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MOPC083 Flat Long Pulse Train Formation Using Multi-pass Structure laser, alignment, polarization, gun 250
 
  • J. Ruan, H. T. Edwards, R. P. Fliller
    Fermilab, Batavia, Illinois
  Flat long pulse train is part of the requirements for International Linear collider. Here in Fermilab the construction of ILCTA at New Meon Lab will present the similar requirements (3MHz, 2810 Pulses, 5Hz) for the laser systems. In this paper we will report the effort to develop a new multi pass (MP) cavity based on Nd:YLF crystal end-pumped by diode laser. It takes a seed (1054 nm, 4-5ps) from a commercial laser and has a gain of 1000 or more. So far we already tested up to 1000 pulses with 1μs spacing and the pulse train amplitude fluctuation is less than 5% throughout the whole duration. We attribute this to the high optical to optical conversion efficiency achieved using Nd:YLF crystal inside the multi-pass structure. Test with 3MHz spacing train is also discussed and the integration of the new MP cavity into the current laser system is planned.  
 
MOPC091 Benchmarking of Collimation Tracking Using RHIC Beam Loss Data collimation, simulation, beam-losses, proton 274
 
  • G. Robert-Demolaize, K. A. Drees
    BNL, Upton, Long Island, New York
  State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system. These tools can be benchmarked using data taken from operations of the Relativistic Heavy Ion Collider (RHIC) multi-stage collimation system. This article reviews preliminary simulation results on both the location and the intensity of proton losses around the RHIC lattice. Comparison with live measurements from the beam loss monitors are also shown in order to assess the accuracy of the predictions in the LHC case.  
 
MOPC096 Design of a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade collimation, simulation, impedance, shielding 289
 
  • J. C. Smith, J. E. Doyle, L. Keller, S. A. Lundgren, T. W. Markiewicz
    SLAC, Menlo Park, California
  • L. Lari
    EPFL, Lausanne
  The Phase II upgrade to the LHC collimation systems calls for complementing the 30 high robust Phase I graphite collimators with 30 high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and this design will be discussed here. The Phase II collimators must be robust in various operating conditions and accident scenarios. Design issues include:
  1. Collimator jaw deflection due to heating and sagita must be small when operated in the steady state condition,
  2. Collimator jaws must withstand transitory periods of high beam impaction with no permanent damage,
  3. Jaws must recover from accident scenario where up to 8 full intensity beam pulses impact on the jaw surface and
  4. The beam impedance contribution due to the collimators must be small to minimize coherent beam instabilities.
The current design will be presented.
 
 
MOPD005 Recent Activities in ILC R&D at Hitachi vacuum, superconducting-RF, cryogenics, radiation 457
 
  • T. Semba, Y. Itou, S. Kajiura, Y. Tsujioka, T. Yoshinari
    Hitachi Ltd., Ibaraki-ken
  • M. Abe
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • H. Hayano, Y. Higashi, S. Noguchi, N. Ohuchi, K. Saito, K. Tsuchiya
    KEK, Ibaraki
  • N. Torii
    Hitachi High-Technologies Corp., Ibaraki-ken
  We participated in the construction of STF (Superconducting RF Test Facility) cryomodule. This paper describes our recent activities in ILC R&D.  
 
MOPD031 Automatic Implementation of Radiation Protection Algorithms in Programs Generated by GCC Compiler radiation, controls, synchrotron 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.  
 
MOPP056 Beam Coupling Impedance in the ILC Damping Rings impedance, damping, vacuum, coupling 670
 
  • M. Korostelev, O. B. Malyshev, A. Wolski
    Cockcroft Institute, Warrington, Cheshire
  • A. F. Grant, J. Lucas
    STFC/DL, Daresbury, Warrington, Cheshire
  The ILC damping rings have stringent specifications for beam quality and stability. To avoid instabilities, the various components in the vacuum chamber will need to be carefully designed to minimize the longitudinal and transverse wake fields. We present the results of impedance calculations for various components that are expected to make a significant contribution to the overall machine impedance.  
 
MOPP093 Fast L-band Waveguide Phase Shifter scattering, acceleration 769
 
  • S. Kazakov, S. V. Shchelkunov
    Omega-P, Inc., New Haven, Connecticut
  • J. L. Hirshfield
    Yale University, Physics Department, New Haven, CT
  • A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio
  • E. Nenasheva
    Ceramics Ltd., St. Petersburg
  • V. P. Yakovlev
    Fermilab, Batavia, Illinois
  During the operation of accelerators it is often important to rapidly change the parameters of the RF system, such as cavity resonant frequency, coupling, or electrical length. For this purpose a fast L-band planar phase shifter has been designed, that has advantages compared to the coaxial scheme considered before by the authors (EPAC 06). The phase shifter is based on a new ferroelectric ceramic, whose permittivity changes with application of an external voltage. The switching time depends on only the external HV circuit and can by less than a few microseconds. The conceptual design and electrical parameters of the new phase shifter are presented, as are first results of low power measurements on a 1/3 model.  
 
MOPP120 Full Characterization of the Piezo Blade Tuner for Superconducting RF Cavities controls, feedback, cryogenics, superconducting-RF 838
 
  • A. Bosotti, C. Pagani, N. Panzeri, R. Paparella
    INFN/LASA, Segrate (MI)
  • C. Albrecht, K. Jensch, R. Lange, L. Lilje
    DESY, Hamburg
  • J. Knobloch, O. Kugeler, A. Neumann
    BESSY GmbH, Berlin
  Cavity tuners are mechanical devices designed to precisely match the resonant frequency of the superconducting (SC) cavity to the RF frequency synchronous with the beam. The blade tuner is mounted coaxially to the cavity and changes the resonator frequency by varying its length. A high tuning range is desired together with small mechanical hysteresis, to allow easy and reproducible resonator setup operations. High stiffness is also demanded to the tuner system both to ensure mechanical stability and to mitigate the frequency instabilities induced by perturbations. In high gradient SC resonators, the main sources of resonant frequency instability are the Lorentz Force Detuning (LFD) under pulsed mode operation, and the microphonic noise, in continuous wave (CW) with high loaded quality factors. Piezoceramic elements add dynamic tuning capabilities to the system, allowing fast compensation of these instabilities with the help of feed-forward and feedback loops. The piezo blade tuner has been extensively tested both at room temperature and at cold once assembled on a TESLA type cavity in its final configuration. This paper presents the summary of the complete characterization tests.  
 
MOPP123 Design and Fabrication of the Cornell ERL Injector Cryomodule vacuum, linac, alignment, shielding 844
 
  • E. P. Chojnacki, S. A. Belomestnykh, Z. A. Conway, J. J. Kaufman, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, P. Quigley, J. Sears, V. D. Shemelin, V. Veshcherevich
    CLASSE, Ithaca
  The Energy Recovery Linac (ERL) development effort at Cornell will first produce an ERL beam source. The source will consist of a DC photo-gun, a buncher cavity, beam optics, and then an SRF Injector cryomodule to accelerate the 33-100 mA cw beam from 0.3-0.5 MeV to 5-15 MeV. The Injector cryomodule is based on TTF III technology with modifications to allow cw operation and the flexibility to accommodate the wide range of beam currents, bunch lengths, and beam energy. To deliver the 0.5 MWCW average power to the beam, the Injector cryomodule will contain five SRF 2-cell cavities, each cavity having two 50 kWCW coax couplers to deliver power from 100 kWCW klystrons, of which there are five for the Injector. Both the couplers and klystrons have been tested with 30% overhead in performance. Cold beamline HOM loads are placed between each cavity and outboard of the first and last cavities. Details of the Injector cryomodule design will be presented along with insight gained from the fabrication process, which will benefit the future ERL Linac cryomodule design and proto-typing.  
 
MOPP159 Results of Vertical Tests for the KEK-ERL Single Cell Superconducting Cavities acceleration, linac, pick-up, superconductivity 925
 
  • K. Umemori, T. Furuya, T. Takahashi
    KEK, Ibaraki
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • M. Sawamura
    JAEA/ERL, Ibaraki
  The development of the superconducting cavities is indispensable for realizing the 5 GeV-class energy recovery linacs. The KEK-ERL cavity had been recently designed. Its features are the optimized cell shapes and adoption of the enlarged beampipes with eccentric-fluted structures. In order to confirm our cavity design, two types of single cell cavities had been fabricated. One is a center-cell type cavity, whose aim is a validation of the cell shape, and another is an end-cell type cavity, which has complex structure such as the eccentric-fluted beampipes. After applying a series of surface treatments, we had assembled the cavities and performed vertical tests at KEK D10 area. Promising results have been obtained. In this presentation, we will present the results of vertical tests for these cavities.  
 
TUPC041 Design of Cold BPM Feedthrough simulation, resonance, impedance, cryogenics 1146
 
  • K. Iwamoto, Y. Ikeda
    KFG, NEUSS
  • T. Kitamura, T. Matsuoka
    KYOCERA Corporation, Higashiomi-city, Shiga
  We have designed many BPM feedthrough used metallized ceramic components. We select the best material of ceramic and metal ajusted for magnetism and the material of chamber. The request for accelerator application that low temperature and RF property has increased in recent years. In this presentation,we report on the design of the BPM feedthrough for low temperature and for the RF up to 20GHz. We appreciated the bonding strength for ceramic and metal in low temperature 4K,77K. Mo/Mn metallised ceramic is brazed between Fe-Ni-Co Alloy metal components using Ag-Cu brazing material. Ceramic is 99% Alumina which is commonly used for UHV application. The tensile strength in low temperature is lower than in R. T.approximately 10%, but the dispersion affected by brazing flow condition is bigger than this temperature effect. The influence of low temperature is less than brazing flow condition, therefore the bonding strength of metallised ceramic is enough for UHV application at 4K.  
 
TUPC128 Air Temperature Analysis and Control Improvement for the EPU 5.6 at TLS controls, simulation, storage-ring, insertion-device 1368
 
  • J.-C. Chang, Y.-C. Chung, C.-Y. Liu, Z.-D. Tsai
    NSRRC, Hsinchu
  This paper presents the air temperature analysis and control improvement for area of the elliptically polarizing undulator EPU 5.6 in the Taiwan Light Source (TLS). To enhance uniformity of ambient air temperature, we applied mini environmental controls and installed five cross flow fans in this area. Eight temperature sensors were installed around the EPU to monitor temperature variation. We also simulated the flow field and temperature distribution in this area by using a computational fluid dynamics (CFD) code. The simulation results were validated by comparing to measured data. The temperature variation along time and spatial temperature differences were controlled within 0.1 degree C and 0.5 degree C, respectively.  
 
TUPP002 Uniform Motion Control Solution for Variety of Motion Applications controls, feedback, acceleration, power-supply 1526
 
  • J. Dedic, G. Jansa, M. Plesko, R. Sabjan
    Cosylab, Ljubljana
  Control solutions for motion applications require high degree of flexibility regarding the use and connectivity. Being fairly simple or highly complex, micro- or millimeter precision, one or multiple axis… the system designer has to tackle specific interfacing issues. One platform should fit different applications and provide cost effective solutions. Flexible software platform is required on one side to satisfy control system (CS) application requirements. On the other side variety of hardware (HW)–controlled by motion controller, i.e., power stages, position feedback–also requires some degree of connection flexibility. Paper presents a design of a motion control platform that offers flexible interfacing both to CS and HW, elegant extendibility options for selection of feedback protocols, low-level direct access for engineering control and enables large distances between controller and motors.  
 
TUPP029 Beam Coupling Impedance Measurement and Mitigation for a TOTEM Roman Pot impedance, resonance, coupling, vacuum 1598
 
  • M. Deile, F. Caspers, T. Kroyer, M. Oriunno, E. Radermacher, A. Soter
    CERN, Geneva
  • F. Roncarolo
    UMAN, Manchester
  The longitudinal and transverse beam coupling impedance of the first final TOTEM Roman Pot unit has been measured in the laboratory with the wire method. For the evaluation of transverse impedance the wire position has been kept constant, and the insertions of the RP were moved asymmetrically. With the original configuration of the RP, resonances with fairly high Q values were observed. In order to mitigate this problem, RF-absorbing ferrite plates were mounted in appropriate locations. As a result, all resonances were sufficiently damped to meet the stringent LHC beam coupling impedance requirements.  
 
TUPP046 Tunable Ferroelectric Based Technologies for Accelerator Components controls, linac, luminosity, vacuum 1646
 
  • A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio
  • S. Kazakov
    KEK, Ibaraki
  • E. Nenasheva
    Ceramics Ltd., St. Petersburg
  • A. Tagantsev
    EPFL, Lausanne
  • V. P. Yakovlev
    Fermilab, Batavia, Illinois
  Low loss ferroelectric materials can be used as key elements in RF tuning and phase shifting components to provide fast, electronic control. These devices are under development for different accelerator applications in X, Ka and L - frequency bands. The exact design of these devices depends on the electrical parameters of the particular ferroelectric material to be used- its dielectric constant, loss tangent and tunability. BST based ferroelectric-oxide compounds have been found to be suitable materials for a fast electrically-controlled tuner for BNL and for high-power fast RF phase shifters to be used for SNS vector modulation applications. We present recent results on the development of BST based ferroelectric compositions synthesized for use in high power technology components. The BST(M) ferroelectrics have been tested using a transverse dc bias field. The tunability factor vs. dc field magnitude has been evaluated and the feasibility of transverse bias tuning for ferroelectric based accelerator components has been demonstrated.  
 
WEOCG02 Post-mortem Diagnostic for the Taiwan Light Source kicker, diagnostics, controls, beam-losses 1932
 
  • K. H. Hu, J. Chen, P. C. Chiu, K. T. Hsu, S. Y. Hsu, C. H. Kuo, D. Lee, C.-J. Wang, C. Y. Wu
    NSRRC, Hsinchu
  Analyzing the reasons of various trip events is essential to improve reliability of a synchrotron light source. To identify the causes of trip at Taiwan Light Source (TLS), various diagnostics tool were employed. These diagnostic tools can capture beam trip, interlock signals of superconducting RF system, waveform of the injection kickers, quench and interlock signals of the superconducting insertion device, and instability signals of the stored beam for post-mortem analysis. These diagnostics can be routine monitor signal and record beam trip event. Features of trip diagnostic tools are available now. System configuration experiences will be summarized in this report.  
slides icon Slides  
 
WEPC006 Beam Lifetime and Collective Effects in Taiwan Photon Source impedance, ion, insertion-device, vacuum 1992
 
  • P. J. Chou, H.-P. Chang, C.-C. Kuo, W. T. Liu, H.-J. Tsai
    NSRRC, Hsinchu
  The design of Taiwan Photon Source (TPS) has a natural emittance less than 2 nm-rad and low emittance coupling. The nominal rms bunch length is less than 3 mm. Several small-gap undulators are planned to provide x-ray photon beam with extremely high brightness. The vertical gap of these undulators are in the range of 5-7 mm. The TPS ring will be operated at top-up mode with high beam current. Various collective effects due to high beam current are investigated. Impacts of small-gap undulators to the beam lifetime are carefully studied. The results of theoretical analysis are presented. Proposals to overcome deleterious effects due to high beam current and small-gap undulators are also discussed.  
 
WEPC007 Vacuum Performance of the Diamond Light Source In-vacuum Insertion Devices vacuum, storage-ring, target, ion 1995
 
  • M. P. Cox, S. Bryan, B. F. Macdonald, H. S. Shiers
    Diamond, Oxfordshire
  Diamond Light Source is the UK's new 3 GeV 3rd generation synchrotron light source with a 562 m circumference electron storage ring. At the start of user operations in January 2007, 5 in-vacuum undulators were in operation and a further 3 units have been installed subsequently. This paper describes the vacuum performance of these devices. 3 different mechanical configurations with different undulator canting angle and different pumping arrangements of the interconnecting vessels are installed. One configuration has non-evaporable getter (NEG) coated interconnecting vessels. Vacuum simulations were carried out on these configurations as part of the vacuum design process to predict their performance. Following final magnetic characterization, each of the devices was vacuum assembled and baked ex-situ for an extended period and then installed under dry nitrogen purge conditions, eliminating the need for a time-consuming in-situ bakeout in most cases. After a period of pump down and beam conditioning, the operating pressures in all the in-vacuum undulators were below the target specification and produced acceptably low Gas Bremsstrahlung radiation levels in the beamlines.  
 
WEPC010 Upgrade of the ESRF Accelerator Complex undulator, insertion-device, storage-ring, lattice 2004
 
  • P. Elleaume, J. C. Biasci, J-F. B. Bouteille, J. M. Chaize, J. Chavanne, L. Farvacque, L. Goirand, M. Hahn, L. Hardy, J. Jacob, R. Kersevan, J. M. Koch, J. M. Mercier, A. Panzarella, C. Penel, T. P. Perron, E. Plouviez, E. Rabeuf, J.-L. Revol, A. Ropert, K. B. Scheidt, D. Schmied, V. Serriere
    ESRF, Grenoble
  The ESRF, the first third generation synchrotron radiation source, opened its first beamline in 1994 and has been continuously developed since then to satisfy the user community. However, the need arose to make a major upgrade of the infrastructure and accelerator complex in order to fulfil the request for new scientific applications*. The experimental Hall will be expanded and half of the beamlines reconstructed. The storage ring lattice will be modified to provide space for longer as well as a larger number of insertion devices. New insertion devices will be developed possibly based on in-vacuum permanent magnets at cryogenic temperature. The electron beam positioning system will be rebuilt to provide a higher photon beam stability. The RF system will face a major reconstruction with a new type of RF transmitters and HOM damped cavities allowing stable operation at a ring current of 300 mA without feedback. The injector system will be upgraded to operate the 16 and 4 bunch fillings in the top-up mode in order to increase the average current and obtain a higher photon beam stability.

*ESRF Science and Technology Programme, 2008-2017.

 
 
WEPC016 Operation Status and Performances Upgrade on SOLEIL Storage Ring undulator, feedback, vacuum, photon 2022
 
  • J.-M. Filhol, J. C. Besson, F. Bouvet, P. Brunelle, L. Cassinari, M.-E. Couprie, J.-C. Denard, C. Herbeaux, J.-F. Lamarre, J.-P. Lavieville, P. Lebasque, M.-P. Level, A. Loulergue, P. Marchand, A. Nadji, L. S. Nadolski, R. Nagaoka, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  SOLEIL is the French 2.75 GeV third generation synchrotron light source delivering beam to users since January 2007. Beginning of 2008 up to 13 beam-lines are taking beam, 7 from insertion devices (IDs), 2 from IR ports, and 4 from dipole ports, and 6 of them are open to external Users. Users have a full control of their IDs. With a 300 mA stored beam current in multi-bunch filling pattern, and position stability in the few micron range, the main target performances have been reached. A beam of 50 mA in 8 bunches was delivered to users for the first time in December 2007 for time structure experiments. Operation and performance status will first be given, namely subsystem behaviour (RF, vacuum, …), beam optics, orbit stability, beam lifetime, and operation statistics. Then the main objectives for 2008 will be reviewed: delivery of 4000 hours of user beam time, installation and commissioning of a second cryomodule for reaching the 500 mA current target, construction and installation of 6 new IDs leading to a total number of 17, improvement of the orbit stability with a fast orbit feedback complementary to the slow orbit one, and preparation for top-up operation.  
 
WEPC035 Present Status of PF-ring and PF-AR in KEK injection, undulator, insertion-device, photon 2064
 
  • Y. Kobayashi, S. Asaoka, K. Ebihara, K. Haga, K. Harada, T. Honda, T. Ieiri, M. Izawa, T. Kageyama, T. Kasuga, M. Kikuchi, K. Kudo, H. Maezawa, K. Marutsuka, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. T. Nakamura, T. Nogami, T. Obina, K. Oide, M. Ono, T. Ozaki, C. O. Pak, H. Sakai, Y. Sakamoto, S. Sakanaka, H. Sasaki, Y. Sato, M. Shimada, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, S. Takasaki, Y. Tanimoto, M. Tejima, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto, Ma. Yoshida, M. Yoshimoto
    KEK, Ibaraki
  In KEK, we have two synchrotron light sources which were constructed in the early 1980s. One is the Photon Factory storage ring (PF-ring) and the other is the Photon Factory advanced ring (PF-AR). The PF-ring is usually operated at 2.5 GeV and sometimes ramped up to 3.0 GeV to provide photons with the energy from VUV to hard X-ray region. The PF-AR is mostly operated in a single-bunch mode of 6.5GeV to provide pulsed hard X-rays. Operational performances of them have been upgraded through several reinforcements. After the reconstruction of the straight section of the PF-ring in 2005, two short-period-gap undulators have been stably operated. They allow us to produce higher brilliant hard X-rays even at the energy of 2.5 GeV. In March 2008, the circular polarized undulator will be installed in the long straight section of 8.9 m. In the PF-AR, new tandem undulators have been operated since September 2006 to generate much stronger pulsed hard X-rays for the sub-ns resolved X-ray diffraction experiments. In this conference, we report present status of the PF-ring and the PF-AR.  
 
WEPC039 PLS Upgrade Plan lattice, emittance, booster, linac 2070
 
  • T.-Y. Lee
    PAL, Pohang, Kyungbuk
  Pohang Light Source (PLS) has operated for 14 year successfully. To meet the request of the increasing user community, an upgrade plan of PLS is under consideration. The design goal is to achieve an emittance as low as 5 nm rad and to install as many insertion devices as possible. To minimize the necessary relocation of existing beamlines, the new lattice will still be a TBA. But, adopting combined function magnets, it is possible to achieve low emittance while the insertion straight is as long as 8.8 m where two insertion devices will be installed. The PLS upgrade plan and the lattice design will be presented in this paper.  
 
WEPC043 Commissioning of 360 mA Top-up Operation at TLS injection, feedback, booster, insertion-device 2082
 
  • Y.-C. Liu, H.-P. Chang, K.-K. Lin, Y. K. Lin, G.-H. Luo
    NSRRC, Hsinchu
  Taiwan light source started the 200 mA top-up operation in October, 2005, and subsequently, the stored top-up beam current was raised to 300 mA. Several machine issues were observed and solved during past two years. We study the possibility and ability of 360 mA top-up operation at Taiwan light source.  
 
WEPC048 Experimental Characterization of the Insertion Device Effects on Beam Dynamics at SOLEIL undulator, focusing, injection, coupling 2097
 
  • P. Brunelle, C. Benabderrahmane, F. Briquez, O. V. Chubar, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski
    SOLEIL, Gif-sur-Yvette
  SOLEIL, the French 2.75 GeV third generation light source, has been delivering photons to beam lines in routine operation since January 2007. The storage ring is presently equipped with eleven insertion devices: 3 in-vacuum 20mm period undulators (U20), 1 Apple-II type 52mm period undulator (HU52), 3 Apple-II type 80mm period undulators (HU80), 3 electromagnetic 256mm period undulators (HU256) and 1 electromagnetic 640mm period 10m long undulator (HU640). Commissioning of insertion devices consists of characterizing all the effects on beam dynamics in terms of focussing, injection efficiency, beam lifetime and sensitivity to working point, and also in optimizing feedforward tables in order to compensate for closed orbit distortions during field variations (this last point is detailed in other papers). We will focus here on the significant effects observed with some undulators. Measurements, using electron beam, of the transverse variation of field integrals, were helpful to understand bad effects impacting the daily operation. The introduction of real magnetic characteristics in the lattice model is in progress in order to further optimize the working point.  
 
WEPC053 An Experimental Study of Radiation-induced Demagnetization of Insertion Device Permanent Magnets radiation, electron, proton, insertion-device 2112
 
  • N. Simos, P. K. Job
    BNL, Upton, Long Island, New York
  • N. V. Mokhov
    Fermilab, Batavia, Illinois
  High brilliance in the 3GeV new light source NSLS II is obtained from the high magnetic fields in insertion devices (ID). The beam lifetime is limited to 3h by single Coulomb scattering in the Bunch (Touschek effect). This effect occurs everywhere around the circumference and there is unavoidable beam loss in the adjacent low-aperture insertion devices. This raises the issue of degradation and damage of the permanent magnetic material by irradiation with high energy electrons and corresponding shower particles. It is expected that IDs, especially those in-vacuum, would experience changes resulting from exposure to gamma rays, x-rays, electrons and neutrons. By expanding an on-going material radiation damage study at BNL the demagnetization effect of irradiation consisting primarily of neutrons, gamma rays and electrons on a set of NdFeB magnets is studied. Integrated doses of several Mrad to a few Grad were achieved at the BNL Isotope Facility with a 112-MeV, 90-uA proton beam. Detailed information on dose distributions and particle energy spectra on the NdFeB magnets was obtained with the MARS15 Monte-Carlo code. This paper summarizes the results of this study.

Work performed under the auspices of the US DOE.

 
 
WEPC065 The Lattice Design of Hefei Advanced Light Source (HALS) Storage Ring emittance, insertion-device, lattice, radiation 2142
 
  • L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang
    USTC/NSRL, Hefei, Anhui
  The purpose of Hefei Advanced Light Source is to provide high brilliant and coherent synchrotron radiation in the VUV and soft X-ray range to synchrotron radiation users. To enhance high brilliance and transverse coherent, very low beam emittance is required. The design goal of beam emittance is lower than 0.2 nmrad, whose synchrotron radiation is fully transverse coherent beyond the 2.5nm. Considering achievable undulator radiation spectrum and energy dependence of emittance, the energy of storage ring is set as 1.5GeV. Limiting the circumference of storage ring, the more dipole and strong focusing are needed for lowering emittance. On the other side, strong chromatic sextupoles are needed to compensate large natural chromaticity. The storage ring became strong nonlinear. The linear optics and nonlinear dynamics of HALS storage ring were introduced in this paper.  
 
WEPC100 Superconducting Insertion Devices with Variable Period Length undulator, wiggler, photon, brilliance 2231
 
  • A. Bernhard, T. Baumbach, P. Peiffer, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • R. Rossmanith
    FZK, Karlsruhe
  The tuning range and functionality of superconducting insertion devices may be significantly enhanced by period length switching. Period length switching can be achieved by employing two or more individually powerable subsets of superconducting coils in such a way that a current reversal in a part of these coil sets results in a period length variation. In this paper the opportunities and restrictions of period length switching in superconducting undulators are discussed from a general point of view. As a particular example, the design of a hybrid superconducting undulator/wiggler (SCUW) for ANKA based upon the period length switching technique is presented.  
 
WEPC102 Commissioning of the Electromagnetic Insertion Devices at SOLEIL undulator, radiation, power-supply, insertion-device 2237
 
  • F. Briquez, P. Brunelle, O. V. Chubar, M.-E. Couprie, J.-M. Filhol, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski, M. Valleau, J. Vétéran
    SOLEIL, Gif-sur-Yvette
  SOLEIL is the French 2.75 GeV third generation synchrotron radiation light source. Eleven undulators are installed yet in the storage ring and nineteen more Insertion Devices (ID) will be installed on the ring by January 2010. Among the installed IDs, there are four electromagnetic undulators of two different designs: one 640 mm period air coils undulator called HU640 and three 256 mm period undulators called HU256, made up of independent H yoke dipoles. The HU640 provides photons in any polarisation from linear to elliptical, in a range extending from 5 to 40 eV, thanks to three different groups of coils powered independently. The HU256, which are subject to hysteresis, provide horizontal and vertical, periodic or quasi-periodic linear polarisations, and also circular polarisation, covering a total range from 10 eV to 1 keV. The effects of each undulator on the closed orbit have been extensive studied, and compensated, using dedicated embedded steering coils. The correction method will be explained and its results will be shown and compared to the magnetic measurements. Finally, the first measurements of the radiation produced will be shown and compared to previsions.  
 
WEPC106 Compensation of Variable Skew- and Normal quadrupole Focusing Effects of APPLE-II Undulators with Computer-aided Shimming undulator, quadrupole, radiation, insertion-device 2246
 
  • O. V. Chubar, F. Briquez, M.-E. Couprie, J.-M. Filhol, E. Leroy, F. Marteau, F. Paulin, O. Rudenko
    SOLEIL, Gif-sur-Yvette
  Variable (phase- and gap-dependent) skew- and normal-quadrupole focusing effects of APPLE II undulators on electron beam are reportedly complicating practical use of this type of insertion devices in many synchrotron radiation sources. We show that these undesirable effects, whatever their "origin", can be well controlled and in many cases efficiently compensated during the standard "virtual" shimming of APPLE-II undulators. Our method exploits small variations of the skew- and normal-quadrupole focusing components resulting from extra magnetic interaction, introduced by displacements of permanent magnet blocks during the shimming procedure, at different undulator phase and gap values. These variations can be calculated to a high accuracy, included into the corresponding "shim signatures" of magnetic field integrals, and used, along with undulator magnetic measurements data, for calculation of the most efficient magnet displacements. This approach is well suited for a computer-aided (e.g., genetic optimization based) shimming procedure. Practical results obtained with several APPLE-II undulators, which are currently successfully operating on the SOLEIL storage ring, are presented.  
 
WEPC111 Latest Progress in Insertion Devices at ACCEL Instruments undulator, insertion-device, alignment, synchrotron 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.  
 
WEPC119 First Year's Experience of Diamond Insertion Devices injection, undulator, photon, wiggler 2285
 
  • E. C. Longhi, R. T. Fielder, I. P.S. Martin, J. C. Schouten, B. Singh
    Diamond, Oxfordshire
  • R. Bartolini
    JAI, Oxford
  Diamond was commissioned at 3GeV with seven insertion devices (IDs) already installed. The phase 1 IDs include five in-vacuum permanent magnet undulators, an APPLE–2 variable polarization device, and a superconducting wiggler. Since initial commissioning of the ring, three more in-vacuum undulators have been installed, and another three devices will be installed in the coming year. In this paper, we describe commissioning, characterizing, and operating with these IDs.  
 
WEPC120 An In Vacuum Wiggler WSV50 for Producing Hard X-rays at SOLEIL wiggler, vacuum, photon, insertion-device 2288
 
  • O. Marcouillé, P. Brunelle, O. V. Chubar, M.-E. Couprie, J.-M. Filhol, C. Herbeaux, J. L. Marlats, A. Mary, K. Tavakoli
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a medium energy storage ring (2.75 GeV) operating since 2006. The production of intense high energy photon beams requires insertion devices with high magnetic field and large number of periods. To cover the 20 keV-50 keV Photon Energy range, an in vacuum wiggler has been preferred to a superconducting wiggler. This choice results from a compromise between photon flux, investment and running cost. Deep studies have been performed to find the optimum magnetic field and period producing the maximum flux in the dedicated spectral range (20-50 keV). The wiggler is composed of 38 periods of 50 mm producing a 2.1 T magnetic field at a minimum gap of 5.5 mm. To minimize the high magnetic forces acting between the magnet arrays (10 tons), two compensation systems, composed of either springs or magnet blocks, have been designed. This paper presents the spectral performances of the wiggler compared with an optimized superconducting wiggler, the mechanical and magnetic design of the wiggler and the first tests of the compensation system.  
 
WEPC125 Development of Three New Superconducting Insertion Devices for the ANKA Storage Ring undulator, wiggler, synchrotron, 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.  
 
WEPC131 Insertion Devices for NSLS-II Baseline and Future undulator, insertion-device, wiggler, electron 2314
 
  • T. Tanabe
    RIKEN/RARF/CC, Saitama
  • J. Bengtsson, D. A. Harder, S. L. Kramer, G. Rakowsky, J. Rank
    BNL, Upton, New York
  NSLS-II is going to employ Damping Wigglers not only for emittance reduction but also as broadband hard X-ray source. In-Vacuum Undulators with minimum RMS phase error (< 2 degree) and possible cryo-capability are planned for X-ray planar device, and Elliptically Polarized Undulators are utilized for polarization controls. Due to lack of hard X-ray flux from weak dipole field (0.4 Tesla), three pole wigglers of peak field over 1 Tesla will be mainly used by NSLS bending magnet beam line users. Magnetic designs and kick maps for dynamic aperture surveys were created using the latest version of Radia for Mathematica 6 which we supported the development. There are other devices planned for later stage of the project, such as quasi-periodic EPU, superconducting wiggler/undulator, and Cryo-Permanent Magnet Undulator with Praseodymium Iron Boron (PrFeB) magnets and textured Dysprosium poles. For R&D, Hybrid PrFeB arrays were assembled and field measured at room temperature, liquid nitrogen and liquid helium temperature using our vertical test facility. We have also developed a specialized power supply for pulsed wire measurement.  
 
WEPC133 Status of the PETRA III Insertion Devices undulator, controls, multipole, insertion-device 2320
 
  • M. Tischer, M. Barthelmess, U. Englisch, J. Pflueger, A. Schoeps, J. Skupin
    DESY, Hamburg
  The PETRA storage ring is presently reconstructed towards a third generation light source. In total, 14 undulator beamlines will be available in the new octant of the machine. We report on the status of Petra III undulators. Three prototypes with 29mm period length, two 2m and one 5m long device have been investigated by mechanical and magnetic measurements. The prototype results are the basis for the refined design of the remaining 8 planar devices which are in the procurement phase. We present preliminary magnetic results of the prototypes and also report on the APPLE–2 and the in-vacuum undulator for PETRA III.  
 
WEPC155 Experimental Characterization of Permanent Magnet Harmonic Corrector Rings permanent-magnet, quadrupole, dipole, insertion-device 2371
 
  • A. Madur, S. Marks, S. Prestemon, D. Schlueter
    LBNL, Berkeley, California
  A total of three permanent magnet chicane magnets have been installed at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The magnet design incorporates counter-rotating permanent magnet pairs with trim coils. The purpose is to provide a fixed angular separation between two successive elliptically polarizing undulator (EPU) photon fans and to correct steering perturbation resulting from EPU polarization state and gap changes. This paper presents a method for the determination of the permanent magnets parameters and setting relative orientations of the rotors by performing magnetic measurements with rotating coils. The measurement method will be developed and illustrated with experimental data from the measurement of a 16 cylinder permanent magnet harmonic corrector ring.  
 
WEPC161 Some Remarks about Characterization of Magnetic Blocks with Helmholtz Coil dipole, insertion-device, synchrotron, 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.  
 
WEPD009 The CERN High Field Magnet Program dipole, luminosity, quadrupole, radiation 2419
 
  • G. De Rijk
    CERN, Geneva
  With the LHC, magnets of 10T peak field Nb-Ti technology were developed and this technology reached full maturity. The next step in field level, with a peak field in the range of 15T, will be needed for the LHC phase II upgrade. For this upgrade the temperature margin and radiation resistance of the Nb-Ti coil technology is not sufficient. Begin 2008 CERN starts a program to develop high field magnets for LHC upgrades and other future programs. For this mostly Nb3Sn conductors will be employed but also HTS conductors will be considered. In this paper an overview will be presented of the projects for which this HFM technology will be needed. The the program will be presented in terms of R&D chapters and work packages. The need and opportunities for collaborations with other institutes will be discussed.  
 
WEPD010 Electronic Systems for the Protection of Superconducting Devices in the LHC dipole, extraction, quadrupole, power-supply 2422
 
  • R. Denz, K. Dahlerup-Petersen, K. H. Mess
    CERN, Geneva
  The Large Hadron Collider LHC incorporates an unprecedented amount of superconducting components: magnets, bus-bars, and current leads. Most of them require active protection in case of a transition from the superconducting to the resistive state, the so-called quench. The electronic systems ensuring the reliable quench detection and further protection of these devices have been developed and produced over the last years and are currently being put into operation. The paper will describe the various protection devices and hereby focus on the final test and commissioning phase of the system. First results from operation will be presented as well as an analysis of the system performance.  
 
WEPD026 The Special LHC Interconnections: Technologies, Organization and Quality Control cryogenics, controls, vacuum, superconducting-magnet 2464
 
  • J.-P. G. Tock, F. F. Bertinelli, D. Bozzini, P. Cruikshank, O. Desebe, M. F. Felip-Hernando, C. Garion, A. Jacquemod, N. Kos, F. Laurent, A. Poncet, S. Russenschuck, I. Slits, L. R. Williams
    CERN, Geneva
  • L. Hajduk
    HNINP, Krakow
  • L. Vaudaux
    IEG, St-Genis-Pouilly
  In addition to the standard interconnections of the continuous cryostat of the Large Hadron Collider (LHC), there exists a variety of special ones related to specific components and assemblies, such as cryomagnets of the insertion regions, electrical feedboxes and superconducting links. Though they are less numerous, their specificities created many additional interconnection types, requiring a larger variety of assembly operations and quality control techniques, keeping very high standards of quality. Considerable flexibility and adaptability from all the teams involved (CERN staff, collaborating institutes, contractors) were the key points to ensure the success of this task. This paper first describes the special interconnections and presents the employed technologies which are adapted from the standard work. Then, the organization adopted for this non-repetitive work is described. Examples of non-conformities that were resolved are also discussed. Figures of merit in terms of quality and productivity are given and compared with standard interconnections work.  
 
WEPP004 Overall Optics Solutions for Very High Beta in Atlas optics, emittance, injection, luminosity 2527
 
  • S. M. White, H. Burkhardt, P. M. Puzo
    CERN, Geneva
  • S. Cavalier, M. Heller
    LAL, Orsay
  An insertion optics with a beta-star of at least 2600 m has been requested by the ATLAS experiment at the LHC. This is very far from the standard LHC physics optics and implies a significant reduction in the phase advance from this insertion corresponding to about half a unit in tune. We describe several alternatives how this could be integrated in overall LHC optics solutions with the possibility to inject, ramp and un-squeeze to the required very high beta.  
 
WEPP009 Collimator Integration and Installation Example of One Object to be Installed in the LHC vacuum, collimation, alignment, survey 2542
 
  • K. Foraz, O. Aberle, R. W. Assmann, C. Bertone, R. Chamizo, S. Chemli, J.-P. Corso, F. Delsaux, J. L. Grenard, J. M. Jimenez, Y. Kadi, K. Kershaw, M. Lazzaroni, R. Perret, Th. Weiler
    CERN, Geneva
  • J. Coupard
    IN2P3-CNRS, Orsay
  The collimation system is a vital part of the LHC project, protecting the accelerator against unavoidable regular and irregular beam loss. About 80 collimators will be installed in the machine before the first run. Two insertion regions are dedicated to collimation and these regions will be among the most radioactive in the LHC. The space available in the collimation regions is very restricted. It was therefore important to ensure that the 3-D integration of these areas of the LHC tunnel would allow straightforward installation of collimators and also exchange of collimators under the remote handling constraints imposed by high radiation levels. The paper describes the 3-D integration studies and verifications of the collimation regions combining the restricted space available, the dimensions of the different types of collimators and the space needed for transport and handling. The paper explains how installation has been planned and carried out taking into account the handling system and component availability.  
 
WEPP012 Analysis of Optical Layouts for the Phase 1 Upgrade of the CERN Large Hadron Collider Insertion Regions optics, quadrupole, dipole, dynamic-aperture 2551
 
  • M. Giovannozzi, F. Borgnolutti, O. S. Brüning, U. Dorda, S. D. Fartoukh, W. Herr, M. Meddahi, E. Todesco, R. Tomas, F. Zimmermann
    CERN, Geneva
  • R. de Maria
    EPFL, Lausanne
  In the framework of the studies for the upgrade of the insertions of the CERN Large Hadron Collider, four optical layouts were proposed with the aim of reducing the beta-function at the collision point down to 25 cm. The different candidate layouts are presented. Results from the studies performed on mechanical and dynamic aperture are summarized, together with the evaluation of beam-beam effects. Particular emphasis is given to the comparison of the optics performance, which led to retain two promising layouts for further investigation and development.  
 
WEPP024 Non-linear Correction Schemes for the Phase 1 LHC Insertion Region Upgrade and Dynamic Aperture Studies dynamic-aperture, resonance, quadrupole, optics 2569
 
  • R. Tomas, M. Giovannozzi, R. de Maria
    CERN, Geneva
  The Phase 1 LHC Interaction Region (IR) upgrade aims at increasing the machine luminosity essentially by reducing the beam size at the Interaction Point (IP). This requires a total redesign of the full IR. A large set of options have been proposed with conceptually different designs. This paper reports on a general approach for the compensation of the multipolar errors of the IR magnets in the design phase. The goal is to use the same correction approach for the different designs. The correction algorithm is based on the computation of the IR transfer map. Its performance is tested using the dynamic aperture as figure of merit.  
 
WEPP030 LHC Luminosity Upgrade: Protecting Insertion Region Magnets from Collision Debris shielding, luminosity, cryogenics, dipole 2584
 
  • E. Y. Wildner, F. Cerutti, A. Ferrari, M. Mauri, A. Mereghetti
    CERN, Geneva
  The Large Hadron Collider built at CERN now enters a starting-up phase where with the present design luminosities up to 1034 cm-2 s-1 will be reached after the running in phase. A possible upgrading of the machine to luminosities up to 1035 cm-2 s-1 requires a completely new insertion region design, and will be implemented in essentially two phases. The energy from collision debris is deposited in the insertion regions and in particular in the superconducting magnet coils with a possible risk of quench. We describe here how to protect the interaction region magnets against this irradiation to keep the energy deposition below critical values estimated for safe operation. The constraint is to keep the absorber size as small as possible to leave most of the magnet aperture available for the beam. This can be done by choosing a suitable material and design minimizing the load on the cryogenic system. We will describe a proposal of a design for the phase I upgrade lay-out (i.e., luminosities up to 2.5 1034 cm-2 s-1).  
 
WEPP031 Energy Deposited in the High Luminosity Inner Triplets of the LHC by Collision Debris luminosity, quadrupole, superconducting-magnet, kaon 2587
 
  • E. Y. Wildner, F. Cerutti, A. Ferrari, C. Hoa, J.-P. Koutchouk
    CERN, Geneva
  • F. Broggi
    INFN/LASA, Segrate (MI)
  • N. V. Mokhov
    Fermilab, Batavia, Illinois
  The 14 TeV center of mass proton-proton collisions in the LHC produce not only interesting events for physics but also debris ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of the deposited heat, that has to be transferred to the cryogenic system, have been made to guarantee that the energy deposition in the superconducting magnets does not exceed limits for magnet quenching and the capacity of the cryogenic system. The models of the LHC baseline are detailed and include description of, for energy deposition, essential elements like beam-pipes and corrector magnets. The evaluations made using the Monte-Carlo code FLUKA are compared to previous studies using MARS. For the comparison and consolidation of the calculations, a dedicated study of a simplified model has been made, showing satisfactory agreement.  
 
WEPP032 Parametric Study of Energy Deposition in the LHC Inner Triplet for the Phase 1 Upgrade quadrupole, interaction-region, dipole, luminosity 2590
 
  • E. Y. Wildner, F. Borgnolutti, F. Cerutti, M. Mauri, A. Mereghetti, E. Todesco
    CERN, Geneva
  To be able to make a global parametric analysis and to have some basic understanding of the influence of critical parameters, scaling laws may be of help. For the design of the LHC collision insertion regions, one of the critical parameters is the energy deposited in the insertion superconducting magnet coils, to avoid magnet quench, too heavy load on the cryogenic system, and degradation of the superconductor due to radiation. The influence on energy deposition of some key parameters for magnet design, such as the magnet apertures, the magnet lengths and positions, has been studied for some specified optical beta-value at the collision point.  
 
WEPP044 Commissioning the 90° Lattice for the PEP II High Energy Ring lattice, synchrotron, luminosity, 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.  
 
WEPP069 Tracking Tools to Estimate the Quench Time Constants for Magnet Failures in LHC simulation, superconducting-magnet, beam-losses, proton 2677
 
  • A. Gomez Alonso
    CERN, Geneva
  At LHC, beam losses, with about 360MJ of stored energy per beam at nominal collision operation, are potentially dangerous for the accelerator equipment and can also affect the operational efficiency by inducing quenches in superconducting magnets. Magnet failures may affect the beam leading to proton losses primarily in collimators and secondary in superconducting magnets due to scattering of protons from collimator jaws. The evolution of the beam during magnet failures has been simulated using MAD-X with a variable magnetic field. The impacts of particles in the collimators have been recorded as a function of time. A second program, CollTrack, has been used to determine the loss patterns of scattered particles from each collimator as a function of the initial impact parameter. The magnets that are likely to quench are identified and an estimation of the time between the beginning of a failure and a quench is obtained by combining the results from the simulations. The time to a start of a quench is a relevant parameter to determine the dump threshold of beam loss monitors in order to optimize protection redundancy and operation smoothness for LHC.  
 
WEPP110 Design and Operational Experience of the MICE Target target, beam-losses, injection, acceleration 2764
 
  • C. N. Booth, P. Hodgson, L. C. Howlett, M. T. Mohammad, R. Nicholson, P. J. Smith
    Sheffield University, Sheffield
  • N. Schofield
    University of Manchester, School of Electrical and Electronic Engineering, Manchester
  The MICE experiment requires a beam of low energy muons to test muon cooling. This beam will be derived parasitically from the ISIS synchrotron. A novel target mechanism has been developed which allows the insertion of a small titanium target into the proton beam halo on demand. The target must remain outside of the beam envelope during acceleration, and then overtake the beam during the last 2ms before extraction. The technical specifications are demanding, and require large accelerations and precise and reproducible location of the target in each cycle. The mechanism must also operate in a high radiation environment, and the moving parts and materials must be compatible with the stringent requirements of operating in a working accelerator. The design, and the commissioning and operational experience using this system during the first operating periods in 2008 is described.  
 
WEPP148 Generation of High Gradient Wakefields in Dielectric Loaded Structures electron, gun, laser, monitoring 2835
 
  • M. E. Conde, S. P. Antipov, F. J. Franchini, W. Gai, F. Gao, R. Konecny, W. Liu, J. G. Power, Z. M. Yusof
    ANL, Argonne, Illinois
  • C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio
  Dielectric loaded wakefield structures have potential to be used as high gradient accelerator components. Using the high current drive beam at the Argonne Wakefield Accelerator Facility, we employed cylindrical dielectric loaded wakefield structures to generate accelerating fields of up to 100 MV/m. Short electron bunches (13 ps FWHM) of up to 86 nC are used to drive these fields, either as single bunches or as bunch trains. These recently tested standing-wave structures have a field probe near the outer edge of the dielectric to sample the RF fields generated by the electron bunches. Monitoring of these high intensity RF fields serves to verify the absence of electric breakdown.  
 
WEPP151 Metallic Photonic Band Gap Accelerator Structure Experiments and Design vacuum, damping, radiation, electron 2841
 
  • R. A. Marsh, M. A. Shapiro, R. J. Temkin
    MIT/PSFC, Cambridge, Massachusetts
  Damping wakefields is a critical issue in the next generation of high gradient accelerators. Photonic bandgap (PBG) structures have unique properties that offer significant wakefield damping. The goal of this work is to quantify the higher order mode (HOM) wakefield content of a constructed metallic PBG accelerator structure, in order to test the theory of wakefield excitation in these structures and to provide direction for future structure design. Experimental measurements of wakefields excited by an 18 MeV electron beam in a 6 cell, 17.14 GHz metallic PBG traveling wave accelerator structure are reported. Because the electron beam used to generate wakefields in the PBG structure is bunched at the 17.14 GHz rf frequency, all wakefields observed were at integer multiples of 17.14 GHz. Using diode detectors, radiation has been observed at the input and output coupler ports as well as through a quartz window in the surrounding vacuum vessel. Estimates of wakefield radiation, made using HFSS and basic wakefield theory, compare well with experiment.  
 
WEPP165 GdfidL Simulations of International Linear Collider Candidate Collimator Assemblies simulation, linear-collider, collider, vacuum 2874
 
  • J. D.A. Smith
    Cockcroft Institute, Warrington, Cheshire
  Collimator performance is critical to the successful operation of any collider. Building on previous GdfidL simulations of collimator jaws, this paper describes simulations where STL files of the complete assembly are investigated and wakefield performance is determined and optimised.  
 
THPC033 Global Optimization of the Magnetic Lattice Using Genetic Algoritihms lattice, emittance, quadrupole, storage-ring 3050
 
  • D. Robin, F. Sannibale, C. Steier, W. Wan, L. Yang
    LBNL, Berkeley, California
  The traditional process of designing and tuning the magnetic lattice of a particle storage ring lattice to produce certain desired properties is not straight forward. Often solutions are found through trial and error and it is not clear that the solutions are close to optimal. In this paper we employ a technique we call GLASS (GLobal scan of All Stable Settings) that allows us to rapidly scan and find all possible stable modes and then characterize their associated properties. In this paper we illustrate how the GLASS technique gives a global and comprehensive vision of the capabilities of the lattice. In a sense, GLASS functions as a lattice observatory clearly displaying all possibilities. The power of the GLASS technique is that it is very fast and comprehensive. There is no fitting involved. It gives the lattice designer clear guidance as to where to look for interesting operational points. We demonstrate the technique by applying it to two existing storage ring lattices - the triple bend achromat of the ALS and the double bend achromat of CAMD. We extend the analysis to more complex lattices using multiobjective evolutionary analysis.  
 
THPC063 First Frequency Maps for Probing the Non-linear Dynamics of SOLEIL lattice, multipole, injection, quadrupole 3128
 
  • L. S. Nadolski, P. Brunelle, J.-P. Lavieville, P. Lebasque, A. Nadji, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a 2.75 GeV third generation synchrotron light source delivering photons to beam-lines since January 2007. With a 3.7 nm.rad horizontal emittance, its optics is based on a strong focusing lattice. Large on- and off-momentum apertures are required in order to provide good injection efficiency and as large as possible beam lifetime. It is then fundamental to be able to understand the limitations of these key figures. In order to probe the transverse non linear dynamics two pinger magnets have been installed into the injection straight section during last summer shutdown period. In this paper, their calibration will be described. Then first comparisons between modeled and real machine will be given for betatron tune shifts with amplitudes, and frequency maps. To end the non linear impact of insertion devices on beam dynamics will be discussed.  
 
THPC080 The VEPP-4M Dynamic Aperture Determination with Beam-beam Effects dynamic-aperture, beam-beam-effects, simulation, collider 3170
 
  • A. N. Zhuravlev, V. A. Kiselev, E. B. Levichev, O. I. Meshkov, P. A. Piminov, D. N. Shatilov, V. V. Smaluk
    BINP SB RAS, Novosibirsk
  To determine experimentally the particle stable area under the influence of beam-beam effects in the electron-positron collider VEPP-4M we measure the beam lifetime with high accuracy as a function of moving aperture. The measurement is performed by a photodiode installed in the collider diagnostic beam line. The experimental setup and the measurement results are described. Comparison with the tracking simulation is presented.  
 
THPC115 Commissioning of SOLEIL Fast Orbit Feedback system feedback, photon, storage-ring, controls 3248
 
  • N. Hubert, L. Cassinari, J.-C. Denard, J.-M. Filhol, N. Leclercq, A. Nadji, L. S. Nadolski, D. Pedeau
    SOLEIL, Gif-sur-Yvette
  The Fast Orbit Feedback system at SOLEIL is fully integrated into the BPM system equipped with Libera modules. Indeed, the correction algorithm has been embedded into the Libera FPGA which directly drives the power supplies of dedicated air coil correctors. The beam position measurements of the 120 BPMs are distributed around the storage ring by a dedicated network. Then, the correction is computed and applied at a rate of 10 kHz to 48 correctors installed over stainless-steel bellows, on each side of every straight section. The BPM system has been operational for some time. The fast orbit feedback system is in its commissioning phase. The design and first results of the latter are reported.  
 
THPC129 Coupling Correction in NSLS X-ray Ring quadrupole, coupling, electron, storage-ring 3290
 
  • M. G. Fedurin, I. Pinayev
    BNL, Upton, Long Island, New York
  In this paper we describe MATLAB script for reduction of the transverse coupling in the NSLS X-ray storage ring. The algorithm is based on varying strength of the skew quadrupoles and observation of the vertical beam size. The details of the iterative procedure are also discussed.  
 
THPC147 Generation of 1.5 Million Beam Loss Threshold Values proton, simulation, beam-losses, collimation 3333
 
  • E. B. Holzer, B. Dehning, L. Ponce, M. Sapinski, M. Stockner
    CERN, Geneva
  • D. K. Kramer
    TUL, Liberec
  • P. Priebe
    Poznan University of Technology, Poznan
  CERN's Large Hadron Collider will store an unprecedented amount of energy in its circulating beams. Beam-loss monitoring (BLM) is, therefore, critical for machine protection. It must protect against the consequences (equipment damage, quenches of superconducting magnets) of excessive beam loss. 4000 monitors will be installed at critical loss locations. Each monitor has 384 beam abort thresholds associated; for 12 integrated loss durations (40 us to 83 s) and 32 energies (450 GeV to 7 TeV). Depending on monitor location, the thresholds vary by orders of magnitude. For simplification, the monitors are grouped in 'families'. Monitors of one family have the same thresholds at start-up; they protect similar magnets against equivalent loss scenarios. The start-up calibration of the BLM system is required to be within a factor of five in accuracy; and the final accuracy should be a factor of two. Simulations (backed-up by control measurements) determine the relation between the BLM signal, the deposited energy and the critical energy deposition for damage or quench (temperature of the coil). The paper presents the details and systematic of determining 1.5 million threshold values.  
 
THPP138 Achievement and Evaluation of the Beam Vacuum Performance of the LHC Long Straight Sections vacuum, instrumentation, ion, proton 3685
 
  • G. Bregliozzi, V. Baglin, S. Blanchard, J. Hansen, J. M. Jimenez, K. Weiss
    CERN, Geneva
  The bake-out and activation of the 6 km Long Straight Sections (LSS) of the Large Hadron Collider (LHC) is in its final step. After bake-out and activation of the NEG coating, the average ultimate pressure, over more than one hundred vacuum sectors, is below 10-11 mbar. Therefore, the nominal requirement for the four experimental insertions is guaranteed. The nominal performances are also ensured for all the other insertions where collimators, RF cavities and beam dumping systems are present. The main difficulties encountered during the bake-out and activation of NEG coated chambers of the LSS vacuum sectors will be presented and discussed. In particular, the acceptance test and the limiting factors of the reached ultimate pressures will be addressed. Furthermore, the influence on the ultimate pressures of the beam vacuum elements (collimators, beam instrumentation, etc.) will be discussed. Finally, preliminary results obtained from a laboratory NEG pilot sector dedicated to the quality control of the LHC beam vacuum and to the evaluation of the NEG performance will be presented.  
 
THPP140 First Experience on NEG Coated Chambers at the Australian Synchrotron Light Source vacuum, synchrotron, storage-ring, 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.