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undulator

      
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MOZBPA01 Results from the VUV-FEL radiation, electron, FEL, laser 34
 
  • J. Rossbach
    DESY, Hamburg
  The talk will provide the latest results from the VUV-FEL. It will cover the general performance of the machine and comparison to theory. A status will be given of the performance of key systems: the gun, accelerating modules and RF systems, electron and photon beam diagnostics, timing and synchronization and undulator performance. Future developments and implementations will also be discussed (and implications to the XFEL).  
slides icon Transparencies
 
MOPCH002 Seeding the FEL of the SCSS Phase 1 Facility with the 13th Laser Harmonic of a Ti: Sa Laser Produced in Gas laser, FEL, radiation, SASE 44
 
  • G. Lambert, M. Bougeard, W. Boutu, P. Breger, B. Carré, D. Garzella, M. Labat, H. Merdji, P. Monchicourt, P. Salieres
    CEA, Gif-sur-Yvette
  • O.V. Chubar, M.-E. Couprie
    SOLEIL, Gif-sur-Yvette
  • T. Hara, H. Kitamura, T. Shintake
    RIKEN Spring-8 Harima, Hyogo
  • D. Nutarelli
    LAC, Orsay
  A seeding configuration, in which the 13th harmonic (60 nm) of a Ti: Sa laser (50 mJ, 10 Hz, 130 fs) generated in a gas cell is used as the external source, will be tested in 2006 on the SCSS test facility (SPring-8 Compact Sase Source, Japan). This facility is based on a thermionic cathode electron gun (1 nC of bunch charge), a C-band LINAC (5712 MHz, 35 MV/m) and two in-vacuum undulators (15 mm of period). The maximum electron beam energy is 250 MeV and the SASE emission from visible to 60 nm can be obtained. The High order Harmonic Generation (HHG) experiment was mounted off-line at the end of last December. A first chamber is dedicated to harmonic generation. A second one is used for spectral selection and adaptation of the harmonic waist in the modulator. The tests are performed in Saclay with the LUCA (Laser Ultra Court Accordable) laser (15 mJ, 10 Hz, 50 fs) from January to March at 266 nm, 160 nm and 60 nm and its results are presented here. Also, before performing the real tests in SPring-8 FEL presence, final theoretical estimations of the performances relying on 1D simulations using PERSEO code and 3D simulations using GENESIS and SRW codes are given.  
 
MOPCH003 Seeding SPARC Facility with Harmonic Generation in Gases: Preliminary Tests of the Harmonic Generation in Gas Chamber laser, FEL, electron, radiation 47
 
  • O. Tcherbakoff, M. Bougeard, P. Breger, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Monchicourt, P. Salieres
    CEA, Gif-sur-Yvette
  • M.-E. Couprie
    SOLEIL, Gif-sur-Yvette
  • A. Doria, L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma)
  In High Gain Harmonic Generation Free Electron Laser configuration, an external light source is injected in the first part of an undulator. The electron-photon interaction leads to a coherent light emission in the second part of the undulator. We propose to use the High Order Harmonic Generation in gases process as the seed for SPARC project (Frascati, Italy). With this facility, the electron beam is accelerated to 200 MeV and passes through an undulator of 6 sections. The preliminary tests on the seeding chambers presented in this paper have been realised at the CEA (Saclay, France). The experiment is based on three vacuum chambers. In the first one, a Ti: Sa laser (800 nm, 2.5 mJ, 50 fs, 10 Hz) is focussed in a 10 Hz pulsed gas jet (Argon or Xenon), producing harmonics of the fundamental. Filters in the second chamber enable the selection of the harmonic (3rd or 5th). Finally, a telescope focuses the harmonic beam at a given position. The whole module is to be moved to the SPARC facility. Appropriate tuning of the undulator gaps will amplify the 3rd and 5th harmonics seeded, as well as non-linear harmonics of those wavelengths, allowing the perspective of producing a FEL at 53 nm  
 
MOPCH004 Coherent Harmonic Generation Experiment on UVSOR-II Storage Ring laser, electron, storage-ring, klystron 50
 
  • M. Labat
    CEA, Gif-sur-Yvette
  • M.-E. Couprie
    SOLEIL, Gif-sur-Yvette
  • T. Hara
    RIKEN Spring-8 Harima, Hyogo
  • M. Hosaka, M. Katoh, A. Mochihashi, M. Shimada, J. Yamazaki
    UVSOR, Okazaki
  • G. Lambert
    RIKEN Spring-8, Hyogo
  • D. Nutarelli
    LAC, Orsay
  • Y. Takashima
    Nagoya University, Nagoya
  Harmonic Generation schemes on Free Electron Laser devices are very promising. The injection of a traditional laser source inside the first undulator leads to an efficient energy modulation of the electron bunch, and therefore, its spatial modulation, resulting in a more coherent light emission along the second undulator. Experiments have been performed on the UVSOR-II Storage Ring at Okazaki (Japan) with electrons stored at an energy of 600 MeV, and using a 2.5 mJ Ti:Sa laser at 800 nm wavelength, 1 kHz repetition rate, and 100 fs up to 2 ps pulse duration. The experimental setup is presented, including the transport alignment and synchronisation between the laser and the electron beam. The third harmonic at 266 nm has been characterised versus various parameters: current, RF cavity voltage, undulator gap, magnetic functions of the storage ring, and laser pulse duration. Those results are compared with theory via analytical models and simulations.  
 
MOPCH005 The ARC-EN-CIEL FEL Proposal emittance, laser, radiation, FEL 53
 
  • M.-E. Couprie, C. Bruni, O.V. Chubar, A. Loulergue, L. Nahon
    SOLEIL, Gif-sur-Yvette
  • B. Carré, D. Garzella, M. Jablonka, M. Labat, G. Lambert, F. Meot, P. Monot, A. Mosnier
    CEA, Gif-sur-Yvette
  • J.-R. Marquès
    LULI, Palaiseaux
  • D. Nutarelli
    LAC, Orsay
  • J.-M. Ortega
    CLIO/ELYSE/LCP, Orsay
  ARC-EN-CIEL (Accelerator-Radiation Complex for Enhanced Coherent Intense Extended Light), the French project of a fourth generation light source aims at providing the user community with coherent femtosecond light pulses covering from UV to soft X ray. It is based on a CW 1 GeV superconducting linear accelerator delivering high charge, subpicosecond, low emittance electron bunches with a high repetition rate (1 kHz). Electron beam calculations will be presented. The FEL is based on the injection of High Harmonics Generated in Gases (HHG) in a High Gain Harmonic Generation scheme, leading to a rather compact solution. The produced radiation extending down to 0.8 nm with the Non Linear Harmonics reproduces the good longitudinal and transverse coherence of the harmonics in gas. Calculations are preformed with PERSEO, taking into account the proper transverse overlap between HHG and the electron beam, and with SRW. Optional beam loops are foreseen to increase the beam current or the energy. They will accommodate fs synchrotron infrared Coherent Synchrotron Radiation sources, VUV and X ray ranges and a FEL oscillator in the 10 nm range. An important synergy is expected between accelerat  
 
MOPCH006 Beam Adaptation at the Infrared FEL, CLIO FEL, electron, simulation, quadrupole 56
 
  • J.P. Berthet, F. Glotin, J.-M. Ortega
    CLIO/ELYSE/LCP, Orsay
  • W. Salah
    The Hashemite University, Zarka
  The infrared free-electron laser CLIO is tunable from 3 to 150 5m by operating its driver RF linear accelerator between 50 and 12 MeV. This is the largest spectral range ever obtained with a single optical cavity. We have studied the electron beam transverse adaptation in the FEL undulator throughout the spectral and energy range. Each beam dimension is measured by a moving wire whose temperature dependant resistivity is monitored. The results are compared with simulations computed with the TRANSPORT code.  
 
MOPCH007 Undulators for a Seeded HGHG-FEL Test Bench at MAX-lab electron, FEL, radiation, laser 59
 
  • J. Bahrdt, H.-J. Baecker, W.F. Frentrup, A. Gaupp, K. Goldammer, A. Meseck, M. Scheer
    BESSY GmbH, Berlin
  • S. Werin
    MAX-lab, Lund
  Undulators for a Seeded HGHG-FEL at MAX-lab Within the European FEL Design Study a seeded HGHG-FEL will be set up at MAX-lab. In the modulator, a planar pure permanent magnet undulator, the 3rd harmonic of a Ti:Sapphire laser (267nm) interacts with the electron beam. In the following dispersive section the energy modulation is converted into a spatial modulation. The radiator emits at the third harmonic (89nm). The radiator has an APPLE II type magnetic structure providing full polarization control. The undulators and the dispersive section are currently built at BESSY. The electron beam height at MAX-lab of 400mm requires a specific design of the undulator carriages. The magnetic and mechanical design of the HGHG stage will be presented.  
 
MOPCH009 The BESSY 2nd Generation Soft X-ray FEL User Facility FEL, radiation, laser, controls 65
 
  • J. Knobloch
    BESSY GmbH, Berlin
  Future VUV-to-soft-X-ray FEL facilities promise to open fundamentally new frontiers for the synchrotron user community. So-called 2nd generation FELs, which use seeded schemes rather than SASE, can deliver reproducible ultra-short photon pulses at an energy level of mJ/pulse. BESSY has been designing a High-Gain-Harmonic-Generation (HGHG) based FEL with a 2.3 GeV superconducting driver linac that covers photon energies from 24 eV to 1 keV. The design provides full tuneability of photon energy, variable beam polarization and complete synchronization to external lasers—all essential for future femtosecond, time-resolved pump-probe experiments. Also, the CW linac offers great flexibility for the repetition rates and pulse patterns. BESSY-organized User Workshops helped identify the user requirements for such an FEL. This information provided the basis for the Technical Design Report that was submitted to the German Wissenschaftsrat in 2004, which then held an on-site review in 2005. Meanwhile, preparatory studies continue at BESSY. They include start-to-end simulations, tolerance studies, and the development of superconducting RF technology in the HoBiCaT test facility.  
 
MOPCH015 Impact of Undulator Wakefileds and Tapering on European X-ray FEL Performance radiation, FEL, simulation, SASE 83
 
  • I. Zagorodnov, M. Dohlus, T. Limberg
    DESY, Hamburg
  The European X-ray Free-Electron Laser (XFEL) based on self-amplified spontaneous emission (SASE) requires an electron beam with a few kA peak current and a small-gap undulator system up to 250 m in length. The interaction between the high-current electron bunch and the undulator vacuum chamber affects the FEL performance. In this paper we estimate the induced wakefields in elliptical pipe geometry, taking into account the main geometrical variations of the chamber. To study the expected performance in the presence of the calculated wakefields, we are doing start-to-end simulations with the tracking codes ASTRA, CSRtrack and GENESIS. To compensate the wakefield impact on the FEL performance, an adiabatic change of undulator parameters is considered.  
 
MOPCH024 Future Seeding Experiments at SPARC FEL, laser, radiation, resonance 95
 
  • L. Giannessi, S. Ambrogio, F. Ciocci, G. Dattoli, A. Doria, G.P. Gallerano, E. Giovenale, M. Quattromini, A. Renieri, C. Ronsivalle, I.P. Spassovsky
    ENEA C.R. Frascati, Frascati (Roma)
  • D. Alesini, M.E. Biagini, R. Boni, M. Castellano, A. Clozza, A. Drago, M. Ferrario, V. Fusco, A. Gallo, A. Ghigo, M. Migliorati, L. Palumbo, C. Sanelli, F. Sgamma, B. Spataro, S. Tomassini, C. Vaccarezza, C. Vicario
    INFN/LNF, Frascati (Roma)
  • M. Bougeard, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Salieres, O. Tcherbakoff
    CEA, Gif-sur-Yvette
  • M.-E. Couprie
    SOLEIL, Gif-sur-Yvette
  • A. Dipace, E. Sabia
    ENEA Portici, Portici (Napoli)
  • M. Mattioli, P. Musumeci, M. Petrarca
    Università di Roma I La Sapienza, Roma
  • M. Nisoli, G. Sansone, S. Stagira, S. de Silvestri
    Politecnico/Milano, Milano
  • L. P. Poletto, G. T. Tondello
    Univ. degli Studi di Padova, Padova
  • L. Serafini
    INFN-Milano, Milano
  Sources based on High order Harmonics Generated in gases (HHG) with high power Ti:Sa lasers pulses represent promising candidates as seed for FEL amplifiers for several reasons, as spatial and temporal coherence, wavelength tunability and spectral range, which extends down to the nm wavelength scale. This communication describes the research work plan that is under implementation at the SPARC FEL facility in the framework of the EUROFEL programme. The main goal of the collaboration is to study and test the amplification and the FEL harmonic generation process of an input seed signal obtained as higher order harmonics generated both in crystals (400 nm and 266 nm) and in gases (266 nm, 160 nm, 114 nm). The SPARC FEL can be configured to test several cascaded FEL layouts that will be analysed in this contribution.  
 
MOPCH028 Status of the SPARX FEL Project emittance, linac, simulation, brightness 107
 
  • C. Vaccarezza, D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, D. Filippetto, V. Fusco, A. Gallo, A. Ghigo, S. Guiducci, M. Migliorati, L. Palumbo, L. Pellegrino, M.A. Preger, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stella, F. Tazzioli, M. Vescovi, C. Vicario
    INFN/LNF, Frascati (Roma)
  • F. Alessandria, A. Bacci, F. Broggi, C. De Martinis, D. Giove, M. Mauri
    INFN/LASA, Segrate (MI)
  • L. Catani, E. Chiadroni, A. Cianchi, C. Schaerf
    INFN-Roma II, Roma
  • S. Cialdi, C. Maroli, V. Petrillo, M. Rome, L. Serafini
    INFN-Milano, Milano
  • F. Ciocci, G. Dattoli, A. Doria, F. Flora, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P.L. Ottaviani, G. Parisi, L. Picardi, M. Quattromini, A. Renieri, C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma)
  • P. Emma
    SLAC, Menlo Park, California
  • L. Ficcadenti, A. Mostacci
    Rome University La Sapienza, Roma
  • M. Mattioli
    Università di Roma I La Sapienza, Roma
  • P. Musumeci
    INFN-Roma, Roma
  • S. Reiche, J.B. Rosenzweig
    UCLA, Los Angeles, California
  The SPARX project consists in an X-ray-FEL facility jointly supported by MIUR (Research Department of Italian Government), Regione Lazio, CNR, ENEA, INFN and Rome University Tor Vergata. It is the natural extension of the ongoing activities of the SPARC collaboration. The aim is the generation of electron beams characterized by ultra-high peak brightness at the energy of 1 and 2 GeV, for the first and the second phase respectively. The beam is expected to drive a single pass FEL experiment in the range of 13.5-6 nm and 6-1.5 nm, at 1 GeV and 2 GeV respectively, both in SASE and SEEDED FEL configurations. A hybrid scheme of RF and magnetic compression will be adopted, based on the expertise achieved at the SPARC high brightness photoinjector presently under commissioning at Frascati INFN-LNF Laboratories. The use of superconducting and exotic undulator sections will be also exploited. In this paper we report the progress of the collaboration together with start to end simulation results based on a combined scheme of RF compression techniques.  
 
MOPCH029 Status of the SPARC Project laser, emittance, gun, electron 110
 
  • P. Musumeci, D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca
    Università di Roma I La Sapienza, Roma
  • D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario
    INFN/LNF, Frascati (Roma)
  • F. Alessandria, A. Bacci, I. Boscolo, F. Broggi, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, M. Mauri, V. Petrillo, M. Rome, A.R. Rossi, L. Serafini
    INFN-Milano, Milano
  • L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, S. Tazzari
    INFN-Roma II, Roma
  • F. Ciocci, G. Dattoli, A. Dipace, A. Doria, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P.L. Ottaviani, S. Pagnutti, L. Picardi, M. Quattromini, A. Renieri, G. Ronci, C. Ronsivalle, M. Rosetti, E. Sabia, M. Sassi, A. Torre, A. Zucchini
    ENEA C.R. Frascati, Frascati (Roma)
  • A. Perrone
    INFN-Lecce, Lecce
  • S. Reiche, J.B. Rosenzweig, G. Travish
    UCLA, Los Angeles, California
  The SPARC Project is starting the commissioning of its photo-injector. RF gun, RF sources, RF network and control, power supplies, emittance meter, beam diagnostics and control to measure the RF gun beam are installed. The photocathode drive laser has been characterized in terms of pulse shape and quality. We expect to conduct beam measurements at RF gun exit in the next future and consequently to start the installation of accelerating sections. The design of the 12 m undulator for the FEL experiment has been completed and the first undulator section out of 6 is under construction: we expect to characterize it at Frascati ENEA laboratory within the next months. SPARC as a facility will host FEL experiments using SASE, seeding and non-linear resonant harmonics. Additional R&D on X-band and S-band structures for velocity bunching are in progress, as well as studies on new photocathode materials and exotic undulator designs. We also present studies on solenoid field defects, beam based alignments, exotic electron bunch production (blow-out of short laser pulses or intensity modulated laser pulses). The possible use of segmented superconducting micro-undulators will be discussed too.  
 
MOPCH034 On a Skeleton CASSINI Ovals Current Undulator electron, laser, radiation, free-electron-laser 119
 
  • A.M. Mihalache, V.I.R. Niculescu
    INFLPR, Bucharest - Magurele
  • V. Babin
    INOE, Bucharest
  • M.R. Leonovici, C. Stancu
    Bucharest University, Faculty of Physics, Bucharest-Magurele
  • F. Scarlat
    Valahia University, Faculty of Sciences, Targoviste
  A new undulator structure for free electron lasers was presented. Current skeleton CASSINI ovals produced magnetic fields which are spatially periodic. The current structure was in the shape of stacks of modified CASSINI ovals. The current has alternating directions. The magnetic field components for each wire present C2 symmetry. CASSINI undulator transverse cross-section* was approximated by polygons. In cartesian coordinates the Biot-Savart law was analytically evaluated. The magnetic field was mainly transversal and easily adjusted with the current. The versatility of this structure introduces a new type of two beams longitudinal undulator or wiggler design for transverse moments.

*Cassini curve; C. Mihu, I.P. Iambor-1989.

 
 
MOPCH038 Predicted Parameters of the Second Stage of High Power Novosibirsk FEL FEL, electron, simulation, ERL 124
 
  • A.V. Kuzmin, O.A. Shevchenko, N. Vinokurov
    BINP SB RAS, Novosibirsk
  The first stage of Novosibirsk high power terahertz FEL was successfully put into operation in 2003*. The measured parameters of the FEL turned out to be in a good agreement with calculations [2]. The second and the third stages of the FEL are under construction now. The beam energy at the second stage will be about 20 MeV and the wavelength will change in the range 40-80 μm. In this paper we present the design parameters for the second stage FEL. The simulations were carried out with the help of 1-D code based on macroparticles. This code was previously used for the first stage simulations**.

*E. A. Antokhin et al. NIM A528 (2004) p.15-18.**A. V. Kuzmin et al. NIM A543 (2005) p.114-117.

 
 
MOPCH040 Simulations for the FEL Test Facility at MAX-lab within EUROFEL FEL, electron, simulation, gun 127
 
  • S. Thorin, M. Brandin, S. Werin
    MAX-lab, Lund
  • M. Abo-Bakr, J. Bahrdt, K. Goldammer
    BESSY GmbH, Berlin
  Within the EUROFEL project a High Gain Harmonic Generation Free Electron Laser will be constructed at MAX-lab in collaboration with BESSY. The electron bunches will be created in the existing MAX-lab injector and transported to the inside of the MAX II ring where the FEL undulators will be located. To predict FEL performance and stability, simulations of the photo injector, linac, recirculator, transport and undulator sections as well as start to end simulations have been carried out.  
 
MOPCH043 An Optimization Study for an FEL Oscillator at TAC Test Facility FEL, electron, radiation, laser 136
 
  • Ö.M. Mete, Ö. Karsli, O. Yavas
    Ankara University, Faculty of Engineering, Tandogan, Ankara
  Recently, conceptual design of the Turkic Accelerator Center (TAC) proposal was completed. The main goal of this proposal is a charm factory that consists of a linac-ring type electron-positron collider. In addition, synchrotron radiation from the positron ring and free electron laser from the electron linac are proposed. The project related with this proposal has been accepted by the Turkish government. It is planned that the Technical Design Report of TAC will have been written in the next three years. In this period, an infrared oscillator free electron laser (IR FEL) will be constructed as a test facility for TAC. 20 and 50 MeV electron energies will be used to obtain infrared FEL. The main parameters of the electron linacs, the optical cavities and the FEL were determined. The possible use of obtained laser beam in basic and applied research areas such as biotechnology, nanotechnology, semiconductors and photo chemistry were discussed.  
 
MOPCH045 A Source of Coherent Soft X-ray Radiation Based on High-order Harmonic Generation and Free Electron Lasers laser, FEL, electron, simulation 142
 
  • M. Gullans, J.S. Wurtele
    UCB, Berkeley, California
  • G. Penn, A. Zholents
    LBNL, Berkeley, California
  We examine a scheme for a Free Electron Laser (FEL) harmonic amplifier seeded by a ~30-nm wavelength signal produced using a process of High-order Harmonic Generation (HHG). The seed is first amplified in an optical klystron from ~100 kW to ~30 MW using a 1 GeV electron beam and then is used for an energy modulation of electrons in the downstream undulator. Subsequently, a 100-MW level of radiation at shorter wavelengths down to 4 nm is obtained by bunching the energy modulated electrons and passing the bunched beam through an undulator tuned to the desired harmonic of 30 nm. We also compare this scheme to a more familiar harmonic cascade FEL by replacing the HHG with an additional stage of harmonic generation.  
 
MOPCH048 Linac Coherent Light Source Electron Beam Collimation linac, collimation, LCLS, cathode 148
 
  • J. Wu, D. Dowell, P. Emma, C. Limborg-Deprey, J.F. Schmerge
    SLAC, Menlo Park, California
  This paper describes the design and preliminary simulations of the electron beam collimation system in the Linac Coherent Light Source (LCLS) linac. Dark current is expected from the gun and some of the accelerating cavities. Particle tracking of the expected dark current through the entire LCLS linac, from L0-linac exit to FEL undulator entrance, is used to estimate final particle extent in the undulator as well as expected beam loss at each collimator or aperture restriction. A table of collimators and aperture restrictions is listed along with halo particle loss results, which includes an estimate of average continuous beam power lost on each individual collimator. In addition, the transverse wakefield alignment tolerances are calculated for each collimator.  
 
MOPCH049 Trajectory Stability Modeling and Tolerances in the LCLS LCLS, quadrupole, linac, CSR 151
 
  • J. Wu, P. Emma
    SLAC, Menlo Park, California
  To maintain stable performance of the Linac Coherent Light Source X-ray Free-electron laser, one has to control undulator trajectory stability to a small fraction of the rms beam size. BPM based feedback loops running at 120 Hz will be effective in controlling jitter at low frequencies less than a few Hz. On the other hand, linac and injector stability tolerances must control jitter at higher frequencies. In this paper, we study the possible sources of such high frequency jitter, including: 1) steering coil current regulation; 2) quadrupole (and solenoid) transverse vibrations; 3) quadrupole (and solenoid) current regulation in presence of typical 200-micron misalignments; 4) charge jitter coupling to RF cavity transverse wakefield due to alignment errors; and 5) bunch length jitter coupling to Coherent Synchrotron Radiation in Chicane. Based on this study, we then set tolerances on each item.  
 
MOPCH066 The Conceptual Design of 4GLS at Daresbury Laboratory linac, radiation, electron, FEL 181
 
  • J.A. Clarke
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  4GLS is a novel next generation proposal for a UK national light source to be sited at Daresbury Laboratory, based on a superconducting energy recovery linac (ERL) with both high average current photon sources (undulators and bending magnets) and three high peak current free electron lasers. Key features are a high gain, seeded FEL amplifier to generate XUV radiation and the prospect of advanced research arising from unique combinations of sources with femtosecond pulse structure. The conceptual design is now completed and a CDR recently published. The 4GLS concept is summarised, highlighting how the significant design challenges have been addressed, and the project status and plans explained.  
 
MOPCH069 Lattice Design for the Fourth Generation Light Source at Daresbury Laboratory linac, FEL, laser, electron 184
 
  • B.D. Muratori, M.A. Bowler, H.L. Owen, S.L. Smith
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • S.V. Miginsky
    BINP SB RAS, Novosibirsk
  The proposed Fourth Generation Light Source (4GLS) has three electron transport paths, an energy recovery loop containing the main linac, IDs and a VUV-FEL, a separate branch after the main linac for an XUV-FEL and a transport path for an IR-FEL. The first two present major challenges in lattice design. The energy recovery loop will be fed by a high average current gun, with bunches of charge of about 80 pC. High charge (1nC) bunches from a high brightness gun will be accelerated prior to the main linac and split into the XUV-FEL branch using energy separation after the main linac. We present a lattice design and results from numerical modelling of the electron bunch transport. The requirements of the machine are short bunches, a small emittance for both branches and an overall topology which gives a reasonable dimension for the building. Different transport and compression schemes were assessed to meet these requirements whilst balancing the disruptive effects of longitudinal and transverse space charge, CSR, wakefields and BBU. Investigations into all of these instabilities are summarized together with other transport issues and the resulting requirements on all IDs.  
 
MOPLS069 Development of a Superconducting Helical Undulator for the ILC Positron Source positron, electron, linear-collider, CERN 706
 
  • Y. Ivanyushenkov, E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, J. Rochford
    CCLRC/RAL, Chilton, Didcot, Oxon
  • I.R. Bailey, D.P. Barber, J.A. Clarke, J.B. Dainton, O.B. Malyshev, D.J. Scott, B.J.A. Shepherd
    Cockcroft Institute, Warrington, Cheshire
  • P. Cooke, L.I. Malysheva
    Liverpool University, Science Faculty, Liverpool
  • G.A. Moortgat-Pick
    CERN, Geneva
  An undulator positron source has been recently selected by the International Linear Collider (ILC) community as a baseline. For the ILC a helical undulator capable of producing 10 MeV photons and with a period as close as possible to 10 mm is required. The HeliCal collaboration in the UK is looking at the merits of both permanent magnet and superconducting technologies for the design of a helical undulator. For the superconducting option, several prototypes have been built and tested. This paper details the design, construction and test results of the first superconducting prototypes.  
 
MOPLS072 Status of the HeLiCal Contribution to the Polarised Positron Source for the International Linear Collider positron, electron, photon, polarization 715
 
  • J.A. Clarke, O.B. Malyshev, D.J. Scott
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • I.R. Bailey, P. Cooke, J.B. Dainton, L.I. Malysheva
    Liverpool University, Science Faculty, Liverpool
  • D.P. Barber
    DESY, Hamburg
  • E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, Y. Ivanyushenkov, J. Rochford
    CCLRC/RAL, Chilton, Didcot, Oxon
  • G.A. Moortgat-Pick
    Durham University, Durham
  The baseline positron source for the International Linear Collider is a helical undulator-based design, which can generate unprecedented quantities of polarised positrons. A major thrust of the global design in this area is led by the UK-based HeLiCal collaboration. The collaboration takes responsibility for the design and prototyping of the helical undulator itself, which is a highly demanding short period device with very small aperture, and also leads the start to end simulations of the polarised particles to ensure that the high polarisation levels generated are maintained from the source, right through the beam transport systems and up to the interaction point itself. This paper will provide an update on the work of the collaboration, focusing on these two topic areas, and will also discuss future plans.  
 
MOPLS105 Collimators for ILC positron, target, electron, radiation 807
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We considered two types of collimators for usage in undulator conversion system of ILC. In the first, the Pyrolytic graphite is used and it is installed in front of a target; the second one uses InGa alloy in rotating cylinder. The last one installed in front of undulator. Collimators allow absorption single train on bunches in ILC and enhace the photon polarization.  
 
MOPLS107 Test of SC Undulator for ILC positron, vacuum, collider, electron 813
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represent details of design and results of test SC 40cm-long undulator having period 10mm and aperture ~8 mm allowing K=0.7. This undulator can be used in ILC positron conversion system.  
 
MOPLS108 Liquid Metal Target for ILC target, positron, single-bunch, electron 816
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We considered the Hg target for gamma/positron conversion suitable for usage in ILC project. Positron scheme generation with undulator allows usage thin Hg jet confined in profiled duct with rectangular cross-section.  
 
MOPLS109 Operational Experience with Undulator for E-166 positron, electron, vacuum, SLAC 819
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represent results of operation of 2.54 mm period, K=0.2, up to 30 Hz undulator used in E-166 experiment for polarized positron production. One peculiarity is in usage of Ferrofluid for cooling.  
 
MOPLS118 Magnetic Modelling of a Short-period Superconducting Helical Undulator for the ILC Positron Source positron, TESLA, photon, cryogenics 840
 
  • J. Rochford, E. Baynham, T.W. Bradshaw, F.S. Carr
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • I.R. Bailey, L.I. Malysheva
    Cockcroft Institute, Warrington, Cheshire
  • D.P. Barber
    DESY, Hamburg
  • A.J. Brummitt, Y. Ivanyushenkov
    CCLRC/RAL, Chilton, Didcot, Oxon
  • J.A. Clarke, O.B. Malyshev, D.J. Scott
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. Cooke, J.B. Dainton
    Liverpool University, Science Faculty, Liverpool
  • G.A. Moortgat-Pick
    Durham University, Durham
  A positron source utilising undulators is now defined as the baseline option for the International Linear Collider (ILC). The ILC requires a short period undulator, as close to 10mm as possible, that is capable of producing 10 MeV photons. The HeliCal collaboration in the UK has undertaken a programme to design, develop and produce a prototype undulator. As part of the programme, the group has used the OPERA software package to perform the magnetic design of the undulator. The design has addressed several issues, including the effect of magnetic material for the undulator former, optimal winding geometry, the magnetic flux inside the superconductor and its variation with undulator period and the winding bore. This paper summarizes the results of both the 2d and the 3d magnetic simulations.  
 
TUYFI02 Latest Developments on Insertion Devices wiggler, permanent-magnet, electron, ESRF 969
 
  • P. Elleaume, J. Chavanne
    ESRF, Grenoble
  A review will be carried out of the developments on Insertion Devices that have taken place world wide in the last few years. These include the development of long period electro-magnet undulators, the operational results of a number of Apple-II undulators, the development of superconducting short period multipole wigglers, as well as the construction and operation of several in-vacuum undulators. The construction of a large number of competitive middle energy synchrotron sources in the hard X-ray range means that the need to increase the photon energy in the fundamental peak of an undulator is becoming a very important issue. Two main development strategies are currently being investigated. One consists of using superconducting undulator technology, the other of a further refinement of the in-vacuum undulator permanent magnet technology with cryogenic cooling of the magnetic assembly. The issues and challenges that are part of each approach will be presented, together with the latest results.  
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TUPCH081 Technical Aspects of the Integration of the Optical Replica Synthesizer for the Diagnostics of Ultra-short Bunches in FLASH at DESY laser, electron, DESY, vacuum 1199
 
  • V.G. Ziemann
    UU/ISV, Uppsala
  • N.X. Javahiraly, P. van der Meulen
    FYSIKUM, AlbaNova, Stockholm University, Stockholm
  • M. Larsson
    Stockholm University, Department of Physics, Stockholm
  • E. Saldin, H. Schlarb, E. Schneidmiller, A. Winter, M.V. Yurkov
    DESY, Hamburg
  In this paper we present an overview of current status of the Optical Replica synthesizer at DESY. The method is based on producing an "optical copy" of the electron bunch with its subsequent analysis with optical techniques*. To this end, a near-IR laser beam is superimposed on the electron beam in the first undulator of an optical klystron. In the following dispersive section the laser-induced energy modulation is transformed into a density modulation . The modulated electron bunch then produces a strong optical pulse in the second undulator. Analysis of this near-IR pulse (the optical copy) then provides information about the profile, the slice emittance and the slice energy spread of the electron bunch. We discuss the implementation of such a measurement set-up at the FLASH facility at DESY and investigate the influence of various parameters on the performance of the device. Topics we address include the dispersive chicane, as well as the requirements for the seed laser pulses and the detection and analysis of the near-IR pulse.

*E. Saldin, et al. "A simple method for the determination of the structure of ultrashort relativistic electron bunches," Nucl. Inst. and Methods A 539 (2005) 499.

 
 
TUPCH155 2D and 1D Surface Photonic Band Gap Structures for Accelerator Applications radiation, electron, plasma, SLAC 1388
 
  • I.V. Konoplev, A.W. Cross, W. He, P. MacInnes, A. Phelps, C.W. Robertson, K. Ronald, C.G. Whyte
    USTRAT/SUPA, Glasgow
  High frequency (26.5GHz to 40GHz), high power (tens of MW) microwave sources are required for cavity testing and conditioning applications in accelerators such as CLIC. The first study of microwave radiation from a co-axial Free-Electron Maser (FEM) based on a two-mirror cavity formed by a 2D Surface Photonic Band Gap (SPBG) structure (input mirror 10.4cm) and 1D SPBG structure (output mirror 10cm) is presented. The electron beam source consisted of a magnetically insulated plasma flare emission carbon cathode. Application of a 450kV voltage pulse of duration ~250ns across the cathode and grounded anode resulted in the production of a 7.0cm diameter annular electron beam of current ~1500A. The output radiation power from the FEM was measured using a Ka-band horn with 60dB of attenuation in front of a microwave detector located at a distance of 1.5m from the output window. By integrating the microwave power measured at the detector over the radiation pattern a total power of 50 (±10) MW corresponding to an efficiency of ~9% was calculated. The location of the operating frequency was found to lie between 35GHz and 39GHz, which agrees with theoretically predicted frequency of 37.2GHz.  
 
TUPLS001 Enhanced Optical Cooling of Ion Beams for LHC ion, kicker, betatron, pick-up 1483
 
  • E.G. Bessonov, M.V. Gorbunkov
    LPI, Moscow
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  Enhanced optical cooling (EOC) of fully stripped lead ions in LHC is investigated. The method of EOC is based on the usage of pickup and kicker undulators and optical amplifier. External selectivity is arranged by a moving screen located on the image plane of the optical system, projecting the emitted undulator radiation there (see physics/0509196). Nonlinear features of cooling and requirements to the ring lattice, optical and laser systems are discussed. Comparison with classical optical stochastic cooling (OSC) is represented as well.  
 
WEPCH015 Measurement and Correction of Dispersion in the VUV-FEL quadrupole, simulation, DESY, electron 1951
 
  • E. Prat, W. Decking, T. Limberg
    DESY, Hamburg
  Increase in transverse beam size in the undulator caused by dispersive effects is one of the major limitations for the operation of FLASH, the VUV-FEL at DESY. Sources of the (spurious) dispersion are field errors and stray magnet fields in the undulator beam line as well as spurious dispersion created upstream of the undulator by, for instance, rf coupler kicks, magnet misalignments and field errors. The impact of these errors on dispersion generation depends on the actual operating conditions of the accelerator, so the dispersion must be measured and controlled frequently. In this paper we present numerical studies of spurious dispersion generation, first dispersion measurements and correction results.  
 
WEPCH021 Generalized Twiss Coefficients Including Transverse Coupling and E-beam Growth electron, emittance, CSR, radiation 1966
 
  • F. Ciocci, G. Dattoli
    ENEA C.R. Frascati, Frascati (Roma)
  • M. Migliorati
    Rome University La Sapienza, Roma
  We use a generalization of the Twiss coefficients to the fully transverse coupled case. We show that the formalism is particularly useful to treat problems involving the beam optics of electrons propagating in undulators or solenoids. The method allows the treatment in analytical terms, we generalize the method including the effect of spatial charges and higher order multi-polar terms. The method is then applied to a specific example relevant to e-beam emittance dilution in solenoid and exotic undulators.  
 
WEPLS046 Radiation Levels and Activation at the ILC Positron Source positron, target, photon, electron 2478
 
  • A. Ushakov, S. Riemann
    DESY Zeuthen, Zeuthen
  • Eckhard. Elsen, K. Floettmann
    DESY, Hamburg
  • K.N. Sanosyan
    CANDLE, Yerevan
  An undulator-based positron source is recommended as baseline design for the International Linear Collider (ILC). Photons generated by electrons passing an undulator hit a rotating target and create electron-positron pairs. The positrons are captured and accelerated. An advantage of this source is the significantly lower radiation level in comparison to a conventional positron source which uses the electron beam directly to produce electron-positron pairs. The fluxes of neutrons and photons have been calculated with the particle transport code FLUKA. The activation of the positron source components has been estimated depending on the parameters of the source. The results for undulator-based and conventional positron sources are compared and presented.  
 
WEPLS048 Development of a Positron Production Target for the ILC Positron Source target, photon, positron, vacuum 2484
 
  • I.R. Bailey, I.R. Bailey, J.B. Dainton, D.J. Scott
    Cockcroft Institute, Warrington, Cheshire
  • V. Bharadwaj, J. Sheppard
    SLAC, Menlo Park, California
  • P. Cooke, P. Sutcliffe
    Liverpool University, Science Faculty, Liverpool
  • J.G. Gronberg, D.J. Mayhall, W.T. Piggott, W. Stein
    LLNL, Livermore, California
  The future International Linear Collider (ILC) will require of order 1014 positrons per second to fulfil its luminosity requirements. The current baseline design produces this unprecedented flux of positrons using an undulator-based source. In this concept, a collimated beam of 10MeV photons produced from the action of an undulator on the main electron beam of the ILC is incident on a conversion target. Positrons produced in the resulting electromagnetic shower can then be captured, accelerated and injected into a damping ring. The international community is pursuing several alternative technologies to develop a target capable of long-term operation in the intense photon beam. In the design being developed jointly by the Cockcroft Institute, LLNL and SLAC, a thin (0.4 radiation length) water-cooled Titanium alloy target wheel of diameter 4m is rotated at approximately 1000rpm to spread the incident power of each pulse over a wide area. We present the latest target design, report on the status of the target prototypes and computer models, and review the interplay between the target technology, capture optics, photon collimator and remote-handling systems.  
 
THXPA02 Overview of the Status of the SOLEIL Project SOLEIL, storage-ring, booster, vacuum 2723
 
  • J.-M. Filhol, J.C. Besson, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.M. Godefroy, C. Herbeaux, V. Le Roux, P. Lebasque, A. Lestrade, M.-P. Level, A. Loulergue, P. Marchand, J.L. Marlats, A. Nadji, L.S. Nadolski, R. Nagaoka, B. Pottin, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  SOLEIL is a third generation synchrotron radiation source, under construction in France near Paris. The storage ring consists of a 357 m circumference ring, with 16 cells and 24 straight sections, out of which up to 21 will house insertion devices (ID). The optics features a low 3.7 nm.rad emittance at the 2.75 GeV operating energy, so as to provide high brilliance, from the VUV up to the hard x-ray domain. To reach a long lifetime, and beam position stabilities in the micron range, significant attention was paid at each design stage (optics, magnets, beam position monitors, vacuum and RF systems…), including on the design of the building, the construction of which is now complete. This resulted in some unprecedented approaches such as the intensive use of NEG coating vessels, or the development of a dedicated SC RF cavity and of 200 kW solid state RF amplifiers. The injector system (100 MeV Linac) and the 3 Hz full energy booster synchrotron have reached nominal operating conditions by fall 2005, while the ring commissioning should start by April 2006. Innovative ID's were designed and built so as to provide the best possible performances in a wide energy range (5 eV to 50 keV).  
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THXPA03 Laser Systems and Accelerators laser, electron, FEL, gun 2728
 
  • H. Schlarb
    DESY, Hamburg
  The presentation will cover the use of laser systems in accelerators. Topics covered will be the use of lasers for the production of electron beam from photocathodes, timing and diagnostics, laser heater systems to control space charge effects, as seed systems. Challenges in terms of stability, pulse shaping, power and pulse lengths, wavelength range and tuning will be covered for the various aspects.  
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THOPA02 Status of the SCSS Test Accelerator and XFEL Project in Japan emittance, electron, cathode, radiation 2741
 
  • T. Shintake
    RIKEN Spring-8 Harima, Hyogo
  Construction of the SCSS* 250 MeV test accelerator was completed in October 2005, and the beam commissioning was started in November 2005. The first light at visible wavelength, which is the spontaneous radiation from undulator, was observed right after machine commissioning. We expect the first SASE beam around 60 nm in 2006. The purpose of the test accelerator is to assemble all hardware components in a real machine, and check their performance, reliability and stability. It is also very important to build all control software and link to the main frame to see system performance. All experience will provide feedback to 8 GeV XFEL design, whose construction will start in April 2006.

*http://www-xfel.spring8.or.jp

 
 
THOAFI02 Ion Instability Observed in PLS Revolver In-vacuum Undulator vacuum, ion, radiation, synchrotron 2771
 
  • H.-S. Kang, J. Choi, M. Kim, T.-Y. Koo, T.-Y. Lee, P.C.D. Park
    PAL, Pohang, Kyungbuk
  Revolver In-Vacuum X-ray Undulator which was designed and fabricated at Spring-8 is under commissioning at PLS. This planar undulator whose permanent magnet array structure is a revolving type with 90-degree step provides 4 different undulator wavelengths of 10, 15, 20, and 24 mm. The minimum gap of the undulator is as small as 5 mm. It was observed that the trailing part of a long bunch train was scraped due to ion instability when the undulator gap was closed below 6 mm. At that time the vacuum pressure in the undulator, which is estimated to be about one order of magnitude lower than that of the undulator gap, increased from 1.4 x 10-10 (gap 20 mm) to 7.9 x 10-10 Torr (gap 6 mm) at the stored beam current of 100 mA. This high vacuum pressure causes fast beam-ion instability: trailing part of a long bunch train oscillates vertically. It was also confirmed that adjusting the orbit along the undulator has improved the situation to some extent. The ion instability measured with a pico-second streak camera and a one-turn BPM as well as the result of orbit adjustment and chromaticity control will be described in this paper.  
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THPCH072 Wakefields in the LCLS Undulator Transitions LCLS, radiation, SLAC, linac 2952
 
  • K.L.F. Bane
    SLAC, Menlo Park, California
  • I. Zagorodnov
    DESY, Hamburg
  We have studied longitudinal wakefields of very short bunches in non-cylindrically symmetric (3D) vacuum chamber transitions using analytical models and the computer program ECHO. The wake (for pairs of well-separated, non-smooth transitions) invariably is resistive, with its shape proportional to the bunch distribution. For the example of an elliptical collimator in a round beam pipe we have demonstrated that—as in the cylindrically symmetric (2D) case—the wake can be obtained from the static primary field of the beam alone. We have obtained the wakes of the LCLS rectangular-to-round transitions using indirect (numerical) field integration combined with a primary beam field calculation. For the LCLS 1 nC bunch charge configuration we find that the total variation in wake-induced energy change is small (0.03% in the core of the beam, 0.15% in the horns of the distribution) compared to that due to the resistive wall wakes of the undulator beam pipe (0.6%).  
 
THPCH073 Reflectivity Measurements for Copper and Aluminum in the Far Infrared and the Resistive Wall Impedance in the LCLS Undulator LCLS, impedance, SLAC, FEL 2955
 
  • K.L.F. Bane, G.V. Stupakov
    SLAC, Menlo Park, California
  • J. Tu
    City College of The City University of New York, New York
  Reflectivity measurements in the far infrared, performed on aluminum and copper samples, are presented and analyzed. Over a frequency range of interest for the LCLS bunch, the data is fit to the free-electron model, and to one including the anomalous skin effect. The models fit well, yielding parameters dc conductivity and relaxation times that are within 30-40\% of expected values. We show that the induced energy in the LCLS undulator region is relative insensitive to variations on this order, and thus we can have confidence that the wake effect will be close to what is expected.  
 
THPCH080 Transverse Impedance of Small-gap Undulators for NSLS-II impedance, vacuum, permanent-magnet, electron 2970
 
  • A. Blednykh, S. Krinsky, B. Podobedov, J.-M. Wang
    BNL, Upton, Long Island, New York
  We discuss the transverse impedance resulting from the use of small-gap undulators in the proposed NSLS-II storage ring. For superconducting undulators, the impedance arises due to the tapered elliptical vacuum chamber. For in-vacuum permanent magnet devices, the impedance results from a more complex geometry. We consider both cases and report results obtained using the electromagnetic simulation program GdfidL.  
 
THPCH102 Fast Global Orbit Feedback System in SPEAR3 feedback, controls, power-supply, diagnostics 3035
 
  • A. Terebilo, T. Straumann
    SLAC, Menlo Park, California
  New digital global orbit feedback system is under commissioning in SPEAR3 light source. The system has 4kHz sampling rate and 200Hz bandwidth. Correction algorithm is based on Singular Value Decomposition (SVD) of the orbit response matrix. For performance tuning and additional flexibility when adding or removing correctors and BPMs, we implemented an independent PID control loop for every orbit eigenvector used. This paper discusses performance of the new system and some advantages of multiple PID loops in the eigenvector space versus a single PID loop working on the raw orbit error.  
 
THPCH132 EPU Assembly Based on Sub-cassettes Magnetic Characterization electron, polarization, synchrotron, radiation 3107
 
  • G. Tosin, R. Basilio, J.F. Citadini, M. Potye
    LNLS, Campinas
  A procedure to speed up the magnetic field correction of an EPU type undulator is proposed and its results are shown. Such procedure consists in segmenting each one of the four magnetic blocks linear arrays (cassettes) in seven sub-cassettes and making their individual magnetic and mechanical characterization. One theoretical perfect sub-cassette, which is composed of four segments per period in Halbach configuration, is taken as the standard field profile. The peak fields and the fields integrated in each semi-period of one sub-cassette are chosen to be the optimization parameters. The magnetic blocks are displaced (virtual shims) to minimize the difference of the optimization parameters between the sub-cassette magnetic measurement and the standard profile. The sub-cassette magnetic measurements are performed with Hall probes, using the same bench employed in insertion devices characterization.  
 
THPCH133 Conceptual Design of an EPU for VUV Radiation Production at LNLS controls, polarization, synchrotron, vacuum 3110
 
  • G. Tosin, R. Basilio, J.F. Citadini, R.T. Neuenschwander, M. Potye, X.R. Resende, M. Rocha, P.F. Tavares
    LNLS, Campinas
  We describe the magnetic and mechanical design of an elliptically polarizing undulator (EPU) currently under construction at the (Brazilian Synchrotron Light Source - LNLS). The device is designed to cover the photon flux in the range from 100eV to 1000eV (124Å a 12.4 Å), allowing linear, elliptical and circular polarizations. With this device it is possible to reach absorption edges of several elements such as Si, S, Br, C, N, O, Fe, F, Cl and to measure magnetic dichroism. The EPU's magnetic design is conventional, and field corrections are done by means of virtual shims, with horizontal and vertical displacements. Each one of the four magnetic blocks linear arrays (cassettes) is segmented in seven sub-cassettes. The separate magnetic measurement of each sub-cassette allows corrections of the magnetic field profile to be made before final assembly and makes the verification of mechanical tolerances easier and faster, decreasing the expected time that will be spent in the magnetic tuning of the device. The mechanical structure is composed of a C-Frame, gap and phase actuators. The gaps actuators and phase actuators use absolute encoders and bias with springs to eliminate backlash.  
 
THPCH135 65 MEV Neutron Irradiation of ND-FE-B Permanent Magnets radiation, electron, proton, permanent-magnet 3116
 
  • X.-M. Maréchal, T. Bizen
    JASRI/SPring-8, Hyogo-ken
  • Y. Asano
    JAEA/SPring-8, Hyogo
  • H. Kitamura
    RIKEN Spring-8 Harima, Hyogo
  Rare-earth permanent magnets are now playing a major role in accelerator technology, from the development of beam transport systems magnets to their extensive use in synchrotron radiation sources and free electron lasers. Unfortunately, operating in a high radiation environment, rare-earth permanent magnets are subject to demagnetization caused by direct and scattered radiation. The lifetime of these components is therefore a major issue: as a result, the number of studies to clarify the demagnetization mechanism or to test materials of interest for a particular application under specific conditions of irradiation has increased in recent years. However, so far, neutron irradiation experiments have been mainly carried out with reactors, were neutrons have a wide, but mainly low, energy spectrum. We present here the results obtained at the TIARA facility of the Japan Atomic Energy Research Institute, a spalliation source of mono highly energetic neutrons. Four types of Nd-Fe-B permanent magnets (Neomax™ 35EH, 32AH, 27VH and 44H) representing a wide range of characteristics (remanence and coervicity) have been studied.  
 
THPLS003 When Less is More - Construction of the Australian Synchrotron storage-ring, synchrotron, injection, linac 3266
 
  • D. Morris
    ASP, Clayton, Victoria
  The Australian Synchrotron is a 3 GeV facility under construction next to Monash University in Melbourne. The project was launched in January 2003 and is scheduled for completion in March 2007. The funding of Aus$206M (about 125 MEuros) covers all costs associated with the site, building, accelerators and the first nine beamlines. The building contract was placed in July 2003 and completed in February 2005. Installation of the accelerators began in April 2005 and should be complete by May 2006. Commissioning of the injection system began in October 2005, and storage ring commissioning will begin mid-2006, with beamline commissioning beginning January 2007 and facility handover in March 2007. The project is being delivered with a staff of less than 50, which has meant that much of the detailed design work and project management for major systems (e.g., the injection system, RF system, support girders, vacuum vessels and front ends) has been performed by commercial suppliers under turn-key contracts. The presentation will discuss the main technical challenges, and results will be presented of the commissioning of the linac, booster and storage ring.  
 
THPLS004 Canadian Light Source Update coupling, emittance, lattice, electron 3269
 
  • L. O. Dallin, M.J. Sigrist, T. Summers
    CLS, Saskatoon, Saskatchewan
  The Canadian Light Source (CLS) storage ring has been operating routinely since commissioning was completed in the spring of 2004. Beam currents up to 230 mA have been achieved with the single superconducting RF cavity. With steady improvement beam lifetimes (1/e) of 10 hours at 170 mA and 0.25% coupling are now possible. In the last year the vertical tune was increased by 1 integer to produce a smaller vertical beam size in the ID straight sections. This year the horizontal tune will be increased to reduce the beam emittance. The vertical coupling has been reduced both globally and locally using a skew quadrupole response technique. A wide range of photons energies are provided by an initial complement of five insertion devices (IDs) and and two infrared (IR) ports. The 5 m straights have room for two IDs. The light cones from these IDs are separated by about 1.5 mrad by "chicaning" the electron beam in the straights. To date two IDs have been installed in one straight using the chicaning technique. As well, a superconducting wiggler and a in-vacuum undulator have been installed and commissioned. An AppleII type elliptically polarizing undulator will be installed in April 2006.  
 
THPLS011 Operation and Recent Development at the ESRF feedback, ESRF, insertion, insertion-device 3290
 
  • J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, P. Elleaume, L. Farvacque, L. Hardy, J. Jacob, G.A. Naylor, E. Plouviez, A. Ropert, K.B. Scheidt
    ESRF, Grenoble
  We report on the achieved performance of the ESRF storage ring as well as developments accomplished or underway. A new hybrid filling mode based on groups of bunches and a 4-bunch filling pattern are now delivered to the users. Following the increasing demand of users for beam stability, the fast orbit feedback has been upgraded. The installation of 5 m-long, 8 mm vertical aperture NEG coated aluminum chambers is progressing at a rate of one chamber per shutdown. The increase in current from 200 to 300 mA is being prepared; however, operation in this mode is still impaired by HOM driven longitudinal instabilities. To overcome this difficulty, a longitudinal feedback is being commissioned. HOM damped cavities are also under study to possibly replace the existing five-cell cavities. The policy of preventive maintenance has been continued. However, in 2005 the machine availability was affected by water leaks occurring on front-end absorbers and on one dipole crotch absorber. The crotch absorbers suffer all from the same erosion process that could be delayed by a systematic vertical realignment, leaving time for procurement and replacement of the entire pool.  
 
THPLS015 Spectral Fingerprints of Femtoslicing in the THz Regime electron, laser, resonance, radiation 3302
 
  • K. Holldack, S. Khan, T. Quast
    BESSY GmbH, Berlin
  • R. Mitzner
    Universität Muenster, Physikalisches Institut, Muenster
  Femtosecond (fs) THz pulses are observed as a consequence of laser-induced energy modulation of electrons in the BESSY II storage ring in order to generate fs x-ray pulses via femtoslicing*. The THz pulses are spectrally characterized by step-scan and rapid scan FTIR spectroscopy. The temporal shape of the laser-induced density modulation is reconstructed from the THz spectra. It is studied as a function of laser and storage ring parameters and monitored over several revolutions. The results are compared with numerical simulations. The THz spectra acquired over a few seconds are used to optimize the laser parameters for achieving minimum x-ray pulse lengths in femtoslicing experiments.

*A. Zholents and M. Zoloterev, PRL 76 (1996), 912.

 
 
THPLS016 Bunch Shape Diagnostics Using Femtoslicing laser, electron, CSR, radiation 3305
 
  • K. Holldack, T. Quast
    BESSY GmbH, Berlin
  • S. Khan
    Uni HH, Hamburg
  • R. Mitzner
    Universität Muenster, Physikalisches Institut, Muenster
  Laser-energy modulation of relativistic electron bunches as needed for the BESSY femtosecond (fs) x-ray source is accompanied by the emission of fs THz pulses*. The total THz intensity probes the square of the longitudinal particle density within a slice of ~50 fs length (fwhm). The bunch shape can be directly monitored while sweeping the time delay between laser and bunch clock. The method is demonstrated for bunch lengths between 3 and 30 ps (rms) in different operation modes of BESSY II. The use of THz signals from successive turns and the influence of periodic bursts of coherent synchrotron radiation, which lock to the laser pulse under certain conditions, are discussed. The method is used for setting up and stabilizing the temporal overlap between a fs-laser and a relativistic electron bunch.

*K. Holldack et al., Phys. Rev. Lett. (2006), accepted Dec. 2005.

 
 
THPLS021 Dynamic Aperture Studies for PETRA III sextupole, dynamic-aperture, PETRA, wiggler 3320
 
  • Y.J. Li, K. Balewski, W. Decking
    DESY, Hamburg
  PETRA III is a low-emittance storage ring dedicated to synchrotron radiation. For efficient injection in the top-up mode, the dynamic aperture has to be larger than 30 mm-mrad in the horizontal plane. This paper presents the choice of tunes and the optimization of the sextupole configuration. Tracking simulations have been performed, including the non-linear effects of 20 four-meters-long damping wigglers and a representative set of undulators. Misalignment and multipole errors are considered as well, leading to specifications for the magnet design and alignment procedure.  
 
THPLS026 Front Ends at Diamond radiation, multipole, wiggler, storage-ring 3335
 
  • J. Strachan, D.G. Clarke
    CCLRC/DL, Daresbury, Warrington, Cheshire
  • H.C. Huang, J. Kay
    Diamond, Oxfordshire
  This paper describes the three different types of Front End that have been designed to transmit the intense synchrotron radiation generated by the undulator, multi-pole wiggler and bending magnet sources in the Diamond storage ring to the experiments. The functions of the main components and their location in the layout are described. The Finite Element Analysis that has been carried out to verify the performance under the high heat loads generated by Diamond is also described along with the limits on temperature and stress that have been employed in the design.  
 
THPLS036 Results of the Straight-sections Upgrade of the Photon Factory Storage Ring vacuum, storage-ring, photon, factory 3365
 
  • T. Honda, S. Asaoka, W.X. Cheng, K. Haga, K. Harada, Y. Hori, M. Izawa, T. Kasuga, Y. Kobayashi, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. Nogami, T. Obina, C.O. Pak, S. Sakanaka, H. Sasaki, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  At the 2.5-GeV ring of the Photon Factory (PF), a large reconstruction of the lattice around the straight sections* has been accomplished in 2005. As a result, four short straight sections of 1.5 m have been newly created, and the lengths of the existing straight sections have been much improved. For example, the length of the longest straight section has been extended to 9 m from 5 m. The optics has been optimized for installing short-period narrow-gap (in-vacuum) undulators at the new straight sections. The reconstruction work on the ring was held from March to September 2005. In the range over two-thirds of the storage ring, all the quadrupole magnets and all the beam ducts have been renewed and rearranged. Commissioning of the storage ring was started from the end of September 2005 and continued for one month. The operation for the user experiment was resumed from the end of October on schedule. Though we made no in-situ baking after the installation for the beam ducts, the vacuum scrubbing by the synchrotron radiation is running very well. The product of the beam lifetime and the beam current exceeded 700 A min for the operation current 450 mA at the end of December 2005.

*S. Asaoka et al. "New Upgrade Project for the Photon Factory Storage Ring", AIP Conf. Proc. 705, p161 (2004).

 
 
THPLS037 Beam Position and Angular Monitor for Undulator by Using SR Monitor Technique electron, focusing, injection, radiation 3368
 
  • T. Mitsuhashi, M. Tadano
    KEK, Ibaraki
  We presented a beam position monitor by using SR monitor technique in the last PAC05. In this monitor, a visible SR in far tail of the undulator spectrum is extracted by a water-cooled beryllium mirror. We applied a focusing system to observe a beam position in the undulator through an optical image of beam. We continue further study of this monitor, and this time, we add the afocal system like a Kepler type telescope to measure the angular deviation of the beam. This system converts the angular deviation of optical axis of input ray into position deviation, and we can measure an angular deviation of the beam through its position deviation on the CCD. The results show us this method is applicable to monitor an angular deviation of beam in the undulator independent from position deviation, and gap change of undulator has no effect for the beam position monitoring.  
 
THPLS040 Present Status of the UVSOR-II electron, laser, emittance, FEL 3374
 
  • M. Katoh, K. Hayashi, M. Hosaka, A. Mochihashi, J. Yamazaki
    UVSOR, Okazaki
  • T. Hara
    RIKEN Spring-8 Harima, Hyogo
  • M. Shimada
    KEK, Ibaraki
  UVSOR electron storage ring, which was a 2nd-generation synchrotron radiation (SR) light source for VUV and soft x-ray region, has been renewed as UVSOR-II at the beginning of 2003. Because of the improvement, the beam emittance has been reduced from 165nm-rad to 27nm-rad, and longer straight sections with smaller vertical betatron functions have been provided. In addition to a helical/linear undulator, two in-vacuum undulators have been installed in the long straight sections at the improvement. New variably polarized undulator will be also installed in summer 2006. Improvement of booster synchrotron will be also performed in summer 2006 with aiming to top-up operation in the future. Now UVSOR-II has been operated in 750MeV with the emittance of 27nm-rad in daily users runs. Not only the development of high quality SR beams but also basic investigations for new light source have been performed; development of storage ring FEL and investigation of intense THz burst SR. Bunch slicing experiment with a Ti:Sa laser (800nm) has also been started since 2005, and experiments for coherent harmonic generation and coherent SR generation with the laser-beam interaction have been performed.  
 
THPLS055 Effects of Phase 1 Insertion Devices at the ALBA Project resonance, lattice, wiggler, electron 3407
 
  • M. Belgroune, M. Muñoz
    CELLS, Bellaterra (Cerdanyola del Vallès)
  The ALBA new third generation light source offers a large number of straight sections to its community of users. Three types of straights will be available, 4 of 8 m, 12 of 4.2 m and 8 of 2.6 m. The compact lattice of a 268 m circumference ring is now mature and its main components are already fixed. We discuss here the beam dynamics studies performed for Phase 1 Insertion Devices (IDs) where two helical devices HU71, two in-vacuum undulators U21 and a multipole wiggler have been modeled using the kick map approach. This allowed defining the suitable compensation scheme in a machine where the vertical focusing is mainly controlled by the gradients in the dipole magnets. In addition, the Touschek lifetime computations and the identification of the limiting resonances using Frequency Map Analysis showed how strong the working point is in the presence of these IDs. Tolerances on the multipolar components due to the fields' roll-off have also been defined and allowed the progress in the IDs design.  
 
THPLS059 Status of the MAX IV Light Source Project storage-ring, linac, radiation, electron 3418
 
  • M. Eriksson, M. Berglund, K.I. Blomqvist, M. Brandin, T. Hansen, D. Kumbaro, L.-J. Lindgren, L. Malmgren, M. Sjöström, H. Svensson, H. Tarawneh, S. Thorin, E.J. Wallén, S. Werin
    MAX-lab, Lund
  • B. Anderberg
    AMACC, Uppsala
  The present development of the accelerator part of the MAX IV synchrotron radiation project is presented. The main features of the 3 GeV injector linac and the two storage rings operated at different electron energies to cover a broad spectral range of high brilliance undulator radiation are described in some detail. A third ring, the existing MAX III ring, is planned to be transferred to the new facility. The preparation of the injector linac to serve as a free electron laser source and the major sub-systems of the facility are also presented.  
 
THPLS062 Sub-picosecond X-ray Source FEMTO at SLS laser, SLS, wiggler, storage-ring 3427
 
  • A. Streun, A. Al-Adwan, P. Beaud, M. Böge, G. Ingold, S. Johnson, A. Keller, T. Schilcher, V. Schlott, T. Schmidt, L. Schulz, D. Zimoch
    PSI, Villigen
  The FEMTO source at the SLS (Swiss Light Source) employs laser/e-beam 'slicing' to produce sub-picosecond x-ray pulses for time resolved pump/probe experiments. The final design of the source, the status of construction and commissioning as well as the first experimental results will be presented.  
 
THPLS082 Status of the Top-off Upgrade of the ALS injection, radiation, brightness, storage-ring 3469
 
  • C. Steier, D. Robin, T. Scarvie
    LBNL, Berkeley, California
  In order to provide higher brightness and better stability, the ALS is being upgraded to top-off injection. One main part of the top-off modifications is an upgrade of the booster as well as extraction and injection elements and the transfer line for full energy. Further upgrades include new diagnostics, improved controls and timing system, and new radiation safety systems (monitors and interlocks).  
 
THPLS097 Model of the CSR Induced Bursts in Slicing Experiments laser, CSR, electron, SLAC 3502
 
  • G.V. Stupakov, S.A. Heifets
    SLAC, Menlo Park, California
  In a recent experiment on 'femtoslicing' at the Advanced Light Source in LBNL, it has been observed that the beam slicing initiates correlated bursts of coherent synchrotron radiation (CSR) of the beam. In this paper, we suggest a model describing such bursts. The model is based on the linear theory of the CSR instability in electron rings. We describe how an initial perturbation of the beam generated by the laser pulse evolves in time when the beam is unstable due to the CSR wakefield. Although this model does not give quantitative predictions, it qualitatively explains the evolution of the induced CSR bursts.  
 
THPLS117 In-vacuum and FEL Undulators at Danfysik SLS, insertion-device, insertion, FEL 3553
 
  • F. Bødker, H. Bach, E.B. Christensen, E. Juul, C.W.O. Ostenfeld, M. Pedersen, T.L. Svendsen
    Danfysik A/S, Jyllinge
  Danfysik has recently designed and produced two in-vacuum insertion devices. The first device is a 19 mm period device made for the Swiss Light Source and the second is a 20 mm period device for SOLEIL. Both are hybrid undulators with Samarium Cobalt magnets where the SLS device is made with steel poles while the SOLEIL undulator is optimized for high peak field using Vanadium Permendur poles and relative large magnet blocks. A quasi-periodic undulator has been built for FEL applications at the FOM-Institute for Plasma Physics. The device is based on a standard pure permanent undulator design but then converted into a quasi-periodic device. The magnetic performance of the device was in excellent agreement with theoretical calculations with high suppression of the 3. and 5. harmonics. A conventional undulator has also been built for FEL applications at FZR Rossendorf. A high degree of software assistance and automation has been developed for the magnet mounting, shimming and magnetic testing of the insertion devices. This technique reduces the shimming time significantly, reduces the need for highly trained personnel and results in superior magnetic performance.  
 
THPLS118 Status of the SOLEIL Insertion Devices SOLEIL, insertion, insertion-device, polarization 3556
 
  • F. Briquez, C. Benabderrahmane, P. Berteaud, O.V. Chubar, M.-E. Couprie, L. Dubois, J.-M. Filhol, M. Girault, O. Marcouillé, F. Marteau, M. Massal, F. Paulin, M.V. Valleau, J. Vétéran
    SOLEIL, Gif-sur-Yvette
  • A. Dael
    CEA, Gif-sur-Yvette
  SOLEIL is the French 2.75 GeV synchrotron radiation light source of low emittance under construction near Paris. It will provide high intensity photons covering a wide spectral range from the IR to the hard x-rays. The storage ring commissioning will start in April 2006, and the first photons in the beam lines are expected during summer 2006. The first set of Insertion Devices (ID) will be installed before the commissioning or within the first year of operation of the machine. They consist of one 640 mm period and three 256 mm period electromagnetic helical undulators, three 80 mm period Apple II type undulators, and three 20 mm period in-vacuum undulators. All these ID's make use of a wide panoply of technical solutions for generating various types of magnetic fields. Magnetic and conceptual designs were performed by SOLEIL, and the technical realisation was carried out together with the different manufacturers. The design specificities of the different types of ID's and the magnetic field characterisation and optimisation will be reported. The first commissioning on the beam of these undulators will be described.  
 
THPLS119 Development of a Cryogenic Permanent Magnet In-vacuum Undulator at the ESRF ESRF, cryogenics, vacuum, permanent-magnet 3559
 
  • C.A. Kitegi, J. Chavanne, D. Cognie, P. Elleaume, C. Penel, B. Plan, F. Revol, M. Rossat
    ESRF, Grenoble
  Lowering the temperature of NdFeB materials increases their field remanence and intrinsic coercivity*. This property is potentially interesting for the construction of cryogenic permanent in-vacuum undulators (CPMU)**. Around 150K, the coercivity is increased to such an extent that the NdFeB material is comparable to the Sm2Co17 as far as resistance to radiation damages is concerned. The improvement in field remanence is less remarkable (15% at 150K) and is dominated by a reversible Spin Reorientation Transition (SRT) occurring around 135K. Below this temperature, the remanence decreases. The complete magnetization curves of NdFeB material measured at different cryogenic temperatures are presented. Non-linear models have been constructed and used in the RADIA code in order to compute the field performance of a hybrid NdFeB in-vacuum undulator. A prototype CPMU is presently under construction at the ESRF. It has a period of 18mm and a magnetic length of 2m. The field integral and local field measurements of the cryogenic device require new systems operated in vacuum. A stretched wire bench and a hall probe bench are under construction; their main characteristics will be presented.

*D. Givord et al. Analysis of hysteresis loops in NdFeB sintered magnets, J. Appl. Phys. 60(9) (3263-3265).**T. Hara et al. Cryogenic permanent undulator, Phys.rev. ST AB volume 7 050702 (2004).

 
 
THPLS120 Tracking Simulations and Dynamic Multipole Shimming for Helical Undulators multipole, simulation, insertion, insertion-device 3562
 
  • G. Wuestefeld, J. Bahrdt, M. Scheer
    BESSY GmbH, Berlin
  Symplectic and fast tracking simulations of an APPLE type undulator for the BESSY II storage ring are presented. The simulation is based on a multiple harmonic decomposition of the magnetic field and on a generating function approach. Because of the relatively large undulator period length of 112 mm, corrections of the dynamic multipoles are required to achieve a good dynamical aperture.  
 
THPLS122 Investigations of the Thermal Beam Load of a Superconducting In-vacuum Undulator vacuum, radiation, synchrotron, synchrotron-radiation 3568
 
  • S. Casalbuoni, MH. Hagelstein, B.K. Kostka, R. Rossmanith
    FZK, Karlsruhe
  • T. Baumbach, A. Bernhard, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • E. Steffens, M. Weisser
    Erlangen University, Erlangen
  Both the resistive wall effect and the synchrotron radiation~\cite{wallen, casalbuoni, chou} can warm up the cold bore of a superconductive in-vacuum undulator. For the in ANKA installed superconducting undulator measurements showed that the dominant heat load contribution comes from the synchrotron radiation generated in the upstream bending magnet: 1 W per 100 mA stored current at a beam energy of 2.5 GeV and an undulator gap of 8 mm.  
 
THPLS123 A Year's Experience with a Superconducting Undulator in the Storage Ring ANKA emittance, optics, synchrotron, synchrotron-radiation 3571
 
  • R. Rossmanith, S. Casalbuoni, MH. Hagelstein, B.K. Kostka, A.-S. Müller
    FZK, Karlsruhe
  • T. Baumbach, A. Bernhard, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • R. Frahm, B. Griesebock, U. Haake
    BUW, Wuppertal
  • F. Schoeck, E. Steffens, M. Weisser
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  In ANKA the worldwide first superconducting undulator demonstrator designed for a storage ring was operated during the last year. The undulator has 100 periods and a period length of 14 mm. During the first year the heat transfer from the beam to the cold bore was investigated and the spectra and the electrical tunability together with a monochromator was measured. The results are so encouraging that plans exist to equip ANKA with two more undulators, one with the opportunity to double electrically the period length and one with electrically variable polarization direction.  
 
THPLS124 The Second Generation of Superconductive Insertion Devices for ANKA wiggler, insertion, insertion-device, radiation 3574
 
  • A. Bernhard, T. Baumbach, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • S. Casalbuoni, MH. Hagelstein, R. Rossmanith
    FZK, Karlsruhe
  • T. Schneider
    FZ Karlsruhe, Karlsruhe
  • F. Schoeck, E. Steffens, M. Weisser
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  After the superconducting undulator SCU14 was installed and successfully started operation at ANKA in spring 2005, a second generation of superconducting insertion devices for ANKA is under development. The ANKA soft x-ray analytics beamline WERA is planned to be equipped with a superconducting elliptically polarising undulator (SCEPU) with electrically tunable polarisation, and a superconducting combined undulator/wiggler (SCUW) capable of period tripling will serve as the source for the planned ANKA imaging beamline. In this paper the studies on the ANKA superconducting EPU and the status of the SCUW-project will be reviewed.  
 
THPLS125 A Concept on Electric Field Error Compensation for the ANKA Superconductive Undulator electron, photon, permanent-magnet, simulation 3577
 
  • D. Wollmann, T. Baumbach, A. Bernhard
    University of Karlsruhe, Karlsruhe
  • S. Casalbuoni, MH. Hagelstein, B.K. Kostka, R. Rossmanith
    FZK, Karlsruhe
  • G. Gerlach
    University of Dresden, Institute for Solid-State Electronics, Dresden
  • F. Schoeck, E. Steffens, M. Weisser
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
  In April 2005 a superconductive undulator test device, the so-called SCU14 (period length 14 mm, 100 periods) was installed at ANKA. Before installation, the magnetic field was measured and documented. This was the first test of a superconductive undulator in a storage ring and the dominating questions to be answered were related to the interaction of the undulator with the beam. The field quality was of lower importance and will be improved by a modified mechanical fabrication technique at the next superconductive undulators. Nevertheless, after finishing the fundamental beam tests the question was discussed how one would improve the field quality (minimize the phase error) of the existing undulator by local correction devices. The concepts could be used later in a weaker form for local field corrections at future undulators, if necessary.  
 
THPLS126 Construction and Testing of a Pair of Focusing Undulators for ALPHA-X electron, focusing, insertion-device, insertion 3580
 
  • B.J.A. Shepherd, J.A. Clarke
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  ALPHA-X is a four-year project shared between several research groups in the UK to build a laser-plasma accelerator and produce coherent short-wavelength radiation in an FEL. A pair of undulators for the project have been designed and built by ASTeC at Daresbury Laboratory. The undulators are 1.5m long, 100 period permanent magnet devices with a minimum gap of 3.5mm, a peak field of 0.7T and a two-plane focusing design. The devices were modelled using RADIA, and data from the magnet block manufacturer was used to sort the blocks. To optimise the trajectory in the real devices, magnetic testing (using Hall probe and flipping coil techniques) and block swapping has been performed in Daresbury's dedicated insertion device test facility. The measurements agree well with the models, and the undulators will perform well within specification.  
 
THPLS130 Thermal Neutron Demagnetization of NdFeB Magnets electron, vacuum, ion, photon 3589
 
  • R.W. Klaffky
    DOE/OFES, Germantown, Maryland
  • R.M. Lindstrom
    NIST, Gaithersburg, Maryland
  • B. Maranville, R. Shull
    National Institute of Standards and Technology, Gaithersburg, Maryland
  • B.J. Micklich, J.H. Vacca
    ANL, Argonne, Illinois
  At the Advanced Photon Source at Argonne National Laboratory, NdFeB insertion device magnets have shown losses of magnetization on a few straight sections where the largest electron beam losses occur due to limiting vacuum chamber apertures. In the worst case, these magnetization losses were evident after a three month operational period. To isolate the effect that thermal neutrons have on these magnets, the magnetization and coercivity were studied for two NdFeB grades as a function of dose from 7.5 x 10(12) to 6 x 10(13) neutrons/cm2. After saturation, the remanent magnetization was found to decrease linearly with the logarithm of the dose. At a dose of 7.5 x 10(12) neutrons/cm2.sec, there was already a 43 percent magnetization loss for the N45 grade and a 15 percent loss for the N48 grade. There was no apparent change in coercivity with dose. The change in remanent magnetization is a consequence of boron thermal neutron capture through the 10B(n,alpha)7Li reaction, which generates MeV energy alpha particles and lithium ions.  
 
THPLS132 Physics Requirement of a PLS-XFEL Undulator radiation, SASE, FEL, XFEL 3592
 
  • D.E. Kim, C.W. Chung, I.S. Ko, J.-S. Oh, K.-H. Park
    PAL, Pohang, Kyungbuk
  Pohang Accelerator Laboratory(PAL)is planning a 0.3nm SASE (Self Amplification of Spontaneous Emission) XFEL based on a 3.7GeV linear accelerator. For short saturation length, application of the SPring8 type in the vacuum undulator is needed. This reflects the experiences from the Spring8 SCSS project. The end structures were designed to be asymmetric along the beam direction to ensure systematic zero 1st field integral. The thickness of the last magnets was adjusted to minimize the transition distance to the fully developed periodic field. This approach is more convenient to control than adjusting the strength of the end magnets. The final design features 4mm minimum pole gap, 15mm period, and peak effective field of 1.09 Tesla. In this article, the physical design of the undulator, the design of the end structure, and the physics requirements of the undulator system will be presented.  
 
THPLS133 Simulations of Electromagnetic Undulator for Far Infrared Coherent Source of TTF at DESY electron, radiation, FIR, simulation 3595
 
  • E. Syresin, V.V. Borisov, E.A. Matushevsky, N.A. Morozov
    JINR, Dubna, Moscow Region
  • O. Grimm, M.V. Yurkov
    DESY, Hamburg
  • J. Rossbach
    Uni HH, Hamburg
  A perspective extension of the VUV FEL user facility at DESY is infrared coherent source on the base of electromagnetic undulator. The undulator consists of 9 periods, period length is 40 cm long, and peak magnetic field is up to 1.2 T. With the energy of electron beam of 500 MeV maximum radiation wavelength is about 200 mkm. An important feature of the beam formation system of the VUV FEL is the possibility to produce ultra-short, down to 50 mkm rms electron bunches. Such short bunches produce powerful coherent radiation with multi-megawatt power level. FIR coherent source operates in a parasitic mode utilizing electron beam passed VUV undulator. Generation of two-colors by a single electron bunch reveals unique possibility to perform pump-probe experiments with VUV and FIR radiation pulses. In this report we present simulations of the undulator magnetic system and beam dynamics.  
 
THPLS134 A General View of IDs to be Installed at ALBA on Day One wiggler, polarization, ELETTRA, radiation 3598
 
  • J. Campmany, F. Becheri, D. Bertwistle, D. Einfeld, J. Marcos, V. Massana
    ALBA, Bellaterra
  • Z. Martí
    LLS, Bellaterra (Cerdanyola del Vallès)
  The new 3rd generation synchrotron radiation source ALBA to be built nearby Barcelona is planned to start operation in 2009 with several different insertion devices installed in the storage ring either from "day one" or within the first year of operation. The list of high-priority insertion devices includes: 2 planar PPM SmCo in-vacuum undulators with the period of 21.3 mm; 2 Apple-II type PPM NdFeB undulators with the period of 71 mm; 1 superconducting planar wiggler with the period of 30 mm and a maximum field of 2 T, and a 1 conventional wiggler with the period of 65 mm and a maximum field of 1.55 T. The emission of these undulators covers wide spectral range extending from hard X-rays to UV. Pre-design of the IDs was done by ALBA. The construction will be done by industrial companies and institutions with production capabilities. ALBA will set up a magnetic measurement laboratory for the acceptance tests. The paper will present peculiarities of the magnetic design, calculated maximum-flux spectra and associated heat load in various modes of operation.  
 
THPLS135 The Study of Errors of ALBA Fixed Stretched Wire Bench pick-up, alignment, insertion-device, insertion 3601
 
  • J. Marcos, J. Campmany, D. Einfeld
    ALBA, Bellaterra
  The new synchrotron radiation source ALBA to be built nearby Barcelona is planned to start operation in 2009. The facility includes a laboratory for magnetic measurements laboratory devoted to IDs. The stretched wire measurement technique is widely used to obtain magnetic field integrals. This technique is based upon the displacement of a stretched wire relative to the magnetic structure to be measured. In the most usual configuration, the magnets are kept fixed while the wire is moved. This arrangement is especially well suited for measuring big structures such as full undulators or its jaws. In contrast, in the fixed stretched wire configuration the magnetic structure is moved relative to a stationary pick-up coil with a straight segment. This layout is convenient for the measurement of small units, such as individual magnet blocks or magnetic modules. These measurements allow characterising the inhomogeneities of the building blocks of an undulator. In this paper we present an exhaustive analysis of error sources and tolerance requirements for a particular design of a fixed stretched wire bench made at ALBA, based both in the ESRF, SOLEIL and BESSY previous existing designs.  
 
THPLS136 Magnetic Field Multipole Measurement with Hall Probe multipole, insertion-device, insertion, simulation 3604
 
  • Z. Martí
    LLS, Bellaterra (Cerdanyola del Vallès)
  • J. Campmany
    ALBA, Bellaterra
  When assembling an insertion device before shimming, sorting algorithms are used to reduce the field errors by choosing the best arrangement of magnetic blocks. In order to carry it out, magnets to be placed in the array are measured with the Helmholtz coil. This yields the magnetic dipolar moment of each one. In fact, Helmholtz coil measurements assume a dipolar filed for each block. The development of narrow gap insertion devices yields a growing interest in the effect of magnetic inhomogeneities. Magnetic inhomogeneities introduce multipolar terms that are added to those corresponding to the multipole development of an ideal magnetic source. However, magnetic inhomogeneities are not measured so far with the Helmholtz coil, because it evaluates the magnetic field far from the magnet, and the multipolar terms decay faster than the dipolar with distance. In order to take into account inhomogeneities, a new approach could be used, based on the measurement of multipoles corresponding to each block. In this paper we propose a method for the fast measurement of the multipoles corresponding to an arbitrary magnetic block, using a Hall probe scanning along a single straight line.  
 
THPLS137 Insertion Devices for the MAX IV Light Source storage-ring, insertion, insertion-device, radiation 3607
 
  • E.J. Wallén, K.I. Blomqvist, B. N. Jensen, U. Johansson
    MAX-lab, Lund
  The foreseen insertion devices and expected brilliance for the MAX IV light source are presented. The planned MAX IV light source consists of three low emittance storage rings and a 3 GeV linac. The linac is used as a full energy injector. The three storage rings will be operated at 700 MeV, 1.5 GeV, and 3.0 GeV, which makes it possible to cover a large spectral range from IR to hard X-rays with insertion devices optimised for each storage ring.  
 
FRYBPA01 Overview of Single Pass Free Electron Lasers electron, radiation, FEL, laser 3636
 
  • C. Pellegrini
    UCLA, Los Angeles, California
  The presentation will cover world wide status of single pass free electron lasers. A general status will be given of the projects. Common themes will be discussed, as will the challenges of these themes. Unique characteristics of individual projects will also be covered. Here the emphasis will be on a description of novel and challenging techniques: for example examples seeding of the FEL, different types of guns for high brightness electron beam production, very short or very long pulse production, etc.  
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