by Landau damping using partial filling and the second one by a transverse feedback system.  
 
TUPP038 On the Longitudinal Coupling Impedance and Transmission Coefficient from Uniform and Hollow Ring Sources impedance, space-charge, coupling, electromagnetic-fields 1625
 
  • A. M. Al-Khateeb, O. Boine-Frankenheim, R. W. Hasse
    GSI, Darmstadt
  • J. M. Shobaki
    Yarmouk, Irbid
  The longitudinal coupling impedance and the transmission coefficient resulting from a thin ring and from a uniform disk are obtained analytically for a resistive cylindrical beam-pipe of finite wall thickness. The impedances are derived and then compared with the well known corresponding expression for perturbations on a uniform, coasting beam. The transmission coefficients from both sources are found to be exactly the same. Differences do appear in the expressions for the electromagnetic fields within the beam region, and therefore leading to different coupling impedances. By applying the results to parameters relevant for the SIS-18 synchrotron at GSI, it is found that the formula from the ring source underestimates the space-charge impedance at all beam energies and it shows a noticeable deviation from the disk formula for all frequencies. Although their mathematical expressions are different, resistive-wall impedances from the two sources are found to be numerically equal. The space-charge impedances become equal asymptotically only in the so called ultra-relativistic limit.

A. Al-Khateeb is on leave from Yarmouk University, Irbid, Jordan

 
 
TUPP039 Wake-field Compensation in Energy Recovery Linacs linac, acceleration, radiation, synchrotron-radiation 1628
 
  • G. Hoffstaetter, M. G. Billing, Y. H. Lau
    CLASSE, Ithaca
  Problems created by the correlated energy spread that wake fields can produce are strongly enhanced in Energy Recovery Linacs (ERLs), as compared to conventional linacs. This is due to the fact that in ERLs the spent beam is decelerated by a potentially large factor, which increases the relative energy spread proportionally. We show how severe this problem is for the impedance budget of the x-ray ERL that Cornell plans to build, and we analyze several different possibilities to compensate the correlated energy spread involving de-phasing linac components, linear and nonlinear time-of-flight terms in different accelerator sections, or high frequency accelerating cavities. Because of the particular design, which has a turn-around loop between two sections of the linac, there are many options for these techniques which we compare and evaluate.  
 
TUPP041 CSR Shielding in the Beam Dynamics Code BMAD radiation, shielding, synchrotron-radiation, simulation 1634
 
  • G. Hoffstaetter, C. E. Mayes, U. Sae-Ueng, D. Sagan
    CLASSE, Ithaca
  Short bunches radiate coherently at wavelengths that are longer than their bunch length. This radiation can catch up with the bunch in bends and the electromagnetic fields can become large enough to significantly damage longitudinal and transverse bunch properties. This is relevant for many accelerators that relies on bunch compression. It is also important for Energy Recovery Linacs, where spent beams are decelerated by a potentially large factor. Because this deceleration increases the relative energy spread, all sources of wake fields, especially Coherent Synchrotron Radiation (CSR), become much more important. In this paper we show how the beam dynamics code BMAD computes the effect of CSR and how the shielding effect of vacuum chambers is included by the method of image charges. We compare the results to established codes: to Elegant for cases without shielding and to a numerical solution of simplified Maxwell equations as well as to analytical csr-wake formulas. Good agreement is generally found, and in cases where numerical solutions of the simplified Maxwell equations do not agree with the csr-wake formulas, we show that BMAD agrees with these analytic formulas.  
 
TUPP042 Status of the ORBIT Code: Recent Developments and Plans scattering, acceleration, injection, collimation 1637
 
  • J. A. Holmes, S. M. Cousineau, A. P. Shishlo
    ORNL, Oak Ridge, Tennessee
  We report on recent enhancements to the physics modules of the ORBIT Code and on progress toward a new implementation of ORBIT using python. We have developed the capability to track particles through general three dimensional electromagnetic field configurations. This facility has proved essential in modeling beam transport through the complicated magnetic field regions of the SNS injection chicane and injection dump line, where beam losses are high. We have also enhanced the acceleration module to provide more flexibility for synchrotron calculations. Finally, progress continues on the migration of the ORBIT physics models to a python user environment, and we present the status of this work.  
 
TUPP050 Electron Cloud Mitigation by Fast Bunch Compression in the CERN PS extraction, electron, pick-up, proton 1658
 
  • H. Damerau, S. Hancock, T. Kroyer, E. Mahner, M. Schokker
    CERN, Geneva
  A fast transverse instability has been observed with nominal LHC beams in the CERN Proton Synchrotron (PS) in 2006. The instability develops within less than 1 ms, starting when the bunch length decreases below a threshold of 11.5 ns during the RF procedure to shorten the bunches immediately prior to extraction. An alternative longitudinal beam manipulation, double bunch rotation, has been proposed to compress the bunches from 14 ns to the 4 ns required at extraction within 0.9 ms, saving some 4.5 ms with respect to the present compression scheme. The resultant bunch length is found to be equivalent for both schemes. In addition, electron cloud and vacuum measurements confirm that the development of an electron cloud and the onset of an associated fast pressure rise are delayed with the new compression scheme. Beam dynamics simulations and measurements of the double bunch rotation are presented as well as evidence for its beneficial effect from the electron cloud standpoint.  
 
TUPP054 A Model of an Electrical Discharge in the Flange Contacts with Omega Seals at High Currents in PEP-II radiation, vacuum, resonance, synchrotron-radiation 1667
 
  • A. Novokhatski, J. Seeman, M. K. Sullivan
    SLAC, Menlo Park, California
  During operation with high currents at HER (High Energy Ring), high temperature elevation was found at almost every location of the vacuum chamber flange contacts. Omega RF seals were strongly damaged or even evaporated by sparks and electrical discharge. We suggest a physical model, which may explain this effect.  
 
TUPP055 Loss Factor of the PEP-II Rings radiation, resonance, synchrotron-radiation, luminosity 1670
 
  • A. Novokhatski, M. K. Sullivan
    SLAC, Menlo Park, California
  RF power balance method is used to measure the synchrotron radiation losses and the wake field losses. We present the history of the loss factor during the last several runs, which reveals many interesting correlations with vacuum chamber improvement and processing.  
 
TUPP059 Study of Controlled Longitudinal Emittance Blow-up for High Intensity LHC Beams in the CERN SPS emittance, damping, quadrupole, beam-loading 1676
 
  • G. Papotti, T. Bohl, T. P.R. Linnecar, E. N. Shaposhnikova, J. Tuckmantel
    CERN, Geneva
  Preventive longitudinal emittance blow-up, in addition to a fourth harmonic Landau damping RF system, is required to keep the LHC beam in the SPS stable up to extraction. The beam is blown-up in a controlled way during the acceleration ramp by using band-limited phase noise targeted to act inside the synchrotron frequency spread, which is itself modified both by the second RF system and by intensity effects (beam loading and others). For a high intensity beam these latter effects can lead to a non-uniform emittance blow-up and even loss of stability for certain bunches in the batch. In this paper we present studies of the emittance blow-up achieved with high intensity beams under different conditions of both RF and noise parameters.  
 
TUPP066 CERN SPS Impedance in 2007 impedance, kicker, quadrupole, shielding 1691
 
  • E. Métral, G. Arduini, T. Bohl, H. Burkhardt, F. Caspers, H. Damerau, T. Kroyer, H. Medina, G. Rumolo, M. Schokker, E. N. Shaposhnikova, J. Tuckmantel
    CERN, Geneva
  • R. Calaga
    BNL, Upton, Long Island, New York
  • B. Salvant
    EPFL, Lausanne
  • B. Spataro
    INFN/LNF, Frascati (Roma)
  Each year several measurements of the beam coupling impedance are performed in both longitudinal and transverse planes of the CERN Super Proton Synchrotron to keep track of its evolution. In parallel, after the extensive and successful campaign of identification, classification and cure of the possible sources of (mainly longitudinal) impedance between 1998 and 2001, a new campaign (essentially for the transverse impedance this time) has started few years ago, in view of the operation of the SPS with higher intensity for the LHC luminosity upgrade. The present paper summarizes the results obtained from the measurements performed over the last few years and compares them to our predictions. In particular, it reveals that the longitudinal impedance is reasonably well understood and the main contributors have already been identified. However, the situation is quite different in the transverse plane: albeit the relative evolution of the transverse impedance over the last few years can be well explained by the introduction of the nine MKE kickers necessary for beam extraction towards the LHC, significant contributors to the SPS transverse impedance have not been identified yet.  
 
TUPP082 Longitudinal Stability of Flat Bunches with Space-charge or Inductive Impedance impedance, damping, space-charge, dipole 1721
 
  • F. Zimmermann
    CERN, Geneva
  • I. Santiago Gonzalez
    University of the Basque Country, Bilbao
  We study the loss of Landau damping for the longitudinal plane via the ''Sacherer formalism''. Stability limits are calculated for several longitudinal beam distributions, in particular for two types of flat bunches, which could be of interest to the LHC upgrade. The resulting Landau stability diagrams are computed and displayed for different azimuthal modes. A general recipe is given for calculating the threshold intensity in the case of a capacitive impedance below transition or, equivalently, for a purely inductive impedance above transition. Specific results are finally presented for the case of the PS Booster, as an example of space-charge impedance below transition, and for the SPS, as an example of inductive impedance above transition.  
 
TUPP097 New Formalism in the Spin Tracking Code Spink quadrupole, resonance, radio-frequency, extraction 1756
 
  • A. U. Luccio, F. Lin
    BNL, Upton, Long Island, New York
  The code Spink*, in use for more than 10 years to track polarized hadrons in a synchrotron, was overhauled with the introduction of a new system of coordinates based on a generalized Frenet-Serret system in all dimensions in space, which allows a better treatment of the curvature of the reference orbit. Two more improvements are (a) treatment of tensor polarization for particles like polarized deuterons, and (b) inclusion of space charge and beam-beam effects, so the code can be used to track spin in synchrotrons with high luminosity like new generation colliders.

*A. U. Luccio. Proc. Adriatico Research Conf. on Trends in Colliders
Spin Physics. Trieste, Italy, 12/5-8, 1995.

 
 
TUPP105 Theoretical Field Analysis for Superferric Accelerator Magnets Using Elliptic Multipoles and its Advantages multipole, dipole, simulation, magnet-design 1773
 
  • P. Schnizer, E. S. Fischer
    GSI, Darmstadt
  • P. G. Akishin
    JINR, Dubna, Moscow Region
  • B. Schnizer
    TUG/ITP, Graz
  FAIR will build a set of accelerators and storage rings at GSI Darmstadt. Nearly all of them transport beams of elliptical shape (SIS 100, CR, NESR, RESR, SuperFRS). Magnetic field calculations as well as magnetic measurements provide precise field information, which is used to improve the properties of machine using numerical simulations. We had developed elliptical multipoles fulfilling the Laplace equation which enable us to describe the field within the whole aperture consistently. Now the representation of these has been simplified considerably as compared to earlier ones. Meanwhile we found analytical expressions to derive circular multipoles directly from the elliptic multipoles. We illustrate the advantage of this data representation on SIS 100 magnet data and show how a concise set of harmonics can be derived from rotating coil measurements.  
 
TUPP109 Meshless Solution of the Vlasov Equation Using a Low-discrepancy Sequence site, simulation, controls, damping 1776
 
  • R. L. Warnock
    SLAC, Menlo Park, California
  • J. A. Ellison, K. A. Heinemann, G. Q. Zhang
    UNM, Albuquerque, New Mexico
  A successful method for solving the nonlinear Vlasov equation is the semi-Lagrangian method, in which the phase space density is represented by its values on a fixed Cartesian grid with interpolation to off-grid points. Integration for a time step consists of following orbits backward in time from initial conditions on the grid, with the collective force frozen during the time step. We ask whether it would be more efficient to use scattered data sites rather than grid points, namely sites from a low-discrepancy sequence as used in quasi - Monte Carlo integration. This requires a technique for interpolation of scattered data, and with such a technique in hand one can try either backward or forward orbits. Here we explore the forward choice, with the data sites themselves following forward orbits. We treat a problem well studied by the backward method, longitudinal motion in the SLAC damping rings. Over one or two synchrotron periods results are encouraging, in that the number of data sites can be reduced by a large factor. Over longer times it appears that the sites must be redistributed or changed in number from time to time, because of clustering.  
 
TUPP116 Development of Scanning System at HIMAC target, controls, simulation, heavy-ion 1794
 
  • T. Furukawa, T. Inaniwa, Y. Iwata, T. Kanai, S. Minohara, S. Mori, T. Murakami, A. Nagano, K. Noda, N. Saotome, S. Sato, T. Shirai, E. Takada, Y. Takei
    NIRS, Chiba-shi
  A new treatment facility project, as an extension of the existing HIMAC facility, has been initiated for the further development of carbon-ion therapy. This new treatment facility will be equipped with a three-dimensional irradiation system with pencil beam scanning. For moving-tumor treatments with high accuracy, the most important part of the design study is how to realize this by scanning irradiation. For this purpose, we have studied a combination of the rescanning technique and the gated irradiation method. In order to avoid hot and/or cold spots even by a relatively larger number of rescannings within the acceptable irradiation time, we studied a fast scanning system. Further, this concept was experimentally demonstrated at the HIMAC. The design and the related study of the scanning system for the HIMAC new treatment facility will be presented.  
 
TUPP118 Update of an Accelerator Control System for the New Treatment Facility at HIMAC controls, extraction, ion, target 1800
 
  • Y. Iwata, T. Furukawa, K. Noda, T. Shirai, E. Takada
    NIRS, Chiba-shi
  • T. Kadowaki, Y. Sano, H. Uchiyama
    AEC, Chiba
  Tumor therapy using energetic carbon ions, as provided by the HIMAC, has been performed since June 1994, and more than 3200 patients were treated until now. With the successful clinical results over more than ten years, we started to construct a new treatment facility. The new facility would have three treatment rooms; two of them have both horizontal and vertical fixed-irradiation-ports, and the other has a rotating-gantry-port. For all the ports, a scanning irradiation method is applied. The new facility will be constructed in conjunction with the HIMAC, and heavy-ion beams will be provided by the HIMAC accelerators. To fulfill requirements for the scanning irradiation, we are planning to update the accelerator control system. The proposed control system would enable us to provide heavy ions having variable energies within a single synchrotron-pulse; the beam energy would be changed a few tenth of times within a pulse by an energy step corresponding to a water range of 2 mm. Since the beam range would be adjusted without using range compensators, an excellent irradiation field could be obtained. We will present our project on updating the accelerator control system.  
 
TUPP119 Lattice Design of a Carbon Ion Synchrotron for Cancer Therapy extraction, resonance, lattice, betatron 1803
 
  • H.-S. Kang, H. S. Suh
    PAL, Pohang, Kyungbuk
  A synchrotron accelerator for carbon ion cancer therapy was designed to be compact for a hospital based therapy facility. The circumference of the synchrotron is only 60 meter and the lattice is the FODO structure of 6 cells. Each cell has two dipole magnets with a angle of 30 degree. The lattice satisfies the requirement of Hardt condition for slow beam extraction which is to align the separatrices of different momenta of the particles.  
 
TUPP124 Status of the Particle Therapy Accelerator System Built by DANFYSIK A/S vacuum, dipole, ion, quadrupole 1815
 
  • S. P. Møller, T. Andersen, F. Bødker, A. Baurichter, M. Budde, P. A. Elkiaer, C. E. Hansen, N. Hauge, T. Holst, I. Jensen, L. K. Kruse, S. M. Madsen, M. Schmidt
    Danfysik A/S, Jyllinge
  • K. Blasche
    BTE Heidelberg, Ingeniurbüro, Schriesheim
  • B. J. Franczak
    GSI, Darmstadt
  Danfysik and Siemens have entered a cooperation to market and build Particle Therapy* systems for cancer therapy. The accelerators will consist of an injector (7 MeV/u proton and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u in less than 1s. These beams can be slowly extracted over a period of up to 10s and delivered to treatment rooms through a choice of fixed-angle horizontal and semi-vertical beamlines and Gantry Systems. The intensity for protons and carbon ions will be sufficient for the needs of scanning beam applications. The design of a particular system, with three horizontal beamlines and one semi-vertical (45°) beamline, will be described. At the time of EPAC08, most components have been manufactured and hardware tested. The detailed layout of the facility will be presented, together with some of the components and their performance.

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

 
 
TUPP125 New Heavy-ion Cancer Treatment Facility at HIMAC target, extraction, controls, ion 1818
 
  • K. Noda, T. Furukawa, T. Inaniwa, Y. Iwata, T. Kanai, M. Kanazawa, S. Minohara, S. Mori, T. Murakami, S. Sato, T. Shirai, E. Takada, Y. Takei, M. Torikoshi
    NIRS, Chiba-shi
  The first clinical trial of cancer treatment with carbon beams generated from the HIMAC was conducted in June 1994. Based on more than ten years of experience with HIMAC, we have proposed a new treatment facility for the purpose of further development of the heavy-ion cancer therapy with HIMAC. This facility, which is connected with the HIMAC synchrotron, consists of three treatment rooms: two rooms equipped with horizontal and vertical beam-delivery systems and one room with a rotating gantry. In both the fixed beam-delivery and rotating gantry systems, a 3D beam-scanning method is employed with gated irradiation with patient’s respiration in order to increase the treatment accuracy. Since the beam control for the size, the position and the time structure plays an essential role in the 3D beam scanning with the irradiation gated with respiration, the R&D study has been carried out with the HIMAC synchrotron since 2006. At December 2007, the Japanese government approved this project. We will report the design and R&D studies toward the construction of the new treatment facility.  
 
TUPP127 Spill Structure Measurements at the Heidelberg Ion Therapy Centre ion, proton, controls, beam-losses 1824
 
  • A. Peters, R. Cee, T. Haberer, T. Winkelmann
    HIT, Heidelberg
  • T. Hoffmann, A. Reiter, M. Schwickert
    GSI, Darmstadt
  A specially designed accelerator facility for tumour irradiation located at the Heidelberg University Hospital was built up, the commissioning is still ongoing. Technically the Heidelberg Ion Therapy Center (HIT) fully relies on the three dimensional intensity-controlled rasterscan technique developed at GSI. This method demands for smoothly extracted ion beams (from protons to oxygen) from the HIT synchrotron. For this purpose a RF knock-out system consisting of a RF-exciter in combination with an electrostatic septum, two septum magnets and two sextupoles is used. To characterize the extracted beams scintillators for low intensities and ionization chambers for higher currents are installed in the high energy transport lines. Using a PXI-based DAQ system full spills are recorded with a time bin of 100 μs. Typical raw data will be shown as well as derived statistics like Fourier spectra and maximum-to-average ratios that proof the beam quality for its applicability to produce outstanding dose distributions via beam scanning. In addition, safety aspects like the performance of the spill interrupt procedure will be demonstrated with measured data.  
 
TUPP129 Accelerator Development for Advanced Particle Beam Therapy extraction, acceleration, proton, linac 1827
 
  • K. Saito, K. Moriyama, H. Nihongi, H. Nishiuchi, H. Sakurabata, S. Totake, M. Umezawa
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  Particle beam therapy has become one of the most effective modalities of cancer treatment. High reliability, high throughput and high precision irradiation are strongly demanded for the therapy system. In order to meet the requirements, we have developed several key technologies of synchrotron-based accelerator system, such as multi-harmonic RF acceleration, extracted beam intensity feedback, respiration-synchronized operation and beam tuning for spot scanning irradiation. Almost all these technologies have already been applied to the proton beam therapy system at M. D. Anderson Cancer Center. Beam specifications required for the spot scanning irradiation have successfully been achieved. In this paper, present status of the accelerator development will be described.  
 
TUPP134 Commissioning of the Carbon Beam Gantry at the Heidelberg Ion Therapy (HIT) Accelerator ion, proton, beam-transport, quadrupole 1842
 
  • U. Weinrich, C. M. Kleffner
    GSI, Darmstadt
  The HIT facility comprises the only carbon ion gantry worldwide. This gantry is especially unique in offering fully flexible beam transport to the patient for carbon ions up to an energy of 430 MeV/u. It includes a full 3D-beam scanning system and full medical treatment environment. The gantry can be rotated by 360 degree so that the beam may be directed at the patient from arbitrary directions. Commissioning with beam of the gantry was successfully started in January 2008 when the first proton and carbons beams were transported into the gantry treatment room. Based on theoretical calculations for rotation independent settings of the beam optics, the beam commissioning aims for an efficient practical way to realize the full variety of required beam properties (2 ion types, 10 intensities, 255 energy steps, and four beam sizes) in the isocenter independent of the gantry angle. The presentation will report on the concept and progress of the beam commissioning process.  
 
TUPP162 High Heat Load Components in TPS Front Ends undulator, radiation, synchrotron-radiation, photon 1890
 
  • A. Sheng, J.-R. Chen, C. K. Kuan, Z.-D. Tsai
    NSRRC, Hsinchu
  National Synchrotron Radiation Research Center (NSRRC) will build a new synchrotron accelerator (TPS, Taiwan Photon Source) with a great heat-load power. Various IDs have been proposed. For instance, at 3.3 GeV, 350 mA, superconductivity wiggler SW4.8 may generate 5.8mrad wide, 57 kW/mrad2 power whereas undulator CU1.8 will be 0.7 mrad, 148 kW/mrad2. The function of the fixed mask in TPS front ends not only to protect the downstream vacuum from being hit by the radiation during miss-steering, but also shadow the unwanted power. More than one fixed masks are introduced in some high heat load front ends. High conductivity, high thermomechaical strength GlidCop® is used; design and thermomechanical analysis is also presented in this paper.  
 
WEZG02 Commissioning of an Accelerator: Tools and Management controls, optics, storage-ring, diagnostics 1926
 
  • A. Nadji
    SOLEIL, Gif-sur-Yvette
  During the life of an accelerator project, the commissioning is a very important and exciting phase. It is preceded by a long period of design, calculations, magnetic measurements, installation, and alignment. We want the commissioning stage to be successful and fast; that is, attaining rapidly the set goals and make the machine available for impatient users. This paper summarizes the experience of several commissioning phases for different types of accelerators such as SNS, JPARC, and LHC, as well as synchrotron light sources such as DIAMOND, SOLEIL, and SSRF. The importance of preparation for commissioning on both technical and personnel levels will be covered. We will also talk about the concept of stages, anticipation of problems, and the early involvement of many specialists in addition to accelerator physicists and future accelerator operators. Furthermore, we will outline the importance of having a command control that is practical, fast, and has the capacity to offer high level automated applications. Finally, we will discuss the indispensable role of diagnostics for the first injection and first turns of the beam.  
slides icon Slides  
 
WEOBM01 R&D Activities Aimed at Developing a Curved Fast Ramped Superconducting Dipole for FAIR SIS300 dipole, coupling, ion, antiproton 1950
 
  • P. Fabbricatore, S. Farinon, R. Musenich
    INFN Genova, Genova
  • F. Alessandria, G. Bellomo, G. Volpini
    INFN/LASA, Segrate (MI)
  • U. Gambardella
    INFN/LNF, Frascati (Roma)
  • J. E. Kaugerts, G. Moritz
    GSI, Darmstadt
  • R. Marabotto
    ASG, Genova
  • M. Sorbi
    Universita' degli Studi di Milano & INFN, Segrate
  One of the basic components of the FAIR facility, under development at GSI, is the synchrotron SIS300 (300 Tm rigidity). In order to reach the required high intensities of proton and heavy ion beams, the magnets of this synchrotron have to be pulsed from the injection magnetic field of 1.5 T up to 4.5 T maximum field at the rate of 1 T/s. These 7.8 m long, cos-teta shaped coils with a 100 mm bore have the particular characteristic to be curved (the sagitta is 114 mm). All these aspects demand for a challenging R&D, aimed at the development of a low loss conductor and of a suitable winding technology for curved coil. Further design issues are related to the optimization of the stress distribution involving materials able to hold 107 cycles and to the maximization of the heat transfer to coolant (supercritical helium at 4.7 K). At the present time, design activities are going on with the aim to design, construct and test a 3.8 m long prototype within 2009. In order to achieve this objective, several intermediate milestones are included in the R&D program. One of the most challenging is the industrial development of a method for winding a curved cos-teta dipole.  
slides icon Slides  
 
WEIM05 Institutional and Industrial Partnerships linac, controls, feedback, instrumentation 1972
 
  • C. J. Bocchetta
    Instrumentation Technologies, Solkan
  To be successful, accelerator projects require close interaction with industry for design, engineering and construction. Partnership and cooperation between institutes and industry is a means to transfer knowledge and foster innovation in the private sector, while the public sector benefits from best practices, efficient use of resources and pooled knowledge. An overview of partnerships between institutions and industry is given with examples from active projects.  
slides icon Slides  
 
WEPC025 First 18 Months Operation of the Diamond Storage Ring RF System storage-ring, vacuum, controls, resonance 2037
 
  • M. Jensen, M. Maddock, P. J. Marten, S. A. Pande, S. Rains, A. F. Rankin, D. Spink, A. V. Watkins
    Diamond, Oxfordshire
  Since the Diamond Light Source became operational in January 2007, the storage ring RF system has operated for 5000 hours in 2007 and is scheduled to operate for 5350 hrs in 2008. This paper presents some of the key challenges of the storage ring RF system including reliability, performance observations and future improvements.  
 
WEPC027 Coherent THz Radiation at ELETTRA radiation, electron, synchrotron-radiation, single-bunch 2043
 
  • E. Karantzoulis, G. Penco, A. Perucchi
    ELETTRA, Basovizza, Trieste
  • S. Lupi
    Coherentia, Naples
  Coherent infra red radiation (CIR) has been observed since some time at ELETTRA under several machine parameter settings in the beam-line SISSI. Effort has been made to produce a “stable” THz signal for experimental use. The description of the machine settings to that end and the measurements performed are presented and discussed.  
 
WEPC033 Coherent Synchrotron Radiation at the Metrology Light Source of the PTB radiation, electron, synchrotron-radiation, storage-ring 2058
 
  • R. Müller, A. Hoehl, R. Klein, G. Ulm
    PTB, Berlin
  • M. Abo-Bakr, K. B. Buerkmann-Gehrlein, J. Feikes, M. V. Hartrott, J. S. Lee, J. Rahn, U. Schade, G. Wuestefeld
    BESSY GmbH, Berlin
  The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has set up a low-energy electron storage ring in Berlin-Adlershof in close cooperation with the BESSY GmbH. The new storage ring, named Metrology Light Source (MLS), is mainly dedicated to metrology and technological developments in the EUV, VUV, and IR spectral range. Additionally, the MLS is the first machine designed and prepared for a special machine optics mode (low-alpha operation mode) based on an octupole correction scheme, for the production of coherent synchrotron radiation in the FIR and THz region. Two beamlines dedicated to the use of IR synchrotron radiation are now under commissioning: an IR bending magnet beamline optimized for the MIR to FIR and an IR edge radiation beamline. We report the status of the MLS operated in the low alpha mode and present first results from the commissioning.  
 
WEPC034 Present Status of Siam Photon Source storage-ring, undulator, photon, injection 2061
 
  • P. Klysubun, S. Cheedket, G. G. Hoyes, M. Oyamada, W. Pairsuwan, S. Rugmai, P. Sudmuang
    NSRC, Nakhon Ratchasima
  The Siam Photon Source (SPS) is a 1.2 GeV synchrotron light source situated in Nakhon Ratchasima, Thailand. It is currently in the fourth year of routine operation for synchrotron radiation users. In order to address the increasing user demand for increasing beamtime, better beam position stability, and improved machine reliability, several machine improvements and upgrades have been undertaken during the past year. This report first briefly gives the overview and important parameters of the light source, and then describes the current operation status and operation statistics in 2007. Recent machine improvements, for instance, modernization of injector components, improvement of vacuum system, recalibration of beam position monitors, and orbit correction, are presented together with the initial synopsis of the successful installation of the first insertion device, a permanent magnet planar undulator.  
 
WEPC037 Preparations of BESSY for Top Up Operation injection, kicker, storage-ring, septum 2067
 
  • P. Kuske, M. Abo-Bakr, W. Anders, T. Birke, K. B. Buerkmann-Gehrlein, M. Dirsat, O. Dressler, V. Duerr, F. Falkenstern, W. Gericke, R. Goergen, F. Hoffmann, T. Kamps, J. Kuszynski, I. Mueller, R. Mueller, K. Ott, J. Rahn, T. Schneegans, D. Schueler, T. Westphal, G. Wuestefeld
    BESSY GmbH, Berlin
  • D. Lipka
    DESY, Hamburg
  The synchrotron light source BESSY went into operation for users in 1998. BESSY was not designed initially to allow for Top Up operation, a mode where lost electrons are replaced after minutes while the beam shutters are open and users take data. Since 3 years the facility is improved in order to guarantee safe operation in this risky mode. The work culminated in a one week long Top Up test run at the beginning of this year. The efforts and achievements are described in detail: Improvements of the injector, the pulsed injection elements, the timing system, insertion devices, the additional safety interlocks, and the shielding of the ring.  
 
WEPC040 Commissioning of the SSRF Booster booster, linac, dipole, electron 2073
 
  • H. H. Li, Q. Gu, D. M. Li, L. G. Liu, D. Wang, Z. T. Zhao
    SINAP, Shanghai
  The SSRF Booster, designed to accelerate the electrons from 150MeV to 3.5GeV, is a FODO structure synchrotron with 180m circumference and 2Hz repetition rate. The commissioning of the SSRF booster from the LTB transfer line started on Sept. 30th evening, 2007, the first turns of beam in the booster was obtained in 20 hours. With about 60 hours effective commissioning effort, the electrons were accelerated to 3.5GeV on October 5th morning, 2007. And then the first 3.5GeV beam was extracted to BTS transfer line on October 30th, 2007. In this paper, the SSRF booster is introduced and its commissioning results are presented.  
 
WEPC046 Characterizing THz Coherent Synchrotron Radiation at the ANKA Storage Ring radiation, synchrotron-radiation, single-bunch, storage-ring 2091
 
  • A.-S. Müller, I. Birkel, S. Casalbuoni, B. Gasharova, E. Huttel, Y.-L. Mathis, D. A. Moss, N. J. Smale, P. Wesolowski
    FZK, Karlsruhe
  • E. Bruendermann
    Ruhr-Universität Bochum, Bochum
  • T. Bueckle, M. Klein
    University of Karlsruhe, Karlsruhe
  In a synchrotron radiation source coherent infrared (IR) radiation is emitted when the bunch length is comparable to the wavelength of the emitted radiation. To generate coherent THz (far IR) radiation, the ANKA storage ring is operated regularly in a dedicated low-alpha optics. Different bunch lengths, corresponding to different spectral ranges of the THz spectrum and various electron beam energies can be offered, depending on user demand. The radiation emitted in the fringe field of a dipole magnet, the so-called edge radiation, is detected at the ANKA-IR beamline. This paper presents radiation properties like THz beam profiles and power measurements in the framework of characterising the coherent THz radiation to optimise the power, frequency and spatial output of the ANKA storage ring. First experiments showed a time averaged power of up to 0.2 mW suggesting a THz pulse peak power of at least several tens of mW.  
 
WEPC047 Modeling the Shape of Coherent THz Pulses Emitted by Short Bunches in an Electron Storage Ring radiation, synchrotron-radiation, storage-ring, electron 2094
 
  • A.-S. Müller, S. Casalbuoni, M. Fitterer, E. Huttel, Y.-L. Mathis
    FZK, Karlsruhe
  • M. T. Schmelling
    MPI-K, Heidelberg
  A sufficiently short electron bunch will emit coherent synchrotron radiation of wavelengths equal to or larger than the bunch length. The shape of the emitted THz pulse depends amongst other things on the original shape and length of the bunch’s charge distribution. A Michelson interferogram of the THz signal therefore contains information on the generating bunch. However, systematic effects make a bunch length measurement based on that technique non-trivial. In order to understand the variables involved, an analytical model of the pulse generation is needed. In this paper, a derivation of the THz pulse shape form first principles with special emphasis in the time domain is presented. The impact of charge distribution parameters on the Michelson interferogram is discussed.  
 
WEPC049 Novel Schemes for Simultaneously Satisfying High Flux and TOF Experiments in a Synchrotron Light Source kicker, storage-ring, radiation, single-bunch 2100
 
  • D. Robin, G. J. Portmann, F. Sannibale, W. Wan
    LBNL, Berkeley, California
  Storage Ring Light Sources have proven to be extremeley succesful tools for probing matter. One of their most desirable features is that they are able to supply synchrotron radiation to multiple experiments simultaneously. However two classes of applications are difficult to satisfy simultaneously - high flux applications and time of flight applications. High flux experiments require filling as many buckets as possible while time of flight experiments require long gaps between bunches. In this paper we examine schemes for operating the synchrotron light source for for both communities simultaneously.  
 
WEPC050 Future Plans for the Advanced Light Source lattice, emittance, injection, brightness 2103
 
  • D. Robin, H. Nishimura, G. J. Portmann, F. Sannibale, C. Steier
    LBNL, Berkeley, California
  The Advanced Light Source is now in its 15th year of operation. The facility has managed to continue to improve through continual upgrades to both the capabilities and capacities. Studies have shown that there is still plenty of room for improvements. Here we present plans to provide sustantial relevant improvements with modest cost.  
 
WEPC058 Operational Performance of the Taiwan Light Source photon, feedback, injection, synchrotron-radiation 2124
 
  • Ch. Wang, H.-P. Chang, J.-C. Chang, J.-R. Chen, F.-T. Chung, F. Z. Hsiao, G.-Y. Hsiung, K. T. Hsu, C. K. Kuan, C.-C. Kuo, K. S. Liang, K.-K. Lin, Y.-H. Lin, K.-B. Liu, Y.-C. Liu, G.-H. Luo, R. J. Sheu, D.-J. Wang, M.-S. Yeh
    NSRRC, Hsinchu
  The Taiwan light source (TLS) is a 1.5 GeV third generation light source at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan. It has been routinely operated since its opening in 1993. Several major machine upgrade projects have been undertaken and successfully completed in last 5 years, including implementing of digital bunch-by-bunch feedbacks, superconducting accelerating RF cavity, top-up mode injection, etc. The light source now moves forward to its era of mature operation. It delivers more than 5000 hours user time in 2007 with an up-time of more than 98% and a mean time between failures better than 80 hours. Here, we review its annual operational performance with detailed statistics and discuss the possible improvement directions of machine performance.  
 
WEPC060 Studies on the Beam Current Dependent Phenomena in the BEPC-II Storage Rings vacuum, single-bunch, electron, luminosity 2130
 
  • Q. Qin, N. Huang, W. B. Liu, Y. D. Liu, Y. M. Peng, J. Qiu, D. Wang, J. Q. Wang, N. Wang, X. H. Wang, Y. Wei, X. M. Wen, J. Xing, G. Xu, C. H. Yu, C. Zhang, Y. Zhang, Z. Zhao, D. M. Zhou
    IHEP Beijing, Beijing
  The upgrade project of the Beijing Electron Positron Collider (BEPC-II) has been being commissioned since Nov. 2006. Besides the commissioning of the luminosity, which is expected to be 100 times higher than the BEPC, the BEPC-II also provided beam to the synchrotron radiation users as a light source during these two years. Some beam current dependent phenomena, such as bunch lengthening, single beam instabilities, blow-up in collision, etc., in both collision and synchrotron radiation modes are observed in the machine performance. In this paper, some observations and analyses on these phenomena are given.  
 
WEPC062 The SRS at Daresbury Laboratory: a Eulogy to the World's First Dedicated High-energy Synchrotron Radiation Source storage-ring, lattice, wiggler, electron 2133
 
  • D. J. Holder, N. G. Wyles
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. D. Quinn
    STFC/DL/SRD, Daresbury, Warrington, Cheshire
  2008 marks the last year of operation of the Synchrotron Radiation Source (SRS) at Daresbury Laboratory, which circulated its first 2 GeV beam in 1981. This paper provides a look back at the significant milestones passed on the way and records the achievements of many of those involved in its thirty-year programme. Many of the technologies and techniques developed at the SRS at Daresbury are now standard practice at synchrotron light sources around the world; and there are few light source laboratories that do not benefit from the skills of someone who spent their formative years working on the SRS. The provision of synchrotron light for the UK is now being met by DIAMOND, whose success is a testament to the skills of its designers, honed as they were on the SRS at Daresbury. These skills are now being used to design the UK’s next-generation light source, to provide the pulsed and longer-wavelength light that DIAMOND cannot.  
 
WEPC063 The Concept of Hefei Advanced Light Source (HALS) emittance, radiation, storage-ring, synchrotron-radiation 2136
 
  • L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  The Hefei Light Source is a dedicated VUV and soft X-ray light source. The layout of magnet lattice limits the achievalbe beam emittance and available straight section for insertion device. To enhance competitiveness of National Synchrotron Radiation Laboratory in synchrotron radiation application research region, a concept of new dedicated VUV and soft X-ray synchrotron radiation light source was put forward, which is named Hefei Advanced Light Source. Comparing the advantages, difficulties and performance/foundation of energy recovery linac, linac-based free electron laser and storage ring based light source, the scheme of a 1.5GeV storage ring with very low beam emittance was adopted as the baseline design. At same time, a low emittance 1.5 GeV linac would be as its full-energy injector, which can provide ultra-short radiation pulse. The HALS would provide more brilliant and transverse coherent synchrotron radiation in the VUV and soft X-ray range to various users.  
 
WEPC064 The Possibility of Conversion of Hefei Light Source Storage Ring Into a Dedicated THz Radiation Source radiation, synchrotron-radiation, storage-ring, collective-effects 2139
 
  • L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  In the future of National Synchrotron Radiation Laboratory, a new advanced VUV and soft X-ray light source would be contructed and provide synchrotron radiation with high brilliance and transverse coherence. At that time, the current HLS storage ring would be replaced by the new one. Instead of retire of the old ring, there is another case, that is upgrading current low energy storage ring as a dedicated THz light source. In this paper, the possibility of lattice upgrading were evaluated. And its performance was estimated according to exist theoretical model.  
 
WEPC076 Remote Tilt-control System of Injection Bump Magnet in the SPring-8 Storage Ring injection, synchrotron-radiation, coupling, radiation 2172
 
  • K. Fukami, C. Mitsuda, M. Oishi, M. Shoji, K. Soutome, H. Yonehara, C. Zhang
    JASRI/SPring-8, Hyogo-ken
  • M. Hasegawa, T. Nakanishi
    SES, Hyogo-pref.
  • T. Ohshima
    RIKEN/SPring-8, Hyogo
  The SPring-8 storage ring has four pulse-bump magnets to generate bump orbit for beam injection. Rotational error of the bump magnets around a beam-axis (tilt) induces the stored-beam oscillation in vertical direction due to horizontal error field. In the top-up operation, vertical perturbation of the stored-beam during beam injection is mainly produced by the tilt. We evaluated the tilt angle by measuring of the perturbation turn-by-turn using a single-pass BPM system and realigned bump magnets manually inside the accelerator tunnel. It was required to repeat the measurement and realignment processes two or three times for convergence. To correct the tilts smoothly, we developed a remote tilt-control system. The system consists of two fixed and one movable supports in vertical direction under each bump magnets. The movable support is driven by a stepper motor through 1/30 worm gear in the range of ±4 mrad with the accuracy of less than 0.1 mrad. By using this system, we succeeded complete on-beam reduction of the perturbation.  
 
WEPC082 Technical Considerations of the TPS Linac linac, electron, controls, bunching 2186
 
  • A. P. Lee, H.-P. Chang, J. Chen, C.-S. Fann, K. T. Hsu, S. Y. Hsu, W. K. Lau, K.-K. Lin, K.-B. Liu, Y.-C. Liu, C. Y. Wu
    NSRRC, Hsinchu
  The technical considerations of the TPS (Taiwan Photon Source) linac will be presented in this report. A 150 MeV turn-key linac is chosen in this case in order to provide the ease of injection into the booster in which the electron energy will be raised up to 3 GeV. This linac will be similar to that equipping at recently commissioned synchrotron light sources. The major beam parameters are derived from the booster and storage ring injection requirements. The beam diagnostics arrangement for linac commissioning purpose will be briefly described.  
 
WEPC103 Design of a Cold Vacuum Chamber for Diagnostics electron, vacuum, diagnostics, storage-ring 2240
 
  • S. Casalbuoni, T. Baumbach, A. W. Grau, M. Hagelstein, R. Rossmanith
    FZK, Karlsruhe
  • V. Baglin, B. Jenninger
    CERN, Geneva
  • R. Cimino
    INFN/LNF, Frascati (Roma)
  • M. P. Cox
    Diamond, Oxfordshire
  • E. M. Mashkina
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  • E. J. Wallén
    MAX-lab, Lund
  • R. Weigel
    Max-Planck Institute for Metal Research, Stuttgart
  Preliminary studies performed with the cold bore superconducting undulator installed in the ANKA storage ring suggest that the beam heat load is mainly due to the electron wall bombardment. Low energy electrons (few eV) are accelerated by the electric field of the beam to the wall of the vacuum chamber, induce non-thermal outgassing from the cryogenic surface and heat the undulator. In this contribution we report on the design of a cold vacuum chamber for diagnostics to be installed in the ANKA (ANgstrom source KArlsruhe) storage ring and possibly in third generation light sources. The diagnostics implemented are:
  1. retarding field analyzers to measure the electron energy and flux,
  2. temperature sensors to measure the total heat load,
  3. pressure gauges,
  4. and a mass spectrometer to measure the gas content.
The aim of this device is to gain a deeper understanding on the heat load mechanisms to a cold vacuum chamber in a storage ring and find effective remedies. The outcome of the study is of relevance for the design and operation of cold bore superconducting insertion devices in synchrotron light sources. 		 
 
WEPC110 Development of a Conventional Multipole Wiggler MPW-80 wiggler, multipole, power-supply, electron 2258
 
  • D. J. Waterman, A. Deyhim, J. Kulesza, E. Van Every
    Advanced Design Consulting, Inc, Lansing, New York
  • K. I. Blomqvist
    MAX-lab, Lund
  The design for an 80 mm period hybrid wiggler is presented. The design requirements and mechanical difficulties for holding, positioning, and driving the magnetic arrays are explored. The structural and finite element analysis, magnetic design, and electrical considerations that influenced the design are then analyzed. This wiggler will be installed at ALBA a new synchrotron radiation source being built at the site of the Centre Direccional in Cerdanyola del Vallès, nearby Barcelona, and will produce ultra-violet and X-ray beams of exceptional brightness. The facility will comprise a 3 GeV electron storage ring, injected from a ~100 MeV linac through a full energy booster synchrotron.  
 
WEPC111 Latest Progress in Insertion Devices at ACCEL Instruments undulator, insertion, insertion-device, alignment 2261
 
  • D. Doelling, B. Fischer, A. Hobl, P. A. Komorowski, D. Krischel, M. Meyer-Reumers, H. Vogel
    ACCEL, Bergisch Gladbach
  ACCEL Instruments GmbH has designed, manufactured, and tested several insertion devices for synchrotron light sources and free electron lasers around the world. ACCEL has been awarded for the construction of two In – Vacuum – Undulators for the ALBA/CELLS synchrotron light source in Barcelona, Spain. The design originates from the standard ESRF IVU based on the license agreement with their ID group. The status of the design work will be summarized. Also ACCEL is manufacturing two granite measurement benches for the FERMI project at Elettra in Trieste, Italy. Both benches are designed to characterize insertion devices in a fast and accurate way. A summary of the commissioning results will be presented. A full functional prototype Hybrid Undulator for the European X-FEL project in Hamburg was delivered successfully and, as the first device, in full compliance with the technical specification. Also the industrial study requested by DESY for the adaptation of the design towards a large series production of 5m long undulators for the European X-FEL, was completed as the first one in full compliance with the DESY specification and the basic conclusions are presented.  
 
WEPC113 Heat Load Issues of Superconducting Undulator Operated at TPS Storage Ring radiation, undulator, storage-ring, synchrotron-radiation 2267
 
  • C.-S. Hwang, J. C. Jan, P. H. Lin
    NSRRC, Hsinchu
  The superconducting undulator with periodic length of 1.5 cm and magnet gap of 5.6 mm has been studied. The magnetic flux density of 1.4 T has been achieved. However, the heat loads from image current of the electron in the storage ring and the synchrotron radiation from bending magnet are the critical issues. The calculated power from the image current and the synchrotron radiation of bending magnet are about 3.5 W/m and 1.7 W, respectively. The superconducting undulator will be operated at the 3 GeV TPS storage ring that the operation current and the magnet flux density of dipole magnet is 400 mA and 1.19 T, respectively. The superconducting RF cavity will be installed in the TPS such that the bunch length is only 2.8 mm. Hence, the superconducting Landau cavity is necessary to extend the bunch length for reducing the heat load on the beam duct. In addition, some strategies are needed to be studied to avoid the synchrotron radiation heating on the 4.2 K vacuum chamber. The soft-end dipole design and the chicane mechanism are studied to solve the issue herein.  
 
WEPC114 Improved Winding of Superconducting Undulator and Measurement of Quenching Tolerance radiation, undulator, synchrotron-radiation, storage-ring 2270
 
  • J. C. Jan, C.-H. Chang, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  The superconducting (SC) wire windings of the mini-pole superconducting undulator at National Synchrotron Radiation Research Center (NSRRC) have an improved performance. A precise measurement of the magnetic field was undertaken to examine the quality of the wire winding. We improved the insulation between wires and the iron pole to avoid SC wire degradation when the coil was trained up to high current. A Teflon coating (layer thickness 0.035-0.045 mm) on the iron pole is capable of providing insulation to 0.5 kV. We pasted extra Teflon tape (thickness 0.12 mm) on the coating layer; this Teflon tape serves as a buffer that avoids the SC wires scraping the Teflon coating layer during adjustment of the position of the SC wire during winding. A quenching experiment was also performed to detect the heat tolerance of the SC wires during extra heating of the beam duct; a heating tape (Ni80Cr20) simulated the heating of the beam duct by synchrotron radiation. The SC wires and heater are separated by the stainless steel (SS) beam duct (thickness 0.3 mm) and an epoxy layer (thickness 0.1 mm). This result is an important issue in cryostat design.  
 
WEPC121 Magnetic Measurement Device for Superconductive Undulator Mock-up Coils at ANKA undulator, vacuum, electron, superconductivity 2291
 
  • E. M. Mashkina, B. K. Kostka, E. Steffens
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  • T. Baumbach, A. Bernhard, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • S. Casalbuoni, A. W. Grau, M. Hagelstein, R. Rossmanith
    FZK, Karlsruhe
  A device for precise magnetic measurements of superconductive coils was designed, built and installed at the synchrotron radiation source ANKA, Forschungszentrum Karlsruhe. Accurate magnetic field measurements are a prerequisite for the characterization and optimization of insertion devices. The new device allows measuring the magnetic field magnitude of test coils with a longitudinal precision of 10 μm using a 2D Hall probe bench. The cylindrical liquid He cryostat allows mounting coils of maximum dimensions 50 cm in length and 30 cm in diameter. The set-up is computer controlled. The contribution will present the new device as well as the results obtained.  
 
WEPC125 Development of Three New Superconducting Insertion Devices for the ANKA Storage Ring undulator, wiggler, insertion, insertion-device 2300
 
  • R. Rossmanith, S. Casalbuoni, A. W. Grau, M. Hagelstein
    FZK, Karlsruhe
  • T. Baumbach, A. Bernhard, P. Peiffer, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • C. Boffo, M. Borlein, W. Walter
    BNG, Würzburg
  • B. K. Kostka, E. M. Mashkina, E. Steffens
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  After a first successful test of a superconductive cold bore undulator in ANKA a new generation of superconductive insertion devices is under construction or in a detailed planning phase. The first one, referred to as as SCU14 and now under construction, is an improved version of the existing undulator (14 mm period length, 100 periods long) with a new cooling scheme for small gap operation and a reduced field error. The period length of the second device called SCUW can be switched electrically between 15 and 45 mm. The third one is a superconductive undulator which can tolerate a beam heat load of several Watts in combination with a small field error named SCU2. It is designed for third generation light sources with a heat load of up to 6 Watt from the beam to the cold bore.  
 
WEPC128 SPUR: A New Code for the Calculation of Synchrotron Radiation from Very Long Undulator Systems undulator, radiation, electron, synchrotron-radiation 2305
 
  • N. C. Ryder, D. J. Scott
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • S. Reiche
    UCLA, Los Angeles, California
  The accurate calculation of synchrotron radiation from an undulator is a common problem and numerous codes have been developed that describe analytic and measured fields. However, for very long undulator systems, comprising of many individual modules and total lengths in excess of 100s of meters, for example as found in the LCLS, X-FEL, the ILC positron source undulator systems, there is not a suitable code that can handle the amount of data in a convenient manner and which runs in a practically realisable time limit. The development of a new code, SPontaneous Undulator Radiation, SPUR, is presented which computes the spontaneous radiation from electron beams passing through a system of undulators. The code supports parallel architecture, and uses the HDF5 technology to efficiently handle the multi-dimensional data. The latest results developments and benchmarking are presented.  
 
WEPC138 Transient Electromagnetic Analysis and Thermal Design on the Magnet of 3-GeV Synchrotron magnet-design, proton, quadrupole, linac 2332
 
  • M. Abe, S. Tounos
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • T. Adachi
    KEK, Ibaraki
  • Y. Chida
    Hitachi Ltd., Ibaraki-ken
  • K. Nakamura, T. Watanabe
    Hitachi. Ltd., Hitachi Works, Hitachi-shi
  • T. Takayanagi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • N. Tani
    JAEA/LINAC, Ibaraki-ken
  J-PARC 3GeV synchrotron is operated at 25Hz alternatively, which can generate eddy currents and heat. They can disturb continuous operations. We prepared a design technique to analyze them and manage the temperature rises of the magnets. Eddy current and hysteresis heat generations were calculated with 3D models then temperature rises were evaluated with natural convection cooling from surfaces. The technique was applied on the dipole, quadrupole and bump magnets. Slits on intense eddy current position can decrease the heat generation, however deep slits can disturb magnetic field distribution. Their depth and positions were optimized for the temperature rise reduction. So far, the synchrotron operation is fair with reasonable temperature rises.  
 
WEPC152 Magnet Block Optimization of the APPLE-II Elliptically Polarized Undulator polarization, undulator, radiation, synchrotron-radiation 2362
 
  • T. Wang, Q. K. Jia
    USTC/NSRL, Hefei, Anhui
  The uniform field region of elliptically polarized undulator (EPU) of APPLE-II type is very short especially in the horizonta axis. The magnet block arrangements with a approximately parabolic pole face or of APPLE-II undulator can enlarge the horizontal field roll-off and shorten the vertical field roll-off. We studied the dfferent shapes to expect a optimizaed horizotal and vertical field roll-off.  
 
WEPC161 Some Remarks about Characterization of Magnetic Blocks with Helmholtz Coil dipole, insertion, insertion-device, induction 2386
 
  • G. Tosin, R. A. Pimenta
    LNLS, Campinas
  The use of Helmholtz coils for magnetic block characterization is a widespread technique because of its small sensitivity to block positioning errors and high precision. In this paper we present some calculations related to the influence of block positioning for the cases where the Helmholtz condition is not exactly satisfied. Also the comparison between a model based on point dipolar magnetic moment and magnetized blocks with real dimensions is analyzed, as well as the corrections associated to the effect of self-demagnetization of the blocks.  
 
WEPD011 Development Work for a Short Curved Superconducting Dipole Magnet for the HESR at FAIR dipole, storage-ring, antiproton, lattice 2425
 
  • F. M. Esser, R. Greven, G. Hansen, F. Klehr, J. Schillings, H. Soltner, R. Tölle
    FZJ, Jülich
  Forschungszentrum Juelich has taken the leadership of a consortium being responsible for the design of the High-Energy Storage Ring (HESR) going to be part of the FAIR project at GSI. Within these activities a design for a short cosine-theta superconducting dipole has been carried out together with industry partners. Its length will be approximately one third of the original HESR dipole whereas all other design parameter will be the same. The main design criterion is the short bending radius of 15.3 m of the magnet implying that the coil itself has a curved shape. Beside the geometrical design of the cold mass, this paper will focus particularly on the finite element calculations from the assembly through the cool down to the operating temperature of the magnet. First manufacturing tests as well as a status report on the achievements so far will be presented and future plans will be discussed.  
 
WEPD017 Full Size Prototype Magnets for Heavy Ion Superconducting Synchrotron SIS100 at GSI: Status of Manufacturing and Test at JINR dipole, quadrupole, ion, antiproton 2443
 
  • A. D. Kovalenko, N. N. Agapov, A. V. Alfeev, A. V. Bychkov, A. V. Gromov, H. G. Khodzhibagiyan, G. L. Kuznetsov, A. Y. Starikov
    JINR, Dubna, Moscow Region
  • E. S. Fischer, G. Moritz, P. J. Spiller
    GSI, Darmstadt
  • A. V. Shabunov
    JINR/LHE, Moscow
  The SIS100 synchrotron is designed for acceleration of high intensity beams with a pulse repetition rate of 1 Hz. The use of superferric Nuclotron-type dipoles, quadrupoles and corrector magnets is planned in the accelerator magnetic system. The magnet coils are made of hollow NbTi composite cable cooled with two-phase helium flow at 4.5 K. The lattice comprises 108 dipoles, 168 quadrupoles and necessary set of steerer and multipole corrector magnets. We present recent results from the design and optimization of the SIS100 magnetic elements parameters. The status of manufacturing full size prototypes is presented. The essential features of the magnets production and the new test results are discussed.  
 
WEPD021 Magnetic Field Characteristics of a SIS 100 Full Size Dipole vacuum, multipole, dipole, injection 2452
 
  • P. Schnizer, E. S. Fischer
    GSI, Darmstadt
  • P. G. Akishin
    JINR, Dubna, Moscow Region
  • R. V. Kurnyshov
    Electroplant, Moscow
  • B. Schnizer
    TUG/ITP, Graz
  • P. A. Shcherbakov
    IHEP Protvino, Protvino, Moscow Region
  • G. Sikler, W. Walter
    BNG, Würzburg
  FAIR will feature two superconducting fast ramped synchrotrons. The dipole magnets for one of them, SIS 100, have been designed and prototypes were built. The properties of the magnetic field were analysed using OPERA (for DC operation) and ANSYS for dynamic calculations. Elliptic multipoles fulfilling the Laplace Equation in plane elliptic coordinates describe the field within the whole aperture consistently within a single expansion. Further circular multipoles, valid within the ellipse, can be calculated analytically from the elliptic multipoles. The advantage of this data representation is illustrated on the FEM calculation performed for SIS 100 dipoles and quadrupoles currently foreseen for the machine. The magnetic field of one of these prototypes was measured using a mole. We compare the results of the calculation to the measurement for the static as well as the dynamic mode.  
 
WEPD039 Evolution of the Standard Helium Liquefier and Refrigerator Range designed by Air Liquide DTA, France cryogenics, controls, neutral-beams, simulation 2497
 
  • S. Crispel, G. Aigouy, A. Caillaud, F. Delcayre, V. Grabie
    Air Liquide, Division Techniques Avancées, Sassenage
  The standard helium liquefier and refrigerator range, called HELIAL, designed by Air Liquide DTA, has been upgraded with significant improvement of efficiency as a result of technological development.. Indeed in the demanding high tech markets, (international laboratories, aerospace applications, synchrotrons, HTS applications…), cryogenic systems must provide increasingly high performances. The new HELIAL Evolution is equipped with Air Liquide's expansion turbines, well known for their extremely high reliability and efficiency,. The results of this development endowing the HELIAL Evolution with twice liquefaction capacity, are presented in this paper.  
 
WEPD041 Continuous Operation of Cryogenic System for Synchrotron Light Source cryogenics, controls, superconducting-magnet, storage-ring 2503
 
  • F. Z. Hsiao, S.-H. Chang, W.-S. Chiou, H. C. Li, H. H. Tsai
    NSRRC, Hsinchu
  The availability of user time is an important index for the performance evaluation of a synchrotron light source. In NSRRC two cryogenic plants are installed for liquid helium supply to the superconducting magnets and the superconducting cavity of the electron storage ring. As a subsystem of the storage ring, the objective of continuous helium supply without interruption is important for the cryogenic plant. The target to shorten the recovery time of the storage ring, if the cryogenic plant trips, is another issue. Component failure and system maintenance are two main reasons interrupting operation of the cryogenic plant. This paper shows our strategy on the scheduled maintenance of either the cryogenic plant or the utility system to keep continuous liquid helium supply. Two tests to shorten the recovery time are presented: the first is liquid helium supply from both cryogenic plants simultaneously; the second is restarting the on-duty cryogenic plant with the other dewar providing helium to the superconducting devices.  
 
WEPD042 Development of a Simulation Module for the Cryogenic System cryogenics, simulation, controls, superconducting-magnet 2506
 
  • H. C. Li, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H. H. Tsai
    NSRRC, Hsinchu
  In NSRRC two 450W cryogenic systems were installed on the year 2002 and 2006, respectively. After long time operation some behavior and setting parameters of the cryogenic system did not satisfy our requirement because of the deterioration of electrical sensors and valves. To ask the manufacturer to solve those problems, it took lots of time in the communication of problem description and the modification of control program. A simulation module for the cryogenic system is thus developed to trace the procedure before and after modification of the control program. This paper details the simulation module and shows the usefulness of this module on evaluation of the software modification for cryogenic system.  
 
WEPD044 Efficiency Analysis for the Cryogenic System at NSRRC cryogenics, simulation, superconducting-magnet, controls 2512
 
  • H. H. Tsai, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H. C. Li
    NSRRC, Hsinchu
  Three superconducting magnets and one superconducting cavity for RF are cooled by two 450W liquid helium system at NSRRC. These two systems were made up of Claude cycle which is usually compared in their performance to that of the ideal Carnot cycle. This paper presents the efficiency analysis for the cryogenic system. Based on the analysis, the power transfer to the process change for the operation will be performed. In addition, it also shows the way to identify the problems when done the trouble shooting for part of erratic response of the plant. The carnot efficiency also provides an important index of the performance, especially when we done the process control.  
 
WEPD045 Hydrogen Cryosorption on Multi Walled Carbon Nanotubes vacuum, collider, cryogenics, background 2515
 
  • F. Xu, M. Barberio, P. Barone, A. Oliva, L. Papagno, V. Pirronello, R. Vasta
    INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza)
  We present a Temperature Programmed Desorption (TPD) study on H2 adsorption on multiwalled carbon nanotubes (MWNT) at very low pressure (< 10-6 Torr) and temperature (12-30 K). Our results show a hydrogen take up limit in the range of 10-8 mol per gram depending on the adsorption temperature. We compare the MWNT cryosorption capacity with that of commonly used activated carbon and discuss the possibility of employing MWNT as cryosorber in large particle accelerators.  
 
WEPP001 Energy Loss of Coasting Gold Ions and Deutrons in RHIC radiation, synchrotron-radiation, ion, impedance 2518
 
  • N. P. Abreu, M. Blaskiewicz, K. A. Brown, J. J. Butler, W. Fischer, M. Harvey, S. Tepikian
    BNL, Upton, Long Island, New York
  • H. Burkhardt
    CERN, Geneva
  The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.  
 
WEPP037 Independent Component Analysis of Tevatron Turn-by-turn BPM Measurements betatron, collider, optics, extraction 2602
 
  • A. V. Petrenko
    BINP SB RAS, Novosibirsk
  • V. A. Lebedev, A. Valishev
    Fermilab, Batavia, Illinois
  Transverse dipole coherent beam oscillations in the Tevatron were analyzed with different independent component analysis algorithms. This allowed to obtain the model-independent values of coupled beta-functions as well as betatron phase advance and dispersion along the ring from a single kick measurement. Using a 1-turn shift of turn-by-turn BPM readings for virtual doubling of the number of BPMs it is also possible to measure the fractional part of betatron tunes with high accuracy. Good agreement with the linear optical model of the Tevatron was observed.  
 
WEPP044 Commissioning the 90° Lattice for the PEP II High Energy Ring lattice, luminosity, insertion, emittance 2617
 
  • W. Wittmer, Y. Cai, W. X. Cheng, W. S. Colocho, F.-J. Decker, S. Ecklund, A. S. Fisher, Y. Nosochkov, A. Novokhatski, M. K. Sullivan, U. Wienands, Y. T. Yan, G. Yocky
    SLAC, Menlo Park, California
  In order to benefit from further reduction of the vertical IP beta function of the PEP-II HER the bunch length should be reduced. This will be achieved by changing the phase advance from 60 deg to 90 deg in the four arcs not adjacent to the IR region, thus reducing momentum compaction by about 30% and reducing bunch length from a present 12 mm down to 8.5 mm at low beam current. In preparation to implement the 90 deg lattice the main HER quadrupole and sextupole strings and their power supplies have been reconfigured. Compared to the 60 deg lattice it was expected that dynamic aperture and injection will be more difficult. The synchrotron tune initially will be lower but can be brought back by raising the rf voltage. Beam emittance is held at 48 nmr by introducing a significant dispersion beat in the arcs. The lattice was successfully commissioned at currents up to 800mA in August 2007. In this paper we will compare the actual machine with the predicted behaviour, explain the correction strategies used and give an overall assessment of the operation and the benefit of the new lattice configuration.  
 
WEPP063 R-matrices of the Fast Beam Extraction Section of AGS extraction, kicker, quadrupole, optics 2662
 
  • N. Tsoupas, L. Ahrens, J. W. Glenn, W. W. MacKay, T. Satogata
    BNL, Upton, Long Island, New York
  The Fast Beam Extraction (FEB) system of the Alternating Gradient synchrotron (AGS) extracts the beam bunches from AGS into the AGS-to-RHIC (AtR) beam transfer line, and the extracted bunches are injected into the Relativistic Heavy Ion Collider (RHIC) synchrotron. In a particular section of the beam extraction line the beam bunches are transported through the fringe field region of three main AGS magnets. Optical characteristics of this section change with trajectory and momentum. Therefore the calculation of the R-matrices in this part of the extraction line requires special attention. To describe accurately the R-matrices, the magnetic field of the AGS main magnets was measured on the median plane of the AGS magnet in both, the circulating beam region and the fringe field region, where the extracted beam is transported. Using these magnetic field maps we describe the procedure we use to calculate the R-matrices at the beam extraction region. These R-matrices are used to calculate the beam parameters at the starting point of the AtR beam transfer line and the required quadrupole settings to match to RHIC’s acceptance.  
 
WEPP073 Simulation Studies of Impact of SPS Beam with Collimator Materials target, proton, simulation, single-bunch 2689
 
  • N. A. Tahir
    GSI, Darmstadt
  • R. W. Assmann, M. Brugger, R. Schmidt
    CERN, Geneva
  • V. E. Fortov, I. Lomonosov, A. Shutov
    IPCP, Chernogolovka, Moscow region
  • D. Hoffmann
    TU Darmstadt, Darmstadt
  • R. Piriz
    Universidad de Castilla-La Mancha, Ciudad Real
  Over the past years detailed simulations were carried out to study the impact of the full LHC 7 TeV beam on a target to assess the damage caused to the equipment as a result of an accident, especially to collimators and beam absorbers, and to estimate the thickness of a sacrificial absorber that would be required to stop the beam. This study has shown that the target material will be strongly heated by the beam and transformed into plasma. It has been estimated that the beam would tunnel up to 30 m in solid copper and to about 10 m in solid carbon*. Another interesting outcome of this study was that the LHC beam could be used as a tool to study High-Energy-Density (HED) states in matter. Using the same tools, we recently studied the impact of the SPS 450 GeV proton beam on tungsten and copper targets**. It has been found that the material will be seriously damaged and some tunneling of the beam into the target is expected. It should be possible to validate the predictions with a test facility to deflect the high energy high intensity SPS beam on collimator and absorber materials that will become operational in the next years.

*N. A. Tahir et al. J. Appl. Phys. 97 (2005) 083532.
*N. A. Tahir et al. Laser Part. Beams 25 (2007) 639.

 
 
WEPP124 The Status of Turkish Accelerator Complex Project factory, linac, electron, positron 2788
 
  • A. Aksoy, Ö. Karsli, B. Ketenoglu, O. Yavas
    Ankara University, Faculty of Engineering, Tandogan, Ankara
  • A. K. Ciftci
    Ankara University, Faculty of Sciences, Tandogan/Ankara
  • S. Sultansoy
    TOBB ETU, Ankara
  The Turkish Accelerator Complex (TAC) is proposed as a regional facility for accelerator based fundamental and applied research in 1997 with support of Turkish State Planning Organization (DPT). The feasibility and conceptual design phases of TAC proposal were completed in 2001 and 2005, respectively. Again with support of DPT, the technical design phase of TAC was started at the beginning of 2006. The complex will include 1 GeV electron linac and 3.56 GeV positron ring for linac on ring type electron-positron collider as a charm factory and a few GeV proton linac. Besides the particle factory, it is also planned to produce SASE FEL from electron linac and synchrotron radiation from positron ring. It is planed that the TDR of TAC Project will be completed in 2011 and the construction will be performed during following ten years .  
 
WEPP129 Digital Acceleration Scheme of the KEK All-ion Accelerator acceleration, induction, ion, controls 2797
 
  • T. S. Dixit
    GUAS/AS, Ibaraki
  • Y. Arakida, T. Iwashita, K. Takayama
    KEK, Ibaraki
  R&D works to realize an all-ion accelerator (AIA)*-capable of accelerating all ions of any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006 **, is going on. In the induction synchrotron, unlike an RF synchrotron, operational performance is not limited due to the frequency band-width, since the switching power supply to energize the induction acceleration system is triggered by signals obtained from the bunch monitor. For a POP experiment of AIA, argon ions will be accelerated in the KEK-500 MeV booster ring, a Rapid Cycle Synchrotron (f=20 Hz) and the RCS requires a dynamic change in the acceleration voltage. Since the induction acceleration voltage per pulse is fixed, a novel technique combining the pulse density control and intermittent operation of multi-acceleration cells has been proposed. The acceleration scheme of the AIA fully employing this technique was verified by computer simulation and demonstrated at our test facility, where a new induction acceleration cell generating an acceleration voltage pulse of 2 μsec long was triggered by a beam simulator to mimic a circulating Ar beam in the KEK-AIA

* K. Takayama, Y. Arakida, T. Iwashita, Y. Shimosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).

 
 
WEPP158 Simulation of beam Halo in CLIC Collimation Systems simulation, collimation, synchrotron-radiation, radiation 2859
 
  • G. A. Blair, S. Malton
    Royal Holloway, University of London, Surrey
  • I. V. Agapov, A. Latina, D. Schulte
    CERN, Geneva
  Full simulation of the CLIC and ILC collimation systems are performed to take account of collimator wakefield effects from the core beam on the halo. In addition full simulation of the interaction of the halo with the collimator material is performed to study the effect of multiple scattering and also the production of neutrons in the electromagnetic showers. The effect of beam-gas scattering downstream of the collimators is also included.  
 
THXG03 Upgrades to ISIS for the New Second Target Station target, proton, extraction, septum 2902
 
  • J. W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  The new ISIS Second Target Station (TS-2) represents a major enhancement of the capabilities of the successful ISIS spallation neutron source, and correspondingly major enhancements have had to be made to the accelerator systems. As well as providing an outline of the new target station itself, the talk will describe the new dual harmonic RF system for the ISIS synchrotron which significantly increases the accelerated beam current to meet the needs of TS-2, and also the new proton beam transport line which diverts one out of every five pulses from the synchrotron to TS-2. In addition, the talk will summarise the substantial upgrades that have had to be made elsewhere on the ISIS accelerator system to underpin operation for at least another fifteen years, and will address possible future upgrades.  
slides icon Slides  
 
THPC013 Start to End Simulations of Transverse to Longitudinal Emittance Exchange at the A0 Photoinjector emittance, simulation, radiation, space-charge 3002
 
  • R. P. Fliller, H. T. Edwards, J. Ruan
    Fermilab, Batavia, Illinois
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  Various schemes to exchange the transverse and longitudinal emittance have been proposed (Cornacchia and Emma, Kim et.al). One scheme involves a deflecting mode RF cavity between two doglegs to exchange the horizontal and longitudinal emittances. This will produce a complete and uncoupled emittance exchange in the thin cavity limit using first order matrix optics. Various other effects, such as a finite length cavity, can leave the emittances coupled after the exchange and dilute the final emittances. Other effects such as space charge and synchrotron radiation can only be investigated through simulations. An exchange experiment is underway at the A0 Photoinjector at Fermilab. In this paper we present start to end simulations of the experiment using various codes to account for space charge and Coherent Synchrotron Radiation effects. Astra is used to simulate all of the straight sections, including the deflecting mode RF cavity. CSR track simulates the doglegs, and the spectrometer. The results of these simulations are compared with analytical approximations and preliminary data. The effect on the exchange is also discussed.  
 
THPC014 Investigation of Possible CSR Induced Energy Spread Effects with the A0 Photoinjector Bunch Compressor simulation, radiation, emittance, electron 3005
 
  • R. P. Fliller, H. T. Edwards, G. M. Kazakevich, J. Ruan, R. Thurman-Keup
    Fermilab, Batavia, Illinois
  • T. W. Koeth
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  The bunch compressor of the A0 Photoinjector at Fermilab was removed this past spring to install a transverse to longitudinal emittance exchange experiment. Prior to its removal questions arose about the possibility of observing the effects of Coherent Synchrotron Radiation on the compressed beam. The energy spread of the beam with and without compression was measured to observe any changes. Various beam charges were used to look for square law effects associated with CSR. No direct observation of CSR was attempted because the design of the vacuum chamber did not allow it. In this paper we report the results of these experiments and comparison with simulations using ASTRA and CSRTrack. The results are compared with analytical approximations. The implications for the ongoing transverse to longitudinal emittance exchange experiment are discussed.  
 
THPC044 Accurate Calculation of Higher Order Momentum Compaction Factor in a Small Ring storage-ring, sextupole, radiation, synchrotron-radiation 3074
 
  • L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  The key issues to obtain short beam bunch in storage ring is to lowering momentum compaction factor. When the linear momentum compaction factor is small, higher order momentum compaction factor can produce significant effects in the longitudinal beam dynamics. In the small storage ring, higher order momentum comaction factor is determined not only by sextupoles, and also by the fringe field of main magnets. In this paper, the higher order momentum factor formula including the effects of fringe field is deduced. As a example, the momentum compaction factor of HLS storage ring was calculated.  
 
THPC050 Experimental Evidence of Beam Trapping with One-third and One-fifth Resonance Crossing resonance, octupole, proton, sextupole 3092
 
  • S. S. Gilardoni, F. Franchi, M. Giovannozzi
    CERN, Geneva
  Beam trapping in stable islands of the horizontal phase space generated by non-linear magnetic fields is realized by means of a given tune variation so to cross a resonance of order n. Whenever the resonance is stable, n+1 beamlets are created whereas if the resonance is unstable, the beam is split in n parts. Experiments at the CERN Proton Synchrotron showed protons trapped in stable islands while crossing the one-third and one-fifth resonance with the creation of 3 and 6 stable beamlets, respectively. The results are presented and discussed in details.  
 
THPC051 Adiabaticity and Reversibility Studies for Beam Splitting Using Stable Resonances resonance, coupling, emittance, proton 3095
 
  • S. S. Gilardoni, F. Franchi, M. Giovannozzi
    CERN, Geneva
  At the CERN Proton Synchrotron, a series of beam experiments proved beam splitting by crossing the one-fourth resonance. Depending on the speed at which the horizontal resonance is crossed, the splitting process is more or less adiabatic, and a different fraction of the initial beam is trapped in the islands. Experiments prove that when the trapping process is reversed and the islands merged together, the final distribution features thick tails. The beam population in such tails is correlated to the speed of the resonance crossing and to the fraction of the beam trapped in the stable islands. Experiments, simulations, and possible theoretical explanations are discussed.  
 
THPC056 Stability Change of Fourth-order Resonance with Application to Multi-turn Extraction Schemes resonance, extraction, simulation, emittance 3110
 
  • M. Giovannozzi, D. Quatraro
    CERN, Geneva
  • G. Turchetti
    Bologna University, Bologna
  Recently, a novel multi-turn extraction scheme was proposed, based on particle trapping inside stable resonances. Numerical simulations and experimental tests confirmed the feasibility of such a scheme for low order resonances. While the 3rd order resonance is generically unstable and those higher than 4th order are generically stable, the 4th order resonance can be either stable or unstable depending on the details of the system under consideration. By means of the normal form approach a general formula to control the stability of the 4th order resonance is derived. Numerical simulations confirm the analytical results and show that by crossing the unstable 4th order resonance the region around the centre of phase space is depleted and particles are trapped only in the four stable islands. This indicates that a four-turn extraction could be envisaged based on this technique.  
 
THPC058 High Order Super-periodic Structural Resonances resonance, lattice, storage-ring, synchrotron-radiation 3116
 
  • Y. Jiao, S. X. Fang, J. Q. Wang
    IHEP Beijing, Beijing
  High order super-periodic structural resonances, which arise from the study of SSRF lattice optimization, are found to have large effects on beam dynamics. The mechanism and feature of this kind of resonances are described in the text. The limit to beam dynamics of other light sources are also found from these resonances.  
 
THPC086 Transverse Mismatch Oscillations of a Bunched Beam in Presence of Space Charge and External Nonlinearities emittance, simulation, lattice, space-charge 3188
 
  • C. Benedetti, G. Turchetti
    Bologna University, Bologna
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  The damping of transverse mismatch oscillations depends on the combined effect of space charge as well as external nonlinearities. Previous studies of this problem for high intensity beams in a synchrotron have not included the combined effect of synchrotron oscillation and external nonlinearities on mismatch. In this paper we explore by 2.5D particle in cell simulations the effect on emittance growth, halo and beam loss caused by space charge, synchrotron oscillation and external nonlinearities. Different tunes are considered in order to understand the importance of external nonlinearities as function of the distance of the working point from the resonance condition.  
 
THPC101 Transverse Schottky Noise and Beam Transfer Functions with Space Charge space-charge, ion, emittance, heavy-ion 3212
 
  • S. Paret, O. Boine-Frankenheim, V. Kornilov
    GSI, Darmstadt
  • T. Weiland
    TEMF, Darmstadt
  The heavy ion synchrotron SIS18 will serve as booster for the synchrotron SIS100 to be built as part of the Facility for Antiproton and Ion Research (FAIR). As such the SIS18 should accelerate ion beams with a factor of 10-100 higher intensity, compared to the present performance. Beams of such intensities may suffer instabilities due to collective effects. Particularly at injection-energy space charge and the resistive wall impedance will affect the beam remarkably. Experiments for the investigation of direct space charge were performed in SIS18. Transverse Schottky signals and beam transfer functions (BTF) of coasting ion beams affected by space charge were measured. A distortion of the Schottky bands and BTF was observed and compared to a simple model allowing for linear space charge. The model reproduced the deformation and yielded parameters of the beam.  
 
THPC108 Observation of Bound States of Particles in the Storage Ring storage-ring, electron, radiation, vacuum 3230
 
  • A. S. Tarasenko, I. S. Guk
    NSC/KIPT, Kharkov
  The deviation of n-particle state lifetime from the law T1/n, where T1 is a mean lifetime of one particle, in the storage ring was experimentally observed. Authors relate this deviation to interaction between the particles, conditioned by the fields directed in passive resonant devices of vacuum chamber of the storage ring. Depending on type of connection of the beam with passive resonant device, the interaction can be repulsive or attracting. The binding energy of a pair of particles for a case of their effective attraction is calculated.  
 
THPC136 Design and Commissioning of a Bunch by Bunch Feedback System for the Australian Synchrotron feedback, kicker, damping, storage-ring 3306
 
  • M. J. Spencer, G. LeBlanc, K. Zingre
    ASP, Clayton, Victoria
  A transverse bunch feedback system has been designed in order to fight the effects of coupled bunch instabilities. This system is currently in the commissioning phase. A digital system was chosen because of its flexibility and diagnostic potential. While the major components were sourced from a private company, time has also been spent on in house development of an analogue front-end and the diagnostic components of the software.  
 
THPP012 Beam Injection Issues of FFAG for Particle Therapy proton, controls, injection, target 3401
 
  • T. Yokoi, J. H. Cobb, G. Morgan
    OXFORDphysics, Oxford, Oxon
  • M. J. Easton, J. K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London
  • K. J. Peach
    JAI, Oxford
  Spot scanning irradiation is a next generation treatment scheme of particle therapy. The pulsed beam of FFAG accelerator is well fitted to the treatment. In order to form a uniform dose distribution in the target volume, intensity modulation is a requirement in spot scanning and it requires special consideration in injection in order to realize short time treatment using the pulsed beam of the FFAG. In this paper, injection related issues of NS-FFAG are discussed from the point of particle therapy, especially for spot scanning.  
 
THPP050 Recent Status of Laser Cooling for Mg Realized at S-LSR laser, ion, coupling, electron 3476
 
  • A. Noda, M. Ikegami, T. Ishikawa, M. Nakao, T. Shirai, H. Souda, M. Tanabe, H. Tongu, A. Wakita
    Kyoto ICR, Uji, Kyoto
  • M. Grieser
    MPI-K, Heidelberg
  • I. N. Meshkov, A. V. Smirnov
    JINR, Dubna, Moscow Region
  • K. Noda
    NIRS, Chiba-shi
  At an ion storage and cooler ring, S-LSR, a laser cooling has been applied to the 40 keV 24Mg+ ion beam guiding a laser with the wave length of 280nm parallel to the ion beam together with the deceleration by an induction voltage. Up to now, the longitudinal temperature has been cooled down to 3.6 Kelvin for the ion number of 3x104 although the transverse one still remains around 500 Kelvin. The longitudinal temperature is limited by the heat transfer from the transverse degree of freedom through intra-beam scattering, which becomes stronger according to increase of ion number. It is found that the equilibrium longitudinal temperature is linearly coupled with the transverse one* for our experimental condition up to now. In the present paper, recent experimental data will be presented together with the procedure of beam diagnosis with the use of optical methods using a spontaneous emission of the Mg ions. Possible approach to realize the resonant coupling through synchro-betatron coupling** is also to be presented.

* M. Tanabe et al., To be published in Applied Physics Express (APEX).
** Okamoto, A. M. Sessler, D Möhl, Phys. Rev. Lett. 72 (1994)3977.

 
 
THPP054 Laser Cooling of Bunched Ion Beam at S-LSR laser 3488
 
  • H. Souda, M. Ikegami, T. Ishikawa, M. Nakao, A. Noda, T. Shirai, M. Tanabe, H. Tongu, A. Wakita, M. Yamada
    Kyoto ICR, Uji, Kyoto
  S-LSR is an ion storage ring equipped with an electron cooler and a laser cooling system. The laser cooling experiments of coasting beams were carried out during last year*. Now we started bunched beam laser cooling. 40keV Mg+ beams are bunched by an untuned RF cavity for harmonic number 5-50, and is cooled by a single 280nm laser. Bunch length are measured by electrostatic pickups. When RF harmonic number is five, bunch lengths is shorten from 1m to under 0.14m by laser cooling. Since the bunch length after cooling is shorter than present monitor resolution, fluorescence measurement is in preparation. We have installed another small RF cavity for harmonic number 100. Synchrotron-betatron coupling will be induced by dispersion at the place of this cavity**. This effect is expected to realize three dimensional laser cooling. In this paper we present the result of bunched beam cooling and the trial to three dimensional laser cooling.

*M. Tanabe et al. Appl. Phys. Express, in press.
**H. Okamoto. Phys. Rev. E 50, 4982 (1994).

 
 
THPP083 Megawatt Upgrades for the ISIS Facility linac, injection, target, space-charge 3554
 
  • J. W.G. Thomason, D. J. Adams, D. J.S. Findlay, I. S.K. Gardner, B. Jones, A. P. Letchford, S. J. Payne, B. G. Pine, A. Seville, C. M. Warsop, R. E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • D. C. Plostinar, C. R. Prior, G. H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Presently, it runs at beam powers of 0.2 MW, with upgrades in place to supply increased powers for the new Second Target Station due to start operation in autumn 2008. This paper outlines schemes for major upgrades to the facility in the megawatt regime, with options for 1, 2 and 5 MW. The ideas centre around new 3.2 GeV RCS designs that can be employed to increase the energy of the existing ISIS beam to provide powers of ~1 MW or, possibly as a second upgrade stage, accumulate and accelerate beam from a new 0.8 GeV linac for 2-5 MW beams. Summaries of ring designs are presented, along with studies and simulations to assess the key loss mechanisms that will impose intensity limitations. Important factors include injection, RF systems, instabilities, longitudinal and transverse space charge.  
 
THPP096 Injection Optimisation on the ISIS Synchrotron injection, closed-orbit, betatron, simulation 3587
 
  • B. Jones, D. J. Adams, C. M. Warsop
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. At its core is a 50 Hz proton synchrotron which, as the commissioning of a new dual harmonic RF system concludes, can accelerate 3.75·1013 protons per pulse from 70 to 800 MeV, delivering a mean beam power of 0.24 MW. The multi-turn charge-exchange injection process strongly affects transverse beam distributions, space charge forces and beam loss, which ultimately limits operational intensity. The evolution of longitudinal distributions and subsequent trapping efficiency is also intimately linked with injection. Optimising injection is therefore a key consideration for present and future upgrades. This paper summarises injection studies including 2D space-charge simulations of the ISIS injection process using the ORBIT code. Comparisons of simulation results with measurements for a range of beam intensities are presented and an assessment is made of a correlated painting scheme in contrast to the usual anti-correlated configuration.  
 
THPP108 Temperature Measurements of Carbon Stripper Foil by Pulsed 650keV H- Ion Beam target, ion, ion-source, linac 3620
 
  • A. Takagi, Y. Irie, I. Sugai, Y. Takeda
    KEK, Ibaraki
  Thick carbon foils (>300 mg/cm2) has been used for stripping of H- ion beam at the 3 GeV Rapid Cycling Synchrotron　(3GeV-RCS) of the J-PARC. The carbon stripper foils with long lifetime against high temperature >1800 °K are strongly required. We have recently developed a new irradiation system for lifetime measurement using the KEK 650keV Cockcroft-Walton accelerator with high current pulsed and dc H- beams, which can simulate the high-energy deposition upon foils in the RCS. The experimental results from the measured temperature of carbon stripper foil by the pulsed 650keV H- ion beam (-6mApeak, 0.3ms, 25Hz) and the observed time structure in the beam spot by a photo-transistor are described.  
 
THPP120 Measurements on an A/D Interface Used in the Power Supply Control System of the Main Dipoles of CNAO dipole, power-supply, pick-up, controls 3638
 
  • G. Franzini, D. Pellegrini, M. Serio, A. Stella
    INFN/LNF, Frascati (Roma)
  • M. Donetti, M. Pezzetta, M. Pullia
    CNAO Foundation, Milan
  The CNAO (the Italian Centre of Oncological Hadrontherapy, near Pavia) is in its final step of construction and is about to be fully operative. It is based on a synchrotron that can accelerate protons up to 250MeV and carbon ions up to 400MeV/u for the treatment of patients. In this paper we describe an A/D interface, used in the power supply control system of the synchrotron main dipoles, called B-Train. The field is measured in a dedicated dipole connected in series with the sixteen ones of the synchrotron and is then fed back to the power supply. The field is obtained integrating and digitizing the voltage induced on a pickup coil inserted in the gap of the seventeenth dipole. The A/D interface under study is based on a 64-channel current to frequency converter ASIC, in CMOS 0.35 μm technology, followed by a counter and uses a recycling integrator technique. The digital signal obtained is then used to generate a feedback signal for control system of the dipoles power supply. We present the electronic structure, the lab measurements and the behavior for various setups of the A/D interface described.  
 
THPP122 Fast High-Power Power Supply for Scanning Magnets of CNAO Accelerator controls, power-supply, booster, dipole 3643
 
  • M. Incurvati
    OCEM spa, San Giorgio di Piano Bologna
  • F. Burini, M. F. Farioli, G. Taddia
    O. C.E. M. S.p. A., Bologna
  • I. De Cesaris, C. Sanelli, F. Voelker
    INFN/LNF, Frascati (Roma)
  • M. Donetti, S. Toncelli
    CNAO Foundation, Milan
  • S. Giordanengo, F. Marchetto
    INFN-Torino, Torino
  • G. Venchi
    University of Pavia, Pavia
  The paper presents the design aspects and performance measurements of the CNAO Scanning Magnets’ power supply (PS) rated ±550A/±660V and developed in collaboration between OCEM SpA and INFN-CNAO. CNAO is a medical synchrotron producing carbon ions and protons for the cure of deep tumours. The Scanning Magnets are dipole magnets used to move the beam in an x-y plane at the very end of the beam extraction line. The PS current will be set in order to cover the targeted tumour area. To accomplish such a task the specifications of the PS are very stringent: current ramp speed is required to be as fast as 100 kA/s with an overall precision class of 100 ppm. Moreover the wide (20x20 cm2) area to be covered by the beam requires a wide current range. High voltage peaks are required during transients whereas low voltage is needed during steady state. The above characteristics are challenging design issues both with respect to topology and control optimization.  
 
THPP136 The Replacement of the Isis White-circuit Choke coupling, factory, proton, power-supply 3679
 
  • S. West, M. G. Glover, J. W. Gray
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • K. Papp, K. Pointner
    TA, Leonding
  • L. A.E. Van Lieshout
    Imtech Vonk, Coevorden
  ISIS, located at the Rutherford Appleton Laboratory is the world’s leading pulsed neutron source. It produces intense bursts of neutrons every 20mS when 800MeV protons are fired into a heavy metal target by an accelerating synchrotron. The ISIS synchrotron is based on a resonant “White Circuit”* allowing superimposed DC and AC currents to circulate in the ring of dipole and quadrupole magnets. The magnets themselves resonate with tuned capacitor banks at 50Hz and a large ten-winding choke allows both a path for the DC component of the current and a means to inject the AC power which maintains the 50Hz AC oscillation. This choke, which dates from the 1960’s, was a veteran of the “NINA” synchrotron in Daresbury before it began service at ISIS. Should it fail it could take at years to repair and a scheme is now well under way to replace it with ten individual chokes with in-situ spares so that the system will gain redundancy and robustness. This paper covers progress to date and the problems that have been encountered and their solutions.

*M. G. White et al. "A 3-BeV High Intensity Proton Synchrotron," The Princeton-Pennsylvania Accelerator, CERN Symp.1956 Proc., p525.

 
 
THPP139 Stainless Steel Vacuum Chambers for the SSRF Storage Ring vacuum, storage-ring, synchrotron-radiation, radiation 3688
 
  • D. K. Jiang, Y. L. Chen, Y. Liu, Y. Lu, Y. M. Wen, L. Yin, Z. T. Zhao
    SINAP, Shanghai
  • G. D. Liu, Z. A. Zheng
    Shanghai Sanjin Vacuum Equipment Ltd. Company, Shanghai
  Stainless steel 316LN plate was adopted as main material for SSRF storage ring vacuum chambers and ante-chamber structure was used just as other 3rd light source. The analysis for the deformation of the chambers under atmospheric pressure and the thermal situation under synchrotron radiation were done with ANASYS program. Many problems on the structure design and fabrication technique were revealed and suitable solving methods were found in the process of development and manufacture of nine chamber prototypes. Deep draw die was used to form the chambers’ figuration. Wire cutting and CNC machining were used to manufacture the main components. The flatness tolerance, straightness tolerance and the deformation of the chambers under atmospheric pressure were all less than 1mm. After annealed in the vacuum furnace at 850℃, the magnetic permeability of welding seal was reduced from 2.5 to 1.02, the residual stress was deleted, and the vacuum performance was improved. Now SSRF vacuum system is being operated very well. The average pressure without beam is about 2.5×10-8 Pa and the average pressure with beam of 3GeV/100mA is about 8×10-7 Pa.  
 
THPP140 First Experience on NEG Coated Chambers at the Australian Synchrotron Light Source vacuum, storage-ring, insertion, insertion-device 3690
 
  • P. Manini, A. Conte, S. Raimondi
    SAES Getters S.p. A., Lainate
  • B. Mountford
    ASP, Clayton, Victoria
  The Australian Synchrotron, a 3 GeV third generation Light Source saw its first light in 2006. At full capacity it will house more than 30 photon beam lines providing state of the art facilities to support fundamental and applied research to the Australian scientific community. In the regional context, the Australian Synchrotron will also effectively complement the lower energy synchrotrons in Singapore (0,8 Gev) and Taiwan (1.5 GeV). The vacuum system of the storage ring, 216 m circumference, includes ion pumps and NEG cartridge pumps. Two NEG coated, ESRF style, aluminium Insertion Devices, each 2,5 m long, have been also installed in the storage ring to boost machine parameters and broaden the spectrum of wavelength available for experiments. Preliminary vacuum results obtained during conditioning and initial operation of the Insertion Devices are reported and compared to uncoated chambers. These results confirm the effectiveness of the NEG coating technology in reducing pressure build up inside conductance limited narrow chambers. Technological issues related to the chambers preparation, film deposition, quality control and characterization will be also discussed.  
 
THPP141 Test of a NEG Coated Copper Dipole Vacuum Chamber vacuum, dipole, storage-ring, photon 3693
 
  • E. J. Wallén, M. Berglund, A. Hansson
    MAX-lab, Lund
  • R. Kersevan
    ESRF, Grenoble
  The paper reports about a test carried out at the 1.5 GeV storage ring MAX II where a standard dipole chamber made of stainless steel was replaced by a NEG coated chamber made of copper. The standard MAX II stainless steel dipole vacuum chamber is connected to an ion pump and a sublimation pump while the NEG-coated copper dipole vacuum chamber has no additional pumps. The NEG-coated dipole chamber made of copper has been demonstrated to work well with a stable vacuum level in the region where it is installed. The coating procedure for the bent dipole chamber copper tube is slightly more complicated than the coating procedure for a straight chamber of similar size due to its curvature and lack of line-of-sight. The procedure is also described in some detail. The main motivation for the interest in NEG-coated vacuum tubes is the reduced cost of the vacuum system and also the possibility to build more slender vacuum systems, thus simplifying and optimizing the design of accelerator magnet systems.  
 
THPP142 Vacuum Conditioning of the SOLEIL Storage Ring with Extensive Use of NEG Coating vacuum, quadrupole, storage-ring, photon 3696
 
  • C. Herbeaux, N. Béchu, J.-M. Filhol
    SOLEIL, Gif-sur-Yvette
  The vacuum system of the SOLEIL storage ring is designed using a combination of standard pumps like Sputter Ion Pumps and Titanium Sublimation Pumps (TSP) and Non Evaporable Getter (NEG) coating. Following the ESRF results on low gap insertion device (ID) chambers, it was decided to use, in addition to the traditional pumps, NEG coating deposited by magnetron sputtering on extruded aluminium vessels. This has been applied in an extensive way to all the straight vessels of the storage ring that means quadrupole vessels and ID vessels, which represent about 56% of the circumference. The starting configuration of the SOLEIL vacuum system included all the NEG coated low gap ID chambers among which a 10.5 m long chamber. Conditioning of the vacuum system over an integrated beam dose of 500 A.h will be presented. The periodical re-activations of the TSP performed early 2007 improved significantly the conditioning rate. A comparison of the vacuum behaviour of two similar cells one with NEG coating and traditional pumping versus one with only NEG coating demonstrates the ability of the NEG coating to keep alone the pressure at low level.  
 
THPP144 The Vacuum System for SSRF Storage Ring vacuum, photon, power-supply, storage-ring 3702
 
  • D. K. Jiang, L. Chen, Y. L. Chen, W. Li, Y. Liu, Y. Lu, H. Zhang
    SINAP, Shanghai
  The vacuum system for SSRF was completed at the end of 2007 and has run for one month without any malfunction. The vacuum chamber for the storage ring made from stainless steel 316LN plate. About 180 absorbers and 80 RF bellows with a single finger structure are used for the storage ring. About 292 compound pumps (SIP+NEG) and 188 TSP are used. After the vacuum system in the straight section of a cell and all pumps in the bending section were baked, the ultimate pressure reached 2×10－8 Pa. Normally, the temperature raise on the chambers any where is less than 4℃ with current 100mA. The temperature raise of the cooling water for all absorbers is less than 3℃. The vacuum control and interlock system are on working order.  
 
THPP147 NEG Coated Chambers at SOLEIL: Technological Issues and Experimental Results vacuum, controls, radiation, storage-ring 3711
 
  • P. Manini, A. Bonucci, A. Conte, S. Raimondi
    SAES Getters S.p. A., Lainate
  • N. Béchu, C. Herbeaux
    SOLEIL, Gif-sur-Yvette
  The SOLEIL accelerator complex includes a 100 MeV LINAC pre-injector, a full energy booster synchrotron and a 2.75 GeV electron storage ring with a 354-meter circumference, which provides synchrotron light to 24 photon beam lines. SOLEIL is the first synchrotron facility specifically designed to make extensive use of Non Evaporable Getter (NEG) coating technology to improve the vacuum, reduce bremsstralhung radiation and boost beam performances. In fact, NEG coating of the straight parts of the vacuum system covers more than 50% of the overall storage ring surface and includes 110 quadrupole and sextupole chambers as well as several conductance limited narrow insertion devices. Use of such a large amount of NEG coated chambers has posed several challenges in term of coating technology, chamber testing, installation and machine commissioning. We report in the present paper main technological issues related to the chambers preparation, film deposition, quality control and characterization. Chambers installation in the main ring, conditioning and activation procedures as well as preliminary vacuum performances will be also discussed.  
 
FRXCGM01 High Quality GeV Electron Beams from Plasma-Laser Accelerators electron, laser, free-electron-laser, plasma 3733
 
  • W. Leemans
    LBNL, Berkeley, California
  Accelerators are essential tools of discovery and have many practical uses. At the forefront of accelerator technology are the machines that deliver beams for particle physics, for synchrotron and free electron based radiation sources. The technology that drives these accelerators is extremely sophisticated but is limited by the maximum sustainable accelerating field. This impacts the size and cost of the device. More than two decades ago, lasers were proposed as power source for driving novel accelerators based on plasmas as the accelerating medium. An overview will be presented of what these devices can produce to date, including the 2004 demonstration of high quality electron beams* and the 2006 demonstration of GeV class beams from a 3 cm long accelerating structure**. We then discuss the key challenges for broad applicability of the technology and our goal of making a laser accelerator driven a VUV/soft x-ray free electron laser.

* C. G.R. Geddes et al., Nature 431, 538-541 (2004); S. P.D. Mangles et al., ibidem, p.535-538; J. Faure et al., ibidem, p. 541-544.
** W. P. Leemans et al., Nature Physics 2, 696-699 (2006).

 
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FRYAGM01 Upgrade Issues for the CERN Accelerator Complex luminosity, proton, linac, injection 3734
 
  • R. Garoby
    CERN, Geneva
  The Large Hadron Collider at CERN is at a very advanced stage of construction and the first beam collisions in the experiments are expected during the year 2008. Work has now started for maximizing its physics reach and for preparing for other foreseeable needs. Beyond upgrades in the LHC itself, mainly in the optics of the insertions, the injector complex has to be renewed to deliver beam with upgraded characteristics with a high reliability. In a first phase, a new 160 MeV H- linac (“Linac4”) will be built to replace the present 50 MeV proton linac (Linac2) and extensive consolidation will be made. In a second phase, the present 26 GeV PS and its set of injectors (Linac2 + PSB) are planned to be replaced with a ~50 GeV synchrotron (“PS2”) using a 4 GeV superconducting proton linac (“SPL”) as injector. The SPS itself will also be the subject of major improvements, to be able to cope with a 50 GeV injection energy and with beams of much higher brightness. These proposals are described as well as their potential to evolve and fit the needs of future facilities for radioactive ions and/or neutrinos.  
slides icon Slides